src/ble/sm.c (Bluetooth LE Stack)

Outline

#define BTSTACK_FILE__

#include <string.h>

#include <inttypes.h>

#include "ble/le_device_db.h"

#include "ble/core.h"

#include "ble/sm.h"

#include "bluetooth_company_id.h"

#include "btstack_bool.h"

#include "btstack_crypto.h"

#include "btstack_debug.h"

#include "btstack_event.h"

#include "btstack_linked_list.h"

#include "btstack_memory.h"

#include "btstack_tlv.h"

#include "gap.h"

#include "hci.h"

#include "hci_dump.h"

#include "l2cap.h"

#define IS_RESPONDER

#define USE_CMAC_ENGINE

#define BTSTACK_TAG32

derived_key_generation_t

random_address_update_t

cmac_state_t

stk_generation_method_t

sm_user_response_t

sm_aes128_state_t

address_resolution_mode_t

address_resolution_event_t

ec_key_generation_state_t

sm_state_var_t

sm_sc_oob_state_t

sm_key24_t

sm_key56_t

sm_key256_t

sm_initialized

test_use_fixed_local_csrk

test_use_fixed_local_irk

sm_accepted_stk_generation_methods

sm_max_encryption_key_size

sm_min_encryption_key_size

sm_auth_req

sm_io_capabilities

sm_fixed_passkey_in_display_role

sm_reconstruct_ltk_without_le_device_db_entry

sm_slave_request_security

sm_persistent_keys_random_active

sm_tlv_impl

sm_tlv_context

sm_persistent_er

sm_persistent_ir

sm_persistent_dhk

sm_persistent_irk

dkg_state

rau_state

sm_random_address

sm_address_resolution_test

sm_address_resolution_addr_type

sm_address_resolution_address

sm_address_resolution_context

sm_address_resolution_mode

sm_address_resolution_general_queue

sm_aes128_state

sm_crypto_random_request

sm_crypto_aes128_request

sm_random_data

sm_aes128_key

sm_aes128_plaintext

sm_aes128_ciphertext

hci_event_callback_registration

sm_event_handlers

sm_run_timer

sm_setup_context

the_setup

setup

sm_active_connection_handle

sm_get_oob_data

sm_get_sc_oob_data

sm_get_ltk_callback

log_info_hex16(const char *, uint16_t)

sm_pairing_packet_get_io_capability(uint8_t *)

sm_pairing_packet_get_oob_data_flag(uint8_t *)

sm_pairing_packet_get_auth_req(uint8_t *)

sm_pairing_packet_get_max_encryption_key_size(uint8_t *)

sm_pairing_packet_get_initiator_key_distribution(uint8_t *)

sm_pairing_packet_get_responder_key_distribution(uint8_t *)

sm_pairing_packet_set_code(uint8_t *, uint8_t)

sm_pairing_packet_set_io_capability(uint8_t *, uint8_t)

sm_pairing_packet_set_oob_data_flag(uint8_t *, uint8_t)

sm_pairing_packet_set_auth_req(uint8_t *, uint8_t)

sm_pairing_packet_set_max_encryption_key_size(uint8_t *, uint8_t)

sm_pairing_packet_set_initiator_key_distribution(uint8_t *, uint8_t)

sm_pairing_packet_set_responder_key_distribution(uint8_t *, uint8_t)

sm_is_null_random(uint8_t *)

sm_is_null_key(uint8_t *)

sm_run_timer_handler(btstack_timer_source_t *)

sm_trigger_run()

sm_reset_tk()

sm_truncate_key(uint8_t *, int)

sm_er_ir_set_default()

sm_er_is_default()

sm_ir_is_default()

sm_dispatch_event(uint8_t, uint16_t, uint8_t *, uint16_t)

sm_setup_event_base(uint8_t *, int, uint8_t, hci_con_handle_t, uint8_t, uint8_t *)

sm_notify_client_base(uint8_t, hci_con_handle_t, uint8_t, uint8_t *)

sm_notify_client_index(uint8_t, hci_con_handle_t, uint8_t, uint8_t *, uint16_t)

sm_notify_client_status(uint8_t, hci_con_handle_t, uint8_t, uint8_t *, uint8_t)

sm_reencryption_started(sm_connection_t *)

sm_reencryption_complete(sm_connection_t *, uint8_t)

sm_pairing_started(sm_connection_t *)

sm_pairing_complete(sm_connection_t *, uint8_t, uint8_t)

sm_timeout_handler(btstack_timer_source_t *)

sm_timeout_start(sm_connection_t *)

sm_timeout_stop()

sm_timeout_reset(sm_connection_t *)

gap_random_adress_type

gap_random_address_update_timer

gap_random_adress_update_period

gap_random_address_trigger()

gap_random_address_update_handler(btstack_timer_source_t *)

gap_random_address_update_start()

gap_random_address_update_stop()

sm_ah_r_prime(uint8_t *, uint8_t *)

sm_d1_d_prime(uint16_t, uint16_t, uint8_t *)

sm_c1_t1(uint8_t *, uint8_t *, uint8_t *, uint8_t, uint8_t, uint8_t *)

sm_c1_t3(uint8_t *, uint8_t *, uint8_t *, uint8_t *)

sm_s1_r_prime(uint8_t *, uint8_t *, uint8_t *)

sm_setup_tk()

sm_key_distribution_flags_for_set(uint8_t)

sm_setup_key_distribution(uint8_t, uint8_t)

sm_address_resolution_idle()

sm_address_resolution_start_lookup(uint8_t, hci_con_handle_t, uint8_t *, address_resolution_mode_t, void *)

sm_address_resolution_lookup(uint8_t, uint8_t *)

sm_trigger_user_response_basic(sm_connection_t *, uint8_t)

sm_trigger_user_response_passkey(sm_connection_t *, uint8_t)

sm_trigger_user_response(sm_connection_t *)

sm_key_distribution_all_received()

sm_done_for_handle(hci_con_handle_t)

sm_master_pairing_success(sm_connection_t *)

sm_key_distribution_flags_for_auth_req()

sm_reset_setup()

sm_init_setup(sm_connection_t *)

sm_stk_generation_init(sm_connection_t *)

sm_address_resolution_handle_event(address_resolution_event_t)

sm_store_bonding_information(sm_connection_t *)

sm_pairing_error(sm_connection_t *, uint8_t)

sm_le_device_db_index_lookup(bd_addr_type_t, uint8_t *)

sm_remove_le_device_db_entry(uint16_t)

sm_key_distribution_validate_received(sm_connection_t *)

sm_key_distribution_handle_all_received(sm_connection_t *)

sm_pdu_received_in_wrong_state(sm_connection_t *)

sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t *)

sm_run_dpkg()

sm_run_rau()

sm_run_irk_lookup()

sm_run_oob()

sm_send_connectionless(sm_connection_t *, const uint8_t *, uint16_t)

sm_run_basic()

sm_run_activate_connection()

sm_run_send_keypress_notification(sm_connection_t *)

sm_run_distribute_keys(sm_connection_t *)

sm_ctkd_from_le(sm_connection_t *)

sm_key_distribution_complete_responder(sm_connection_t *)

sm_key_distribution_complete_initiator(sm_connection_t *)

sm_run_non_connection_logic()

sm_run()

sm_handle_encryption_result_enc_a(void *)

sm_handle_encryption_result_enc_b(void *)

sm_handle_encryption_result_enc_c(void *)

sm_handle_encryption_result_enc_d(void *)

sm_handle_encryption_result_enc_stk(void *)

sm_handle_encryption_result_enc_ph3_y(void *)

sm_handle_encryption_result_enc_ph4_y(void *)

sm_handle_encryption_result_enc_ph3_ltk(void *)

sm_handle_encryption_result_enc_csrk(void *)

sm_handle_encryption_result_enc_ph4_ltk(void *)

sm_handle_encryption_result_address_resolution(void *)

sm_handle_encryption_result_dkg_irk(void *)

sm_handle_encryption_result_dkg_dhk(void *)

sm_handle_encryption_result_rau(void *)

sm_handle_random_result_rau(void *)

sm_handle_random_result_ph2_random(void *)

sm_handle_random_result_ph2_tk(void *)

sm_handle_random_result_ph3_div(void *)

sm_handle_random_result_ph3_random(void *)

sm_validate_er_ir()

sm_handle_random_result_ir(void *)

sm_handle_random_result_er(void *)

sm_connection_init(sm_connection_t *, hci_con_handle_t, uint8_t, uint8_t, uint8_t *)

sm_event_packet_handler(uint8_t, uint16_t, uint8_t *, uint16_t)

sm_calc_actual_encryption_key_size(int)

sm_validate_stk_generation_method()

sm_pdu_validate_and_get_opcode(uint8_t, const uint8_t *, uint16_t)

sm_pdu_handler(sm_connection_t *, uint8_t, const uint8_t *)

sm_channel_handler(uint8_t, hci_con_handle_t, uint8_t *, uint16_t)

sm_register_oob_data_callback(int (*)(uint8_t, uint8_t *, uint8_t *))

sm_register_sc_oob_data_callback(int (*)(uint8_t, uint8_t *, uint8_t *, uint8_t *))

sm_register_ltk_callback(bool (*)(hci_con_handle_t, uint8_t, uint8_t *, uint8_t *))

sm_add_event_handler(btstack_packet_callback_registration_t *)

sm_remove_event_handler(btstack_packet_callback_registration_t *)

sm_set_accepted_stk_generation_methods(uint8_t)

sm_set_encryption_key_size_range(uint8_t, uint8_t)

sm_set_authentication_requirements(uint8_t)

sm_set_io_capabilities(io_capability_t)

sm_set_request_security(bool)

sm_set_er(uint8_t *)

sm_set_ir(uint8_t *)

sm_test_set_irk(uint8_t *)

sm_test_use_fixed_local_csrk()

sm_state_reset()

sm_init()

sm_deinit()

sm_use_fixed_passkey_in_display_role(uint32_t)

sm_allow_ltk_reconstruction_without_le_device_db_entry(int)

sm_get_connection_for_handle(hci_con_handle_t)

sm_cache_ltk(sm_connection_t *, const uint8_t *)

sm_send_security_request(hci_con_handle_t)

sm_request_pairing(hci_con_handle_t)

sm_authorization_decline(hci_con_handle_t)

sm_authorization_grant(hci_con_handle_t)

sm_bonding_decline(hci_con_handle_t)

sm_just_works_confirm(hci_con_handle_t)

sm_numeric_comparison_confirm(hci_con_handle_t)

sm_passkey_input(hci_con_handle_t, uint32_t)

sm_keypress_notification(hci_con_handle_t, uint8_t)

sm_identity_resolving_state(hci_con_handle_t)

sm_le_device_index(hci_con_handle_t)

sm_get_ltk(hci_con_handle_t, uint8_t *)

gap_random_address_type_requires_updates()

own_address_type()

gap_random_address_set_mode(gap_random_address_type_t)

gap_random_address_get_mode()

gap_random_address_set_update_period(int)

gap_random_address_set(const uint8_t *)

gap_advertisements_set_params(uint16_t, uint16_t, uint8_t, uint8_t, uint8_t *, uint8_t, uint8_t)

gap_reconnect_security_setup_active(hci_con_handle_t)

sm_set_secure_connections_only_mode(bool)

gap_get_persistent_irk()

gap_delete_bonding(bd_addr_type_t, uint8_t *)

Files

SourceVuRaspberry Pi Pico SDK and ExamplesBluetooth LE Stacksrc/ble/sm.c

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

690

691

692

693

694

695

696

697

698

699

700

701

702

703

704

705

706

707

708

709

710

711

712

713

714

715

716

717

718

719

720

721

722

723

724

725

726

727

728

729

730

731

732

733

734

735

736

737

738

739

740

741

742

743

744

745

746

747

748

749

750

751

752

753

754

755

756

757

758

759

760

761

762

763

764

765

766

767

768

769

770

771

772

773

774

775

776

777

778

779

780

781

782

783

784

785

786

787

788

789

790

791

792

793

794

795

796

797

798

799

800

801

802

803

804

805

806

807

808

809

810

811

812

813

814

815

816

817

818

819

820

821

822

823

824

825

826

827

828

829

830

831

832

833

834

835

836

837

838

839

840

841

842

843

844

845

846

847

848

849

850

851

852

853

854

855

856

857

858

859

860

861

862

863

864

865

866

867

868

869

870

871

872

873

874

875

876

877

878

879

880

881

882

883

884

885

886

887

888

889

890

891

892

893

894

895

896

897

898

899

900

901

902

903

904

905

906

907

908

909

910

911

912

913

914

915

916

917

918

919

920

921

922

923

924

925

926

927

928

929

930

931

932

933

934

935

936

937

938

939

940

941

942

943

944

945

946

947

948

949

950

951

952

953

954

955

956

957

958

959

960

961

962

963

964

965

966

967

968

969

970

971

972

973

974

975

976

977

978

979

980

981

982

983

984

985

986

987

988

989

990

991

992

993

994

995

996

997

998

999

1000

1001

1002

1003

1004

1005

1006

1007

1008

1009

1010

1011

1012

1013

1014

1015

1016

1017

1018

1019

1020

1021

1022

1023

1024

1025

1026

1027

1028

1029

1030

1031

1032

1033

1034

1035

1036

1037

1038

1039

1040

1041

1042

1043

1044

1045

1046

1047

1048

1049

1050

1051

1052

1053

1054

1055

1056

1057

1058

1059

1060

1061

1062

1063

1064

1065

1066

1067

1068

1069

1070

1071

1072

1073

1074

1075

1076

1077

1078

1079

1080

1081

1082

1083

1084

1085

1086

1087

1088

1089

1090

1091

1092

1093

1094

1095

1096

1097

1098

1099

1100

1101

1102

1103

1104

1105

1106

1107

1108

1109

1110

1111

1112

1113

1114

1115

1116

1117

1118

1119

1120

1121

1122

1123

1124

1125

1126

1127

1128

1129

1130

1131

1132

1133

1134

1135

1136

1137

1138

1139

1140

1141

1142

1143

1144

1145

1146

1147

1148

1149

1150

1151

1152

1153

1154

1155

1156

1157

1158

1159

1160

1161

1162

1163

1164

1165

1166

1167

1168

1169

1170

1171

1172

1173

1174

1175

1176

1177

1178

1179

1180

1181

1182

1183

1184

1185

1186

1187

1188

1189

1190

1191

1192

1193

1194

1195

1196

1197

1198

1199

1200

1201

1202

1203

1204

1205

1206

1207

1208

1209

1210

1211

1212

1213

1214

1215

1216

1217

1218

1219

1220

1221

1222

1223

1224

1225

1226

1227

1228

1229

1230

1231

1232

1233

1234

1235

1236

1237

1238

1239

1240

1241

1242

1243

1244

1245

1246

1247

1248

1249

1250

1251

1252

1253

1254

1255

1256

1257

1258

1259

1260

1261

1262

1263

1264

1265

1266

1267

1268

1269

1270

1271

1272

1273

1274

1275

1276

1277

1278

1279

1280

1281

1282

1283

1284

1285

1286

1287

1288

1289

1290

1291

1292

1293

1294

1295

1296

1297

1298

1299

1300

1301

1302

1303

1304

1305

1306

1307

1308

1309

1310

1311

1312

1313

1314

1315

1316

1317

1318

1319

1320

1321

1322

1323

1324

1325

1326

1327

1328

1329

1330

1331

1332

1333

1334

1335

1336

1337

1338

1339

1340

1341

1342

1343

1344

1345

1346

1347

1348

1349

1350

1351

1352

1353

1354

1355

1356

1357

1358

1359

1360

1361

1362

1363

1364

1365

1366

1367

1368

1369

1370

1371

1372

1373

1374

1375

1376

1377

1378

1379

1380

1381

1382

1383

1384

1385

1386

1387

1388

1389

1390

1391

1392

1393

1394

1395

1396

1397

1398

1399

1400

1401

1402

1403

1404

1405

1406

1407

1408

1409

1410

1411

1412

1413

1414

1415

1416

1417

1418

1419

1420

1421

1422

1423

1424

1425

1426

1427

1428

1429

1430

1431

1432

1433

1434

1435

1436

1437

1438

1439

1440

1441

1442

1443

1444

1445

1446

1447

1448

1449

1450

1451

1452

1453

1454

1455

1456

1457

1458

1459

1460

1461

1462

1463

1464

1465

1466

1467

1468

1469

1470

1471

1472

1473

1474

1475

1476

1477

1478

1479

1480

1481

1482

1483

1484

1485

1486

1487

1488

1489

1490

1491

1492

1493

1494

1495

1496

1497

1498

1499

1500

1501

1502

1503

1504

1505

1506

1507

1508

1509

1510

1511

1512

1513

1514

1515

1516

1517

1518

1519

1520

1521

1522

1523

1524

1525

1526

1527

1528

1529

1530

1531

1532

1533

1534

1535

1536

1537

1538

1539

1540

1541

1542

1543

1544

1545

1546

1547

1548

1549

1550

1551

1552

1553

1554

1555

1556

1557

1558

1559

1560

1561

1562

1563

1564

1565

1566

1567

1568

1569

1570

1571

1572

1573

1574

1575

1576

1577

1578

1579

1580

1581

1582

1583

1584

1585

1586

1587

1588

1589

1590

1591

1592

1593

1594

1595

1596

1597

1598

1599

1600

1601

1602

1603

1604

1605

1606

1607

1608

1609

1610

1611

1612

1613

1614

1615

1616

1617

1618

1619

1620

1621

1622

1623

1624

1625

1626

1627

1628

1629

1630

1631

1632

1633

1634

1635

1636

1637

1638

1639

1640

1641

1642

1643

1644

1645

1646

1647

1648

1649

1650

1651

1652

1653

1654

1655

1656

1657

1658

1659

1660

1661

1662

1663

1664

1665

1666

1667

1668

1669

1670

1671

1672

1673

1674

1675

1676

1677

1678

1679

1680

1681

1682

1683

1684

1685

1686

1687

1688

1689

1690

1691

1692

1693

1694

1695

1696

1697

1698

1699

1700

1701

1702

1703

1704

1705

1706

1707

1708

1709

1710

1711

1712

1713

1714

1715

1716

1717

1718

1719

1720

1721

1722

1723

1724

1725

1726

1727

1728

1729

1730

1731

1732

1733

1734

1735

1736

1737

1738

1739

1740

1741

1742

1743

1744

1745

1746

1747

1748

1749

1750

1751

1752

1753

1754

1755

1756

1757

1758

1759

1760

1761

1762

1763

1764

1765

1766

1767

1768

1769

1770

1771

1772

1773

1774

1775

1776

1777

1778

1779

1780

1781

1782

1783

1784

1785

1786

1787

1788

1789

1790

1791

1792

1793

1794

1795

1796

1797

1798

1799

1800

1801

1802

1803

1804

1805

1806

1807

1808

1809

1810

1811

1812

1813

1814

1815

1816

1817

1818

1819

1820

1821

1822

1823

1824

1825

1826

1827

1828

1829

1830

1831

1832

1833

1834

1835

1836

1837

1838

1839

1840

1841

1842

1843

1844

1845

1846

1847

1848

1849

1850

1851

1852

1853

1854

1855

1856

1857

1858

1859

1860

1861

1862

1863

1864

1865

1866

1867

1868

1869

1870

1871

1872

1873

1874

1875

1876

1877

1878

1879

1880

1881

1882

1883

1884

1885

1886

1887

1888

1889

1890

1891

1892

1893

1894

1895

1896

1897

1898

1899

1900

1901

1902

1903

1904

1905

1906

1907

1908

1909

1910

1911

1912

1913

1914

1915

1916

1917

1918

1919

1920

1921

1922

1923

1924

1925

1926

1927

1928

1929

1930

1931

1932

1933

1934

1935

1936

1937

1938

1939

1940

1941

1942

1943

1944

1945

1946

1947

1948

1949

1950

1951

1952

1953

1954

1955

1956

1957

1958

1959

1960

1961

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

2022

2023

2024

2025

2026

2027

2028

2029

2030

2031

2032

2033

2034

2035

2036

2037

2038

2039

2040

2041

2042

2043

2044

2045

2046

2047

2048

2049

2050

2051

2052

2053

2054

2055

2056

2057

2058

2059

2060

2061

2062

2063

2064

2065

2066

2067

2068

2069

2070

2071

2072

2073

2074

2075

2076

2077

2078

2079

2080

2081

2082

2083

2084

2085

2086

2087

2088

2089

2090

2091

2092

2093

2094

2095

2096

2097

2098

2099

2100

2101

2102

2103

2104

2105

2106

2107

2108

2109

2110

2111

2112

2113

2114

2115

2116

2117

2118

2119

2120

2121

2122

2123

2124

2125

2126

2127

2128

2129

2130

2131

2132

2133

2134

2135

2136

2137

2138

2139

2140

2141

2142

2143

2144

2145

2146

2147

2148

2149

2150

2151

2152

2153

2154

2155

2156

2157

2158

2159

2160

2161

2162

2163

2164

2165

2166

2167

2168

2169

2170

2171

2172

2173

2174

2175

2176

2177

2178

2179

2180

2181

2182

2183

2184

2185

2186

2187

2188

2189

2190

2191

2192

2193

2194

2195

2196

2197

2198

2199

2200

2201

2202

2203

2204

2205

2206

2207

2208

2209

2210

2211

2212

2213

2214

2215

2216

2217

2218

2219

2220

2221

2222

2223

2224

2225

2226

2227

2228

2229

2230

2231

2232

2233

2234

2235

2236

2237

2238

2239

2240

2241

2242

2243

2244

2245

2246

2247

2248

2249

2250

2251

2252

2253

2254

2255

2256

2257

2258

2259

2260

2261

2262

2263

2264

2265

2266

2267

2268

2269

2270

2271

2272

2273

2274

2275

2276

2277

2278

2279

2280

2281

2282

2283

2284

2285

2286

2287

2288

2289

2290

2291

2292

2293

2294

2295

2296

2297

2298

2299

2300

2301

2302

2303

2304

2305

2306

2307

2308

2309

2310

2311

2312

2313

2314

2315

2316

2317

2318

2319

2320

2321

2322

2323

2324

2325

2326

2327

2328

2329

2330

2331

2332

2333

2334

2335

2336

2337

2338

2339

2340

2341

2342

2343

2344

2345

2346

2347

2348

2349

2350

2351

2352

2353

2354

2355

2356

2357

2358

2359

2360

2361

2362

2363

2364

2365

2366

2367

2368

2369

2370

2371

2372

2373

2374

2375

2376

2377

2378

2379

2380

2381

2382

2383

2384

2385

2386

2387

2388

2389

2390

2391

2392

2393

2394

2395

2396

2397

2398

2399

2400

2401

2402

2403

2404

2405

2406

2407

2408

2409

2410

2411

2412

2413

2414

2415

2416

2417

2418

2419

2420

2421

2422

2423

2424

2425

2426

2427

2428

2429

2430

2431

2432

2433

2434

2435

2436

2437

2438

2439

2440

2441

2442

2443

2444

2445

2446

2447

2448

2449

2450

2451

2452

2453

2454

2455

2456

2457

2458

2459

2460

2461

2462

2463

2464

2465

2466

2467

2468

2469

2470

2471

2472

2473

2474

2475

2476

2477

2478

2479

2480

2481

2482

2483

2484

2485

2486

2487

2488

2489

2490

2491

2492

2493

2494

2495

2496

2497

2498

2499

2500

2501

2502

2503

2504

2505

2506

2507

2508

2509

2510

2511

2512

2513

2514

2515

2516

2517

2518

2519

2520

2521

2522

2523

2524

2525

2526

2527

2528

2529

2530

2531

2532

2533

2534

2535

2536

2537

2538

2539

2540

2541

2542

2543

2544

2545

2546

2547

2548

2549

2550

2551

2552

2553

2554

2555

2556

2557

2558

2559

2560

2561

2562

2563

2564

2565

2566

2567

2568

2569

2570

2571

2572

2573

2574

2575

2576

2577

2578

2579

2580

2581

2582

2583

2584

2585

2586

2587

2588

2589

2590

2591

2592

2593

2594

2595

2596

2597

2598

2599

2600

2601

2602

2603

2604

2605

2606

2607

2608

2609

2610

2611

2612

2613

2614

2615

2616

2617

2618

2619

2620

2621

2622

2623

2624

2625

2626

2627

2628

2629

2630

2631

2632

2633

2634

2635

2636

2637

2638

2639

2640

2641

2642

2643

2644

2645

2646

2647

2648

2649

2650

2651

2652

2653

2654

2655

2656

2657

2658

2659

2660

2661

2662

2663

2664

2665

2666

2667

2668

2669

2670

2671

2672

2673

2674

2675

2676

2677

2678

2679

2680

2681

2682

2683

2684

2685

2686

2687

2688

2689

2690

2691

2692

2693

2694

2695

2696

2697

2698

2699

2700

2701

2702

2703

2704

2705

2706

2707

2708

2709

2710

2711

2712

2713

2714

2715

2716

2717

2718

2719

2720

2721

2722

2723

2724

2725

2726

2727

2728

2729

2730

2731

2732

2733

2734

2735

2736

2737

2738

2739

2740

2741

2742

2743

2744

2745

2746

2747

2748

2749

2750

2751

2752

2753

2754

2755

2756

2757

2758

2759

2760

2761

2762

2763

2764

2765

2766

2767

2768

2769

2770

2771

2772

2773

2774

2775

2776

2777

2778

2779

2780

2781

2782

2783

2784

2785

2786

2787

2788

2789

2790

2791

2792

2793

2794

2795

2796

2797

2798

2799

2800

2801

2802

2803

2804

2805

2806

2807

2808

2809

2810

2811

2812

2813

2814

2815

2816

2817

2818

2819

2820

2821

2822

2823

2824

2825

2826

2827

2828

2829

2830

2831

2832

2833

2834

2835

2836

2837

2838

2839

2840

2841

2842

2843

2844

2845

2846

2847

2848

2849

2850

2851

2852

2853

2854

2855

2856

2857

2858

2859

2860

2861

2862

2863

2864

2865

2866

2867

2868

2869

2870

2871

2872

2873

2874

2875

2876

2877

2878

2879

2880

2881

2882

2883

2884

2885

2886

2887

2888

2889

2890

2891

2892

2893

2894

2895

2896

2897

2898

2899

2900

2901

2902

2903

2904

2905

2906

2907

2908

2909

2910

2911

2912

2913

2914

2915

2916

2917

2918

2919

2920

2921

2922

2923

2924

2925

2926

2927

2928

2929

2930

2931

2932

2933

2934

2935

2936

2937

2938

2939

2940

2941

2942

2943

2944

2945

2946

2947

2948

2949

2950

2951

2952

2953

2954

2955

2956

2957

2958

2959

2960

2961

2962

2963

2964

2965

2966

2967

2968

2969

2970

2971

2972

2973

2974

2975

2976

2977

2978

2979

2980

2981

2982

2983

2984

2985

2986

2987

2988

2989

2990

2991

2992

2993

2994

2995

2996

2997

2998

2999

3000

3001

3002

3003

3004

3005

3006

3007

3008

3009

3010

3011

3012

3013

3014

3015

3016

3017

3018

3019

3020

3021

3022

3023

3024

3025

3026

3027

3028

3029

3030

3031

3032

3033

3034

3035

3036

3037

3038

3039

3040

3041

3042

3043

3044

3045

3046

3047

3048

3049

3050

3051

3052

3053

3054

3055

3056

3057

3058

3059

3060

3061

3062

3063

3064

3065

3066

3067

3068

3069

3070

3071

3072

3073

3074

3075

3076

3077

3078

3079

3080

3081

3082

3083

3084

3085

3086

3087

3088

3089

3090

3091

3092

3093

3094

3095

3096

3097

3098

3099

3100

3101

3102

3103

3104

3105

3106

3107

3108

3109

3110

3111

3112

3113

3114

3115

3116

3117

3118

3119

3120

3121

3122

3123

3124

3125

3126

3127

3128

3129

3130

3131

3132

3133

3134

3135

3136

3137

3138

3139

3140

3141

3142

3143

3144

3145

3146

3147

3148

3149

3150

3151

3152

3153

3154

3155

3156

3157

3158

3159

3160

3161

3162

3163

3164

3165

3166

3167

3168

3169

3170

3171

3172

3173

3174

3175

3176

3177

3178

3179

3180

3181

3182

3183

3184

3185

3186

3187

3188

3189

3190

3191

3192

3193

3194

3195

3196

3197

3198

3199

3200

3201

3202

3203

3204

3205

3206

3207

3208

3209

3210

3211

3212

3213

3214

3215

3216

3217

3218

3219

3220

3221

3222

3223

3224

3225

3226

3227

3228

3229

3230

3231

3232

3233

3234

3235

3236

3237

3238

3239

3240

3241

3242

3243

3244

3245

3246

3247

3248

3249

3250

3251

3252

3253

3254

3255

3256

3257

3258

3259

3260

3261

3262

3263

3264

3265

3266

3267

3268

3269

3270

3271

3272

3273

3274

3275

3276

3277

3278

3279

3280

3281

3282

3283

3284

3285

3286

3287

3288

3289

3290

3291

3292

3293

3294

3295

3296

3297

3298

3299

3300

3301

3302

3303

3304

3305

3306

3307

3308

3309

3310

3311

3312

3313

3314

3315

3316

3317

3318

3319

3320

3321

3322

3323

3324

3325

3326

3327

3328

3329

3330

3331

3332

3333

3334

3335

3336

3337

3338

3339

3340

3341

3342

3343

3344

3345

3346

3347

3348

3349

3350

3351

3352

3353

3354

3355

3356

3357

3358

3359

3360

3361

3362

3363

3364

3365

3366

3367

3368

3369

3370

3371

3372

3373

3374

3375

3376

3377

3378

3379

3380

3381

3382

3383

3384

3385

3386

3387

3388

3389

3390

3391

3392

3393

3394

3395

3396

3397

3398

3399

3400

3401

3402

3403

3404

3405

3406

3407

3408

3409

3410

3411

3412

3413

3414

3415

3416

3417

3418

3419

3420

3421

3422

3423

3424

3425

3426

3427

3428

3429

3430

3431

3432

3433

3434

3435

3436

3437

3438

3439

3440

3441

3442

3443

3444

3445

3446

3447

3448

3449

3450

3451

3452

3453

3454

3455

3456

3457

3458

3459

3460

3461

3462

3463

3464

3465

3466

3467

3468

3469

3470

3471

3472

3473

3474

3475

3476

3477

3478

3479

3480

3481

3482

3483

3484

3485

3486

3487

3488

3489

3490

3491

3492

3493

3494

3495

3496

3497

3498

3499

3500

3501

3502

3503

3504

3505

3506

3507

3508

3509

3510

3511

3512

3513

3514

3515

3516

3517

3518

3519

3520

3521

3522

3523

3524

3525

3526

3527

3528

3529

3530

3531

3532

3533

3534

3535

3536

3537

3538

3539

3540

3541

3542

3543

3544

3545

3546

3547

3548

3549

3550

3551

3552

3553

3554

3555

3556

3557

3558

3559

3560

3561

3562

3563

3564

3565

3566

3567

3568

3569

3570

3571

3572

3573

3574

3575

3576

3577

3578

3579

3580

3581

3582

3583

3584

3585

3586

3587

3588

3589

3590

3591

3592

3593

3594

3595

3596

3597

3598

3599

3600

3601

3602

3603

3604

3605

3606

3607

3608

3609

3610

3611

3612

3613

3614

3615

3616

3617

3618

3619

3620

3621

3622

3623

3624

3625

3626

3627

3628

3629

3630

3631

3632

3633

3634

3635

3636

3637

3638

3639

3640

3641

3642

3643

3644

3645

3646

3647

3648

3649

3650

3651

3652

3653

3654

3655

3656

3657

3658

3659

3660

3661

3662

3663

3664

3665

3666

3667

3668

3669

3670

3671

3672

3673

3674

3675

3676

3677

3678

3679

3680

3681

3682

3683

3684

3685

3686

3687

3688

3689

3690

3691

3692

3693

3694

3695

3696

3697

3698

3699

3700

3701

3702

3703

3704

3705

3706

3707

3708

3709

3710

3711

3712

3713

3714

3715

3716

3717

3718

3719

3720

3721

3722

3723

3724

3725

3726

3727

3728

3729

3730

3731

3732

3733

3734

3735

3736

3737

3738

3739

3740

3741

3742

3743

3744

3745

3746

3747

3748

3749

3750

3751

3752

3753

3754

3755

3756

3757

3758

3759

3760

3761

3762

3763

3764

3765

3766

3767

3768

3769

3770

3771

3772

3773

3774

3775

3776

3777

3778

3779

3780

3781

3782

3783

3784

3785

3786

3787

3788

3789

3790

3791

3792

3793

3794

3795

3796

3797

3798

3799

3800

3801

3802

3803

3804

3805

3806

3807

3808

3809

3810

3811

3812

3813

3814

3815

3816

3817

3818

3819

3820

3821

3822

3823

3824

3825

3826

3827

3828

3829

3830

3831

3832

3833

3834

3835

3836

3837

3838

3839

3840

3841

3842

3843

3844

3845

3846

3847

3848

3849

3850

3851

3852

3853

3854

3855

3856

3857

3858

3859

3860

3861

3862

3863

3864

3865

3866

3867

3868

3869

3870

3871

3872

3873

3874

3875

3876

3877

3878

3879

3880

3881

3882

3883

3884

3885

3886

3887

3888

3889

3890

3891

3892

3893

3894

3895

3896

3897

3898

3899

3900

3901

3902

3903

3904

3905

3906

3907

3908

3909

3910

3911

3912

3913

3914

3915

3916

3917

3918

3919

3920

3921

3922

3923

3924

3925

3926

3927

3928

3929

3930

3931

3932

3933

3934

3935

3936

3937

3938

3939

3940

3941

3942

3943

3944

3945

3946

3947

3948

3949

3950

3951

3952

3953

3954

3955

3956

3957

3958

3959

3960

3961

3962

3963

3964

3965

3966

3967

3968

3969

3970

3971

3972

3973

3974

3975

3976

3977

3978

3979

3980

3981

3982

3983

3984

3985

3986

3987

3988

3989

3990

3991

3992

3993

3994

3995

3996

3997

3998

3999

4000

4001

4002

4003

4004

4005

4006

4007

4008

4009

4010

4011

4012

4013

4014

4015

4016

4017

4018

4019

4020

4021

4022

4023

4024

4025

4026

4027

4028

4029

4030

4031

4032

4033

4034

4035

4036

4037

4038

4039

4040

4041

4042

4043

4044

4045

4046

4047

4048

4049

4050

4051

4052

4053

4054

4055

4056

4057

4058

4059

4060

4061

4062

4063

4064

4065

4066

4067

4068

4069

4070

4071

4072

4073

4074

4075

4076

4077

4078

4079

4080

4081

4082

4083

4084

4085

4086

4087

4088

4089

4090

4091

4092

4093

4094

4095

4096

4097

4098

4099

4100

4101

4102

4103

4104

4105

4106

4107

4108

4109

4110

4111

4112

4113

4114

4115

4116

4117

4118

4119

4120

4121

4122

4123

4124

4125

4126

4127

4128

4129

4130

4131

4132

4133

4134

4135

4136

4137

4138

4139

4140

4141

4142

4143

4144

4145

4146

4147

4148

4149

4150

4151

4152

4153

4154

4155

4156

4157

4158

4159

4160

4161

4162

4163

4164

4165

4166

4167

4168

4169

4170

4171

4172

4173

4174

4175

4176

4177

4178

4179

4180

4181

4182

4183

4184

4185

4186

4187

4188

4189

4190

4191

4192

4193

4194

4195

4196

4197

4198

4199

4200

4201

4202

4203

4204

4205

4206

4207

4208

4209

4210

4211

4212

4213

4214

4215

4216

4217

4218

4219

4220

4221

4222

4223

4224

4225

4226

4227

4228

4229

4230

4231

4232

4233

4234

4235

4236

4237

4238

4239

4240

4241

4242

4243

4244

4245

4246

4247

4248

4249

4250

4251

4252

4253

4254

4255

4256

4257

4258

4259

4260

4261

4262

4263

4264

4265

4266

4267

4268

4269

4270

4271

4272

4273

4274

4275

4276

4277

4278

4279

4280

4281

4282

4283

4284

4285

4286

4287

4288

4289

4290

4291

4292

4293

4294

4295

4296

4297

4298

4299

4300

4301

4302

4303

4304

4305

4306

4307

4308

4309

4310

4311

4312

4313

4314

4315

4316

4317

4318

4319

4320

4321

4322

4323

4324

4325

4326

4327

4328

4329

4330

4331

4332

4333

4334

4335

4336

4337

4338

4339

4340

4341

4342

4343

4344

4345

4346

4347

4348

4349

4350

4351

4352

4353

4354

4355

4356

4357

4358

4359

4360

4361

4362

4363

4364

4365

4366

4367

4368

4369

4370

4371

4372

4373

4374

4375

4376

4377

4378

4379

4380

4381

4382

4383

4384

4385

4386

4387

4388

4389

4390

4391

4392

4393

4394

4395

4396

4397

4398

4399

4400

4401

4402

4403

4404

4405

4406

4407

4408

4409

4410

4411

4412

4413

4414

4415

4416

4417

4418

4419

4420

4421

4422

4423

4424

4425

4426

4427

4428

4429

4430

4431

4432

4433

4434

4435

4436

4437

4438

4439

4440

4441

4442

4443

4444

4445

4446

4447

4448

4449

4450

4451

4452

4453

4454

4455

4456

4457

4458

4459

4460

4461

4462

4463

4464

4465

4466

4467

4468

4469

4470

4471

4472

4473

4474

4475

4476

4477

4478

4479

4480

4481

4482

4483

4484

4485

4486

4487

4488

4489

4490

4491

4492

4493

4494

4495

4496

4497

4498

4499

4500

4501

4502

4503

4504

4505

4506

4507

4508

4509

4510

4511

4512

4513

4514

4515

4516

4517

4518

4519

4520

4521

4522

4523

4524

4525

4526

4527

4528

4529

4530

4531

4532

4533

4534

4535

4536

4537

4538

4539

4540

4541

4542

4543

4544

4545

4546

4547

4548

4549

4550

4551

4552

4553

4554

4555

4556

4557

4558

4559

4560

4561

4562

4563

4564

4565

4566

4567

4568

4569

4570

4571

4572

4573

4574

4575

4576

4577

4578

4579

4580

4581

4582

4583

4584

4585

4586

4587

4588

4589

4590

4591

4592

4593

4594

4595

4596

4597

4598

4599

4600

4601

4602

4603

4604

4605

4606

4607

4608

4609

4610

4611

4612

4613

4614

4615

4616

4617

4618

4619

4620

4621

4622

4623

4624

4625

4626

4627

4628

4629

4630

4631

4632

4633

4634

4635

4636

4637

4638

4639

4640

4641

4642

4643

4644

4645

4646

4647

4648

4649

4650

4651

4652

4653

4654

4655

4656

4657

4658

4659

4660

4661

4662

4663

4664

4665

4666

4667

4668

4669

4670

4671

4672

4673

4674

4675

4676

4677

4678

4679

4680

4681

4682

4683

4684

4685

4686

4687

4688

4689

4690

4691

4692

4693

4694

4695

4696

4697

4698

4699

4700

4701

4702

4703

4704

4705

4706

4707

4708

4709

4710

4711

4712

4713

4714

4715

4716

4717

4718

4719

4720

4721

4722

4723

4724

4725

4726

4727

4728

4729

4730

4731

4732

4733

4734

4735

4736

4737

4738

4739

4740

4741

4742

4743

4744

4745

4746

4747

4748

4749

4750

4751

4752

4753

4754

4755

4756

4757

4758

4759

4760

4761

4762

4763

4764

4765

4766

4767

4768

4769

4770

4771

4772

4773

4774

4775

4776

4777

4778

4779

4780

4781

4782

4783

4784

4785

4786

4787

4788

4789

4790

4791

4792

4793

4794

4795

4796

4797

4798

4799

4800

4801

4802

4803

4804

4805

4806

4807

4808

4809

4810

4811

4812

4813

4814

4815

4816

4817

4818

4819

4820

4821

4822

4823

4824

4825

4826

4827

4828

4829

4830

4831

4832

4833

4834

4835

4836

4837

4838

4839

4840

4841

4842

4843

4844

4845

4846

4847

4848

4849

4850

4851

4852

4853

4854

4855

4856

4857

4858

4859

4860

4861

4862

4863

4864

4865

4866

4867

4868

4869

4870

4871

4872

4873

4874

4875

4876

4877

4878

4879

4880

4881

4882

4883

4884

4885

4886

4887

4888

4889

4890

4891

4892

4893

4894

4895

4896

4897

4898

4899

4900

4901

4902

4903

4904

4905

4906

4907

4908

4909

4910

4911

4912

4913

4914

4915

4916

4917

4918

4919

4920

4921

4922

4923

4924

4925

4926

4927

4928

4929

4930

4931

4932

4933

4934

4935

4936

4937

4938

4939

4940

4941

4942

4943

4944

4945

4946

4947

4948

4949

4950

4951

4952

4953

4954

4955

4956

4957

4958

4959

4960

4961

4962

4963

4964

4965

4966

4967

4968

4969

4970

4971

4972

4973

4974

4975

4976

4977

4978

4979

4980

4981

4982

4983

4984

4985

4986

4987

4988

4989

4990

4991

4992

4993

4994

4995

4996

4997

4998

4999

5000

5001

5002

5003

5004

5005

5006

5007

5008

5009

5010

5011

5012

5013

5014

5015

5016

5017

5018

5019

5020

5021

5022

5023

5024

5025

5026

5027

5028

5029

5030

5031

5032

5033

5034

5035

5036

5037

5038

5039

5040

5041

5042

5043

5044

5045

5046

5047

5048

5049

5050

5051

5052

5053

5054

5055

5056

5057

5058

5059

5060

5061

5062

5063

5064

5065

5066

5067

5068

5069

5070

5071

5072

5073

5074

5075

5076

5077

5078

5079

5080

5081

5082

5083

5084

5085

5086

5087

5088

5089

5090

5091

5092

5093

5094

5095

5096

5097

5098

5099

5100

5101

5102

5103

5104

5105

5106

5107

5108

5109

5110

5111

5112

5113

5114

5115

5116

5117

5118

5119

5120

5121

5122

5123

5124

5125

5126

5127

5128

5129

5130

5131

5132

5133

5134

5135

5136

5137

5138

5139

5140

5141

5142

5143

5144

5145

5146

5147

5148

5149

5150

5151

5152

5153

5154

5155

5156

5157

5158

5159

5160

5161

5162

5163

5164

5165

5166

5167

5168

5169

5170

5171

5172

5173

5174

5175

5176

5177

5178

5179

5180

5181

5182

5183

5184

5185

5186

5187

5188

5189

5190

5191

5192

5193

5194

5195

5196

5197

5198

5199

5200

5201

5202

5203

5204

5205

5206

5207

5208

5209

5210

5211

5212

5213

5214

5215

5216

5217

5218

5219

5220

5221

5222

5223

5224

5225

5226

5227

5228

5229

5230

5231

5232

5233

5234

5235

5236

5237

5238

5239

5240

5241

5242

5243

5244

5245

5246

5247

5248

5249

5250

5251

5252

5253

5254

5255

5256

5257

5258

5259

5260

5261

5262

5263

5264

5265

5266

5267

5268

5269

5270

5271

5272

5273

5274

5275

5276

5277

5278

5279

5280

5281

5282

5283

5284

5285

5286

5287

5288

5289

5290

5291

5292

5293

5294

5295

5296

5297

5298

5299

5300

5301

5302

5303

5304

5305

5306

5307

5308

5309

5310

5311

5312

5313

5314

5315

5316

5317

5318

5319

5320

5321

5322

5323

5324

5325

5326

5327

5328

5329

5330

5331

5332

5333

5334

5335

5336

5337

5338

5339

5340

5341

5342

5343

5344

5345

5346

5347

5348

5349

5350

5351

5352

5353

5354

5355

5356

5357

5358

5359

5360

5361

5362

5363

5364

5365

5366

5367

5368

5369

5370

5371

5372

5373

5374

5375

5376

5377

5378

5379

5380

5381

5382

5383

5384

5385

5386

5387

5388

5389

5390

5391

5392

5393

5394

5395

5396

5397

5398

5399

5400

5401

5402

5403

5404

5405

5406

5407

5408

5409

5410

5411

5412

5413

5414

5415

5416

5417

5418

5419

5420

5421

5422

5423

5424

5425

5426

5427

5428

5429

5430

5431

5432

5433

5434

5435

5436

5437

5438

5439

5440

5441

5442

5443

5444

5445

5446

5447

5448

5449

5450

5451

5452

5453

5454

5455

5456

5457

5458

5459

5460

5461

5462

5463

5464

5465

5466

5467

5468

5469

5470

5471

5472

5473

5474

5475

5476

5477

5478

5479

5480

5481

5482

5483

5484

5485

5486

5487

5488

5489

5490

5491

5492

5493

5494

5495

5496

5497

5498

5499

5500

5501

5502

5503

5504

5505

5506

5507

5508

5509

5510

5511

5512

5513

5514

5515

5516

5517

5518

5519

5520

5521

5522

5523

5524

5525

5526

5527

5528

5529

5530

5531

5532

5533

5534

5535

5536

5537

5538

5539

5540

5541

5542

5543

5544

5545

5546

5547

5548

5549

5550

5551

5552

5553

5554

5555

5556

5557

5558

5559

5560

5561

5562

5563

5564

5565

5566

5567

5568

5569

5570

5571

5572

5573

5574

5575

5576

5577

5578

5579

5580

5581

5582

5583

5584

5585

5586

5587

5588

5589

5590

5591

5592

5593

5594

5595

5596

5597

5598

5599

5600

5601

5602

5603

5604

5605

5606

5607

5608

5609

5610

5611

5612

/* * Copyright (C) 2014 BlueKitchen GmbH * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the copyright holders nor the names of * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * 4. Any redistribution, use, or modification is done solely for * personal benefit and not for any commercial purpose or for * monetary gain. * * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * Please inquire about commercial licensing options at * contact@bluekitchen-gmbh.com * */ #define BTSTACK_FILE__ "sm.c" #include <string.h> #include <inttypes.h> #include "ble/le_device_db.h" #include "ble/core.h" #include "ble/sm.h" #include "bluetooth_company_id.h" #include "btstack_bool.h" #include "btstack_crypto.h" #include "btstack_debug.h" #include "btstack_event.h" #include "btstack_linked_list.h" #include "btstack_memory.h" #include "btstack_tlv.h" #include "gap.h" #include "hci.h" #include "hci_dump.h" #include "l2cap.h" #if !defined(ENABLE_LE_PERIPHERAL) && !defined(ENABLE_LE_CENTRAL) #error "LE Security Manager used, but neither ENABLE_LE_PERIPHERAL nor ENABLE_LE_CENTRAL defined. Please add at least one to btstack_config.h." #endif #if defined(ENABLE_CROSS_TRANSPORT_KEY_DERIVATION) && (!defined(ENABLE_CLASSIC) || !defined(ENABLE_LE_SECURE_CONNECTIONS)) #error "Cross Transport Key Derivation requires support for LE Secure Connections and BR/EDR (Classic)" #endif // assert SM Public Key can be sent/received #ifdef ENABLE_LE_SECURE_CONNECTIONS #if HCI_ACL_PAYLOAD_SIZE < 69 #error "HCI_ACL_PAYLOAD_SIZE must be at least 69 bytes when using LE Secure Conection. Please increase HCI_ACL_PAYLOAD_SIZE or disable ENABLE_LE_SECURE_CONNECTIONS" #endif #endif #if defined(ENABLE_LE_PERIPHERAL) && defined(ENABLE_LE_CENTRAL) #define IS_RESPONDER(role) ((role) == HCI_ROLE_SLAVE) #else #ifdef ENABLE_LE_CENTRAL // only central - never responder (avoid 'unused variable' warnings) #define IS_RESPONDER(role) (0 && ((role) == HCI_ROLE_SLAVE)) #else // only peripheral - always responder (avoid 'unused variable' warnings) #define IS_RESPONDER(role) (1 || ((role) == HCI_ROLE_SLAVE)) #endif #endif #if defined(ENABLE_LE_SIGNED_WRITE) || defined(ENABLE_LE_SECURE_CONNECTIONS) #define USE_CMAC_ENGINE #endif #define BTSTACK_TAG32(A,B,C,D) (((A) << 24) | ((B) << 16) | ((C) << 8) | (D)) // // SM internal types and globals // typedef enum { DKG_W4_WORKING, DKG_CALC_IRK, DKG_CALC_DHK, DKG_READY } derived_key_generation_t; typedef enum { RAU_IDLE, RAU_GET_RANDOM, RAU_W4_RANDOM, RAU_GET_ENC, RAU_W4_ENC, } random_address_update_t; typedef enum { CMAC_IDLE, CMAC_CALC_SUBKEYS, CMAC_W4_SUBKEYS, CMAC_CALC_MI, CMAC_W4_MI, CMAC_CALC_MLAST, CMAC_W4_MLAST } cmac_state_t; typedef enum { JUST_WORKS, PK_RESP_INPUT, // Initiator displays PK, responder inputs PK PK_INIT_INPUT, // Responder displays PK, initiator inputs PK PK_BOTH_INPUT, // Only input on both, both input PK NUMERIC_COMPARISON, // Only numerical compparison (yes/no) on on both sides OOB // OOB available on one (SC) or both sides (legacy) } stk_generation_method_t; typedef enum { SM_USER_RESPONSE_IDLE, SM_USER_RESPONSE_PENDING, SM_USER_RESPONSE_CONFIRM, SM_USER_RESPONSE_PASSKEY, SM_USER_RESPONSE_DECLINE } sm_user_response_t; typedef enum { SM_AES128_IDLE, SM_AES128_ACTIVE } sm_aes128_state_t; typedef enum { ADDRESS_RESOLUTION_IDLE, ADDRESS_RESOLUTION_GENERAL, ADDRESS_RESOLUTION_FOR_CONNECTION, } address_resolution_mode_t; typedef enum { ADDRESS_RESOLUTION_SUCCEEDED, ADDRESS_RESOLUTION_FAILED, } address_resolution_event_t; typedef enum { EC_KEY_GENERATION_IDLE, EC_KEY_GENERATION_ACTIVE, EC_KEY_GENERATION_DONE, } ec_key_generation_state_t; typedef enum { SM_STATE_VAR_DHKEY_NEEDED = 1 << 0, SM_STATE_VAR_DHKEY_CALCULATED = 1 << 1, SM_STATE_VAR_DHKEY_COMMAND_RECEIVED = 1 << 2, } sm_state_var_t; typedef enum { SM_SC_OOB_IDLE, SM_SC_OOB_W4_RANDOM, SM_SC_OOB_W2_CALC_CONFIRM, SM_SC_OOB_W4_CONFIRM, } sm_sc_oob_state_t; typedef uint8_t sm_key24_t[3]; typedef uint8_t sm_key56_t[7]; typedef uint8_t sm_key256_t[32]; // // GLOBAL DATA // static bool sm_initialized; static bool test_use_fixed_local_csrk; static bool test_use_fixed_local_irk; #ifdef ENABLE_TESTING_SUPPORT static uint8_t test_pairing_failure; #endif // configuration static uint8_t sm_accepted_stk_generation_methods; static uint8_t sm_max_encryption_key_size; static uint8_t sm_min_encryption_key_size; static uint8_t sm_auth_req = 0; static uint8_t sm_io_capabilities = IO_CAPABILITY_NO_INPUT_NO_OUTPUT; static uint32_t sm_fixed_passkey_in_display_role; static bool sm_reconstruct_ltk_without_le_device_db_entry; #ifdef ENABLE_LE_PERIPHERAL static bool sm_slave_request_security; #endif #ifdef ENABLE_LE_SECURE_CONNECTIONS static bool sm_sc_only_mode; static uint8_t sm_sc_oob_random[16]; static void (*sm_sc_oob_callback)(const uint8_t * confirm_value, const uint8_t * random_value); static sm_sc_oob_state_t sm_sc_oob_state; #ifdef ENABLE_LE_SECURE_CONNECTIONS_DEBUG_KEY static bool sm_sc_debug_keys_enabled; #endif #endif static bool sm_persistent_keys_random_active; static const btstack_tlv_t * sm_tlv_impl; static void * sm_tlv_context; // Security Manager Master Keys, please use sm_set_er(er) and sm_set_ir(ir) with your own 128 bit random values static sm_key_t sm_persistent_er; static sm_key_t sm_persistent_ir; // derived from sm_persistent_ir static sm_key_t sm_persistent_dhk; static sm_key_t sm_persistent_irk; static derived_key_generation_t dkg_state; // derived from sm_persistent_er // .. // random address update static random_address_update_t rau_state; static bd_addr_t sm_random_address; #ifdef USE_CMAC_ENGINE // CMAC Calculation: General static btstack_crypto_aes128_cmac_t sm_cmac_request; static void (*sm_cmac_done_callback)(uint8_t hash[8]); static uint8_t sm_cmac_active; static uint8_t sm_cmac_hash[16]; #endif // CMAC for ATT Signed Writes #ifdef ENABLE_LE_SIGNED_WRITE static uint16_t sm_cmac_signed_write_message_len; static uint8_t sm_cmac_signed_write_header[3]; static const uint8_t * sm_cmac_signed_write_message; static uint8_t sm_cmac_signed_write_sign_counter[4]; #endif // CMAC for Secure Connection functions #ifdef ENABLE_LE_SECURE_CONNECTIONS static sm_connection_t * sm_cmac_connection; static uint8_t sm_cmac_sc_buffer[80]; #endif // resolvable private address lookup / CSRK calculation static int sm_address_resolution_test; static uint8_t sm_address_resolution_addr_type; static bd_addr_t sm_address_resolution_address; static void * sm_address_resolution_context; static address_resolution_mode_t sm_address_resolution_mode; static btstack_linked_list_t sm_address_resolution_general_queue; // aes128 crypto engine. static sm_aes128_state_t sm_aes128_state; // crypto static btstack_crypto_random_t sm_crypto_random_request; static btstack_crypto_aes128_t sm_crypto_aes128_request; #ifdef ENABLE_LE_SECURE_CONNECTIONS static btstack_crypto_ecc_p256_t sm_crypto_ecc_p256_request; #endif // temp storage for random data static uint8_t sm_random_data[8]; static uint8_t sm_aes128_key[16]; static uint8_t sm_aes128_plaintext[16]; static uint8_t sm_aes128_ciphertext[16]; // to receive events static btstack_packet_callback_registration_t hci_event_callback_registration; #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION static btstack_packet_callback_registration_t l2cap_event_callback_registration; #endif /* to dispatch sm event */ static btstack_linked_list_t sm_event_handlers; /* to schedule calls to sm_run */ static btstack_timer_source_t sm_run_timer; // LE Secure Connections #ifdef ENABLE_LE_SECURE_CONNECTIONS static ec_key_generation_state_t ec_key_generation_state; static uint8_t ec_q[64]; #endif // // Volume 3, Part H, Chapter 24 // "Security shall be initiated by the Security Manager in the device in the master role. // The device in the slave role shall be the responding device." // -> master := initiator, slave := responder // // data needed for security setup typedef struct sm_setup_context { btstack_timer_source_t sm_timeout; // user response, (Phase 1 and/or 2) uint8_t sm_user_response; uint8_t sm_keypress_notification; // bitmap: passkey started, digit entered, digit erased, passkey cleared, passkey complete, 3 bit count // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3 uint8_t sm_key_distribution_send_set; uint8_t sm_key_distribution_sent_set; uint8_t sm_key_distribution_expected_set; uint8_t sm_key_distribution_received_set; // Phase 2 (Pairing over SMP) stk_generation_method_t sm_stk_generation_method; sm_key_t sm_tk; uint8_t sm_have_oob_data; bool sm_use_secure_connections; sm_key_t sm_c1_t3_value; // c1 calculation sm_pairing_packet_t sm_m_preq; // pairing request - needed only for c1 sm_pairing_packet_t sm_s_pres; // pairing response - needed only for c1 sm_key_t sm_local_random; sm_key_t sm_local_confirm; sm_key_t sm_peer_random; sm_key_t sm_peer_confirm; uint8_t sm_m_addr_type; // address and type can be removed uint8_t sm_s_addr_type; // '' bd_addr_t sm_m_address; // '' bd_addr_t sm_s_address; // '' sm_key_t sm_ltk; uint8_t sm_state_vars; #ifdef ENABLE_LE_SECURE_CONNECTIONS uint8_t sm_peer_q[64]; // also stores random for EC key generation during init sm_key_t sm_peer_nonce; // might be combined with sm_peer_random sm_key_t sm_local_nonce; // might be combined with sm_local_random uint8_t sm_dhkey[32]; sm_key_t sm_peer_dhkey_check; sm_key_t sm_local_dhkey_check; sm_key_t sm_ra; sm_key_t sm_rb; sm_key_t sm_t; // used for f5 and h6 sm_key_t sm_mackey; uint8_t sm_passkey_bit; // also stores number of generated random bytes for EC key generation #endif // Phase 3 // key distribution, we generate uint16_t sm_local_y; uint16_t sm_local_div; uint16_t sm_local_ediv; uint8_t sm_local_rand[8]; sm_key_t sm_local_ltk; sm_key_t sm_local_csrk; sm_key_t sm_local_irk; // sm_local_address/addr_type not needed // key distribution, received from peer uint16_t sm_peer_y; uint16_t sm_peer_div; uint16_t sm_peer_ediv; uint8_t sm_peer_rand[8]; sm_key_t sm_peer_ltk; sm_key_t sm_peer_irk; sm_key_t sm_peer_csrk; uint8_t sm_peer_addr_type; bd_addr_t sm_peer_address; #ifdef ENABLE_LE_SIGNED_WRITE int sm_le_device_index; #endif #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION link_key_t sm_link_key; link_key_type_t sm_link_key_type; #endif } sm_setup_context_t; // static sm_setup_context_t the_setup; static sm_setup_context_t * setup = &the_setup; // active connection - the one for which the_setup is used for static uint16_t sm_active_connection_handle = HCI_CON_HANDLE_INVALID; // @return 1 if oob data is available // stores oob data in provided 16 byte buffer if not null static int (*sm_get_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_data) = NULL; static int (*sm_get_sc_oob_data)(uint8_t addres_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random); static bool (*sm_get_ltk_callback)(hci_con_handle_t con_handle, uint8_t addres_type, bd_addr_t addr, uint8_t * ltk); static void sm_run(void); static void sm_state_reset(void); static void sm_done_for_handle(hci_con_handle_t con_handle); static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle); static void sm_cache_ltk(sm_connection_t * connection, const sm_key_t ltk); #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION static sm_connection_t * sm_get_connection_for_bd_addr_and_type(bd_addr_t address, bd_addr_type_t addr_type); #endif static inline int sm_calc_actual_encryption_key_size(int other); static int sm_validate_stk_generation_method(void); static void sm_handle_encryption_result_address_resolution(void *arg); static void sm_handle_encryption_result_dkg_dhk(void *arg); static void sm_handle_encryption_result_dkg_irk(void *arg); static void sm_handle_encryption_result_enc_a(void *arg); static void sm_handle_encryption_result_enc_b(void *arg); static void sm_handle_encryption_result_enc_c(void *arg); static void sm_handle_encryption_result_enc_csrk(void *arg); static void sm_handle_encryption_result_enc_d(void * arg); static void sm_handle_encryption_result_enc_ph3_ltk(void *arg); static void sm_handle_encryption_result_enc_ph3_y(void *arg); #ifdef ENABLE_LE_PERIPHERAL static void sm_handle_encryption_result_enc_ph4_ltk(void *arg); static void sm_handle_encryption_result_enc_ph4_y(void *arg); #endif static void sm_handle_encryption_result_enc_stk(void *arg); static void sm_handle_encryption_result_rau(void *arg); static void sm_handle_random_result_ph2_tk(void * arg); static void sm_handle_random_result_rau(void * arg); #ifdef ENABLE_LE_SECURE_CONNECTIONS static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)); static void sm_ec_generate_new_key(void); static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg); static void sm_handle_random_result_sc_next_send_pairing_random(void * arg); static bool sm_passkey_entry(stk_generation_method_t method); #endif static void sm_pairing_complete(sm_connection_t * sm_conn, uint8_t status, uint8_t reason); static void log_info_hex16(const char * name, uint16_t value){ log_info("%-6s 0x%04x", name, value); } // static inline uint8_t sm_pairing_packet_get_code(sm_pairing_packet_t packet){ // return packet[0]; // } static inline uint8_t sm_pairing_packet_get_io_capability(sm_pairing_packet_t packet){ return packet[1]; } static inline uint8_t sm_pairing_packet_get_oob_data_flag(sm_pairing_packet_t packet){ return packet[2]; } static inline uint8_t sm_pairing_packet_get_auth_req(sm_pairing_packet_t packet){ return packet[3]; } static inline uint8_t sm_pairing_packet_get_max_encryption_key_size(sm_pairing_packet_t packet){ return packet[4]; } static inline uint8_t sm_pairing_packet_get_initiator_key_distribution(sm_pairing_packet_t packet){ return packet[5]; } static inline uint8_t sm_pairing_packet_get_responder_key_distribution(sm_pairing_packet_t packet){ return packet[6]; } static inline void sm_pairing_packet_set_code(sm_pairing_packet_t packet, uint8_t code){ packet[0] = code; } static inline void sm_pairing_packet_set_io_capability(sm_pairing_packet_t packet, uint8_t io_capability){ packet[1] = io_capability; } static inline void sm_pairing_packet_set_oob_data_flag(sm_pairing_packet_t packet, uint8_t oob_data_flag){ packet[2] = oob_data_flag; } static inline void sm_pairing_packet_set_auth_req(sm_pairing_packet_t packet, uint8_t auth_req){ packet[3] = auth_req; } static inline void sm_pairing_packet_set_max_encryption_key_size(sm_pairing_packet_t packet, uint8_t max_encryption_key_size){ packet[4] = max_encryption_key_size; } static inline void sm_pairing_packet_set_initiator_key_distribution(sm_pairing_packet_t packet, uint8_t initiator_key_distribution){ packet[5] = initiator_key_distribution; } static inline void sm_pairing_packet_set_responder_key_distribution(sm_pairing_packet_t packet, uint8_t responder_key_distribution){ packet[6] = responder_key_distribution; } static bool sm_is_null_random(uint8_t random[8]){ return btstack_is_null(random, 8); } static bool sm_is_null_key(uint8_t * key){ return btstack_is_null(key, 16); } #ifdef ENABLE_LE_SECURE_CONNECTIONS static bool sm_is_ff(const uint8_t * buffer, uint16_t size){ uint16_t i; for (i=0; i < size ; i++){ if (buffer[i] != 0xff) { return false; } } return true; } #endif // sm_trigger_run allows to schedule callback from main run loop // reduces stack depth static void sm_run_timer_handler(btstack_timer_source_t * ts){ UNUSED(ts); sm_run(); } static void sm_trigger_run(void){ if (!sm_initialized) return; (void)btstack_run_loop_remove_timer(&sm_run_timer); btstack_run_loop_set_timer(&sm_run_timer, 0); btstack_run_loop_add_timer(&sm_run_timer); } // Key utils static void sm_reset_tk(void){ int i; for (i=0;i<16;i++){ setup->sm_tk[i] = 0; } } // "For example, if a 128-bit encryption key is 0x123456789ABCDEF0123456789ABCDEF0 // and it is reduced to 7 octets (56 bits), then the resulting key is 0x0000000000000000003456789ABCDEF0."" static void sm_truncate_key(sm_key_t key, int max_encryption_size){ int i; for (i = max_encryption_size ; i < 16 ; i++){ key[15-i] = 0; } } // ER / IR checks static void sm_er_ir_set_default(void){ int i; for (i=0;i<16;i++){ sm_persistent_er[i] = 0x30 + i; sm_persistent_ir[i] = 0x90 + i; } } static bool sm_er_is_default(void){ int i; for (i=0;i<16;i++){ if (sm_persistent_er[i] != (0x30+i)) return true; } return false; } static bool sm_ir_is_default(void){ int i; for (i=0;i<16;i++){ if (sm_persistent_ir[i] != (0x90+i)) return true; } return false; } static void sm_dispatch_event(uint8_t packet_type, uint16_t channel, uint8_t * packet, uint16_t size){ UNUSED(channel); // log event hci_dump_btstack_event(packet, size); // dispatch to all event handlers btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &sm_event_handlers); while (btstack_linked_list_iterator_has_next(&it)){ btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); entry->callback(packet_type, 0, packet, size); } } static void sm_setup_event_base(uint8_t * event, int event_size, uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ event[0] = type; event[1] = event_size - 2; little_endian_store_16(event, 2, con_handle); event[4] = addr_type; reverse_bd_addr(address, &event[5]); } static void sm_notify_client_base(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address){ uint8_t event[11]; sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); } static void sm_notify_client_index(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint16_t index){ // fetch addr and addr type from db, only called for valid entries bd_addr_t identity_address; int identity_address_type; le_device_db_info(index, &identity_address_type, identity_address, NULL); uint8_t event[20]; sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); event[11] = identity_address_type; reverse_bd_addr(identity_address, &event[12]); little_endian_store_16(event, 18, index); sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); } static void sm_notify_client_status(uint8_t type, hci_con_handle_t con_handle, uint8_t addr_type, bd_addr_t address, uint8_t status){ uint8_t event[12]; sm_setup_event_base(event, sizeof(event), type, con_handle, addr_type, address); event[11] = status; sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); } static void sm_reencryption_started(sm_connection_t * sm_conn){ if (sm_conn->sm_reencryption_active) return; sm_conn->sm_reencryption_active = true; int identity_addr_type; bd_addr_t identity_addr; if (sm_conn->sm_le_db_index >= 0){ // fetch addr and addr type from db, only called for valid entries le_device_db_info(sm_conn->sm_le_db_index, &identity_addr_type, identity_addr, NULL); } else { // for legacy pairing with LTK re-construction, use current peer addr identity_addr_type = sm_conn->sm_peer_addr_type; // cppcheck-suppress uninitvar ; identity_addr is reported as uninitialized although it's the destination of the memcpy memcpy(identity_addr, sm_conn->sm_peer_address, 6); } sm_notify_client_base(SM_EVENT_REENCRYPTION_STARTED, sm_conn->sm_handle, identity_addr_type, identity_addr); } static void sm_reencryption_complete(sm_connection_t * sm_conn, uint8_t status){ if (!sm_conn->sm_reencryption_active) return; sm_conn->sm_reencryption_active = false; int identity_addr_type; bd_addr_t identity_addr; if (sm_conn->sm_le_db_index >= 0){ // fetch addr and addr type from db, only called for valid entries le_device_db_info(sm_conn->sm_le_db_index, &identity_addr_type, identity_addr, NULL); } else { // for legacy pairing with LTK re-construction, use current peer addr identity_addr_type = sm_conn->sm_peer_addr_type; // cppcheck-suppress uninitvar ; identity_addr is reported as uninitialized although it's the destination of the memcpy memcpy(identity_addr, sm_conn->sm_peer_address, 6); } sm_notify_client_status(SM_EVENT_REENCRYPTION_COMPLETE, sm_conn->sm_handle, identity_addr_type, identity_addr, status); } static void sm_pairing_started(sm_connection_t * sm_conn){ if (sm_conn->sm_pairing_active) return; sm_conn->sm_pairing_active = true; uint8_t event[11]; sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_STARTED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); } static void sm_pairing_complete(sm_connection_t * sm_conn, uint8_t status, uint8_t reason){ if (!sm_conn->sm_pairing_active) return; sm_conn->sm_pairing_active = false; uint8_t event[13]; sm_setup_event_base(event, sizeof(event), SM_EVENT_PAIRING_COMPLETE, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address); event[11] = status; event[12] = reason; sm_dispatch_event(HCI_EVENT_PACKET, 0, (uint8_t*) &event, sizeof(event)); } // SMP Timeout implementation // Upon transmission of the Pairing Request command or reception of the Pairing Request command, // the Security Manager Timer shall be reset and started. // // The Security Manager Timer shall be reset when an L2CAP SMP command is queued for transmission. // // If the Security Manager Timer reaches 30 seconds, the procedure shall be considered to have failed, // and the local higher layer shall be notified. No further SMP commands shall be sent over the L2CAP // Security Manager Channel. A new SM procedure shall only be performed when a new physical link has been // established. static void sm_timeout_handler(btstack_timer_source_t * timer){ log_info("SM timeout"); sm_connection_t * sm_conn = (sm_connection_t*) btstack_run_loop_get_timer_context(timer); sm_conn->sm_engine_state = SM_GENERAL_TIMEOUT; sm_reencryption_complete(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT); sm_pairing_complete(sm_conn, ERROR_CODE_CONNECTION_TIMEOUT, 0); sm_done_for_handle(sm_conn->sm_handle); // trigger handling of next ready connection sm_run(); } static void sm_timeout_start(sm_connection_t * sm_conn){ btstack_run_loop_remove_timer(&setup->sm_timeout); btstack_run_loop_set_timer_context(&setup->sm_timeout, sm_conn); btstack_run_loop_set_timer_handler(&setup->sm_timeout, sm_timeout_handler); btstack_run_loop_set_timer(&setup->sm_timeout, 30000); // 30 seconds sm timeout btstack_run_loop_add_timer(&setup->sm_timeout); } static void sm_timeout_stop(void){ btstack_run_loop_remove_timer(&setup->sm_timeout); } static void sm_timeout_reset(sm_connection_t * sm_conn){ sm_timeout_stop(); sm_timeout_start(sm_conn); } // end of sm timeout // GAP Random Address updates static gap_random_address_type_t gap_random_adress_type; static btstack_timer_source_t gap_random_address_update_timer; static uint32_t gap_random_adress_update_period; static void gap_random_address_trigger(void){ log_info("gap_random_address_trigger, state %u", rau_state); if (rau_state != RAU_IDLE) return; rau_state = RAU_GET_RANDOM; sm_trigger_run(); } static void gap_random_address_update_handler(btstack_timer_source_t * timer){ UNUSED(timer); log_info("GAP Random Address Update due"); btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); btstack_run_loop_add_timer(&gap_random_address_update_timer); gap_random_address_trigger(); } static void gap_random_address_update_start(void){ btstack_run_loop_set_timer_handler(&gap_random_address_update_timer, gap_random_address_update_handler); btstack_run_loop_set_timer(&gap_random_address_update_timer, gap_random_adress_update_period); btstack_run_loop_add_timer(&gap_random_address_update_timer); } static void gap_random_address_update_stop(void){ btstack_run_loop_remove_timer(&gap_random_address_update_timer); } // ah(k,r) helper // r = padding || r // r - 24 bit value static void sm_ah_r_prime(uint8_t r[3], uint8_t * r_prime){ // r'= padding || r memset(r_prime, 0, 16); (void)memcpy(&r_prime[13], r, 3); } // d1 helper // d' = padding || r || d // d,r - 16 bit values static void sm_d1_d_prime(uint16_t d, uint16_t r, uint8_t * d1_prime){ // d'= padding || r || d memset(d1_prime, 0, 16); big_endian_store_16(d1_prime, 12, r); big_endian_store_16(d1_prime, 14, d); } // calculate arguments for first AES128 operation in C1 function static void sm_c1_t1(sm_key_t r, uint8_t preq[7], uint8_t pres[7], uint8_t iat, uint8_t rat, uint8_t * t1){ // p1 = pres || preq || rat’ || iat’ // "The octet of iat’ becomes the least significant octet of p1 and the most signifi- // cant octet of pres becomes the most significant octet of p1. // For example, if the 8-bit iat’ is 0x01, the 8-bit rat’ is 0x00, the 56-bit preq // is 0x07071000000101 and the 56 bit pres is 0x05000800000302 then // p1 is 0x05000800000302070710000001010001." sm_key_t p1; reverse_56(pres, &p1[0]); reverse_56(preq, &p1[7]); p1[14] = rat; p1[15] = iat; log_info_key("p1", p1); log_info_key("r", r); // t1 = r xor p1 int i; for (i=0;i<16;i++){ t1[i] = r[i] ^ p1[i]; } log_info_key("t1", t1); } // calculate arguments for second AES128 operation in C1 function static void sm_c1_t3(sm_key_t t2, bd_addr_t ia, bd_addr_t ra, uint8_t * t3){ // p2 = padding || ia || ra // "The least significant octet of ra becomes the least significant octet of p2 and // the most significant octet of padding becomes the most significant octet of p2. // For example, if 48-bit ia is 0xA1A2A3A4A5A6 and the 48-bit ra is // 0xB1B2B3B4B5B6 then p2 is 0x00000000A1A2A3A4A5A6B1B2B3B4B5B6. sm_key_t p2; // cppcheck-suppress uninitvar ; p2 is reported as uninitialized memset(p2, 0, 16); (void)memcpy(&p2[4], ia, 6); (void)memcpy(&p2[10], ra, 6); log_info_key("p2", p2); // c1 = e(k, t2_xor_p2) int i; for (i=0;i<16;i++){ t3[i] = t2[i] ^ p2[i]; } log_info_key("t3", t3); } static void sm_s1_r_prime(sm_key_t r1, sm_key_t r2, uint8_t * r_prime){ log_info_key("r1", r1); log_info_key("r2", r2); (void)memcpy(&r_prime[8], &r2[8], 8); (void)memcpy(&r_prime[0], &r1[8], 8); } // decide on stk generation based on // - pairing request // - io capabilities // - OOB data availability static void sm_setup_tk(void){ // horizontal: initiator capabilities // vertial: responder capabilities static const stk_generation_method_t stk_generation_method [5] [5] = { { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, { PK_RESP_INPUT, PK_RESP_INPUT, PK_INIT_INPUT, JUST_WORKS, PK_RESP_INPUT }, }; // uses numeric comparison if one side has DisplayYesNo and KeyboardDisplay combinations #ifdef ENABLE_LE_SECURE_CONNECTIONS static const stk_generation_method_t stk_generation_method_with_secure_connection[5][5] = { { JUST_WORKS, JUST_WORKS, PK_INIT_INPUT, JUST_WORKS, PK_INIT_INPUT }, { JUST_WORKS, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, { PK_RESP_INPUT, PK_RESP_INPUT, PK_BOTH_INPUT, JUST_WORKS, PK_RESP_INPUT }, { JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS }, { PK_RESP_INPUT, NUMERIC_COMPARISON, PK_INIT_INPUT, JUST_WORKS, NUMERIC_COMPARISON }, }; #endif // default: just works setup->sm_stk_generation_method = JUST_WORKS; #ifdef ENABLE_LE_SECURE_CONNECTIONS setup->sm_use_secure_connections = ( sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_SECURE_CONNECTION ) != 0u; #else setup->sm_use_secure_connections = false; #endif log_info("Secure pairing: %u", setup->sm_use_secure_connections); // decide if OOB will be used based on SC vs. Legacy and oob flags bool use_oob; if (setup->sm_use_secure_connections){ // In LE Secure Connections pairing, the out of band method is used if at least // one device has the peer device's out of band authentication data available. use_oob = (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) | sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)) != 0; } else { // In LE legacy pairing, the out of band method is used if both the devices have // the other device's out of band authentication data available. use_oob = (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) & sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres)) != 0; } if (use_oob){ log_info("SM: have OOB data"); log_info_key("OOB", setup->sm_tk); setup->sm_stk_generation_method = OOB; return; } // If both devices have not set the MITM option in the Authentication Requirements // Flags, then the IO capabilities shall be ignored and the Just Works association // model shall be used. if (((sm_pairing_packet_get_auth_req(setup->sm_m_preq) & SM_AUTHREQ_MITM_PROTECTION) == 0u) && ((sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_MITM_PROTECTION) == 0u)){ log_info("SM: MITM not required by both -> JUST WORKS"); return; } // Reset TK as it has been setup in sm_init_setup sm_reset_tk(); // Also use just works if unknown io capabilites if ((sm_pairing_packet_get_io_capability(setup->sm_m_preq) > IO_CAPABILITY_KEYBOARD_DISPLAY) || (sm_pairing_packet_get_io_capability(setup->sm_s_pres) > IO_CAPABILITY_KEYBOARD_DISPLAY)){ return; } // Otherwise the IO capabilities of the devices shall be used to determine the // pairing method as defined in Table 2.4. // see http://stackoverflow.com/a/1052837/393697 for how to specify pointer to 2-dimensional array const stk_generation_method_t (*generation_method)[5] = stk_generation_method; #ifdef ENABLE_LE_SECURE_CONNECTIONS // table not define by default if (setup->sm_use_secure_connections){ generation_method = stk_generation_method_with_secure_connection; } #endif setup->sm_stk_generation_method = generation_method[sm_pairing_packet_get_io_capability(setup->sm_s_pres)][sm_pairing_packet_get_io_capability(setup->sm_m_preq)]; log_info("sm_setup_tk: master io cap: %u, slave io cap: %u -> method %u", sm_pairing_packet_get_io_capability(setup->sm_m_preq), sm_pairing_packet_get_io_capability(setup->sm_s_pres), setup->sm_stk_generation_method); } static int sm_key_distribution_flags_for_set(uint8_t key_set){ int flags = 0; if ((key_set & SM_KEYDIST_ENC_KEY) != 0u){ flags |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; flags |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; } if ((key_set & SM_KEYDIST_ID_KEY) != 0u){ flags |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; flags |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; } if ((key_set & SM_KEYDIST_SIGN) != 0u){ flags |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; } return flags; } static void sm_setup_key_distribution(uint8_t keys_to_send, uint8_t keys_to_receive){ setup->sm_key_distribution_received_set = 0; setup->sm_key_distribution_expected_set = sm_key_distribution_flags_for_set(keys_to_receive); setup->sm_key_distribution_send_set = sm_key_distribution_flags_for_set(keys_to_send); setup->sm_key_distribution_sent_set = 0; #ifdef ENABLE_LE_SIGNED_WRITE setup->sm_le_device_index = -1; #endif } // CSRK Key Lookup static bool sm_address_resolution_idle(void){ return sm_address_resolution_mode == ADDRESS_RESOLUTION_IDLE; } static void sm_address_resolution_start_lookup(uint8_t addr_type, hci_con_handle_t con_handle, bd_addr_t addr, address_resolution_mode_t mode, void * context){ (void)memcpy(sm_address_resolution_address, addr, 6); sm_address_resolution_addr_type = addr_type; sm_address_resolution_test = 0; sm_address_resolution_mode = mode; sm_address_resolution_context = context; sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_STARTED, con_handle, addr_type, addr); } int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address){ // check if already in list btstack_linked_list_iterator_t it; sm_lookup_entry_t * entry; btstack_linked_list_iterator_init(&it, &sm_address_resolution_general_queue); while(btstack_linked_list_iterator_has_next(&it)){ entry = (sm_lookup_entry_t *) btstack_linked_list_iterator_next(&it); if (entry->address_type != address_type) continue; if (memcmp(entry->address, address, 6) != 0) continue; // already in list return BTSTACK_BUSY; } entry = btstack_memory_sm_lookup_entry_get(); if (!entry) return BTSTACK_MEMORY_ALLOC_FAILED; entry->address_type = (bd_addr_type_t) address_type; (void)memcpy(entry->address, address, 6); btstack_linked_list_add(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); sm_trigger_run(); return 0; } // CMAC calculation using AES Engineq #ifdef USE_CMAC_ENGINE static void sm_cmac_done_trampoline(void * arg){ UNUSED(arg); sm_cmac_active = 0; (*sm_cmac_done_callback)(sm_cmac_hash); sm_trigger_run(); } int sm_cmac_ready(void){ return sm_cmac_active == 0u; } #endif #ifdef ENABLE_LE_SECURE_CONNECTIONS // generic cmac calculation static void sm_cmac_message_start(const sm_key_t key, uint16_t message_len, const uint8_t * message, void (*done_callback)(uint8_t * hash)){ sm_cmac_active = 1; sm_cmac_done_callback = done_callback; btstack_crypto_aes128_cmac_message(&sm_cmac_request, key, message_len, message, sm_cmac_hash, sm_cmac_done_trampoline, NULL); } #endif // cmac for ATT Message signing #ifdef ENABLE_LE_SIGNED_WRITE static void sm_cmac_generator_start(const sm_key_t key, uint16_t message_len, uint8_t (*get_byte_callback)(uint16_t offset), void (*done_callback)(uint8_t * hash)){ sm_cmac_active = 1; sm_cmac_done_callback = done_callback; btstack_crypto_aes128_cmac_generator(&sm_cmac_request, key, message_len, get_byte_callback, sm_cmac_hash, sm_cmac_done_trampoline, NULL); } static uint8_t sm_cmac_signed_write_message_get_byte(uint16_t offset){ if (offset >= sm_cmac_signed_write_message_len) { log_error("sm_cmac_signed_write_message_get_byte. out of bounds, access %u, len %u", offset, sm_cmac_signed_write_message_len); return 0; } offset = sm_cmac_signed_write_message_len - 1 - offset; // sm_cmac_signed_write_header[3] | message[] | sm_cmac_signed_write_sign_counter[4] if (offset < 3){ return sm_cmac_signed_write_header[offset]; } int actual_message_len_incl_header = sm_cmac_signed_write_message_len - 4; if (offset < actual_message_len_incl_header){ return sm_cmac_signed_write_message[offset - 3]; } return sm_cmac_signed_write_sign_counter[offset - actual_message_len_incl_header]; } void sm_cmac_signed_write_start(const sm_key_t k, uint8_t opcode, hci_con_handle_t con_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t * hash)){ // ATT Message Signing sm_cmac_signed_write_header[0] = opcode; little_endian_store_16(sm_cmac_signed_write_header, 1, con_handle); little_endian_store_32(sm_cmac_signed_write_sign_counter, 0, sign_counter); uint16_t total_message_len = 3 + message_len + 4; // incl. virtually prepended att opcode, handle and appended sign_counter in LE sm_cmac_signed_write_message = message; sm_cmac_signed_write_message_len = total_message_len; sm_cmac_generator_start(k, total_message_len, &sm_cmac_signed_write_message_get_byte, done_handler); } #endif static void sm_trigger_user_response_basic(sm_connection_t * sm_conn, uint8_t event_type){ setup->sm_user_response = SM_USER_RESPONSE_PENDING; uint8_t event[12]; sm_setup_event_base(event, sizeof(event), event_type, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); event[11] = setup->sm_use_secure_connections ? 1 : 0; sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); } static void sm_trigger_user_response_passkey(sm_connection_t * sm_conn, uint8_t event_type){ uint8_t event[16]; uint32_t passkey = big_endian_read_32(setup->sm_tk, 12); sm_setup_event_base(event, sizeof(event), event_type, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); event[11] = setup->sm_use_secure_connections ? 1 : 0; little_endian_store_32(event, 12, passkey); sm_dispatch_event(HCI_EVENT_PACKET, 0, event, sizeof(event)); } static void sm_trigger_user_response(sm_connection_t * sm_conn){ // notify client for: JUST WORKS confirm, Numeric comparison confirm, PASSKEY display or input setup->sm_user_response = SM_USER_RESPONSE_IDLE; sm_conn->sm_pairing_active = true; switch (setup->sm_stk_generation_method){ case PK_RESP_INPUT: if (IS_RESPONDER(sm_conn->sm_role)){ sm_trigger_user_response_basic(sm_conn, SM_EVENT_PASSKEY_INPUT_NUMBER); } else { sm_trigger_user_response_passkey(sm_conn, SM_EVENT_PASSKEY_DISPLAY_NUMBER); } break; case PK_INIT_INPUT: if (IS_RESPONDER(sm_conn->sm_role)){ sm_trigger_user_response_passkey(sm_conn, SM_EVENT_PASSKEY_DISPLAY_NUMBER); } else { sm_trigger_user_response_basic(sm_conn, SM_EVENT_PASSKEY_INPUT_NUMBER); } break; case PK_BOTH_INPUT: sm_trigger_user_response_basic(sm_conn, SM_EVENT_PASSKEY_INPUT_NUMBER); break; case NUMERIC_COMPARISON: sm_trigger_user_response_passkey(sm_conn, SM_EVENT_NUMERIC_COMPARISON_REQUEST); break; case JUST_WORKS: sm_trigger_user_response_basic(sm_conn, SM_EVENT_JUST_WORKS_REQUEST); break; case OOB: // client already provided OOB data, let's skip notification. break; default: btstack_assert(false); break; } } static bool sm_key_distribution_all_received(void) { log_debug("sm_key_distribution_all_received: received 0x%02x, expecting 0x%02x", setup->sm_key_distribution_received_set, setup->sm_key_distribution_expected_set); return (setup->sm_key_distribution_expected_set & setup->sm_key_distribution_received_set) == setup->sm_key_distribution_expected_set; } static void sm_done_for_handle(hci_con_handle_t con_handle){ if (sm_active_connection_handle == con_handle){ sm_timeout_stop(); sm_active_connection_handle = HCI_CON_HANDLE_INVALID; log_info("sm: connection 0x%x released setup context", con_handle); #ifdef ENABLE_LE_SECURE_CONNECTIONS // generate new ec key after each pairing (that used it) if (setup->sm_use_secure_connections){ sm_ec_generate_new_key(); } #endif } } static void sm_master_pairing_success(sm_connection_t *connection) {// master -> all done connection->sm_engine_state = SM_INITIATOR_CONNECTED; sm_pairing_complete(connection, ERROR_CODE_SUCCESS, 0); sm_done_for_handle(connection->sm_handle); } static int sm_key_distribution_flags_for_auth_req(void){ int flags = SM_KEYDIST_ID_KEY; if ((sm_auth_req & SM_AUTHREQ_BONDING) != 0u){ // encryption and signing information only if bonding requested flags |= SM_KEYDIST_ENC_KEY; #ifdef ENABLE_LE_SIGNED_WRITE flags |= SM_KEYDIST_SIGN; #endif #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION // LinkKey for CTKD requires SC and BR/EDR Support if (hci_classic_supported() && ((sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION) != 0)){ flags |= SM_KEYDIST_LINK_KEY; } #endif } return flags; } static void sm_reset_setup(void){ // fill in sm setup setup->sm_state_vars = 0; setup->sm_keypress_notification = 0; setup->sm_have_oob_data = 0; sm_reset_tk(); } static void sm_init_setup(sm_connection_t * sm_conn){ // fill in sm setup setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type; (void)memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6); // query client for Legacy Pairing OOB data if (sm_get_oob_data != NULL) { setup->sm_have_oob_data = (*sm_get_oob_data)(sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_tk); } // if available and SC supported, also ask for SC OOB Data #ifdef ENABLE_LE_SECURE_CONNECTIONS memset(setup->sm_ra, 0, 16); memset(setup->sm_rb, 0, 16); if (setup->sm_have_oob_data && (sm_auth_req & SM_AUTHREQ_SECURE_CONNECTION)){ if (sm_get_sc_oob_data != NULL){ if (IS_RESPONDER(sm_conn->sm_role)){ setup->sm_have_oob_data = (*sm_get_sc_oob_data)( sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_peer_confirm, setup->sm_ra); } else { setup->sm_have_oob_data = (*sm_get_sc_oob_data)( sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, setup->sm_peer_confirm, setup->sm_rb); } } else { setup->sm_have_oob_data = 0; } } #endif sm_pairing_packet_t * local_packet; if (IS_RESPONDER(sm_conn->sm_role)){ // slave local_packet = &setup->sm_s_pres; setup->sm_m_addr_type = sm_conn->sm_peer_addr_type; setup->sm_s_addr_type = sm_conn->sm_own_addr_type; (void)memcpy(setup->sm_m_address, sm_conn->sm_peer_address, 6); (void)memcpy(setup->sm_s_address, sm_conn->sm_own_address, 6); } else { // master local_packet = &setup->sm_m_preq; setup->sm_s_addr_type = sm_conn->sm_peer_addr_type; setup->sm_m_addr_type = sm_conn->sm_own_addr_type; (void)memcpy(setup->sm_s_address, sm_conn->sm_peer_address, 6); (void)memcpy(setup->sm_m_address, sm_conn->sm_own_address, 6); uint8_t key_distribution_flags = sm_key_distribution_flags_for_auth_req(); sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); } log_info("our address %s type %u", bd_addr_to_str(sm_conn->sm_own_address), sm_conn->sm_own_addr_type); log_info("peer address %s type %u", bd_addr_to_str(sm_conn->sm_peer_address), sm_conn->sm_peer_addr_type); uint8_t auth_req = sm_auth_req & ~SM_AUTHREQ_CT2; uint8_t max_encryption_key_size = sm_max_encryption_key_size; #ifdef ENABLE_LE_SECURE_CONNECTIONS // enable SC for SC only mode if (sm_sc_only_mode){ auth_req |= SM_AUTHREQ_SECURE_CONNECTION; max_encryption_key_size = 16; } #endif #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION // set CT2 if SC + Bonding + CTKD const uint8_t auth_req_for_ct2 = SM_AUTHREQ_SECURE_CONNECTION | SM_AUTHREQ_BONDING; if ((auth_req & auth_req_for_ct2) == auth_req_for_ct2){ auth_req |= SM_AUTHREQ_CT2; } #endif sm_pairing_packet_set_io_capability(*local_packet, sm_io_capabilities); sm_pairing_packet_set_oob_data_flag(*local_packet, setup->sm_have_oob_data); sm_pairing_packet_set_auth_req(*local_packet, auth_req); sm_pairing_packet_set_max_encryption_key_size(*local_packet, max_encryption_key_size); } static int sm_stk_generation_init(sm_connection_t * sm_conn){ sm_pairing_packet_t * remote_packet; uint8_t keys_to_send; uint8_t keys_to_receive; if (IS_RESPONDER(sm_conn->sm_role)){ // slave / responder remote_packet = &setup->sm_m_preq; keys_to_send = sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq); keys_to_receive = sm_pairing_packet_get_initiator_key_distribution(setup->sm_m_preq); } else { // master / initiator remote_packet = &setup->sm_s_pres; keys_to_send = sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres); keys_to_receive = sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres); } // check key size #ifdef ENABLE_LE_SECURE_CONNECTIONS // SC Only mandates 128 bit key size if (sm_sc_only_mode && (sm_pairing_packet_get_max_encryption_key_size(*remote_packet) < 16)) { return SM_REASON_ENCRYPTION_KEY_SIZE; } #endif sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(sm_pairing_packet_get_max_encryption_key_size(*remote_packet)); if (sm_conn->sm_actual_encryption_key_size == 0u) return SM_REASON_ENCRYPTION_KEY_SIZE; // decide on STK generation method / SC sm_setup_tk(); log_info("SMP: generation method %u", setup->sm_stk_generation_method); // check if STK generation method is acceptable by client if (!sm_validate_stk_generation_method()) return SM_REASON_AUTHENTHICATION_REQUIREMENTS; #ifdef ENABLE_LE_SECURE_CONNECTIONS // Check LE SC Only mode if (sm_sc_only_mode && (setup->sm_use_secure_connections == false)){ log_info("SC Only mode active but SC not possible"); return SM_REASON_AUTHENTHICATION_REQUIREMENTS; } // LTK (= encryption information & master identification) only used exchanged for LE Legacy Connection if (setup->sm_use_secure_connections){ keys_to_send &= ~SM_KEYDIST_ENC_KEY; keys_to_receive &= ~SM_KEYDIST_ENC_KEY; } #endif // identical to responder sm_setup_key_distribution(keys_to_send, keys_to_receive); // JUST WORKS doens't provide authentication sm_conn->sm_connection_authenticated = (setup->sm_stk_generation_method == JUST_WORKS) ? 0 : 1; return 0; } static void sm_address_resolution_handle_event(address_resolution_event_t event){ // cache and reset context int matched_device_id = sm_address_resolution_test; address_resolution_mode_t mode = sm_address_resolution_mode; void * context = sm_address_resolution_context; // reset context sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; sm_address_resolution_context = NULL; sm_address_resolution_test = -1; hci_con_handle_t con_handle = HCI_CON_HANDLE_INVALID; sm_connection_t * sm_connection; sm_key_t ltk; bool have_ltk; int authenticated; #ifdef ENABLE_LE_CENTRAL bool trigger_pairing; #endif switch (mode){ case ADDRESS_RESOLUTION_GENERAL: break; case ADDRESS_RESOLUTION_FOR_CONNECTION: sm_connection = (sm_connection_t *) context; con_handle = sm_connection->sm_handle; // have ltk -> start encryption / send security request // Core 5, Vol 3, Part C, 10.3.2 Initiating a Service Request // "When a bond has been created between two devices, any reconnection should result in the local device // enabling or requesting encryption with the remote device before initiating any service request." switch (event){ case ADDRESS_RESOLUTION_SUCCEEDED: sm_connection->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; sm_connection->sm_le_db_index = matched_device_id; log_info("ADDRESS_RESOLUTION_SUCCEEDED, index %d", sm_connection->sm_le_db_index); le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, &authenticated, NULL, NULL); have_ltk = !sm_is_null_key(ltk); if (IS_RESPONDER(sm_connection->sm_role)) { #ifdef ENABLE_LE_PERIPHERAL // IRK required before, continue if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ sm_connection->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; break; } // Pairing request before, continue if (sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED_W4_IRK){ sm_connection->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; break; } bool trigger_security_request = sm_connection->sm_pairing_requested || sm_slave_request_security; sm_connection->sm_pairing_requested = false; #ifdef ENABLE_LE_PROACTIVE_AUTHENTICATION // trigger security request for Proactive Authentication if LTK available trigger_security_request = trigger_security_request || have_ltk; #endif log_info("peripheral: pairing request local %u, have_ltk %u => trigger_security_request %u", (int) sm_connection->sm_pairing_requested, (int) have_ltk, trigger_security_request); if (trigger_security_request){ sm_connection->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; if (have_ltk){ sm_reencryption_started(sm_connection); } else { sm_pairing_started(sm_connection); } sm_trigger_run(); } #endif } else { #ifdef ENABLE_LE_CENTRAL // check if pairing already requested and reset requests trigger_pairing = sm_connection->sm_pairing_requested || sm_connection->sm_security_request_received; bool auth_required = sm_auth_req & SM_AUTHREQ_MITM_PROTECTION; log_info("central: pairing request local %u, remote %u => trigger_pairing %u. have_ltk %u", (int) sm_connection->sm_pairing_requested, (int) sm_connection->sm_security_request_received, (int) trigger_pairing, (int) have_ltk); sm_connection->sm_security_request_received = false; sm_connection->sm_pairing_requested = false; bool trigger_reencryption = false; if (have_ltk){ if (trigger_pairing){ // if pairing is requested, re-encryption is sufficient, if ltk is already authenticated or we don't require authentication trigger_reencryption = (authenticated != 0) || (auth_required == false); } else { #ifdef ENABLE_LE_PROACTIVE_AUTHENTICATION trigger_reencryption = true; #else log_info("central: defer enabling encryption for bonded device"); #endif } } if (trigger_reencryption){ log_info("central: enable encryption for bonded device"); sm_connection->sm_engine_state = SM_INITIATOR_PH4_HAS_LTK; break; } // pairing_request -> send pairing request if (trigger_pairing){ sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; break; } #endif } break; case ADDRESS_RESOLUTION_FAILED: sm_connection->sm_irk_lookup_state = IRK_LOOKUP_FAILED; if (IS_RESPONDER(sm_connection->sm_role)) { #ifdef ENABLE_LE_PERIPHERAL // LTK request received before, IRK required -> negative LTK reply if (sm_connection->sm_engine_state == SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK){ sm_connection->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; } // Pairing request before, continue if (sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED_W4_IRK){ sm_connection->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; break; } // send security request if requested bool trigger_security_request = sm_connection->sm_pairing_requested || sm_slave_request_security; sm_connection->sm_pairing_requested = false; if (trigger_security_request){ sm_connection->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; sm_pairing_started(sm_connection); } break; #endif } #ifdef ENABLE_LE_CENTRAL if ((sm_connection->sm_pairing_requested == false) && (sm_connection->sm_security_request_received == false)) break; sm_connection->sm_security_request_received = false; sm_connection->sm_pairing_requested = false; sm_connection->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; #endif break; default: btstack_assert(false); break; } break; default: break; } switch (event){ case ADDRESS_RESOLUTION_SUCCEEDED: sm_notify_client_index(SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address, matched_device_id); break; case ADDRESS_RESOLUTION_FAILED: sm_notify_client_base(SM_EVENT_IDENTITY_RESOLVING_FAILED, con_handle, sm_address_resolution_addr_type, sm_address_resolution_address); break; default: btstack_assert(false); break; } } static void sm_store_bonding_information(sm_connection_t * sm_conn){ int le_db_index = -1; // lookup device based on IRK if ((setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION) != 0u){ int i; for (i=0; i < le_device_db_max_count(); i++){ sm_key_t irk; bd_addr_t address; int address_type = BD_ADDR_TYPE_UNKNOWN; le_device_db_info(i, &address_type, address, irk); // skip unused entries if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; // compare Identity Address if (memcmp(address, setup->sm_peer_address, 6) != 0) continue; // compare Identity Resolving Key if (memcmp(irk, setup->sm_peer_irk, 16) != 0) continue; log_info("sm: device found for IRK, updating"); le_db_index = i; break; } } else { // assert IRK is set to zero memset(setup->sm_peer_irk, 0, 16); } // if not found, lookup via public address if possible log_info("sm peer addr type %u, peer addres %s", setup->sm_peer_addr_type, bd_addr_to_str(setup->sm_peer_address)); if ((le_db_index < 0) && (setup->sm_peer_addr_type == BD_ADDR_TYPE_LE_PUBLIC)){ int i; for (i=0; i < le_device_db_max_count(); i++){ bd_addr_t address; int address_type = BD_ADDR_TYPE_UNKNOWN; le_device_db_info(i, &address_type, address, NULL); // skip unused entries if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; log_info("device %u, sm peer addr type %u, peer addres %s", i, address_type, bd_addr_to_str(address)); if ((address_type == BD_ADDR_TYPE_LE_PUBLIC) && (memcmp(address, setup->sm_peer_address, 6) == 0)){ log_info("sm: device found for public address, updating"); le_db_index = i; break; } } } // if not found, add to db bool new_to_le_device_db = false; if (le_db_index < 0) { le_db_index = le_device_db_add(setup->sm_peer_addr_type, setup->sm_peer_address, setup->sm_peer_irk); new_to_le_device_db = true; } if (le_db_index >= 0){ #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION if (!new_to_le_device_db){ hci_remove_le_device_db_entry_from_resolving_list(le_db_index); } hci_load_le_device_db_entry_into_resolving_list(le_db_index); #else UNUSED(new_to_le_device_db); #endif sm_notify_client_index(SM_EVENT_IDENTITY_CREATED, sm_conn->sm_handle, setup->sm_peer_addr_type, setup->sm_peer_address, le_db_index); sm_conn->sm_irk_lookup_state = IRK_LOOKUP_SUCCEEDED; sm_conn->sm_le_db_index = le_db_index; #ifdef ENABLE_LE_SIGNED_WRITE // store local CSRK setup->sm_le_device_index = le_db_index; if ((setup->sm_key_distribution_sent_set) & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ log_info("sm: store local CSRK"); le_device_db_local_csrk_set(le_db_index, setup->sm_local_csrk); le_device_db_local_counter_set(le_db_index, 0); } // store remote CSRK if (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION){ log_info("sm: store remote CSRK"); le_device_db_remote_csrk_set(le_db_index, setup->sm_peer_csrk); le_device_db_remote_counter_set(le_db_index, 0); } #endif // store encryption information for secure connections: LTK generated by ECDH if (setup->sm_use_secure_connections){ log_info("sm: store SC LTK (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); uint8_t zero_rand[8]; memset(zero_rand, 0, 8); le_device_db_encryption_set(le_db_index, 0, zero_rand, setup->sm_ltk, sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 1); } // store encryption information for legacy pairing: peer LTK, EDIV, RAND else if ( (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) && (setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION )){ log_info("sm: set encryption information (key size %u, authenticated %u)", sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated); le_device_db_encryption_set(le_db_index, setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, sm_conn->sm_actual_encryption_key_size, sm_conn->sm_connection_authenticated, sm_conn->sm_connection_authorization_state == AUTHORIZATION_GRANTED, 0); } } } static void sm_pairing_error(sm_connection_t * sm_conn, uint8_t reason){ sm_conn->sm_pairing_failed_reason = reason; sm_conn->sm_engine_state = SM_GENERAL_SEND_PAIRING_FAILED; } static int sm_le_device_db_index_lookup(bd_addr_type_t address_type, bd_addr_t address){ int i; for (i=0; i < le_device_db_max_count(); i++){ bd_addr_t db_address; int db_address_type = BD_ADDR_TYPE_UNKNOWN; le_device_db_info(i, &db_address_type, db_address, NULL); // skip unused entries if (address_type == BD_ADDR_TYPE_UNKNOWN) continue; if ((address_type == (unsigned int)db_address_type) && (memcmp(address, db_address, 6) == 0)){ return i; } } return -1; } static void sm_remove_le_device_db_entry(uint16_t i) { le_device_db_remove(i); #ifdef ENABLE_LE_PRIVACY_ADDRESS_RESOLUTION // to remove an entry from the resolving list requires its identity address, which was already deleted // fully reload resolving list instead gap_load_resolving_list_from_le_device_db(); #endif } static uint8_t sm_key_distribution_validate_received(sm_connection_t * sm_conn){ // if identity is provided, abort if we have bonding with same address but different irk if ((setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION) != 0u){ int index = sm_le_device_db_index_lookup(BD_ADDR_TYPE_LE_PUBLIC, setup->sm_peer_address); if (index >= 0){ sm_key_t irk; le_device_db_info(index, NULL, NULL, irk); if (memcmp(irk, setup->sm_peer_irk, 16) != 0){ // IRK doesn't match, delete bonding information log_info("New IRK for %s (type %u) does not match stored IRK -> delete bonding information", bd_addr_to_str(sm_conn->sm_peer_address), sm_conn->sm_peer_addr_type); sm_remove_le_device_db_entry(index); } } } return 0; } static void sm_key_distribution_handle_all_received(sm_connection_t * sm_conn){ // abort pairing if received keys are not valid uint8_t reason = sm_key_distribution_validate_received(sm_conn); if (reason != 0){ sm_pairing_error(sm_conn, reason); return; } // only store pairing information if both sides are bondable, i.e., the bonadble flag is set bool bonding_enabled = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_BONDING ) != 0u; if (bonding_enabled){ sm_store_bonding_information(sm_conn); } else { log_info("Ignoring received keys, bonding not enabled"); } } static inline void sm_pdu_received_in_wrong_state(sm_connection_t * sm_conn){ sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); } #ifdef ENABLE_LE_SECURE_CONNECTIONS static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn); static bool sm_passkey_used(stk_generation_method_t method); static bool sm_just_works_or_numeric_comparison(stk_generation_method_t method); static void sm_sc_start_calculating_local_confirm(sm_connection_t * sm_conn){ if (setup->sm_stk_generation_method == OOB){ sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; } else { btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_next_w2_cmac_for_confirmation, (void *)(uintptr_t) sm_conn->sm_handle); } } static void sm_sc_state_after_receiving_random(sm_connection_t * sm_conn){ if (IS_RESPONDER(sm_conn->sm_role)){ // Responder if (setup->sm_stk_generation_method == OOB){ // generate Nb log_info("Generate Nb"); btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_next_send_pairing_random, (void *)(uintptr_t) sm_conn->sm_handle); } else { sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; } } else { // Initiator role switch (setup->sm_stk_generation_method){ case JUST_WORKS: sm_sc_prepare_dhkey_check(sm_conn); break; case NUMERIC_COMPARISON: sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_G2; break; case PK_INIT_INPUT: case PK_RESP_INPUT: case PK_BOTH_INPUT: if (setup->sm_passkey_bit < 20u) { sm_sc_start_calculating_local_confirm(sm_conn); } else { sm_sc_prepare_dhkey_check(sm_conn); } break; case OOB: sm_sc_prepare_dhkey_check(sm_conn); break; default: btstack_assert(false); break; } } } static void sm_sc_cmac_done(uint8_t * hash){ log_info("sm_sc_cmac_done: "); log_info_hexdump(hash, 16); if (sm_sc_oob_state == SM_SC_OOB_W4_CONFIRM){ sm_sc_oob_state = SM_SC_OOB_IDLE; (*sm_sc_oob_callback)(hash, sm_sc_oob_random); return; } sm_connection_t * sm_conn = sm_cmac_connection; sm_cmac_connection = NULL; #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION link_key_type_t link_key_type; #endif switch (sm_conn->sm_engine_state){ case SM_SC_W4_CMAC_FOR_CONFIRMATION: (void)memcpy(setup->sm_local_confirm, hash, 16); sm_conn->sm_engine_state = SM_SC_SEND_CONFIRMATION; break; case SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION: // check if (0 != memcmp(hash, setup->sm_peer_confirm, 16)){ sm_pairing_error(sm_conn, SM_REASON_CONFIRM_VALUE_FAILED); break; } sm_sc_state_after_receiving_random(sm_conn); break; case SM_SC_W4_CALCULATE_G2: { uint32_t vab = big_endian_read_32(hash, 12) % 1000000; big_endian_store_32(setup->sm_tk, 12, vab); sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; sm_trigger_user_response(sm_conn); break; } case SM_SC_W4_CALCULATE_F5_SALT: (void)memcpy(setup->sm_t, hash, 16); sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_MACKEY; break; case SM_SC_W4_CALCULATE_F5_MACKEY: (void)memcpy(setup->sm_mackey, hash, 16); sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_LTK; break; case SM_SC_W4_CALCULATE_F5_LTK: // truncate sm_ltk, but keep full LTK for cross-transport key derivation in sm_local_ltk // Errata Service Release to the Bluetooth Specification: ESR09 // E6405 – Cross transport key derivation from a key of size less than 128 bits // Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." (void)memcpy(setup->sm_ltk, hash, 16); (void)memcpy(setup->sm_local_ltk, hash, 16); sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK; break; case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: (void)memcpy(setup->sm_local_dhkey_check, hash, 16); if (IS_RESPONDER(sm_conn->sm_role)){ // responder if ((setup->sm_state_vars & SM_STATE_VAR_DHKEY_COMMAND_RECEIVED) != 0u){ sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; } else { sm_conn->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; } } else { sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; } break; case SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: if (0 != memcmp(hash, setup->sm_peer_dhkey_check, 16) ){ sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); break; } if (IS_RESPONDER(sm_conn->sm_role)){ // responder sm_conn->sm_engine_state = SM_SC_SEND_DHKEY_CHECK_COMMAND; } else { // initiator sm_conn->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; } break; #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION case SM_SC_W4_CALCULATE_ILK: (void)memcpy(setup->sm_t, hash, 16); sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_BR_EDR_LINK_KEY; break; case SM_SC_W4_CALCULATE_BR_EDR_LINK_KEY: reverse_128(hash, setup->sm_t); link_key_type = sm_conn->sm_connection_authenticated ? AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256 : UNAUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; log_info("Derived classic link key from LE using h6, type %u", (int) link_key_type); gap_store_link_key_for_bd_addr(setup->sm_peer_address, setup->sm_t, link_key_type); if (IS_RESPONDER(sm_conn->sm_role)){ sm_conn->sm_engine_state = SM_RESPONDER_IDLE; } else { sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; } sm_pairing_complete(sm_conn, ERROR_CODE_SUCCESS, 0); sm_done_for_handle(sm_conn->sm_handle); break; case SM_BR_EDR_W4_CALCULATE_ILK: (void)memcpy(setup->sm_t, hash, 16); sm_conn->sm_engine_state = SM_BR_EDR_W2_CALCULATE_LE_LTK; break; case SM_BR_EDR_W4_CALCULATE_LE_LTK: log_info("Derived LE LTK from BR/EDR Link Key"); log_info_key("Link Key", hash); (void)memcpy(setup->sm_ltk, hash, 16); sm_truncate_key(setup->sm_ltk, sm_conn->sm_actual_encryption_key_size); sm_conn->sm_connection_authenticated = setup->sm_link_key_type == AUTHENTICATED_COMBINATION_KEY_GENERATED_FROM_P256; sm_store_bonding_information(sm_conn); sm_done_for_handle(sm_conn->sm_handle); break; #endif default: log_error("sm_sc_cmac_done in state %u", sm_conn->sm_engine_state); break; } sm_trigger_run(); } static void f4_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, uint8_t z){ const uint16_t message_len = 65; sm_cmac_connection = sm_conn; (void)memcpy(sm_cmac_sc_buffer, u, 32); (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); sm_cmac_sc_buffer[64] = z; log_info("f4 key"); log_info_hexdump(x, 16); log_info("f4 message"); log_info_hexdump(sm_cmac_sc_buffer, message_len); sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); } static const uint8_t f5_key_id[] = { 0x62, 0x74, 0x6c, 0x65 }; static const uint8_t f5_length[] = { 0x01, 0x00}; static void f5_calculate_salt(sm_connection_t * sm_conn){ static const sm_key_t f5_salt = { 0x6C ,0x88, 0x83, 0x91, 0xAA, 0xF5, 0xA5, 0x38, 0x60, 0x37, 0x0B, 0xDB, 0x5A, 0x60, 0x83, 0xBE}; log_info("f5_calculate_salt"); // calculate salt for f5 const uint16_t message_len = 32; sm_cmac_connection = sm_conn; (void)memcpy(sm_cmac_sc_buffer, setup->sm_dhkey, message_len); sm_cmac_message_start(f5_salt, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); } static inline void f5_mackkey(sm_connection_t * sm_conn, sm_key_t t, const sm_key_t n1, const sm_key_t n2, const sm_key56_t a1, const sm_key56_t a2){ const uint16_t message_len = 53; sm_cmac_connection = sm_conn; // f5(W, N1, N2, A1, A2) = AES-CMACT (Counter = 0 || keyID || N1 || N2|| A1|| A2 || Length = 256) -- this is the MacKey sm_cmac_sc_buffer[0] = 0; (void)memcpy(sm_cmac_sc_buffer + 01, f5_key_id, 4); (void)memcpy(sm_cmac_sc_buffer + 05, n1, 16); (void)memcpy(sm_cmac_sc_buffer + 21, n2, 16); (void)memcpy(sm_cmac_sc_buffer + 37, a1, 7); (void)memcpy(sm_cmac_sc_buffer + 44, a2, 7); (void)memcpy(sm_cmac_sc_buffer + 51, f5_length, 2); log_info("f5 key"); log_info_hexdump(t, 16); log_info("f5 message for MacKey"); log_info_hexdump(sm_cmac_sc_buffer, message_len); sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); } static void f5_calculate_mackey(sm_connection_t * sm_conn){ sm_key56_t bd_addr_master, bd_addr_slave; bd_addr_master[0] = setup->sm_m_addr_type; bd_addr_slave[0] = setup->sm_s_addr_type; (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); if (IS_RESPONDER(sm_conn->sm_role)){ // responder f5_mackkey(sm_conn, setup->sm_t, setup->sm_peer_nonce, setup->sm_local_nonce, bd_addr_master, bd_addr_slave); } else { // initiator f5_mackkey(sm_conn, setup->sm_t, setup->sm_local_nonce, setup->sm_peer_nonce, bd_addr_master, bd_addr_slave); } } // note: must be called right after f5_mackey, as sm_cmac_buffer[1..52] will be reused static inline void f5_ltk(sm_connection_t * sm_conn, sm_key_t t){ const uint16_t message_len = 53; sm_cmac_connection = sm_conn; sm_cmac_sc_buffer[0] = 1; // 1..52 setup before log_info("f5 key"); log_info_hexdump(t, 16); log_info("f5 message for LTK"); log_info_hexdump(sm_cmac_sc_buffer, message_len); sm_cmac_message_start(t, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); } static void f5_calculate_ltk(sm_connection_t * sm_conn){ f5_ltk(sm_conn, setup->sm_t); } static void f6_setup(const sm_key_t n1, const sm_key_t n2, const sm_key_t r, const sm_key24_t io_cap, const sm_key56_t a1, const sm_key56_t a2){ (void)memcpy(sm_cmac_sc_buffer, n1, 16); (void)memcpy(sm_cmac_sc_buffer + 16, n2, 16); (void)memcpy(sm_cmac_sc_buffer + 32, r, 16); (void)memcpy(sm_cmac_sc_buffer + 48, io_cap, 3); (void)memcpy(sm_cmac_sc_buffer + 51, a1, 7); (void)memcpy(sm_cmac_sc_buffer + 58, a2, 7); } static void f6_engine(sm_connection_t * sm_conn, const sm_key_t w){ const uint16_t message_len = 65; sm_cmac_connection = sm_conn; log_info("f6 key"); log_info_hexdump(w, 16); log_info("f6 message"); log_info_hexdump(sm_cmac_sc_buffer, message_len); sm_cmac_message_start(w, 65, sm_cmac_sc_buffer, &sm_sc_cmac_done); } // g2(U, V, X, Y) = AES-CMACX(U || V || Y) mod 2^32 // - U is 256 bits // - V is 256 bits // - X is 128 bits // - Y is 128 bits static void g2_engine(sm_connection_t * sm_conn, const sm_key256_t u, const sm_key256_t v, const sm_key_t x, const sm_key_t y){ const uint16_t message_len = 80; sm_cmac_connection = sm_conn; (void)memcpy(sm_cmac_sc_buffer, u, 32); (void)memcpy(sm_cmac_sc_buffer + 32, v, 32); (void)memcpy(sm_cmac_sc_buffer + 64, y, 16); log_info("g2 key"); log_info_hexdump(x, 16); log_info("g2 message"); log_info_hexdump(sm_cmac_sc_buffer, message_len); sm_cmac_message_start(x, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); } static void g2_calculate(sm_connection_t * sm_conn) { // calc Va if numeric comparison if (IS_RESPONDER(sm_conn->sm_role)){ // responder g2_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, setup->sm_local_nonce);; } else { // initiator g2_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, setup->sm_peer_nonce); } } static void sm_sc_calculate_local_confirm(sm_connection_t * sm_conn){ uint8_t z = 0; if (sm_passkey_entry(setup->sm_stk_generation_method)){ // some form of passkey uint32_t pk = big_endian_read_32(setup->sm_tk, 12); z = 0x80u | ((pk >> setup->sm_passkey_bit) & 1u); setup->sm_passkey_bit++; } f4_engine(sm_conn, ec_q, setup->sm_peer_q, setup->sm_local_nonce, z); } static void sm_sc_calculate_remote_confirm(sm_connection_t * sm_conn){ // OOB if (setup->sm_stk_generation_method == OOB){ if (IS_RESPONDER(sm_conn->sm_role)){ f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_ra, 0); } else { f4_engine(sm_conn, setup->sm_peer_q, setup->sm_peer_q, setup->sm_rb, 0); } return; } uint8_t z = 0; if (sm_passkey_entry(setup->sm_stk_generation_method)){ // some form of passkey uint32_t pk = big_endian_read_32(setup->sm_tk, 12); // sm_passkey_bit was increased before sending confirm value z = 0x80u | ((pk >> (setup->sm_passkey_bit-1u)) & 1u); } f4_engine(sm_conn, setup->sm_peer_q, ec_q, setup->sm_peer_nonce, z); } static void sm_sc_prepare_dhkey_check(sm_connection_t * sm_conn){ log_info("sm_sc_prepare_dhkey_check, DHKEY calculated %u", (setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) != 0 ? 1 : 0); if ((setup->sm_state_vars & SM_STATE_VAR_DHKEY_CALCULATED) != 0u){ sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; } else { sm_conn->sm_engine_state = SM_SC_W4_CALCULATE_DHKEY; } } static void sm_sc_dhkey_calculated(void * arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (sm_conn == NULL) return; // check for invalid public key detected by Controller if (sm_is_ff(setup->sm_dhkey, 32)){ log_info("sm: peer public key invalid"); sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); return; } log_info("dhkey"); log_info_hexdump(&setup->sm_dhkey[0], 32); setup->sm_state_vars |= SM_STATE_VAR_DHKEY_CALCULATED; // trigger next step if (sm_conn->sm_engine_state == SM_SC_W4_CALCULATE_DHKEY){ sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F5_SALT; } sm_trigger_run(); } static void sm_sc_calculate_f6_for_dhkey_check(sm_connection_t * sm_conn){ // calculate DHKCheck sm_key56_t bd_addr_master, bd_addr_slave; bd_addr_master[0] = setup->sm_m_addr_type; bd_addr_slave[0] = setup->sm_s_addr_type; (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); uint8_t iocap_a[3]; iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); uint8_t iocap_b[3]; iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); if (IS_RESPONDER(sm_conn->sm_role)){ // responder f6_setup(setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); f6_engine(sm_conn, setup->sm_mackey); } else { // initiator f6_setup( setup->sm_local_nonce, setup->sm_peer_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); f6_engine(sm_conn, setup->sm_mackey); } } static void sm_sc_calculate_f6_to_verify_dhkey_check(sm_connection_t * sm_conn){ // validate E = f6() sm_key56_t bd_addr_master, bd_addr_slave; bd_addr_master[0] = setup->sm_m_addr_type; bd_addr_slave[0] = setup->sm_s_addr_type; (void)memcpy(&bd_addr_master[1], setup->sm_m_address, 6); (void)memcpy(&bd_addr_slave[1], setup->sm_s_address, 6); uint8_t iocap_a[3]; iocap_a[0] = sm_pairing_packet_get_auth_req(setup->sm_m_preq); iocap_a[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq); iocap_a[2] = sm_pairing_packet_get_io_capability(setup->sm_m_preq); uint8_t iocap_b[3]; iocap_b[0] = sm_pairing_packet_get_auth_req(setup->sm_s_pres); iocap_b[1] = sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres); iocap_b[2] = sm_pairing_packet_get_io_capability(setup->sm_s_pres); if (IS_RESPONDER(sm_conn->sm_role)){ // responder f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_rb, iocap_a, bd_addr_master, bd_addr_slave); f6_engine(sm_conn, setup->sm_mackey); } else { // initiator f6_setup(setup->sm_peer_nonce, setup->sm_local_nonce, setup->sm_ra, iocap_b, bd_addr_slave, bd_addr_master); f6_engine(sm_conn, setup->sm_mackey); } } #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION // // Link Key Conversion Function h6 // // h6(W, keyID) = AES-CMAC_W(keyID) // - W is 128 bits // - keyID is 32 bits static void h6_engine(sm_connection_t * sm_conn, const sm_key_t w, const uint32_t key_id){ const uint16_t message_len = 4; sm_cmac_connection = sm_conn; big_endian_store_32(sm_cmac_sc_buffer, 0, key_id); log_info("h6 key"); log_info_hexdump(w, 16); log_info("h6 message"); log_info_hexdump(sm_cmac_sc_buffer, message_len); sm_cmac_message_start(w, message_len, sm_cmac_sc_buffer, &sm_sc_cmac_done); } // // Link Key Conversion Function h7 // // h7(SALT, W) = AES-CMAC_SALT(W) // - SALT is 128 bits // - W is 128 bits static void h7_engine(sm_connection_t * sm_conn, const sm_key_t salt, const sm_key_t w) { const uint16_t message_len = 16; sm_cmac_connection = sm_conn; log_info("h7 key"); log_info_hexdump(salt, 16); log_info("h7 message"); log_info_hexdump(w, 16); sm_cmac_message_start(salt, message_len, w, &sm_sc_cmac_done); } // For SC, setup->sm_local_ltk holds full LTK (sm_ltk is already truncated) // Errata Service Release to the Bluetooth Specification: ESR09 // E6405 – Cross transport key derivation from a key of size less than 128 bits // "Note: When the BR/EDR link key is being derived from the LTK, the derivation is done before the LTK gets masked." static void h6_calculate_ilk_from_le_ltk(sm_connection_t * sm_conn){ h6_engine(sm_conn, setup->sm_local_ltk, 0x746D7031); // "tmp1" } static void h6_calculate_ilk_from_br_edr(sm_connection_t * sm_conn){ h6_engine(sm_conn, setup->sm_link_key, 0x746D7032); // "tmp2" } static void h6_calculate_br_edr_link_key(sm_connection_t * sm_conn){ h6_engine(sm_conn, setup->sm_t, 0x6c656272); // "lebr" } static void h6_calculate_le_ltk(sm_connection_t * sm_conn){ h6_engine(sm_conn, setup->sm_t, 0x62726C65); // "brle" } static void h7_calculate_ilk_from_le_ltk(sm_connection_t * sm_conn){ const uint8_t salt[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x74, 0x6D, 0x70, 0x31}; // "tmp1" h7_engine(sm_conn, salt, setup->sm_local_ltk); } static void h7_calculate_ilk_from_br_edr(sm_connection_t * sm_conn){ const uint8_t salt[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x74, 0x6D, 0x70, 0x32}; // "tmp2" h7_engine(sm_conn, salt, setup->sm_link_key); } static void sm_ctkd_fetch_br_edr_link_key(sm_connection_t * sm_conn){ hci_connection_t * hci_connection = hci_connection_for_handle(sm_conn->sm_handle); btstack_assert(hci_connection != NULL); reverse_128(hci_connection->link_key, setup->sm_link_key); setup->sm_link_key_type = hci_connection->link_key_type; } static void sm_ctkd_start_from_br_edr(sm_connection_t * sm_conn){ // only derive LTK if EncKey is set by both bool derive_ltk = (sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres) & sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres) & SM_KEYDIST_ENC_KEY) != 0; if (derive_ltk){ bool use_h7 = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_CT2) != 0; sm_conn->sm_engine_state = use_h7 ? SM_BR_EDR_W2_CALCULATE_ILK_USING_H7 : SM_BR_EDR_W2_CALCULATE_ILK_USING_H6; } else { sm_done_for_handle(sm_conn->sm_handle); } } #endif #endif // key management legacy connections: // - potentially two different LTKs based on direction. each device stores LTK provided by peer // - master stores LTK, EDIV, RAND. responder optionally stored master LTK (only if it needs to reconnect) // - initiators reconnects: initiator uses stored LTK, EDIV, RAND generated by responder // - responder reconnects: responder uses LTK receveived from master // key management secure connections: // - both devices store same LTK from ECDH key exchange. #if defined(ENABLE_LE_SECURE_CONNECTIONS) || defined(ENABLE_LE_CENTRAL) static void sm_load_security_info(sm_connection_t * sm_connection){ int encryption_key_size; int authenticated; int authorized; int secure_connection; // fetch data from device db - incl. authenticated/authorized/key size. Note all sm_connection_X require encryption enabled le_device_db_encryption_get(sm_connection->sm_le_db_index, &setup->sm_peer_ediv, setup->sm_peer_rand, setup->sm_peer_ltk, &encryption_key_size, &authenticated, &authorized, &secure_connection); log_info("db index %u, key size %u, authenticated %u, authorized %u, secure connetion %u", sm_connection->sm_le_db_index, encryption_key_size, authenticated, authorized, secure_connection); sm_connection->sm_actual_encryption_key_size = encryption_key_size; sm_connection->sm_connection_authenticated = authenticated; sm_connection->sm_connection_authorization_state = authorized ? AUTHORIZATION_GRANTED : AUTHORIZATION_UNKNOWN; sm_connection->sm_connection_sc = secure_connection != 0; } #endif #ifdef ENABLE_LE_PERIPHERAL static void sm_start_calculating_ltk_from_ediv_and_rand(sm_connection_t * sm_connection){ (void)memcpy(setup->sm_local_rand, sm_connection->sm_local_rand, 8); setup->sm_local_ediv = sm_connection->sm_local_ediv; // re-establish used key encryption size // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand sm_connection->sm_actual_encryption_key_size = (setup->sm_local_rand[7u] & 0x0fu) + 1u; // no db for authenticated flag hack: flag is stored in bit 4 of LSB sm_connection->sm_connection_authenticated = (setup->sm_local_rand[7u] & 0x10u) >> 4u; // Legacy paring -> not SC sm_connection->sm_connection_sc = false; log_info("sm: received ltk request with key size %u, authenticated %u", sm_connection->sm_actual_encryption_key_size, sm_connection->sm_connection_authenticated); } #endif // distributed key generation static bool sm_run_dpkg(void){ switch (dkg_state){ case DKG_CALC_IRK: // already busy? if (sm_aes128_state == SM_AES128_IDLE) { log_info("DKG_CALC_IRK started"); // IRK = d1(IR, 1, 0) sm_d1_d_prime(1, 0, sm_aes128_plaintext); // plaintext = d1 prime sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_irk, sm_handle_encryption_result_dkg_irk, NULL); return true; } break; case DKG_CALC_DHK: // already busy? if (sm_aes128_state == SM_AES128_IDLE) { log_info("DKG_CALC_DHK started"); // DHK = d1(IR, 3, 0) sm_d1_d_prime(3, 0, sm_aes128_plaintext); // plaintext = d1 prime sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_ir, sm_aes128_plaintext, sm_persistent_dhk, sm_handle_encryption_result_dkg_dhk, NULL); return true; } break; default: break; } return false; } // random address updates static bool sm_run_rau(void){ switch (rau_state){ case RAU_GET_RANDOM: rau_state = RAU_W4_RANDOM; btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_address, 6, &sm_handle_random_result_rau, NULL); return true; case RAU_GET_ENC: // already busy? if (sm_aes128_state == SM_AES128_IDLE) { sm_ah_r_prime(sm_random_address, sm_aes128_plaintext); sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_irk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_rau, NULL); return true; } break; default: break; } return false; } // device lookup with IRK static bool sm_run_irk_lookup(void){ btstack_linked_list_iterator_t it; // -- if IRK lookup ready, find connection that require csrk lookup if (sm_address_resolution_idle()){ hci_connections_get_iterator(&it); while(btstack_linked_list_iterator_has_next(&it)){ hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); sm_connection_t * sm_connection = &hci_connection->sm_connection; if (sm_connection->sm_irk_lookup_state == IRK_LOOKUP_W4_READY){ // and start lookup sm_address_resolution_start_lookup(sm_connection->sm_peer_addr_type, sm_connection->sm_handle, sm_connection->sm_peer_address, ADDRESS_RESOLUTION_FOR_CONNECTION, sm_connection); sm_connection->sm_irk_lookup_state = IRK_LOOKUP_STARTED; break; } } } // -- if csrk lookup ready, resolved addresses for received addresses if (sm_address_resolution_idle()) { if (!btstack_linked_list_empty(&sm_address_resolution_general_queue)){ sm_lookup_entry_t * entry = (sm_lookup_entry_t *) sm_address_resolution_general_queue; btstack_linked_list_remove(&sm_address_resolution_general_queue, (btstack_linked_item_t *) entry); sm_address_resolution_start_lookup(entry->address_type, 0, entry->address, ADDRESS_RESOLUTION_GENERAL, NULL); btstack_memory_sm_lookup_entry_free(entry); } } // -- Continue with device lookup by public or resolvable private address if (!sm_address_resolution_idle()){ bool started_aes128 = false; while (sm_address_resolution_test < le_device_db_max_count()){ int addr_type = BD_ADDR_TYPE_UNKNOWN; bd_addr_t addr; sm_key_t irk; le_device_db_info(sm_address_resolution_test, &addr_type, addr, irk); // skip unused entries if (addr_type == BD_ADDR_TYPE_UNKNOWN){ sm_address_resolution_test++; continue; } log_info("LE Device Lookup: device %u of %u - type %u, %s", sm_address_resolution_test, le_device_db_max_count(), addr_type, bd_addr_to_str(addr)); // map resolved identity addresses to regular addresses int regular_addr_type = sm_address_resolution_addr_type & 1; if ((regular_addr_type == addr_type) && (memcmp(addr, sm_address_resolution_address, 6) == 0)){ log_info("LE Device Lookup: found by { addr_type, address} "); sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCCEEDED); break; } // if connection type is not random (i.e. public or resolved identity), it must be a different entry if (sm_address_resolution_addr_type != BD_ADDR_TYPE_LE_RANDOM){ sm_address_resolution_test++; continue; } // skip AH if no IRK if (sm_is_null_key(irk)){ sm_address_resolution_test++; continue; } if (sm_aes128_state == SM_AES128_ACTIVE) break; log_info("LE Device Lookup: calculate AH"); log_info_key("IRK", irk); (void)memcpy(sm_aes128_key, irk, 16); sm_ah_r_prime(sm_address_resolution_address, sm_aes128_plaintext); sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_aes128_key, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_address_resolution, NULL); started_aes128 = true; break; } if (started_aes128){ return true; } if (sm_address_resolution_test >= le_device_db_max_count()){ log_info("LE Device Lookup: not found"); sm_address_resolution_handle_event(ADDRESS_RESOLUTION_FAILED); } } return false; } // SC OOB static bool sm_run_oob(void){ #ifdef ENABLE_LE_SECURE_CONNECTIONS switch (sm_sc_oob_state){ case SM_SC_OOB_W2_CALC_CONFIRM: if (!sm_cmac_ready()) break; sm_sc_oob_state = SM_SC_OOB_W4_CONFIRM; f4_engine(NULL, ec_q, ec_q, sm_sc_oob_random, 0); return true; default: break; } #endif return false; } static void sm_send_connectionless(sm_connection_t * sm_connection, const uint8_t * buffer, uint16_t size){ l2cap_send_connectionless(sm_connection->sm_handle, sm_connection->sm_cid, (uint8_t*) buffer, size); } // handle basic actions that don't requires the full context static bool sm_run_basic(void){ btstack_linked_list_iterator_t it; hci_connections_get_iterator(&it); while(btstack_linked_list_iterator_has_next(&it)){ hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); sm_connection_t * sm_connection = &hci_connection->sm_connection; switch(sm_connection->sm_engine_state){ // general case SM_GENERAL_SEND_PAIRING_FAILED: { uint8_t buffer[2]; buffer[0] = SM_CODE_PAIRING_FAILED; buffer[1] = sm_connection->sm_pairing_failed_reason; sm_connection->sm_engine_state = sm_connection->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; sm_send_connectionless(sm_connection, (uint8_t*) buffer, sizeof(buffer)); sm_pairing_complete(sm_connection, ERROR_CODE_AUTHENTICATION_FAILURE, sm_connection->sm_pairing_failed_reason); sm_done_for_handle(sm_connection->sm_handle); break; } // responder side case SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY: sm_connection->sm_engine_state = SM_RESPONDER_IDLE; hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); return true; #ifdef ENABLE_LE_SECURE_CONNECTIONS case SM_SC_RECEIVED_LTK_REQUEST: switch (sm_connection->sm_irk_lookup_state){ case IRK_LOOKUP_FAILED: log_info("LTK Request: IRK Lookup Failed)"); sm_connection->sm_engine_state = SM_RESPONDER_IDLE; hci_send_cmd(&hci_le_long_term_key_negative_reply, sm_connection->sm_handle); return true; default: break; } break; #endif default: break; } } return false; } static void sm_run_activate_connection(void){ // Find connections that requires setup context and make active if no other is locked btstack_linked_list_iterator_t it; hci_connections_get_iterator(&it); while((sm_active_connection_handle == HCI_CON_HANDLE_INVALID) && btstack_linked_list_iterator_has_next(&it)){ hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); sm_connection_t * sm_connection = &hci_connection->sm_connection; // - if no connection locked and we're ready/waiting for setup context, fetch it and start bool done = true; int err; UNUSED(err); #ifdef ENABLE_LE_SECURE_CONNECTIONS // assert ec key is ready if ( (sm_connection->sm_engine_state == SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED) || (sm_connection->sm_engine_state == SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST) || (sm_connection->sm_engine_state == SM_RESPONDER_SEND_SECURITY_REQUEST)){ if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ sm_ec_generate_new_key(); } if (ec_key_generation_state != EC_KEY_GENERATION_DONE){ continue; } } #endif switch (sm_connection->sm_engine_state) { #ifdef ENABLE_LE_PERIPHERAL case SM_RESPONDER_SEND_SECURITY_REQUEST: case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: #ifdef ENABLE_LE_SECURE_CONNECTIONS case SM_SC_RECEIVED_LTK_REQUEST: #endif #endif #ifdef ENABLE_LE_CENTRAL case SM_INITIATOR_PH4_HAS_LTK: case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: #endif #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION case SM_BR_EDR_RESPONDER_PAIRING_REQUEST_RECEIVED: case SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST: #endif // just lock context break; default: done = false; break; } if (done){ sm_active_connection_handle = sm_connection->sm_handle; log_info("sm: connection 0x%04x locked setup context as %s, state %u", sm_active_connection_handle, sm_connection->sm_role ? "responder" : "initiator", sm_connection->sm_engine_state); } } } static void sm_run_send_keypress_notification(sm_connection_t * connection){ int i; uint8_t flags = setup->sm_keypress_notification & 0x1fu; uint8_t num_actions = setup->sm_keypress_notification >> 5; uint8_t action = 0; for (i=SM_KEYPRESS_PASSKEY_ENTRY_STARTED;i<=SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED;i++){ if ((flags & (1u<<i)) != 0u){ bool clear_flag = true; switch (i){ case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: case SM_KEYPRESS_PASSKEY_CLEARED: case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: default: break; case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: num_actions--; clear_flag = num_actions == 0u; break; } if (clear_flag){ flags &= ~(1<<i); } action = i; break; } setup->sm_keypress_notification = (num_actions << 5) | flags; // send keypress notification uint8_t buffer[2]; buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION; buffer[1] = action; sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); // try l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, connection->sm_cid); } static void sm_run_distribute_keys(sm_connection_t * connection){ if ((setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION) != 0u){ setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; uint8_t buffer[17]; buffer[0] = SM_CODE_ENCRYPTION_INFORMATION; reverse_128(setup->sm_ltk, &buffer[1]); sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); return; } if ((setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_MASTER_IDENTIFICATION) != 0u){ setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; uint8_t buffer[11]; buffer[0] = SM_CODE_MASTER_IDENTIFICATION; little_endian_store_16(buffer, 1, setup->sm_local_ediv); reverse_64(setup->sm_local_rand, &buffer[3]); sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); return; } if ((setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_INFORMATION) != 0u){ setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_INFORMATION; setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; uint8_t buffer[17]; buffer[0] = SM_CODE_IDENTITY_INFORMATION; reverse_128(sm_persistent_irk, &buffer[1]); sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); return; } if ((setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION) != 0u){ setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; bd_addr_t local_address; uint8_t buffer[8]; buffer[0] = SM_CODE_IDENTITY_ADDRESS_INFORMATION; switch (gap_random_address_get_mode()){ case GAP_RANDOM_ADDRESS_TYPE_OFF: case GAP_RANDOM_ADDRESS_TYPE_STATIC: // public or static random gap_le_get_own_address(&buffer[1], local_address); break; case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: case GAP_RANDOM_ADDRESS_RESOLVABLE: // fallback to public gap_local_bd_addr(local_address); buffer[1] = 0; break; default: btstack_assert(false); break; } reverse_bd_addr(local_address, &buffer[2]); sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); return; } if ((setup->sm_key_distribution_send_set & SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION) != 0u){ setup->sm_key_distribution_send_set &= ~SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; setup->sm_key_distribution_sent_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; #ifdef ENABLE_LE_SIGNED_WRITE // hack to reproduce test runs if (test_use_fixed_local_csrk){ memset(setup->sm_local_csrk, 0xcc, 16); } // store local CSRK if (setup->sm_le_device_index >= 0){ log_info("sm: store local CSRK"); le_device_db_local_csrk_set(setup->sm_le_device_index, setup->sm_local_csrk); le_device_db_local_counter_set(setup->sm_le_device_index, 0); } #endif uint8_t buffer[17]; buffer[0] = SM_CODE_SIGNING_INFORMATION; reverse_128(setup->sm_local_csrk, &buffer[1]); sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); return; } btstack_assert(false); } static bool sm_ctkd_from_le(sm_connection_t *sm_connection) { #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION // requirements to derive link key from LE: // - use secure connections if (setup->sm_use_secure_connections == 0) return false; // - bonding needs to be enabled: bool bonding_enabled = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_BONDING ) != 0u; if (!bonding_enabled) return false; // - need identity address / public addr bool have_identity_address_info = ((setup->sm_key_distribution_received_set & SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION) != 0) || (setup->sm_peer_addr_type == 0); if (!have_identity_address_info) return false; // - there is no stored BR/EDR link key or the derived key has at least the same level of authentication (bail if stored key has higher authentication) // this requirement is motivated by BLURtooth paper. The paper recommends to not overwrite keys at all. // If SC is authenticated, we consider it safe to overwrite a stored key. // If stored link key is not authenticated, it could already be compromised by a MITM attack. Allowing overwrite by unauthenticated derived key does not make it worse. uint8_t link_key[16]; link_key_type_t link_key_type; bool have_link_key = gap_get_link_key_for_bd_addr(setup->sm_peer_address, link_key, &link_key_type); bool link_key_authenticated = gap_authenticated_for_link_key_type(link_key_type); bool derived_key_authenticated = sm_connection->sm_connection_authenticated != 0; if (have_link_key && link_key_authenticated && !derived_key_authenticated) { return false; } // get started (all of the above are true) return true; #else UNUSED(sm_connection); return false; #endif } #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION static bool sm_ctkd_from_classic(sm_connection_t * sm_connection){ hci_connection_t * hci_connection = hci_connection_for_handle(sm_connection->sm_handle); btstack_assert(hci_connection != NULL); // requirements to derive ltk from BR/EDR: // - BR/EDR uses secure connections if (gap_secure_connection_for_link_key_type(hci_connection->link_key_type) == false) return false; // - there is no stored LTK or the derived key has at least the same level of authentication (bail if LTK is authenticated but Link Key isn't) bool link_key_authenticated = gap_authenticated_for_link_key_type(hci_connection->link_key_type); if (link_key_authenticated) return true; int index = sm_le_device_db_index_lookup(BD_ADDR_TYPE_LE_PUBLIC, hci_connection->address); if (index >= 0){ int ltk_authenticated; sm_key_t ltk; le_device_db_encryption_get(sm_connection->sm_le_db_index, NULL, NULL, ltk, NULL, &ltk_authenticated, NULL, NULL); bool have_ltk = !sm_is_null_key(ltk); if (have_ltk && ltk_authenticated) return false; } return true; } #endif static void sm_key_distribution_complete_responder(sm_connection_t * connection){ if (sm_ctkd_from_le(connection)){ bool use_h7 = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_CT2) != 0; connection->sm_engine_state = use_h7 ? SM_SC_W2_CALCULATE_ILK_USING_H7 : SM_SC_W2_CALCULATE_ILK_USING_H6; } else { connection->sm_engine_state = SM_RESPONDER_IDLE; sm_pairing_complete(connection, ERROR_CODE_SUCCESS, 0); sm_done_for_handle(connection->sm_handle); } } static void sm_key_distribution_complete_initiator(sm_connection_t * connection){ if (sm_ctkd_from_le(connection)){ bool use_h7 = (sm_pairing_packet_get_auth_req(setup->sm_m_preq) & sm_pairing_packet_get_auth_req(setup->sm_s_pres) & SM_AUTHREQ_CT2) != 0; connection->sm_engine_state = use_h7 ? SM_SC_W2_CALCULATE_ILK_USING_H7 : SM_SC_W2_CALCULATE_ILK_USING_H6; } else { sm_master_pairing_success(connection); } } #ifdef ENABLE_LE_SECURE_CONNECTIONS static void sm_run_state_sc_send_confirmation(sm_connection_t *connection) { uint8_t buffer[17]; buffer[0] = SM_CODE_PAIRING_CONFIRM; reverse_128(setup->sm_local_confirm, &buffer[1]); if (IS_RESPONDER(connection->sm_role)){ connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; } else { connection->sm_engine_state = SM_SC_W4_CONFIRMATION; } sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); } static void sm_run_state_sc_send_pairing_random(sm_connection_t *connection) { uint8_t buffer[17]; buffer[0] = SM_CODE_PAIRING_RANDOM; reverse_128(setup->sm_local_nonce, &buffer[1]); log_info("stk method %u, bit num: %u", setup->sm_stk_generation_method, setup->sm_passkey_bit); if (sm_passkey_entry(setup->sm_stk_generation_method) && (setup->sm_passkey_bit < 20u)){ log_info("SM_SC_SEND_PAIRING_RANDOM A"); if (IS_RESPONDER(connection->sm_role)){ // responder connection->sm_engine_state = SM_SC_W4_CONFIRMATION; } else { // initiator connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; } } else { log_info("SM_SC_SEND_PAIRING_RANDOM B"); if (IS_RESPONDER(connection->sm_role)){ // responder if (setup->sm_stk_generation_method == NUMERIC_COMPARISON){ log_info("SM_SC_SEND_PAIRING_RANDOM B1"); connection->sm_engine_state = SM_SC_W2_CALCULATE_G2; } else { log_info("SM_SC_SEND_PAIRING_RANDOM B2"); sm_sc_prepare_dhkey_check(connection); } } else { // initiator connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; } } sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); } static void sm_run_state_sc_send_dhkey_check_command(sm_connection_t *connection) { uint8_t buffer[17]; buffer[0] = SM_CODE_PAIRING_DHKEY_CHECK; reverse_128(setup->sm_local_dhkey_check, &buffer[1]); if (IS_RESPONDER(connection->sm_role)){ connection->sm_engine_state = SM_SC_W4_LTK_REQUEST_SC; } else { connection->sm_engine_state = SM_SC_W4_DHKEY_CHECK_COMMAND; } sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); } static void sm_run_state_sc_send_public_key_command(sm_connection_t *connection) { bool trigger_user_response = false; bool trigger_start_calculating_local_confirm = false; uint8_t buffer[65]; buffer[0] = SM_CODE_PAIRING_PUBLIC_KEY; // reverse_256(&ec_q[0], &buffer[1]); reverse_256(&ec_q[32], &buffer[33]); #ifdef ENABLE_TESTING_SUPPORT if (test_pairing_failure == SM_REASON_DHKEY_CHECK_FAILED){ log_info("testing_support: invalidating public key"); // flip single bit of public key coordinate buffer[1] ^= 1; } #endif // stk generation method // passkey entry: notify app to show passkey or to request passkey switch (setup->sm_stk_generation_method){ case JUST_WORKS: case NUMERIC_COMPARISON: if (IS_RESPONDER(connection->sm_role)){ // responder trigger_start_calculating_local_confirm = true; connection->sm_engine_state = SM_SC_W4_LOCAL_NONCE; } else { // initiator connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; } break; case PK_INIT_INPUT: case PK_RESP_INPUT: case PK_BOTH_INPUT: // use random TK for display (void)memcpy(setup->sm_ra, setup->sm_tk, 16); (void)memcpy(setup->sm_rb, setup->sm_tk, 16); setup->sm_passkey_bit = 0; if (IS_RESPONDER(connection->sm_role)){ // responder connection->sm_engine_state = SM_SC_W4_CONFIRMATION; } else { // initiator connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; } trigger_user_response = true; break; case OOB: if (IS_RESPONDER(connection->sm_role)){ // responder connection->sm_engine_state = SM_SC_W4_PAIRING_RANDOM; } else { // initiator connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; } break; default: btstack_assert(false); break; } sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); // trigger user response and calc confirm after sending pdu if (trigger_user_response){ sm_trigger_user_response(connection); } if (trigger_start_calculating_local_confirm){ sm_sc_start_calculating_local_confirm(connection); } } #endif static bool sm_run_non_connection_logic(void){ bool done;; done = sm_run_dpkg(); if (done) return true; done = sm_run_rau(); if (done) return true; done = sm_run_irk_lookup(); if (done) return true; done = sm_run_oob(); return done; } static void sm_run(void){ // assert that stack has already bootet if (hci_get_state() != HCI_STATE_WORKING) return; // assert that we can send at least commands if (!hci_can_send_command_packet_now()) return; // pause until IR/ER are ready if (sm_persistent_keys_random_active) return; // non-connection related behaviour bool done = sm_run_non_connection_logic(); if (done) return; // assert that we can send at least commands - cmd might have been sent by crypto engine if (!hci_can_send_command_packet_now()) return; // handle basic actions that don't requires the full context done = sm_run_basic(); if (done) return; // // active connection handling // -- use loop to handle next connection if lock on setup context is released while (true) { sm_run_activate_connection(); if (sm_active_connection_handle == HCI_CON_HANDLE_INVALID) return; // // active connection handling // sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection_handle); if (!connection) { log_info("no connection for handle 0x%04x", sm_active_connection_handle); return; } // assert that we could send a SM PDU - not needed for all of the following if (!l2cap_can_send_fixed_channel_packet_now(sm_active_connection_handle, connection->sm_cid)) { log_info("cannot send now, requesting can send now event"); l2cap_request_can_send_fix_channel_now_event(sm_active_connection_handle, connection->sm_cid); return; } // send keypress notifications if (setup->sm_keypress_notification != 0u){ sm_run_send_keypress_notification(connection); return; } #ifdef ENABLE_LE_SECURE_CONNECTIONS // assert that sm cmac engine is ready if (sm_cmac_ready() == false){ break; } #endif int key_distribution_flags; UNUSED(key_distribution_flags); #ifdef ENABLE_LE_PERIPHERAL int err; bool have_ltk; uint8_t ltk[16]; #endif log_info("sm_run: state %u", connection->sm_engine_state); switch (connection->sm_engine_state){ // secure connections, initiator + responding states #ifdef ENABLE_LE_SECURE_CONNECTIONS case SM_SC_W2_CMAC_FOR_CONFIRMATION: connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CONFIRMATION; sm_sc_calculate_local_confirm(connection); break; case SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION: connection->sm_engine_state = SM_SC_W4_CMAC_FOR_CHECK_CONFIRMATION; sm_sc_calculate_remote_confirm(connection); break; case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK; sm_sc_calculate_f6_for_dhkey_check(connection); break; case SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK: connection->sm_engine_state = SM_SC_W4_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; sm_sc_calculate_f6_to_verify_dhkey_check(connection); break; case SM_SC_W2_CALCULATE_F5_SALT: connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_SALT; f5_calculate_salt(connection); break; case SM_SC_W2_CALCULATE_F5_MACKEY: connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_MACKEY; f5_calculate_mackey(connection); break; case SM_SC_W2_CALCULATE_F5_LTK: connection->sm_engine_state = SM_SC_W4_CALCULATE_F5_LTK; f5_calculate_ltk(connection); break; case SM_SC_W2_CALCULATE_G2: connection->sm_engine_state = SM_SC_W4_CALCULATE_G2; g2_calculate(connection); break; #endif #ifdef ENABLE_LE_CENTRAL // initiator side case SM_INITIATOR_PH4_HAS_LTK: { sm_reset_setup(); sm_load_security_info(connection); // cache key before using sm_cache_ltk(connection, setup->sm_peer_ltk); sm_key_t peer_ltk_flipped; reverse_128(setup->sm_peer_ltk, peer_ltk_flipped); connection->sm_engine_state = SM_PH4_W4_CONNECTION_ENCRYPTED; log_info("sm: hci_le_start_encryption ediv 0x%04x", setup->sm_peer_ediv); uint32_t rand_high = big_endian_read_32(setup->sm_peer_rand, 0); uint32_t rand_low = big_endian_read_32(setup->sm_peer_rand, 4); hci_send_cmd(&hci_le_start_encryption, connection->sm_handle,rand_low, rand_high, setup->sm_peer_ediv, peer_ltk_flipped); // notify after sending sm_reencryption_started(connection); return; } case SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST: sm_reset_setup(); sm_init_setup(connection); sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); connection->sm_engine_state = SM_INITIATOR_PH1_W4_PAIRING_RESPONSE; sm_send_connectionless(connection, (uint8_t*) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); sm_timeout_reset(connection); // notify after sending sm_pairing_started(connection); break; #endif #ifdef ENABLE_LE_SECURE_CONNECTIONS case SM_SC_SEND_PUBLIC_KEY_COMMAND: sm_run_state_sc_send_public_key_command(connection); break; case SM_SC_SEND_CONFIRMATION: sm_run_state_sc_send_confirmation(connection); break; case SM_SC_SEND_PAIRING_RANDOM: sm_run_state_sc_send_pairing_random(connection); break; case SM_SC_SEND_DHKEY_CHECK_COMMAND: sm_run_state_sc_send_dhkey_check_command(connection); break; #endif #ifdef ENABLE_LE_PERIPHERAL case SM_RESPONDER_SEND_SECURITY_REQUEST: { const uint8_t buffer[2] = {SM_CODE_SECURITY_REQUEST, sm_auth_req}; connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_REQUEST; sm_send_connectionless(connection, (uint8_t *) buffer, sizeof(buffer)); sm_timeout_start(connection); break; } #ifdef ENABLE_LE_SECURE_CONNECTIONS case SM_SC_RECEIVED_LTK_REQUEST: switch (connection->sm_irk_lookup_state){ case IRK_LOOKUP_SUCCEEDED: // assuming Secure Connection, we have a stored LTK and the EDIV/RAND are null // start using context by loading security info sm_reset_setup(); sm_load_security_info(connection); if ((setup->sm_peer_ediv == 0u) && sm_is_null_random(setup->sm_peer_rand) && !sm_is_null_key(setup->sm_peer_ltk)){ (void)memcpy(setup->sm_ltk, setup->sm_peer_ltk, 16); connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; sm_reencryption_started(connection); sm_trigger_run(); break; } log_info("LTK Request: ediv & random are empty, but no stored LTK (IRK Lookup Succeeded)"); connection->sm_engine_state = SM_RESPONDER_IDLE; hci_send_cmd(&hci_le_long_term_key_negative_reply, connection->sm_handle); return; default: // just wait until IRK lookup is completed break; } break; #endif /* ENABLE_LE_SECURE_CONNECTIONS */ case SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED: sm_reset_setup(); // handle Pairing Request with LTK available switch (connection->sm_irk_lookup_state) { case IRK_LOOKUP_SUCCEEDED: le_device_db_encryption_get(connection->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); have_ltk = !sm_is_null_key(ltk); if (have_ltk){ log_info("pairing request but LTK available"); // emit re-encryption start/fail sequence sm_reencryption_started(connection); sm_reencryption_complete(connection, ERROR_CODE_PIN_OR_KEY_MISSING); } break; default: break; } sm_init_setup(connection); // recover pairing request (void)memcpy(&setup->sm_m_preq, &connection->sm_m_preq, sizeof(sm_pairing_packet_t)); err = sm_stk_generation_init(connection); #ifdef ENABLE_TESTING_SUPPORT if ((0 < test_pairing_failure) && (test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED)){ log_info("testing_support: respond with pairing failure %u", test_pairing_failure); err = test_pairing_failure; } #endif if (err != 0){ // emit pairing started/failed sequence sm_pairing_started(connection); sm_pairing_error(connection, err); sm_trigger_run(); break; } sm_timeout_start(connection); // generate random number first, if we need to show passkey, otherwise send response if (setup->sm_stk_generation_method == PK_INIT_INPUT){ btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, (void *)(uintptr_t) connection->sm_handle); break; } /* fall through */ case SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE: sm_pairing_packet_set_code(setup->sm_s_pres,SM_CODE_PAIRING_RESPONSE); // start with initiator key dist flags key_distribution_flags = sm_key_distribution_flags_for_auth_req(); #ifdef ENABLE_LE_SECURE_CONNECTIONS // LTK (= encryption information & master identification) only exchanged for LE Legacy Connection if (setup->sm_use_secure_connections){ key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; } #endif // setup in response sm_pairing_packet_set_initiator_key_distribution(setup->sm_s_pres, sm_pairing_packet_get_initiator_key_distribution(setup->sm_m_preq) & key_distribution_flags); sm_pairing_packet_set_responder_key_distribution(setup->sm_s_pres, sm_pairing_packet_get_responder_key_distribution(setup->sm_m_preq) & key_distribution_flags); // update key distribution after ENC was dropped sm_setup_key_distribution(sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres), sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres)); if (setup->sm_use_secure_connections){ connection->sm_engine_state = SM_SC_W4_PUBLIC_KEY_COMMAND; } else { connection->sm_engine_state = SM_RESPONDER_PH1_W4_PAIRING_CONFIRM; } sm_send_connectionless(connection, (uint8_t*) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); sm_timeout_reset(connection); // notify after sending sm_pairing_started(connection); // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged if (!setup->sm_use_secure_connections || (setup->sm_stk_generation_method == JUST_WORKS)){ sm_trigger_user_response(connection); } return; #endif case SM_PH2_SEND_PAIRING_RANDOM: { uint8_t buffer[17]; buffer[0] = SM_CODE_PAIRING_RANDOM; reverse_128(setup->sm_local_random, &buffer[1]); if (IS_RESPONDER(connection->sm_role)){ connection->sm_engine_state = SM_RESPONDER_PH2_W4_LTK_REQUEST; } else { connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_RANDOM; } sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); break; } case SM_PH2_C1_GET_ENC_A: // already busy? if (sm_aes128_state == SM_AES128_ACTIVE) break; // calculate confirm using aes128 engine - step 1 sm_c1_t1(setup->sm_local_random, (uint8_t*) &setup->sm_m_preq, (uint8_t*) &setup->sm_s_pres, setup->sm_m_addr_type, setup->sm_s_addr_type, sm_aes128_plaintext); connection->sm_engine_state = SM_PH2_C1_W4_ENC_A; sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_a, (void *)(uintptr_t) connection->sm_handle); break; case SM_PH2_C1_GET_ENC_C: // already busy? if (sm_aes128_state == SM_AES128_ACTIVE) break; // calculate m_confirm using aes128 engine - step 1 sm_c1_t1(setup->sm_peer_random, (uint8_t*) &setup->sm_m_preq, (uint8_t*) &setup->sm_s_pres, setup->sm_m_addr_type, setup->sm_s_addr_type, sm_aes128_plaintext); connection->sm_engine_state = SM_PH2_C1_W4_ENC_C; sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_c, (void *)(uintptr_t) connection->sm_handle); break; case SM_PH2_CALC_STK: // already busy? if (sm_aes128_state == SM_AES128_ACTIVE) break; // calculate STK if (IS_RESPONDER(connection->sm_role)){ sm_s1_r_prime(setup->sm_local_random, setup->sm_peer_random, sm_aes128_plaintext); } else { sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); } connection->sm_engine_state = SM_PH2_W4_STK; sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, (void *)(uintptr_t) connection->sm_handle); break; case SM_PH3_Y_GET_ENC: // already busy? if (sm_aes128_state == SM_AES128_ACTIVE) break; // PH3B2 - calculate Y from - enc // dm helper (was sm_dm_r_prime) // r' = padding || r // r - 64 bit value memset(&sm_aes128_plaintext[0], 0, 8); (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); // Y = dm(DHK, Rand) connection->sm_engine_state = SM_PH3_Y_W4_ENC; sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_dhk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_ph3_y, (void *)(uintptr_t) connection->sm_handle); break; case SM_PH2_C1_SEND_PAIRING_CONFIRM: { uint8_t buffer[17]; buffer[0] = SM_CODE_PAIRING_CONFIRM; reverse_128(setup->sm_local_confirm, &buffer[1]); if (IS_RESPONDER(connection->sm_role)){ connection->sm_engine_state = SM_RESPONDER_PH2_W4_PAIRING_RANDOM; } else { connection->sm_engine_state = SM_INITIATOR_PH2_W4_PAIRING_CONFIRM; } sm_send_connectionless(connection, (uint8_t*) buffer, sizeof(buffer)); sm_timeout_reset(connection); return; } #ifdef ENABLE_LE_PERIPHERAL case SM_RESPONDER_PH2_SEND_LTK_REPLY: { // cache key before using sm_cache_ltk(connection, setup->sm_ltk); sm_key_t stk_flipped; reverse_128(setup->sm_ltk, stk_flipped); connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, stk_flipped); return; } case SM_RESPONDER_PH4_SEND_LTK_REPLY: { // allow to override LTK if (sm_get_ltk_callback != NULL){ (void)(*sm_get_ltk_callback)(connection->sm_handle, connection->sm_peer_addr_type, connection->sm_peer_address, setup->sm_ltk); } // cache key before using sm_cache_ltk(connection, setup->sm_ltk); sm_key_t ltk_flipped; reverse_128(setup->sm_ltk, ltk_flipped); connection->sm_engine_state = SM_PH4_W4_CONNECTION_ENCRYPTED; hci_send_cmd(&hci_le_long_term_key_request_reply, connection->sm_handle, ltk_flipped); return; } case SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST: // already busy? if (sm_aes128_state == SM_AES128_ACTIVE) break; log_info("LTK Request: recalculating with ediv 0x%04x", setup->sm_local_ediv); sm_reset_setup(); sm_start_calculating_ltk_from_ediv_and_rand(connection); sm_reencryption_started(connection); // dm helper (was sm_dm_r_prime) // r' = padding || r // r - 64 bit value memset(&sm_aes128_plaintext[0], 0, 8); (void)memcpy(&sm_aes128_plaintext[8], setup->sm_local_rand, 8); // Y = dm(DHK, Rand) connection->sm_engine_state = SM_RESPONDER_PH4_Y_W4_ENC; sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_dhk, sm_aes128_plaintext, sm_aes128_ciphertext, sm_handle_encryption_result_enc_ph4_y, (void *)(uintptr_t) connection->sm_handle); return; #endif #ifdef ENABLE_LE_CENTRAL case SM_INITIATOR_PH3_SEND_START_ENCRYPTION: { // cache key before using sm_cache_ltk(connection, setup->sm_ltk); sm_key_t stk_flipped; reverse_128(setup->sm_ltk, stk_flipped); connection->sm_engine_state = SM_PH2_W4_CONNECTION_ENCRYPTED; hci_send_cmd(&hci_le_start_encryption, connection->sm_handle, 0, 0, 0, stk_flipped); return; } #endif case SM_PH3_DISTRIBUTE_KEYS: // send next key if (setup->sm_key_distribution_send_set != 0){ sm_run_distribute_keys(connection); } // more to send? if (setup->sm_key_distribution_send_set != 0){ return; } // keys are sent if (IS_RESPONDER(connection->sm_role)){ // slave -> receive master keys if any if (sm_key_distribution_all_received()){ sm_key_distribution_handle_all_received(connection); sm_key_distribution_complete_responder(connection); // start CTKD right away continue; } else { connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; } } else { sm_master_pairing_success(connection); } break; #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION case SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST: // fill in sm setup (lite version of sm_init_setup) sm_reset_setup(); setup->sm_peer_addr_type = connection->sm_peer_addr_type; setup->sm_m_addr_type = connection->sm_peer_addr_type; setup->sm_s_addr_type = connection->sm_own_addr_type; (void) memcpy(setup->sm_peer_address, connection->sm_peer_address, 6); (void) memcpy(setup->sm_m_address, connection->sm_peer_address, 6); (void) memcpy(setup->sm_s_address, connection->sm_own_address, 6); setup->sm_use_secure_connections = true; sm_ctkd_fetch_br_edr_link_key(connection); // Enc Key and IRK if requested key_distribution_flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_ENC_KEY; #ifdef ENABLE_LE_SIGNED_WRITE // Plus signing key if supported key_distribution_flags |= SM_KEYDIST_ID_KEY; #endif sm_pairing_packet_set_code(setup->sm_m_preq, SM_CODE_PAIRING_REQUEST); sm_pairing_packet_set_io_capability(setup->sm_m_preq, 0); sm_pairing_packet_set_oob_data_flag(setup->sm_m_preq, 0); sm_pairing_packet_set_auth_req(setup->sm_m_preq, SM_AUTHREQ_CT2); sm_pairing_packet_set_max_encryption_key_size(setup->sm_m_preq, sm_max_encryption_key_size); sm_pairing_packet_set_initiator_key_distribution(setup->sm_m_preq, key_distribution_flags); sm_pairing_packet_set_responder_key_distribution(setup->sm_m_preq, key_distribution_flags); // set state and send pairing response sm_timeout_start(connection); connection->sm_engine_state = SM_BR_EDR_INITIATOR_W4_PAIRING_RESPONSE; sm_send_connectionless(connection, (uint8_t *) &setup->sm_m_preq, sizeof(sm_pairing_packet_t)); break; case SM_BR_EDR_RESPONDER_PAIRING_REQUEST_RECEIVED: // fill in sm setup (lite version of sm_init_setup) sm_reset_setup(); setup->sm_peer_addr_type = connection->sm_peer_addr_type; setup->sm_m_addr_type = connection->sm_peer_addr_type; setup->sm_s_addr_type = connection->sm_own_addr_type; (void) memcpy(setup->sm_peer_address, connection->sm_peer_address, 6); (void) memcpy(setup->sm_m_address, connection->sm_peer_address, 6); (void) memcpy(setup->sm_s_address, connection->sm_own_address, 6); setup->sm_use_secure_connections = true; sm_ctkd_fetch_br_edr_link_key(connection); (void) memcpy(&setup->sm_m_preq, &connection->sm_m_preq, sizeof(sm_pairing_packet_t)); // Enc Key and IRK if requested key_distribution_flags = SM_KEYDIST_ID_KEY | SM_KEYDIST_ENC_KEY; #ifdef ENABLE_LE_SIGNED_WRITE // Plus signing key if supported key_distribution_flags |= SM_KEYDIST_ID_KEY; #endif // drop flags not requested by initiator key_distribution_flags &= sm_pairing_packet_get_initiator_key_distribution(connection->sm_m_preq); // If Secure Connections pairing has been initiated over BR/EDR, the following fields of the SM Pairing Request PDU are reserved for future use: // - the IO Capability field, // - the OOB data flag field, and // - all bits in the Auth Req field except the CT2 bit. sm_pairing_packet_set_code(setup->sm_s_pres, SM_CODE_PAIRING_RESPONSE); sm_pairing_packet_set_io_capability(setup->sm_s_pres, 0); sm_pairing_packet_set_oob_data_flag(setup->sm_s_pres, 0); sm_pairing_packet_set_auth_req(setup->sm_s_pres, SM_AUTHREQ_CT2); sm_pairing_packet_set_max_encryption_key_size(setup->sm_s_pres, connection->sm_actual_encryption_key_size); sm_pairing_packet_set_initiator_key_distribution(setup->sm_s_pres, key_distribution_flags); sm_pairing_packet_set_responder_key_distribution(setup->sm_s_pres, key_distribution_flags); // configure key distribution, LTK is derived locally key_distribution_flags &= ~SM_KEYDIST_ENC_KEY; sm_setup_key_distribution(key_distribution_flags, key_distribution_flags); // set state and send pairing response sm_timeout_start(connection); connection->sm_engine_state = SM_BR_EDR_DISTRIBUTE_KEYS; sm_send_connectionless(connection, (uint8_t *) &setup->sm_s_pres, sizeof(sm_pairing_packet_t)); break; case SM_BR_EDR_DISTRIBUTE_KEYS: if (setup->sm_key_distribution_send_set != 0) { sm_run_distribute_keys(connection); return; } // keys are sent if (IS_RESPONDER(connection->sm_role)) { // responder -> receive master keys if there are any if (!sm_key_distribution_all_received()){ connection->sm_engine_state = SM_BR_EDR_RECEIVE_KEYS; break; } } // otherwise start CTKD right away (responder and no keys to receive / initiator) sm_ctkd_start_from_br_edr(connection); continue; case SM_SC_W2_CALCULATE_ILK_USING_H6: connection->sm_engine_state = SM_SC_W4_CALCULATE_ILK; h6_calculate_ilk_from_le_ltk(connection); break; case SM_SC_W2_CALCULATE_BR_EDR_LINK_KEY: connection->sm_engine_state = SM_SC_W4_CALCULATE_BR_EDR_LINK_KEY; h6_calculate_br_edr_link_key(connection); break; case SM_SC_W2_CALCULATE_ILK_USING_H7: connection->sm_engine_state = SM_SC_W4_CALCULATE_ILK; h7_calculate_ilk_from_le_ltk(connection); break; case SM_BR_EDR_W2_CALCULATE_ILK_USING_H6: connection->sm_engine_state = SM_BR_EDR_W4_CALCULATE_ILK; h6_calculate_ilk_from_br_edr(connection); break; case SM_BR_EDR_W2_CALCULATE_LE_LTK: connection->sm_engine_state = SM_BR_EDR_W4_CALCULATE_LE_LTK; h6_calculate_le_ltk(connection); break; case SM_BR_EDR_W2_CALCULATE_ILK_USING_H7: connection->sm_engine_state = SM_BR_EDR_W4_CALCULATE_ILK; h7_calculate_ilk_from_br_edr(connection); break; #endif default: break; } // check again if active connection was released if (sm_active_connection_handle != HCI_CON_HANDLE_INVALID) break; } } // sm_aes128_state stays active static void sm_handle_encryption_result_enc_a(void *arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_aes128_state = SM_AES128_IDLE; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, setup->sm_c1_t3_value, setup->sm_local_confirm, sm_handle_encryption_result_enc_b, (void *)(uintptr_t) connection->sm_handle); } static void sm_handle_encryption_result_enc_b(void *arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_aes128_state = SM_AES128_IDLE; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; log_info_key("c1!", setup->sm_local_confirm); connection->sm_engine_state = SM_PH2_C1_SEND_PAIRING_CONFIRM; sm_trigger_run(); } // sm_aes128_state stays active static void sm_handle_encryption_result_enc_c(void *arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_aes128_state = SM_AES128_IDLE; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; sm_c1_t3(sm_aes128_ciphertext, setup->sm_m_address, setup->sm_s_address, setup->sm_c1_t3_value); sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, setup->sm_c1_t3_value, sm_aes128_ciphertext, sm_handle_encryption_result_enc_d, (void *)(uintptr_t) connection->sm_handle); } static void sm_handle_encryption_result_enc_d(void * arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_aes128_state = SM_AES128_IDLE; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; log_info_key("c1!", sm_aes128_ciphertext); if (memcmp(setup->sm_peer_confirm, sm_aes128_ciphertext, 16) != 0){ sm_pairing_error(connection, SM_REASON_CONFIRM_VALUE_FAILED); sm_trigger_run(); return; } if (IS_RESPONDER(connection->sm_role)){ connection->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; sm_trigger_run(); } else { sm_s1_r_prime(setup->sm_peer_random, setup->sm_local_random, sm_aes128_plaintext); sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, setup->sm_tk, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_stk, (void *)(uintptr_t) connection->sm_handle); } } static void sm_handle_encryption_result_enc_stk(void *arg){ sm_aes128_state = SM_AES128_IDLE; hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); log_info_key("stk", setup->sm_ltk); if (IS_RESPONDER(connection->sm_role)){ connection->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; } else { connection->sm_engine_state = SM_INITIATOR_PH3_SEND_START_ENCRYPTION; } sm_trigger_run(); } // sm_aes128_state stays active static void sm_handle_encryption_result_enc_ph3_y(void *arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_aes128_state = SM_AES128_IDLE; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); log_info_hex16("y", setup->sm_local_y); // PH3B3 - calculate EDIV setup->sm_local_ediv = setup->sm_local_y ^ setup->sm_local_div; log_info_hex16("ediv", setup->sm_local_ediv); // PH3B4 - calculate LTK - enc // LTK = d1(ER, DIV, 0)) sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_ph3_ltk, (void *)(uintptr_t) connection->sm_handle); } #ifdef ENABLE_LE_PERIPHERAL // sm_aes128_state stays active static void sm_handle_encryption_result_enc_ph4_y(void *arg){ sm_aes128_state = SM_AES128_IDLE; hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; setup->sm_local_y = big_endian_read_16(sm_aes128_ciphertext, 14); log_info_hex16("y", setup->sm_local_y); // PH3B3 - calculate DIV setup->sm_local_div = setup->sm_local_y ^ setup->sm_local_ediv; log_info_hex16("ediv", setup->sm_local_ediv); // PH3B4 - calculate LTK - enc // LTK = d1(ER, DIV, 0)) sm_d1_d_prime(setup->sm_local_div, 0, sm_aes128_plaintext); sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_ltk, sm_handle_encryption_result_enc_ph4_ltk, (void *)(uintptr_t) connection->sm_handle); } #endif // sm_aes128_state stays active static void sm_handle_encryption_result_enc_ph3_ltk(void *arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_aes128_state = SM_AES128_IDLE; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; log_info_key("ltk", setup->sm_ltk); // calc CSRK next sm_d1_d_prime(setup->sm_local_div, 1, sm_aes128_plaintext); sm_aes128_state = SM_AES128_ACTIVE; btstack_crypto_aes128_encrypt(&sm_crypto_aes128_request, sm_persistent_er, sm_aes128_plaintext, setup->sm_local_csrk, sm_handle_encryption_result_enc_csrk, (void *)(uintptr_t) connection->sm_handle); } static void sm_handle_encryption_result_enc_csrk(void *arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_aes128_state = SM_AES128_IDLE; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; sm_aes128_state = SM_AES128_IDLE; log_info_key("csrk", setup->sm_local_csrk); if (setup->sm_key_distribution_send_set != 0u){ connection->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; } else { // no keys to send, just continue if (IS_RESPONDER(connection->sm_role)){ if (sm_key_distribution_all_received()){ sm_key_distribution_handle_all_received(connection); sm_key_distribution_complete_responder(connection); } else { // slave -> receive master keys connection->sm_engine_state = SM_PH3_RECEIVE_KEYS; } } else { sm_key_distribution_complete_initiator(connection); } } sm_trigger_run(); } #ifdef ENABLE_LE_PERIPHERAL static void sm_handle_encryption_result_enc_ph4_ltk(void *arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_aes128_state = SM_AES128_IDLE; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; sm_truncate_key(setup->sm_ltk, connection->sm_actual_encryption_key_size); log_info_key("ltk", setup->sm_ltk); connection->sm_engine_state = SM_RESPONDER_PH4_SEND_LTK_REPLY; sm_trigger_run(); } #endif static void sm_handle_encryption_result_address_resolution(void *arg){ UNUSED(arg); sm_aes128_state = SM_AES128_IDLE; // compare calulated address against connecting device uint8_t * hash = &sm_aes128_ciphertext[13]; if (memcmp(&sm_address_resolution_address[3], hash, 3) == 0){ log_info("LE Device Lookup: matched resolvable private address"); sm_address_resolution_handle_event(ADDRESS_RESOLUTION_SUCCEEDED); sm_trigger_run(); return; } // no match, try next sm_address_resolution_test++; sm_trigger_run(); } static void sm_handle_encryption_result_dkg_irk(void *arg){ UNUSED(arg); sm_aes128_state = SM_AES128_IDLE; log_info_key("irk", sm_persistent_irk); dkg_state = DKG_CALC_DHK; sm_trigger_run(); } static void sm_handle_encryption_result_dkg_dhk(void *arg){ UNUSED(arg); sm_aes128_state = SM_AES128_IDLE; log_info_key("dhk", sm_persistent_dhk); dkg_state = DKG_READY; sm_trigger_run(); } static void sm_handle_encryption_result_rau(void *arg){ UNUSED(arg); sm_aes128_state = SM_AES128_IDLE; (void)memcpy(&sm_random_address[3], &sm_aes128_ciphertext[13], 3); rau_state = RAU_IDLE; hci_le_random_address_set(sm_random_address); sm_trigger_run(); } static void sm_handle_random_result_rau(void * arg){ UNUSED(arg); // non-resolvable vs. resolvable switch (gap_random_adress_type){ case GAP_RANDOM_ADDRESS_RESOLVABLE: // resolvable: use random as prand and calc address hash // "The two most significant bits of prand shall be equal to ‘0’ and ‘1" sm_random_address[0u] &= 0x3fu; sm_random_address[0u] |= 0x40u; rau_state = RAU_GET_ENC; break; case GAP_RANDOM_ADDRESS_NON_RESOLVABLE: default: // "The two most significant bits of the address shall be equal to ‘0’"" sm_random_address[0u] &= 0x3fu; rau_state = RAU_IDLE; hci_le_random_address_set(sm_random_address); break; } sm_trigger_run(); } #ifdef ENABLE_LE_SECURE_CONNECTIONS static void sm_handle_random_result_sc_next_send_pairing_random(void * arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; connection->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; sm_trigger_run(); } static void sm_handle_random_result_sc_next_w2_cmac_for_confirmation(void * arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; connection->sm_engine_state = SM_SC_W2_CMAC_FOR_CONFIRMATION; sm_trigger_run(); } #endif static void sm_handle_random_result_ph2_random(void * arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; connection->sm_engine_state = SM_PH2_C1_GET_ENC_A; sm_trigger_run(); } static void sm_handle_random_result_ph2_tk(void * arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; sm_reset_tk(); uint32_t tk; if (sm_fixed_passkey_in_display_role == 0xffffffffU){ // map random to 0-999999 without speding much cycles on a modulus operation tk = little_endian_read_32(sm_random_data,0); tk = tk & 0xfffff; // 1048575 if (tk >= 999999u){ tk = tk - 999999u; } } else { // override with pre-defined passkey tk = sm_fixed_passkey_in_display_role; } big_endian_store_32(setup->sm_tk, 12, tk); if (IS_RESPONDER(connection->sm_role)){ connection->sm_engine_state = SM_RESPONDER_PH1_SEND_PAIRING_RESPONSE; } else { if (setup->sm_use_secure_connections){ connection->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; } else { connection->sm_engine_state = SM_PH1_W4_USER_RESPONSE; sm_trigger_user_response(connection); // response_idle == nothing <--> sm_trigger_user_response() did not require response if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) connection->sm_handle); } } } sm_trigger_run(); } static void sm_handle_random_result_ph3_div(void * arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; // use 16 bit from random value as div setup->sm_local_div = big_endian_read_16(sm_random_data, 0); log_info_hex16("div", setup->sm_local_div); connection->sm_engine_state = SM_PH3_Y_GET_ENC; sm_trigger_run(); } static void sm_handle_random_result_ph3_random(void * arg){ hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) arg; sm_connection_t * connection = sm_get_connection_for_handle(con_handle); if (connection == NULL) return; reverse_64(sm_random_data, setup->sm_local_rand); // no db for encryption size hack: encryption size is stored in lowest nibble of setup->sm_local_rand setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xf0u) + (connection->sm_actual_encryption_key_size - 1u); // no db for authenticated flag hack: store flag in bit 4 of LSB setup->sm_local_rand[7u] = (setup->sm_local_rand[7u] & 0xefu) + (connection->sm_connection_authenticated << 4u); btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 2, &sm_handle_random_result_ph3_div, (void *)(uintptr_t) connection->sm_handle); } static void sm_validate_er_ir(void){ // warn about default ER/IR bool warning = false; if (sm_ir_is_default()){ warning = true; log_error("Persistent IR not set with sm_set_ir. Use of private addresses will cause pairing issues"); } if (sm_er_is_default()){ warning = true; log_error("Persistent ER not set with sm_set_er. Legacy Pairing LTK is not secure"); } if (warning) { log_error("Please configure btstack_tlv to let BTstack setup ER and IR keys"); } } static void sm_handle_random_result_ir(void *arg){ sm_persistent_keys_random_active = false; if (arg != NULL){ // key generated, store in tlv int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); log_info("Generated IR key. Store in TLV status: %d", status); UNUSED(status); } log_info_key("IR", sm_persistent_ir); dkg_state = DKG_CALC_IRK; if (test_use_fixed_local_irk){ log_info_key("IRK", sm_persistent_irk); dkg_state = DKG_CALC_DHK; } sm_trigger_run(); } static void sm_handle_random_result_er(void *arg){ sm_persistent_keys_random_active = false; if (arg != NULL){ // key generated, store in tlv int status = sm_tlv_impl->store_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); log_info("Generated ER key. Store in TLV status: %d", status); UNUSED(status); } log_info_key("ER", sm_persistent_er); // try load ir int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','I','R'), sm_persistent_ir, 16u); if (key_size == 16){ // ok, let's continue log_info("IR from TLV"); sm_handle_random_result_ir( NULL ); } else { // invalid, generate new random one sm_persistent_keys_random_active = true; btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_ir, 16, &sm_handle_random_result_ir, &sm_persistent_ir); } } static void sm_connection_init(sm_connection_t * sm_conn, hci_con_handle_t con_handle, uint8_t role, uint8_t peer_addr_type, bd_addr_t peer_address){ // connection info sm_conn->sm_handle = con_handle; sm_conn->sm_role = role; sm_conn->sm_peer_addr_type = peer_addr_type; memcpy(sm_conn->sm_peer_address, peer_address, 6); // security properties sm_conn->sm_connection_encrypted = 0; sm_conn->sm_connection_authenticated = 0; sm_conn->sm_connection_authorization_state = AUTHORIZATION_UNKNOWN; sm_conn->sm_le_db_index = -1; sm_conn->sm_reencryption_active = false; // prepare CSRK lookup (does not involve setup) sm_conn->sm_irk_lookup_state = IRK_LOOKUP_W4_READY; sm_conn->sm_engine_state = SM_GENERAL_IDLE; } #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION static void sm_event_handle_classic_encryption_event(sm_connection_t * sm_conn, hci_con_handle_t con_handle){ // CTKD requires BR/EDR Secure Connection if (sm_conn->sm_connection_encrypted != 2) return; // prepare for pairing request if (IS_RESPONDER(sm_conn->sm_role)){ sm_conn->sm_engine_state = SM_BR_EDR_RESPONDER_W4_PAIRING_REQUEST; } else if (sm_conn->sm_pairing_requested){ // check if remote supports fixed channels bool defer = true; const hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (hci_connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE){ // check if remote supports SMP over BR/EDR if ((hci_connection->l2cap_state.fixed_channels_supported & (1 << L2CAP_CID_BR_EDR_SECURITY_MANAGER)) != 0){ log_info("CTKD: SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST"); sm_conn->sm_engine_state = SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST; } else { defer = false; } } else { // wait for fixed channel info log_info("CTKD: SM_BR_EDR_INITIATOR_W4_FIXED_CHANNEL_MASK"); sm_conn->sm_engine_state = SM_BR_EDR_INITIATOR_W4_FIXED_CHANNEL_MASK; } if (defer){ hci_dedicated_bonding_defer_disconnect(con_handle, true); } } } #endif static void sm_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ UNUSED(channel); // ok: there is no channel UNUSED(size); // ok: fixed format HCI events sm_connection_t * sm_conn; hci_con_handle_t con_handle; uint8_t status; bd_addr_t addr; bd_addr_type_t addr_type; switch (packet_type) { case HCI_EVENT_PACKET: switch (hci_event_packet_get_type(packet)) { case BTSTACK_EVENT_STATE: switch (btstack_event_state_get_state(packet)){ case HCI_STATE_WORKING: log_info("HCI Working!"); // setup IR/ER with TLV btstack_tlv_get_instance(&sm_tlv_impl, &sm_tlv_context); if (sm_tlv_impl != NULL){ int key_size = sm_tlv_impl->get_tag(sm_tlv_context, BTSTACK_TAG32('S','M','E','R'), sm_persistent_er, 16u); if (key_size == 16){ // ok, let's continue log_info("ER from TLV"); sm_handle_random_result_er( NULL ); } else { // invalid, generate random one sm_persistent_keys_random_active = true; btstack_crypto_random_generate(&sm_crypto_random_request, sm_persistent_er, 16, &sm_handle_random_result_er, &sm_persistent_er); } } else { sm_validate_er_ir(); dkg_state = DKG_CALC_IRK; if (test_use_fixed_local_irk){ log_info_key("IRK", sm_persistent_irk); dkg_state = DKG_CALC_DHK; } } #ifdef ENABLE_LE_SECURE_CONNECTIONS // trigger ECC key generation if (ec_key_generation_state == EC_KEY_GENERATION_IDLE){ sm_ec_generate_new_key(); } #endif // restart random address updates after power cycle if (gap_random_adress_type == GAP_RANDOM_ADDRESS_TYPE_STATIC){ gap_random_address_set(sm_random_address); } else { gap_random_address_set_mode(gap_random_adress_type); } break; case HCI_STATE_OFF: case HCI_STATE_HALTING: log_info("SM: reset state"); // stop random address update gap_random_address_update_stop(); // reset state sm_state_reset(); break; default: break; } break; #ifdef ENABLE_CLASSIC case HCI_EVENT_CONNECTION_COMPLETE: // ignore if connection failed if (hci_event_connection_complete_get_status(packet)) return; con_handle = hci_event_connection_complete_get_connection_handle(packet); sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) break; hci_event_connection_complete_get_bd_addr(packet, addr); sm_connection_init(sm_conn, con_handle, (uint8_t) gap_get_role(con_handle), BD_ADDR_TYPE_LE_PUBLIC, addr); // classic connection corresponds to public le address sm_conn->sm_own_addr_type = BD_ADDR_TYPE_LE_PUBLIC; gap_local_bd_addr(sm_conn->sm_own_address); sm_conn->sm_cid = L2CAP_CID_BR_EDR_SECURITY_MANAGER; sm_conn->sm_engine_state = SM_BR_EDR_W4_ENCRYPTION_COMPLETE; break; #endif #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION case HCI_EVENT_SIMPLE_PAIRING_COMPLETE: if (hci_event_simple_pairing_complete_get_status(packet) != ERROR_CODE_SUCCESS) break; hci_event_simple_pairing_complete_get_bd_addr(packet, addr); sm_conn = sm_get_connection_for_bd_addr_and_type(addr, BD_ADDR_TYPE_ACL); if (sm_conn == NULL) break; sm_conn->sm_pairing_requested = true; break; #endif case HCI_EVENT_META_GAP: switch (hci_event_gap_meta_get_subevent_code(packet)) { case GAP_SUBEVENT_LE_CONNECTION_COMPLETE: // ignore if connection failed if (gap_subevent_le_connection_complete_get_status(packet) != ERROR_CODE_SUCCESS) break; con_handle = gap_subevent_le_connection_complete_get_connection_handle(packet); sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) break; // Get current peer address addr_type = gap_subevent_le_connection_complete_get_peer_address_type(packet); if (hci_is_le_identity_address_type(addr_type)){ addr_type = BD_ADDR_TYPE_LE_RANDOM; gap_subevent_le_connection_complete_get_peer_resolvable_private_address(packet, addr); } else { gap_subevent_le_connection_complete_get_peer_address(packet, addr); } sm_connection_init(sm_conn, con_handle, gap_subevent_le_connection_complete_get_role(packet), addr_type, addr); sm_conn->sm_cid = L2CAP_CID_SECURITY_MANAGER_PROTOCOL; // track our addr used for this connection and set state #ifdef ENABLE_LE_PERIPHERAL if (gap_subevent_le_connection_complete_get_role(packet) != 0){ // responder - use own address from advertisements #ifdef ENABLE_LE_EXTENDED_ADVERTISING if (hci_le_extended_advertising_supported()){ // cache local resolvable address // note: will be overwritten if random or private address was used in adv set by HCI_SUBEVENT_LE_ADVERTISING_SET_TERMINATED sm_conn->sm_own_addr_type = BD_ADDR_TYPE_LE_RANDOM; gap_subevent_le_connection_complete_get_local_resolvable_private_address(packet,sm_conn->sm_own_address); } else #endif { gap_le_get_own_advertisements_address(&sm_conn->sm_own_addr_type, sm_conn->sm_own_address); } sm_conn->sm_engine_state = SM_RESPONDER_IDLE; } #endif #ifdef ENABLE_LE_CENTRAL if (gap_subevent_le_connection_complete_get_role(packet) == 0){ // initiator - use own address from create connection gap_le_get_own_connection_address(&sm_conn->sm_own_addr_type, sm_conn->sm_own_address); sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; } #endif break; default: break; } break; case HCI_EVENT_LE_META: switch (hci_event_le_meta_get_subevent_code(packet)) { #ifdef ENABLE_LE_PERIPHERAL #ifdef ENABLE_LE_EXTENDED_ADVERTISING case HCI_SUBEVENT_LE_ADVERTISING_SET_TERMINATED: if (hci_subevent_le_advertising_set_terminated_get_status(packet) == ERROR_CODE_SUCCESS){ uint8_t advertising_handle = hci_subevent_le_advertising_set_terminated_get_advertising_handle(packet); con_handle = hci_subevent_le_advertising_set_terminated_get_connection_handle(packet); sm_conn = sm_get_connection_for_handle(con_handle); gap_le_get_own_advertising_set_address(&sm_conn->sm_own_addr_type, sm_conn->sm_own_address, advertising_handle); log_info("Adv set %u terminated -> use addr type %u, addr %s for con handle 0x%04x", advertising_handle, sm_conn->sm_own_addr_type, bd_addr_to_str(sm_conn->sm_own_address), con_handle); } break; #endif #endif case HCI_SUBEVENT_LE_LONG_TERM_KEY_REQUEST: con_handle = hci_subevent_le_long_term_key_request_get_connection_handle(packet); sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) break; log_info("LTK Request: state %u", sm_conn->sm_engine_state); if (sm_conn->sm_engine_state == SM_RESPONDER_PH2_W4_LTK_REQUEST){ sm_conn->sm_engine_state = SM_PH2_CALC_STK; break; } if (sm_conn->sm_engine_state == SM_SC_W4_LTK_REQUEST_SC){ // PH2 SEND LTK as we need to exchange keys in PH3 sm_conn->sm_engine_state = SM_RESPONDER_PH2_SEND_LTK_REPLY; break; } // store rand and ediv reverse_64(&packet[5], sm_conn->sm_local_rand); sm_conn->sm_local_ediv = hci_subevent_le_long_term_key_request_get_encryption_diversifier(packet); // For Legacy Pairing (<=> EDIV != 0 || RAND != NULL), we need to recalculated our LTK as a // potentially stored LTK is from the master if ((sm_conn->sm_local_ediv != 0u) || !sm_is_null_random(sm_conn->sm_local_rand)){ if (sm_reconstruct_ltk_without_le_device_db_entry){ sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; break; } // additionally check if remote is in LE Device DB if requested switch(sm_conn->sm_irk_lookup_state){ case IRK_LOOKUP_FAILED: log_info("LTK Request: device not in device db"); sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; break; case IRK_LOOKUP_SUCCEEDED: sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_REQUEST; break; default: // wait for irk look doen sm_conn->sm_engine_state = SM_RESPONDER_PH0_RECEIVED_LTK_W4_IRK; break; } break; } #ifdef ENABLE_LE_SECURE_CONNECTIONS sm_conn->sm_engine_state = SM_SC_RECEIVED_LTK_REQUEST; #else log_info("LTK Request: ediv & random are empty, but LE Secure Connections not supported"); sm_conn->sm_engine_state = SM_RESPONDER_PH0_SEND_LTK_REQUESTED_NEGATIVE_REPLY; #endif break; default: break; } break; case HCI_EVENT_ENCRYPTION_CHANGE: case HCI_EVENT_ENCRYPTION_CHANGE_V2: con_handle = hci_event_encryption_change_get_connection_handle(packet); sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) break; sm_conn->sm_connection_encrypted = hci_event_encryption_change_get_encryption_enabled(packet); log_info("Encryption state change: %u, key size %u", sm_conn->sm_connection_encrypted, sm_conn->sm_actual_encryption_key_size); log_info("event handler, state %u", sm_conn->sm_engine_state); switch (sm_conn->sm_engine_state){ case SM_PH4_W4_CONNECTION_ENCRYPTED: // encryption change event concludes re-encryption for bonded devices (even if it fails) if (sm_conn->sm_connection_encrypted != 0u) { status = ERROR_CODE_SUCCESS; if (IS_RESPONDER(sm_conn->sm_role)){ sm_conn->sm_engine_state = SM_RESPONDER_IDLE; } else { sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; } } else { status = hci_event_encryption_change_get_status(packet); // set state to 'RE-ENCRYPTION FAILED' to allow pairing but prevent other interactions // also, gap_reconnect_security_setup_active will return true sm_conn->sm_engine_state = SM_GENERAL_REENCRYPTION_FAILED; } // emit re-encryption complete sm_reencryption_complete(sm_conn, status); // notify client, if pairing was requested before if (sm_conn->sm_pairing_requested){ sm_conn->sm_pairing_requested = false; sm_pairing_complete(sm_conn, status, 0); } sm_done_for_handle(sm_conn->sm_handle); break; case SM_PH2_W4_CONNECTION_ENCRYPTED: if (!sm_conn->sm_connection_encrypted) break; // handler for HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE // contains the same code for this state sm_conn->sm_connection_sc = setup->sm_use_secure_connections; if (IS_RESPONDER(sm_conn->sm_role)){ // slave if (sm_conn->sm_connection_sc){ sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; } else { btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); } } else { // master if (sm_key_distribution_all_received()){ // skip receiving keys as there are none sm_key_distribution_handle_all_received(sm_conn); btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); } else { sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; } } break; #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION case SM_BR_EDR_W4_ENCRYPTION_COMPLETE: sm_event_handle_classic_encryption_event(sm_conn, con_handle); break; #endif default: break; } break; case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: con_handle = little_endian_read_16(packet, 3); sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) break; log_info("Encryption key refresh complete, key size %u", sm_conn->sm_actual_encryption_key_size); log_info("event handler, state %u", sm_conn->sm_engine_state); // continue if part of initial pairing switch (sm_conn->sm_engine_state){ case SM_PH4_W4_CONNECTION_ENCRYPTED: if (IS_RESPONDER(sm_conn->sm_role)){ sm_conn->sm_engine_state = SM_RESPONDER_IDLE; } else { sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; } sm_done_for_handle(sm_conn->sm_handle); break; case SM_PH2_W4_CONNECTION_ENCRYPTED: // handler for HCI_EVENT_ENCRYPTION_CHANGE // contains the same code for this state sm_conn->sm_connection_sc = setup->sm_use_secure_connections; if (IS_RESPONDER(sm_conn->sm_role)){ // slave if (sm_conn->sm_connection_sc){ sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; } else { btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); } } else { // master if (sm_key_distribution_all_received()){ // skip receiving keys as there are none sm_key_distribution_handle_all_received(sm_conn); btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); } else { sm_conn->sm_engine_state = SM_PH3_RECEIVE_KEYS; } } break; #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION case SM_BR_EDR_W4_ENCRYPTION_COMPLETE: sm_event_handle_classic_encryption_event(sm_conn, con_handle); break; #endif default: break; } break; case HCI_EVENT_DISCONNECTION_COMPLETE: con_handle = little_endian_read_16(packet, 3); sm_done_for_handle(con_handle); sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) break; // pairing failed, if it was ongoing switch (sm_conn->sm_engine_state){ case SM_GENERAL_IDLE: case SM_INITIATOR_CONNECTED: case SM_RESPONDER_IDLE: break; default: sm_reencryption_complete(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION); sm_pairing_complete(sm_conn, ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION, 0); break; } sm_conn->sm_engine_state = SM_GENERAL_IDLE; sm_conn->sm_handle = 0; break; case HCI_EVENT_COMMAND_COMPLETE: if (hci_event_command_complete_get_command_opcode(packet) == HCI_OPCODE_HCI_READ_BD_ADDR) { // set local addr for le device db reverse_bd_addr(&packet[OFFSET_OF_DATA_IN_COMMAND_COMPLETE + 1], addr); le_device_db_set_local_bd_addr(addr); } break; #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION case L2CAP_EVENT_INFORMATION_RESPONSE: con_handle = l2cap_event_information_response_get_con_handle(packet); sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) break; if (sm_conn->sm_engine_state == SM_BR_EDR_INITIATOR_W4_FIXED_CHANNEL_MASK){ // check if remote supports SMP over BR/EDR const hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if ((hci_connection->l2cap_state.fixed_channels_supported & (1 << L2CAP_CID_BR_EDR_SECURITY_MANAGER)) != 0){ sm_conn->sm_engine_state = SM_BR_EDR_INITIATOR_SEND_PAIRING_REQUEST; } else { sm_conn->sm_engine_state = SM_INITIATOR_CONNECTED; hci_dedicated_bonding_defer_disconnect(con_handle, false); } } break; #endif default: break; } break; default: break; } sm_run(); } static inline int sm_calc_actual_encryption_key_size(int other){ if (other < sm_min_encryption_key_size) return 0; if (other < sm_max_encryption_key_size) return other; return sm_max_encryption_key_size; } #ifdef ENABLE_LE_SECURE_CONNECTIONS static bool sm_just_works_or_numeric_comparison(stk_generation_method_t method){ switch (method){ case JUST_WORKS: case NUMERIC_COMPARISON: return true; default: return false; } } // responder static bool sm_passkey_used(stk_generation_method_t method){ switch (method){ case PK_RESP_INPUT: return true; default: return 0; } } static bool sm_passkey_entry(stk_generation_method_t method){ switch (method){ case PK_RESP_INPUT: case PK_INIT_INPUT: case PK_BOTH_INPUT: return true; default: return false; } } #endif /** * @return ok */ static int sm_validate_stk_generation_method(void){ // check if STK generation method is acceptable by client switch (setup->sm_stk_generation_method){ case JUST_WORKS: return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_JUST_WORKS) != 0u; case PK_RESP_INPUT: case PK_INIT_INPUT: case PK_BOTH_INPUT: return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_PASSKEY) != 0u; case OOB: return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_OOB) != 0u; case NUMERIC_COMPARISON: return (sm_accepted_stk_generation_methods & SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON) != 0u; default: return 0; } } #ifdef ENABLE_LE_CENTRAL static void sm_initiator_connected_handle_security_request(sm_connection_t * sm_conn, const uint8_t *packet){ #ifdef ENABLE_LE_SECURE_CONNECTIONS if (sm_sc_only_mode){ uint8_t auth_req = packet[1]; if ((auth_req & SM_AUTHREQ_SECURE_CONNECTION) == 0){ sm_pairing_error(sm_conn, SM_REASON_AUTHENTHICATION_REQUIREMENTS); return; } } #else UNUSED(packet); #endif int have_ltk; uint8_t ltk[16]; // IRK complete? switch (sm_conn->sm_irk_lookup_state){ case IRK_LOOKUP_FAILED: // start pairing sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; break; case IRK_LOOKUP_SUCCEEDED: le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); have_ltk = !sm_is_null_key(ltk); log_info("central: security request - have_ltk %u, encryption %u", have_ltk, sm_conn->sm_connection_encrypted); if (have_ltk && (sm_conn->sm_connection_encrypted == 0)){ // start re-encrypt if we have LTK and the connection is not already encrypted sm_conn->sm_engine_state = SM_INITIATOR_PH4_HAS_LTK; } else { // start pairing sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; } break; default: // otherwise, store security request sm_conn->sm_security_request_received = true; break; } } #endif static uint8_t sm_pdu_validate_and_get_opcode(uint8_t packet_type, const uint8_t *packet, uint16_t size){ // size of complete sm_pdu used to validate input static const uint8_t sm_pdu_size[] = { 0, // 0x00 invalid opcode 7, // 0x01 pairing request 7, // 0x02 pairing response 17, // 0x03 pairing confirm 17, // 0x04 pairing random 2, // 0x05 pairing failed 17, // 0x06 encryption information 11, // 0x07 master identification 17, // 0x08 identification information 8, // 0x09 identify address information 17, // 0x0a signing information 2, // 0x0b security request 65, // 0x0c pairing public key 17, // 0x0d pairing dhk check 2, // 0x0e keypress notification }; if (packet_type != SM_DATA_PACKET) return 0; if (size == 0u) return 0; uint8_t sm_pdu_code = packet[0]; // validate pdu size if (sm_pdu_code >= sizeof(sm_pdu_size)) return 0; if (sm_pdu_size[sm_pdu_code] != size) return 0; return sm_pdu_code; } static void sm_pdu_handler(sm_connection_t *sm_conn, uint8_t sm_pdu_code, const uint8_t *packet) { log_debug("sm_pdu_handler: state %u, pdu 0x%02x", sm_conn->sm_engine_state, sm_pdu_code); int err; uint8_t max_encryption_key_size; UNUSED(err); switch (sm_conn->sm_engine_state){ // a sm timeout requires a new physical connection case SM_GENERAL_TIMEOUT: return; #ifdef ENABLE_LE_CENTRAL // Initiator case SM_INITIATOR_CONNECTED: if ((sm_pdu_code != SM_CODE_SECURITY_REQUEST) || (sm_conn->sm_role)){ sm_pdu_received_in_wrong_state(sm_conn); break; } sm_initiator_connected_handle_security_request(sm_conn, packet); break; case SM_INITIATOR_PH1_W4_PAIRING_RESPONSE: // Core 5, Vol 3, Part H, 2.4.6: // "The master shall ignore the slave’s Security Request if the master has sent a Pairing Request // without receiving a Pairing Response from the slave or if the master has initiated encryption mode setup." if (sm_pdu_code == SM_CODE_SECURITY_REQUEST){ log_info("Ignoring Security Request"); break; } // all other pdus are incorrect if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ sm_pdu_received_in_wrong_state(sm_conn); break; } // store pairing request (void)memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); // validate encryption key size max_encryption_key_size = sm_pairing_packet_get_max_encryption_key_size(setup->sm_s_pres); if ((max_encryption_key_size < 7) || (max_encryption_key_size > 16)){ sm_pairing_error(sm_conn, SM_REASON_INVALID_PARAMETERS); break; } err = sm_stk_generation_init(sm_conn); #ifdef ENABLE_TESTING_SUPPORT if (0 < test_pairing_failure && test_pairing_failure < SM_REASON_DHKEY_CHECK_FAILED){ log_info("testing_support: abort with pairing failure %u", test_pairing_failure); err = test_pairing_failure; } #endif if (err != 0){ sm_pairing_error(sm_conn, err); break; } // generate random number first, if we need to show passkey if (setup->sm_stk_generation_method == PK_RESP_INPUT){ btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph2_tk, (void *)(uintptr_t) sm_conn->sm_handle); break; } #ifdef ENABLE_LE_SECURE_CONNECTIONS if (setup->sm_use_secure_connections){ // SC Numeric Comparison will trigger user response after public keys & nonces have been exchanged if (setup->sm_stk_generation_method == JUST_WORKS){ sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; sm_trigger_user_response(sm_conn); if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; } } else { sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; } break; } #endif sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; sm_trigger_user_response(sm_conn); // response_idle == nothing <--> sm_trigger_user_response() did not require response if (setup->sm_user_response == SM_USER_RESPONSE_IDLE){ btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) sm_conn->sm_handle); } break; case SM_INITIATOR_PH2_W4_PAIRING_CONFIRM: if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ sm_pdu_received_in_wrong_state(sm_conn); break; } // store s_confirm reverse_128(&packet[1], setup->sm_peer_confirm); // abort if s_confirm matches m_confirm if (memcmp(setup->sm_local_confirm, setup->sm_peer_confirm, 16) == 0){ sm_pdu_received_in_wrong_state(sm_conn); break; } #ifdef ENABLE_TESTING_SUPPORT if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ log_info("testing_support: reset confirm value"); memset(setup->sm_peer_confirm, 0, 16); } #endif sm_conn->sm_engine_state = SM_PH2_SEND_PAIRING_RANDOM; break; case SM_INITIATOR_PH2_W4_PAIRING_RANDOM: if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ sm_pdu_received_in_wrong_state(sm_conn); break;; } // received random value reverse_128(&packet[1], setup->sm_peer_random); sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; break; case SM_INITIATOR_PH4_HAS_LTK: case SM_PH4_W4_CONNECTION_ENCRYPTED: // ignore Security Request, see SM_INITIATOR_PH1_W4_PAIRING_RESPONSE above if (sm_pdu_code != SM_CODE_SECURITY_REQUEST){ sm_pdu_received_in_wrong_state(sm_conn); } break; #endif #ifdef ENABLE_LE_PERIPHERAL // Responder case SM_RESPONDER_IDLE: case SM_RESPONDER_SEND_SECURITY_REQUEST: case SM_RESPONDER_PH1_W4_PAIRING_REQUEST: if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ sm_pdu_received_in_wrong_state(sm_conn); break;; } // store pairing request (void)memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); // validation encryption key size max_encryption_key_size = sm_pairing_packet_get_max_encryption_key_size(sm_conn->sm_m_preq); if ((max_encryption_key_size < 7) || (max_encryption_key_size > 16)){ sm_pairing_error(sm_conn, SM_REASON_INVALID_PARAMETERS); break; } // check if IRK completed switch (sm_conn->sm_irk_lookup_state){ case IRK_LOOKUP_SUCCEEDED: case IRK_LOOKUP_FAILED: sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED; break; default: sm_conn->sm_engine_state = SM_RESPONDER_PH1_PAIRING_REQUEST_RECEIVED_W4_IRK; break; } break; #endif #ifdef ENABLE_LE_SECURE_CONNECTIONS case SM_SC_W4_PUBLIC_KEY_COMMAND: if (sm_pdu_code != SM_CODE_PAIRING_PUBLIC_KEY){ sm_pdu_received_in_wrong_state(sm_conn); break; } // store public key for DH Key calculation reverse_256(&packet[01], &setup->sm_peer_q[0]); reverse_256(&packet[33], &setup->sm_peer_q[32]); // CVE-2020-26558: abort pairing if remote uses the same public key if (memcmp(&setup->sm_peer_q, ec_q, 64) == 0){ log_info("Remote PK matches ours"); sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); break; } // validate public key err = btstack_crypto_ecc_p256_validate_public_key(setup->sm_peer_q); if (err != 0){ log_info("sm: peer public key invalid %x", err); sm_pairing_error(sm_conn, SM_REASON_DHKEY_CHECK_FAILED); break; } // start calculating dhkey btstack_crypto_ecc_p256_calculate_dhkey(&sm_crypto_ecc_p256_request, setup->sm_peer_q, setup->sm_dhkey, sm_sc_dhkey_calculated, (void*)(uintptr_t) sm_conn->sm_handle); log_info("public key received, generation method %u", setup->sm_stk_generation_method); if (IS_RESPONDER(sm_conn->sm_role)){ // responder sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; } else { // initiator // stk generation method // passkey entry: notify app to show passkey or to request passkey switch (setup->sm_stk_generation_method){ case JUST_WORKS: case NUMERIC_COMPARISON: sm_conn->sm_engine_state = SM_SC_W4_CONFIRMATION; break; case PK_RESP_INPUT: sm_sc_start_calculating_local_confirm(sm_conn); break; case PK_INIT_INPUT: case PK_BOTH_INPUT: if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; break; } sm_sc_start_calculating_local_confirm(sm_conn); break; case OOB: // generate Nx log_info("Generate Na"); btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_next_send_pairing_random, (void*)(uintptr_t) sm_conn->sm_handle); break; default: btstack_assert(false); break; } } break; case SM_SC_W4_CONFIRMATION: if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ sm_pdu_received_in_wrong_state(sm_conn); break; } // received confirm value reverse_128(&packet[1], setup->sm_peer_confirm); #ifdef ENABLE_TESTING_SUPPORT if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ log_info("testing_support: reset confirm value"); memset(setup->sm_peer_confirm, 0, 16); } #endif if (IS_RESPONDER(sm_conn->sm_role)){ // responder if (sm_passkey_used(setup->sm_stk_generation_method)){ if (setup->sm_user_response != SM_USER_RESPONSE_PASSKEY){ // still waiting for passkey sm_conn->sm_engine_state = SM_SC_W4_USER_RESPONSE; break; } } sm_sc_start_calculating_local_confirm(sm_conn); } else { // initiator if (sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)){ btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_nonce, 16, &sm_handle_random_result_sc_next_send_pairing_random, (void*)(uintptr_t) sm_conn->sm_handle); } else { sm_conn->sm_engine_state = SM_SC_SEND_PAIRING_RANDOM; } } break; case SM_SC_W4_PAIRING_RANDOM: if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ sm_pdu_received_in_wrong_state(sm_conn); break; } // received random value reverse_128(&packet[1], setup->sm_peer_nonce); // validate confirm value if Cb = f4(Pkb, Pka, Nb, z) // only check for JUST WORK/NC in initiator role OR passkey entry log_info("SM_SC_W4_PAIRING_RANDOM, responder: %u, just works: %u, passkey used %u, passkey entry %u", IS_RESPONDER(sm_conn->sm_role), sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method), sm_passkey_used(setup->sm_stk_generation_method), sm_passkey_entry(setup->sm_stk_generation_method)); if ( (!IS_RESPONDER(sm_conn->sm_role) && sm_just_works_or_numeric_comparison(setup->sm_stk_generation_method)) || (sm_passkey_entry(setup->sm_stk_generation_method)) ) { sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; break; } // OOB if (setup->sm_stk_generation_method == OOB){ // setup local random, set to zero if remote did not receive our data log_info("Received nonce, setup local random ra/rb for dhkey check"); if (IS_RESPONDER(sm_conn->sm_role)){ if (sm_pairing_packet_get_oob_data_flag(setup->sm_m_preq) == 0u){ log_info("Reset rb as A does not have OOB data"); memset(setup->sm_rb, 0, 16); } else { (void)memcpy(setup->sm_rb, sm_sc_oob_random, 16); log_info("Use stored rb"); log_info_hexdump(setup->sm_rb, 16); } } else { if (sm_pairing_packet_get_oob_data_flag(setup->sm_s_pres) == 0u){ log_info("Reset ra as B does not have OOB data"); memset(setup->sm_ra, 0, 16); } else { (void)memcpy(setup->sm_ra, sm_sc_oob_random, 16); log_info("Use stored ra"); log_info_hexdump(setup->sm_ra, 16); } } // validate confirm value if Cb = f4(PKb, Pkb, rb, 0) for OOB if data received if (setup->sm_have_oob_data){ sm_conn->sm_engine_state = SM_SC_W2_CMAC_FOR_CHECK_CONFIRMATION; break; } } // TODO: we only get here for Responder role with JW/NC sm_sc_state_after_receiving_random(sm_conn); break; case SM_SC_W2_CALCULATE_G2: case SM_SC_W4_CALCULATE_G2: case SM_SC_W4_CALCULATE_DHKEY: case SM_SC_W2_CALCULATE_F5_SALT: case SM_SC_W4_CALCULATE_F5_SALT: case SM_SC_W2_CALCULATE_F5_MACKEY: case SM_SC_W4_CALCULATE_F5_MACKEY: case SM_SC_W2_CALCULATE_F5_LTK: case SM_SC_W4_CALCULATE_F5_LTK: case SM_SC_W2_CALCULATE_F6_FOR_DHKEY_CHECK: case SM_SC_W4_DHKEY_CHECK_COMMAND: case SM_SC_W4_CALCULATE_F6_FOR_DHKEY_CHECK: case SM_SC_W4_USER_RESPONSE: if (sm_pdu_code != SM_CODE_PAIRING_DHKEY_CHECK){ sm_pdu_received_in_wrong_state(sm_conn); break; } // store DHKey Check setup->sm_state_vars |= SM_STATE_VAR_DHKEY_COMMAND_RECEIVED; reverse_128(&packet[01], setup->sm_peer_dhkey_check); // have we been only waiting for dhkey check command? if (sm_conn->sm_engine_state == SM_SC_W4_DHKEY_CHECK_COMMAND){ sm_conn->sm_engine_state = SM_SC_W2_CALCULATE_F6_TO_VERIFY_DHKEY_CHECK; } break; #endif #ifdef ENABLE_LE_PERIPHERAL case SM_RESPONDER_PH1_W4_PAIRING_CONFIRM: if (sm_pdu_code != SM_CODE_PAIRING_CONFIRM){ sm_pdu_received_in_wrong_state(sm_conn); break; } // received confirm value reverse_128(&packet[1], setup->sm_peer_confirm); #ifdef ENABLE_TESTING_SUPPORT if (test_pairing_failure == SM_REASON_CONFIRM_VALUE_FAILED){ log_info("testing_support: reset confirm value"); memset(setup->sm_peer_confirm, 0, 16); } #endif // notify client to hide shown passkey if (setup->sm_stk_generation_method == PK_INIT_INPUT){ sm_notify_client_base(SM_EVENT_PASSKEY_DISPLAY_CANCEL, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address); } // handle user cancel pairing? if (setup->sm_user_response == SM_USER_RESPONSE_DECLINE){ sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); break; } // wait for user action? if (setup->sm_user_response == SM_USER_RESPONSE_PENDING){ sm_conn->sm_engine_state = SM_PH1_W4_USER_RESPONSE; break; } // calculate and send local_confirm btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) sm_conn->sm_handle); break; case SM_RESPONDER_PH2_W4_PAIRING_RANDOM: if (sm_pdu_code != SM_CODE_PAIRING_RANDOM){ sm_pdu_received_in_wrong_state(sm_conn); break;; } // received random value reverse_128(&packet[1], setup->sm_peer_random); sm_conn->sm_engine_state = SM_PH2_C1_GET_ENC_C; break; #endif case SM_PH2_W4_CONNECTION_ENCRYPTED: case SM_PH3_RECEIVE_KEYS: switch(sm_pdu_code){ case SM_CODE_ENCRYPTION_INFORMATION: setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_ENCRYPTION_INFORMATION; reverse_128(&packet[1], setup->sm_peer_ltk); break; case SM_CODE_MASTER_IDENTIFICATION: setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_MASTER_IDENTIFICATION; setup->sm_peer_ediv = little_endian_read_16(packet, 1); reverse_64(&packet[3], setup->sm_peer_rand); break; case SM_CODE_IDENTITY_INFORMATION: setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; reverse_128(&packet[1], setup->sm_peer_irk); break; case SM_CODE_IDENTITY_ADDRESS_INFORMATION: setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; setup->sm_peer_addr_type = packet[1]; reverse_bd_addr(&packet[2], setup->sm_peer_address); break; case SM_CODE_SIGNING_INFORMATION: setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; reverse_128(&packet[1], setup->sm_peer_csrk); break; default: // Unexpected PDU log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); break; } // done with key distribution? if (sm_key_distribution_all_received()){ sm_key_distribution_handle_all_received(sm_conn); if (IS_RESPONDER(sm_conn->sm_role)){ sm_key_distribution_complete_responder(sm_conn); } else { if (setup->sm_use_secure_connections){ sm_conn->sm_engine_state = SM_PH3_DISTRIBUTE_KEYS; } else { btstack_crypto_random_generate(&sm_crypto_random_request, sm_random_data, 8, &sm_handle_random_result_ph3_random, (void *)(uintptr_t) sm_conn->sm_handle); } } } break; #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION case SM_BR_EDR_W4_ENCRYPTION_COMPLETE: // GAP/DM/LEP/BI-02-C - reject CTKD if P-192 encryption is used if (sm_pdu_code == SM_CODE_PAIRING_REQUEST){ sm_pairing_error(sm_conn, SM_REASON_CROSS_TRANSPORT_KEY_DERIVATION_NOT_ALLOWED); } break; case SM_BR_EDR_INITIATOR_W4_PAIRING_RESPONSE: // dedicated bonding complete hci_dedicated_bonding_defer_disconnect(sm_conn->sm_handle, false); if (sm_pdu_code != SM_CODE_PAIRING_RESPONSE){ sm_pdu_received_in_wrong_state(sm_conn); break; } // store pairing response (void)memcpy(&setup->sm_s_pres, packet, sizeof(sm_pairing_packet_t)); // validate encryption key size max_encryption_key_size = sm_pairing_packet_get_max_encryption_key_size(setup->sm_s_pres); if ((max_encryption_key_size < 7) || (max_encryption_key_size > 16)){ sm_pairing_error(sm_conn, SM_REASON_INVALID_PARAMETERS); break; } sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(max_encryption_key_size); // SC Only mandates 128 bit key size if (sm_sc_only_mode && (sm_conn->sm_actual_encryption_key_size < 16)) { sm_conn->sm_actual_encryption_key_size = 0; } if (sm_conn->sm_actual_encryption_key_size == 0){ sm_pairing_error(sm_conn, SM_REASON_ENCRYPTION_KEY_SIZE); break; } // prepare key exchange, LTK is derived locally sm_setup_key_distribution(sm_pairing_packet_get_initiator_key_distribution(setup->sm_s_pres) & ~SM_KEYDIST_ENC_KEY, sm_pairing_packet_get_responder_key_distribution(setup->sm_s_pres) & ~SM_KEYDIST_ENC_KEY); // skip receive if there are none if (sm_key_distribution_all_received()){ // distribute keys in run handles 'no keys to send' sm_conn->sm_engine_state = SM_BR_EDR_DISTRIBUTE_KEYS; } else { sm_conn->sm_engine_state = SM_BR_EDR_RECEIVE_KEYS; } break; case SM_BR_EDR_RESPONDER_W4_PAIRING_REQUEST: if (sm_pdu_code != SM_CODE_PAIRING_REQUEST){ sm_pdu_received_in_wrong_state(sm_conn); break; } // store pairing request (void)memcpy(&sm_conn->sm_m_preq, packet, sizeof(sm_pairing_packet_t)); // validate encryption key size max_encryption_key_size = sm_pairing_packet_get_max_encryption_key_size(sm_conn->sm_m_preq); if ((max_encryption_key_size < 7) || (max_encryption_key_size > 16)){ sm_pairing_error(sm_conn, SM_REASON_INVALID_PARAMETERS); break; } sm_conn->sm_actual_encryption_key_size = sm_calc_actual_encryption_key_size(max_encryption_key_size); // SC Only mandates 128 bit key size if (sm_sc_only_mode && (sm_conn->sm_actual_encryption_key_size < 16)) { sm_conn->sm_actual_encryption_key_size = 0; } if (sm_conn->sm_actual_encryption_key_size == 0){ sm_pairing_error(sm_conn, SM_REASON_ENCRYPTION_KEY_SIZE); break; } // trigger response if (sm_ctkd_from_classic(sm_conn)){ sm_conn->sm_engine_state = SM_BR_EDR_RESPONDER_PAIRING_REQUEST_RECEIVED; } else { sm_pairing_error(sm_conn, SM_REASON_CROSS_TRANSPORT_KEY_DERIVATION_NOT_ALLOWED); } break; case SM_BR_EDR_RECEIVE_KEYS: switch(sm_pdu_code){ case SM_CODE_IDENTITY_INFORMATION: setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_INFORMATION; reverse_128(&packet[1], setup->sm_peer_irk); break; case SM_CODE_IDENTITY_ADDRESS_INFORMATION: setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_IDENTITY_ADDRESS_INFORMATION; setup->sm_peer_addr_type = packet[1]; reverse_bd_addr(&packet[2], setup->sm_peer_address); break; case SM_CODE_SIGNING_INFORMATION: setup->sm_key_distribution_received_set |= SM_KEYDIST_FLAG_SIGNING_IDENTIFICATION; reverse_128(&packet[1], setup->sm_peer_csrk); break; default: // Unexpected PDU log_info("Unexpected PDU %u in SM_PH3_RECEIVE_KEYS", packet[0]); break; } // all keys received if (sm_key_distribution_all_received()){ if (IS_RESPONDER(sm_conn->sm_role)){ // responder -> keys exchanged, derive LE LTK sm_ctkd_start_from_br_edr(sm_conn); } else { // initiator -> send our keys if any sm_conn->sm_engine_state = SM_BR_EDR_DISTRIBUTE_KEYS; } } break; #endif default: // Unexpected PDU log_info("Unexpected PDU %u in state %u", packet[0], sm_conn->sm_engine_state); sm_pdu_received_in_wrong_state(sm_conn); break; } // try to send next pdu sm_trigger_run(); } static void sm_channel_handler(uint8_t packet_type, hci_con_handle_t con_handle, uint8_t *packet, uint16_t size){ if ((packet_type == HCI_EVENT_PACKET) && (packet[0] == L2CAP_EVENT_CAN_SEND_NOW)){ sm_run(); } uint8_t sm_pdu_code = sm_pdu_validate_and_get_opcode(packet_type, packet, size); if (sm_pdu_code == 0) return; sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return; if (sm_pdu_code == SM_CODE_PAIRING_FAILED){ sm_reencryption_complete(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE); sm_pairing_complete(sm_conn, ERROR_CODE_AUTHENTICATION_FAILURE, packet[1]); sm_done_for_handle(con_handle); sm_conn->sm_engine_state = sm_conn->sm_role ? SM_RESPONDER_IDLE : SM_INITIATOR_CONNECTED; return; } if (sm_pdu_code == SM_CODE_KEYPRESS_NOTIFICATION){ uint8_t buffer[5]; buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION; buffer[1] = 3; little_endian_store_16(buffer, 2, con_handle); buffer[4] = packet[1]; sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer)); return; } sm_pdu_handler(sm_conn, sm_pdu_code, packet); } // Security Manager Client API void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data)){ sm_get_oob_data = get_oob_data_callback; } void sm_register_sc_oob_data_callback( int (*get_sc_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random)){ sm_get_sc_oob_data = get_sc_oob_data_callback; } void sm_register_ltk_callback( bool (*get_ltk_callback)(hci_con_handle_t con_handle, uint8_t address_type, bd_addr_t addr, uint8_t * ltk)){ sm_get_ltk_callback = get_ltk_callback; } void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ btstack_linked_list_add_tail(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); } void sm_remove_event_handler(btstack_packet_callback_registration_t * callback_handler){ btstack_linked_list_remove(&sm_event_handlers, (btstack_linked_item_t*) callback_handler); } void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods){ sm_accepted_stk_generation_methods = accepted_stk_generation_methods; } void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size){ sm_min_encryption_key_size = min_size; sm_max_encryption_key_size = max_size; } void sm_set_authentication_requirements(uint8_t auth_req){ #ifndef ENABLE_LE_SECURE_CONNECTIONS if (auth_req & SM_AUTHREQ_SECURE_CONNECTION){ log_error("ENABLE_LE_SECURE_CONNECTIONS not defined, but requested by app. Dropping SC flag"); auth_req &= ~SM_AUTHREQ_SECURE_CONNECTION; } #endif sm_auth_req = auth_req; } void sm_set_io_capabilities(io_capability_t io_capability){ sm_io_capabilities = io_capability; } #ifdef ENABLE_LE_PERIPHERAL void sm_set_request_security(bool enable){ sm_slave_request_security = enable; } #endif void sm_set_er(sm_key_t er){ (void)memcpy(sm_persistent_er, er, 16); } void sm_set_ir(sm_key_t ir){ (void)memcpy(sm_persistent_ir, ir, 16); } // Testing support only void sm_test_set_irk(sm_key_t irk){ (void)memcpy(sm_persistent_irk, irk, 16); dkg_state = DKG_CALC_DHK; test_use_fixed_local_irk = true; } void sm_test_use_fixed_local_csrk(void){ test_use_fixed_local_csrk = true; } #ifdef ENABLE_LE_SECURE_CONNECTIONS static void sm_ec_generated(void * arg){ UNUSED(arg); ec_key_generation_state = EC_KEY_GENERATION_DONE; // trigger pairing if pending for ec key sm_trigger_run(); } static void sm_ec_generate_new_key(void) { log_info("sm: generate new ec key"); #ifdef ENABLE_LE_SECURE_CONNECTIONS_DEBUG_KEY // LE Secure Connections Debug Key const uint8_t debug_key_public[64] = { 0x20, 0xb0, 0x03, 0xd2, 0xf2, 0x97, 0xbe, 0x2c, 0x5e, 0x2c, 0x83, 0xa7, 0xe9, 0xf9, 0xa5, 0xb9, 0xef, 0xf4, 0x91, 0x11, 0xac, 0xf4, 0xfd, 0xdb, 0xcc, 0x03, 0x01, 0x48, 0x0e, 0x35, 0x9d, 0xe6, 0xdc, 0x80, 0x9c, 0x49, 0x65, 0x2a, 0xeb, 0x6d, 0x63, 0x32, 0x9a, 0xbf, 0x5a, 0x52, 0x15, 0x5c, 0x76, 0x63, 0x45, 0xc2, 0x8f, 0xed, 0x30, 0x24, 0x74, 0x1c, 0x8e, 0xd0, 0x15, 0x89, 0xd2, 0x8b }; const uint8_t debug_key_private[32] = { 0x3f, 0x49, 0xf6, 0xd4, 0xa3, 0xc5, 0x5f, 0x38, 0x74, 0xc9, 0xb3, 0xe3, 0xd2, 0x10, 0x3f, 0x50, 0x4a, 0xff, 0x60, 0x7b, 0xeb, 0x40, 0xb7, 0x99, 0x58, 0x99, 0xb8, 0xa6, 0xcd, 0x3c, 0x1a, 0xbd }; if (sm_sc_debug_keys_enabled) { memcpy(ec_q, debug_key_public, 64); btstack_crypto_ecc_p256_set_key(debug_key_public, debug_key_private); ec_key_generation_state = EC_KEY_GENERATION_DONE; } else #endif { ec_key_generation_state = EC_KEY_GENERATION_ACTIVE; btstack_crypto_ecc_p256_generate_key(&sm_crypto_ecc_p256_request, ec_q, &sm_ec_generated, NULL); } } #endif #ifdef ENABLE_TESTING_SUPPORT void sm_test_set_pairing_failure(int reason){ test_pairing_failure = reason; } #endif static void sm_state_reset(void) { #ifdef USE_CMAC_ENGINE sm_cmac_active = 0; #endif dkg_state = DKG_W4_WORKING; rau_state = RAU_IDLE; sm_aes128_state = SM_AES128_IDLE; sm_address_resolution_test = -1; // no private address to resolve yet sm_address_resolution_mode = ADDRESS_RESOLUTION_IDLE; sm_address_resolution_general_queue = NULL; sm_active_connection_handle = HCI_CON_HANDLE_INVALID; sm_persistent_keys_random_active = false; #ifdef ENABLE_LE_SECURE_CONNECTIONS ec_key_generation_state = EC_KEY_GENERATION_IDLE; #endif } void sm_init(void){ if (sm_initialized) return; // set default ER and IR values (should be unique - set by app or sm later using TLV) sm_er_ir_set_default(); // defaults sm_accepted_stk_generation_methods = SM_STK_GENERATION_METHOD_JUST_WORKS | SM_STK_GENERATION_METHOD_OOB | SM_STK_GENERATION_METHOD_PASSKEY | SM_STK_GENERATION_METHOD_NUMERIC_COMPARISON; sm_max_encryption_key_size = 16; sm_min_encryption_key_size = 7; sm_fixed_passkey_in_display_role = 0xffffffffU; sm_reconstruct_ltk_without_le_device_db_entry = true; gap_random_adress_update_period = 15 * 60 * 1000L; test_use_fixed_local_csrk = false; // other btstack_run_loop_set_timer_handler(&sm_run_timer, &sm_run_timer_handler); // register for HCI Events hci_event_callback_registration.callback = &sm_event_packet_handler; hci_add_event_handler(&hci_event_callback_registration); #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION // register for L2CAP events l2cap_event_callback_registration.callback = &sm_event_packet_handler; l2cap_add_event_handler(&l2cap_event_callback_registration); #endif // btstack_crypto_init(); // init le_device_db le_device_db_init(); // and L2CAP PDUs + L2CAP_EVENT_CAN_SEND_NOW l2cap_register_fixed_channel(sm_channel_handler, L2CAP_CID_SECURITY_MANAGER_PROTOCOL); #ifdef ENABLE_CLASSIC l2cap_register_fixed_channel(sm_channel_handler, L2CAP_CID_BR_EDR_SECURITY_MANAGER); #endif // state sm_state_reset(); sm_initialized = true; } void sm_deinit(void){ sm_initialized = false; btstack_run_loop_remove_timer(&sm_run_timer); #if defined(ENABLE_LE_SECURE_CONNECTIONS) && defined (ENABLE_LE_SECURE_CONNECTION_DEBUG_KEY) sm_sc_debug_keys_enabled = false; #endif } void sm_use_fixed_passkey_in_display_role(uint32_t passkey){ sm_fixed_passkey_in_display_role = passkey; } void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow){ sm_reconstruct_ltk_without_le_device_db_entry = allow != 0; } static sm_connection_t * sm_get_connection_for_handle(hci_con_handle_t con_handle){ hci_connection_t * hci_con = hci_connection_for_handle(con_handle); if (!hci_con) return NULL; return &hci_con->sm_connection; } static void sm_cache_ltk(sm_connection_t * connection, const sm_key_t ltk){ hci_connection_t * hci_con = hci_connection_for_handle(connection->sm_handle); btstack_assert(hci_con != NULL); memcpy(hci_con->link_key, ltk, 16); hci_con->link_key_type = COMBINATION_KEY; } #ifdef ENABLE_CROSS_TRANSPORT_KEY_DERIVATION static sm_connection_t * sm_get_connection_for_bd_addr_and_type(bd_addr_t address, bd_addr_type_t addr_type){ hci_connection_t * hci_con = hci_connection_for_bd_addr_and_type(address, addr_type); if (!hci_con) return NULL; return &hci_con->sm_connection; } #endif // @deprecated: map onto sm_request_pairing void sm_send_security_request(hci_con_handle_t con_handle){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return; if (!IS_RESPONDER(sm_conn->sm_role)) return; sm_request_pairing(con_handle); } // request pairing void sm_request_pairing(hci_con_handle_t con_handle){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return; // wrong connection bool have_ltk; uint8_t ltk[16]; bool auth_required; int authenticated; bool trigger_reencryption; log_info("sm_request_pairing in role %u, state %u", sm_conn->sm_role, sm_conn->sm_engine_state); if (IS_RESPONDER(sm_conn->sm_role)){ switch (sm_conn->sm_engine_state){ case SM_GENERAL_IDLE: case SM_RESPONDER_IDLE: switch (sm_conn->sm_irk_lookup_state){ case IRK_LOOKUP_SUCCEEDED: le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, NULL, NULL, NULL); have_ltk = !sm_is_null_key(ltk); log_info("have ltk %u", have_ltk); if (have_ltk){ sm_conn->sm_pairing_requested = true; sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; sm_reencryption_started(sm_conn); break; } /* fall through */ case IRK_LOOKUP_FAILED: sm_conn->sm_pairing_requested = true; sm_conn->sm_engine_state = SM_RESPONDER_SEND_SECURITY_REQUEST; sm_pairing_started(sm_conn); break; default: log_info("irk lookup pending"); sm_conn->sm_pairing_requested = true; break; } break; default: break; } } else { // used as a trigger to start central/master/initiator security procedures switch (sm_conn->sm_engine_state){ case SM_INITIATOR_CONNECTED: switch (sm_conn->sm_irk_lookup_state){ case IRK_LOOKUP_SUCCEEDED: le_device_db_encryption_get(sm_conn->sm_le_db_index, NULL, NULL, ltk, NULL, &authenticated, NULL, NULL); have_ltk = !sm_is_null_key(ltk); auth_required = sm_auth_req & SM_AUTHREQ_MITM_PROTECTION; // re-encrypt is sufficient if we have ltk and that is either already authenticated or we don't require authentication trigger_reencryption = have_ltk && ((authenticated != 0) || (auth_required == false)); log_info("have ltk %u, authenticated %u, auth required %u => reencrypt %u", have_ltk, authenticated, auth_required, trigger_reencryption); if (trigger_reencryption){ sm_conn->sm_pairing_requested = true; sm_conn->sm_engine_state = SM_INITIATOR_PH4_HAS_LTK; break; } /* fall through */ case IRK_LOOKUP_FAILED: sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; break; default: log_info("irk lookup pending"); sm_conn->sm_pairing_requested = true; break; } break; case SM_GENERAL_REENCRYPTION_FAILED: sm_conn->sm_engine_state = SM_INITIATOR_PH1_W2_SEND_PAIRING_REQUEST; break; case SM_GENERAL_IDLE: sm_conn->sm_pairing_requested = true; break; default: break; } } sm_trigger_run(); } // called by client app on authorization request void sm_authorization_decline(hci_con_handle_t con_handle){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return; // wrong connection sm_conn->sm_connection_authorization_state = AUTHORIZATION_DECLINED; sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 0); } void sm_authorization_grant(hci_con_handle_t con_handle){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return; // wrong connection sm_conn->sm_connection_authorization_state = AUTHORIZATION_GRANTED; sm_notify_client_status(SM_EVENT_AUTHORIZATION_RESULT, sm_conn->sm_handle, sm_conn->sm_peer_addr_type, sm_conn->sm_peer_address, 1); } // GAP Bonding API void sm_bonding_decline(hci_con_handle_t con_handle){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return; // wrong connection setup->sm_user_response = SM_USER_RESPONSE_DECLINE; log_info("decline, state %u", sm_conn->sm_engine_state); switch(sm_conn->sm_engine_state){ #ifdef ENABLE_LE_SECURE_CONNECTIONS case SM_SC_W4_USER_RESPONSE: case SM_SC_W4_CONFIRMATION: case SM_SC_W4_PUBLIC_KEY_COMMAND: #endif case SM_PH1_W4_USER_RESPONSE: switch (setup->sm_stk_generation_method){ case PK_RESP_INPUT: case PK_INIT_INPUT: case PK_BOTH_INPUT: sm_pairing_error(sm_conn, SM_REASON_PASSKEY_ENTRY_FAILED); break; case NUMERIC_COMPARISON: sm_pairing_error(sm_conn, SM_REASON_NUMERIC_COMPARISON_FAILED); break; case JUST_WORKS: case OOB: sm_pairing_error(sm_conn, SM_REASON_UNSPECIFIED_REASON); break; default: btstack_assert(false); break; } break; default: break; } sm_trigger_run(); } void sm_just_works_confirm(hci_con_handle_t con_handle){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return; // wrong connection setup->sm_user_response = SM_USER_RESPONSE_CONFIRM; if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ if (setup->sm_use_secure_connections){ sm_conn->sm_engine_state = SM_SC_SEND_PUBLIC_KEY_COMMAND; } else { btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) sm_conn->sm_handle); } } #ifdef ENABLE_LE_SECURE_CONNECTIONS if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ sm_sc_prepare_dhkey_check(sm_conn); } #endif sm_trigger_run(); } void sm_numeric_comparison_confirm(hci_con_handle_t con_handle){ // for now, it's the same sm_just_works_confirm(con_handle); } void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return; // wrong connection sm_reset_tk(); big_endian_store_32(setup->sm_tk, 12, passkey); setup->sm_user_response = SM_USER_RESPONSE_PASSKEY; if (sm_conn->sm_engine_state == SM_PH1_W4_USER_RESPONSE){ btstack_crypto_random_generate(&sm_crypto_random_request, setup->sm_local_random, 16, &sm_handle_random_result_ph2_random, (void *)(uintptr_t) sm_conn->sm_handle); } #ifdef ENABLE_LE_SECURE_CONNECTIONS (void)memcpy(setup->sm_ra, setup->sm_tk, 16); (void)memcpy(setup->sm_rb, setup->sm_tk, 16); if (sm_conn->sm_engine_state == SM_SC_W4_USER_RESPONSE){ sm_sc_start_calculating_local_confirm(sm_conn); } #endif sm_trigger_run(); } void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return; // wrong connection if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return; uint8_t num_actions = setup->sm_keypress_notification >> 5; uint8_t flags = setup->sm_keypress_notification & 0x1fu; switch (action){ case SM_KEYPRESS_PASSKEY_ENTRY_STARTED: case SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED: flags |= (1u << action); break; case SM_KEYPRESS_PASSKEY_CLEARED: // clear counter, keypress & erased flags + set passkey cleared flags = (flags & 0x19u) | (1u << SM_KEYPRESS_PASSKEY_CLEARED); break; case SM_KEYPRESS_PASSKEY_DIGIT_ENTERED: if ((flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED)) != 0u){ // erase actions queued num_actions--; if (num_actions == 0u){ // clear counter, keypress & erased flags flags &= 0x19u; } break; } num_actions++; flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED); break; case SM_KEYPRESS_PASSKEY_DIGIT_ERASED: if ((flags & (1u << SM_KEYPRESS_PASSKEY_DIGIT_ENTERED)) != 0u){ // enter actions queued num_actions--; if (num_actions == 0u){ // clear counter, keypress & erased flags flags &= 0x19u; } break; } num_actions++; flags |= (1u << SM_KEYPRESS_PASSKEY_DIGIT_ERASED); break; default: break; } setup->sm_keypress_notification = (num_actions << 5) | flags; sm_trigger_run(); } #ifdef ENABLE_LE_SECURE_CONNECTIONS static void sm_handle_random_result_oob(void * arg){ UNUSED(arg); sm_sc_oob_state = SM_SC_OOB_W2_CALC_CONFIRM; sm_trigger_run(); } uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value)){ static btstack_crypto_random_t sm_crypto_random_oob_request; if (sm_sc_oob_state != SM_SC_OOB_IDLE) return ERROR_CODE_COMMAND_DISALLOWED; sm_sc_oob_callback = callback; sm_sc_oob_state = SM_SC_OOB_W4_RANDOM; btstack_crypto_random_generate(&sm_crypto_random_oob_request, sm_sc_oob_random, 16, &sm_handle_random_result_oob, NULL); return 0; } #endif /** * @brief Get Identity Resolving state * @param con_handle * @return irk_lookup_state_t */ irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return IRK_LOOKUP_IDLE; return sm_conn->sm_irk_lookup_state; } /** * @brief Identify device in LE Device DB * @param handle * @return index from le_device_db or -1 if not found/identified */ int sm_le_device_index(hci_con_handle_t con_handle ){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); if (!sm_conn) return -1; return sm_conn->sm_le_db_index; } uint8_t sm_get_ltk(hci_con_handle_t con_handle, sm_key_t ltk){ hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (hci_connection == NULL){ return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; } if (hci_connection->link_key_type == INVALID_LINK_KEY){ return ERROR_CODE_PIN_OR_KEY_MISSING; } memcpy(ltk, hci_connection->link_key, 16); return ERROR_CODE_SUCCESS; } static int gap_random_address_type_requires_updates(void){ switch (gap_random_adress_type){ case GAP_RANDOM_ADDRESS_TYPE_OFF: case GAP_RANDOM_ADDRESS_TYPE_STATIC: return 0; default: return 1; } } static uint8_t own_address_type(void){ switch (gap_random_adress_type){ case GAP_RANDOM_ADDRESS_TYPE_OFF: return BD_ADDR_TYPE_LE_PUBLIC; default: return BD_ADDR_TYPE_LE_RANDOM; } } // GAP LE API void gap_random_address_set_mode(gap_random_address_type_t random_address_type){ gap_random_address_update_stop(); gap_random_adress_type = random_address_type; hci_le_set_own_address_type(own_address_type()); if (!gap_random_address_type_requires_updates()) return; gap_random_address_update_start(); gap_random_address_trigger(); } gap_random_address_type_t gap_random_address_get_mode(void){ return gap_random_adress_type; } void gap_random_address_set_update_period(int period_ms){ gap_random_adress_update_period = period_ms; if (!gap_random_address_type_requires_updates()) return; gap_random_address_update_stop(); gap_random_address_update_start(); } void gap_random_address_set(const bd_addr_t addr){ gap_random_address_set_mode(GAP_RANDOM_ADDRESS_TYPE_STATIC); (void)memcpy(sm_random_address, addr, 6); // assert msb bits are set to '11' sm_random_address[0] |= 0xc0; hci_le_random_address_set(sm_random_address); } #ifdef ENABLE_LE_PERIPHERAL /* * @brief Set Advertisement Paramters * @param adv_int_min * @param adv_int_max * @param adv_type * @param direct_address_type * @param direct_address * @param channel_map * @param filter_policy * * @note own_address_type is used from gap_random_address_set_mode */ void gap_advertisements_set_params(uint16_t adv_int_min, uint16_t adv_int_max, uint8_t adv_type, uint8_t direct_address_typ, bd_addr_t direct_address, uint8_t channel_map, uint8_t filter_policy){ hci_le_advertisements_set_params(adv_int_min, adv_int_max, adv_type, direct_address_typ, direct_address, channel_map, filter_policy); } #endif bool gap_reconnect_security_setup_active(hci_con_handle_t con_handle){ sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle); // wrong connection if (!sm_conn) return false; // already encrypted if (sm_conn->sm_connection_encrypted) return false; // irk status? switch(sm_conn->sm_irk_lookup_state){ case IRK_LOOKUP_FAILED: // done, cannot setup encryption return false; case IRK_LOOKUP_SUCCEEDED: break; default: // IR Lookup pending return true; } // IRK Lookup Succeeded, re-encryption should be initiated. When done, state gets reset or indicates failure if (sm_conn->sm_engine_state == SM_GENERAL_REENCRYPTION_FAILED) return false; if (sm_conn->sm_role != 0){ return sm_conn->sm_engine_state != SM_RESPONDER_IDLE; } else { return sm_conn->sm_engine_state != SM_INITIATOR_CONNECTED; } } void sm_set_secure_connections_only_mode(bool enable){ #ifdef ENABLE_LE_SECURE_CONNECTIONS sm_sc_only_mode = enable; #else // SC Only mode not possible without support for SC btstack_assert(enable == false); #endif } #if defined(ENABLE_LE_SECURE_CONNECTIONS) && defined (ENABLE_LE_SECURE_CONNECTION_DEBUG_KEY) void sm_test_enable_secure_connections_debug_keys(void) { log_info("Enable LE Secure Connection Debug Keys for testing"); sm_sc_debug_keys_enabled = true; // set debug key sm_ec_generate_new_key(); } #endif const uint8_t * gap_get_persistent_irk(void){ return sm_persistent_irk; } void gap_delete_bonding(bd_addr_type_t address_type, bd_addr_t address){ int index = sm_le_device_db_index_lookup(address_type, address); if (index >= 0){ sm_remove_le_device_db_entry(index); } }

Details