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/*
* EAP peer method: EAP-MSCHAPV2 (draft-kamath-pppext-eap-mschapv2-00.txt)
* Copyright (c) 2004-2008, 2012, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#ifdef EAP_MSCHAPv2
#include "rsn_supp/wpa.h"
#include "crypto/random.h"
#include "crypto/ms_funcs.h"
#include "crypto/tls.h"
#include "eap_peer/eap_i.h"
#include "eap_peer/eap_defs.h"
#include "eap_peer/eap_tls_common.h"
#include "eap_peer/eap_config.h"
#include "eap_peer/mschapv2.h"
#include "eap_peer/eap_methods.h"
#include "common/wpa_ctrl.h"
#define MSCHAPV2_OP_CHALLENGE 1
#define MSCHAPV2_OP_RESPONSE 2
#define MSCHAPV2_OP_SUCCESS 3
#define MSCHAPV2_OP_FAILURE 4
#define MSCHAPV2_OP_CHANGE_PASSWORD 7
#define PASSWD_CHANGE_CHAL_LEN 16
#define MSCHAPV2_KEY_LEN 16
#define ERROR_RESTRICTED_LOGON_HOURS 646
#define ERROR_ACCT_DISABLED 647
#define ERROR_PASSWD_EXPIRED 648
#define ERROR_NO_DIALIN_PERMISSION 649
#define ERROR_AUTHENTICATION_FAILURE 691
#define ERROR_CHANGING_PASSWORD 709
struct eap_mschapv2_hdr {
u8 op_code;
u8 mschapv2_id;
u8 ms_length[2];
} __packed;
struct ms_response {
u8 peer_challenge[MSCHAPV2_CHAL_LEN];
u8 reserved[8];
u8 nt_response[MSCHAPV2_NT_RESPONSE_LEN];
u8 flags;
} __packed;
struct ms_change_password {
u8 encr_password[516];
u8 encr_hash[16];
u8 peer_challenge[MSCHAPV2_CHAL_LEN];
u8 reserved[8];
u8 nt_response[MSCHAPV2_NT_RESPONSE_LEN];
u8 flags[2];
} __packed;
struct eap_mschapv2_data {
u8 auth_response[MSCHAPV2_AUTH_RESPONSE_LEN];
int auth_response_valid;
int prev_error;
u8 passwd_change_challenge[PASSWD_CHANGE_CHAL_LEN];
int passwd_change_challenge_valid;
int passwd_change_version;
u8 *peer_challenge;
u8 *auth_challenge;
int phase2;
u8 master_key[MSCHAPV2_MASTER_KEY_LEN];
int master_key_valid;
int success;
struct wpabuf *prev_challenge;
};
static void
eap_mschapv2_deinit(struct eap_sm *sm, void *priv)
{
struct eap_mschapv2_data *data = priv;
os_free(data->peer_challenge);
os_free(data->auth_challenge);
wpabuf_free(data->prev_challenge);
bin_clear_free(data, sizeof(*data));
}
static void *
eap_mschapv2_init(struct eap_sm *sm)
{
struct eap_mschapv2_data *data;
//Do not init insecure unencapsulated MSCHAPv2 as Phase 1 method, only init if Phase 2
if(!sm->init_phase2)
return NULL;
data = (struct eap_mschapv2_data *)os_zalloc(sizeof(*data));
if (data == NULL)
return NULL;
if (sm->peer_challenge) {
data->peer_challenge = os_memdup(sm->peer_challenge,
MSCHAPV2_CHAL_LEN);
if (data->peer_challenge == NULL) {
eap_mschapv2_deinit(sm, data);
return NULL;
}
}
if (sm->auth_challenge) {
data->auth_challenge = os_memdup(sm->auth_challenge,
MSCHAPV2_CHAL_LEN);
if (data->auth_challenge == NULL) {
eap_mschapv2_deinit(sm, data);
return NULL;
}
}
data->phase2 = sm->init_phase2;
return data;
}
static struct wpabuf *
eap_mschapv2_challenge_reply(
struct eap_sm *sm, struct eap_mschapv2_data *data,
u8 id, u8 mschapv2_id, const u8 *auth_challenge)
{
struct wpabuf *resp;
struct eap_mschapv2_hdr *ms;
u8 *peer_challenge;
int ms_len;
struct ms_response *r;
size_t identity_len, password_len;
const u8 *identity, *password;
int pwhash;
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Generate Challenge Response");
identity = eap_get_config_identity(sm, &identity_len);
password = eap_get_config_password2(sm, &password_len, &pwhash);
if (identity == NULL || password == NULL)
return NULL;
ms_len = sizeof(*ms) + 1 + sizeof(*r) + identity_len;
resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
ms_len, EAP_CODE_RESPONSE, id);
if (resp == NULL)
return NULL;
ms = wpabuf_put(resp, sizeof(*ms));
ms->op_code = MSCHAPV2_OP_RESPONSE;
ms->mschapv2_id = mschapv2_id;
if (data->prev_error) {
/*
* TODO: this does not seem to be enough when processing two
* or more failure messages. IAS did not increment mschapv2_id
* in its own packets, but it seemed to expect the peer to
* increment this for all packets(?).
*/
ms->mschapv2_id++;
}
WPA_PUT_BE16(ms->ms_length, ms_len);
wpabuf_put_u8(resp, sizeof(*r));
/* Response */
r = wpabuf_put(resp, sizeof(*r));
peer_challenge = r->peer_challenge;
if (data->peer_challenge) {
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: peer_challenge generated "
"in Phase 1");
peer_challenge = data->peer_challenge;
os_memset(r->peer_challenge, 0, MSCHAPV2_CHAL_LEN);
} else if (random_get_bytes(peer_challenge, MSCHAPV2_CHAL_LEN)) {
wpabuf_free(resp);
return NULL;
}
os_memset(r->reserved, 0, 8);
if (data->auth_challenge) {
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: auth_challenge generated "
"in Phase 1");
auth_challenge = data->auth_challenge;
}
if (mschapv2_derive_response(identity, identity_len, password,
password_len, pwhash, auth_challenge,
peer_challenge, r->nt_response,
data->auth_response, data->master_key)) {
wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to derive "
"response");
wpabuf_free(resp);
return NULL;
}
data->auth_response_valid = 1;
data->master_key_valid = 1;
r->flags = 0; /* reserved, must be zero */
wpabuf_put_data(resp, identity, identity_len);
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: TX identifier %d mschapv2_id %d "
"(response)", id, ms->mschapv2_id);
return resp;
}
/**
* eap_mschapv2_process - Process an EAP-MSCHAPv2 challenge message
* @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
* @data: Pointer to private EAP method data from eap_mschapv2_init()
* @ret: Return values from EAP request validation and processing
* @req: Pointer to EAP-MSCHAPv2 header from the request
* @req_len: Length of the EAP-MSCHAPv2 data
* @id: EAP identifier used in the request
* Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
* no reply available
*/
static struct wpabuf * eap_mschapv2_challenge(
struct eap_sm *sm, struct eap_mschapv2_data *data,
struct eap_method_ret *ret, const struct eap_mschapv2_hdr *req,
size_t req_len, u8 id)
{
size_t len, challenge_len;
const u8 *pos, *challenge;
if (eap_get_config_identity(sm, &len) == NULL ||
eap_get_config_password(sm, &len) == NULL)
return NULL;
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received challenge");
if (req_len < sizeof(*req) + 1) {
wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Too short challenge data "
"(len %lu)", (unsigned long) req_len);
ret->ignore = true;
return NULL;
}
pos = (const u8 *)(req + 1);
challenge_len = *pos++;
len = req_len - sizeof(*req) - 1;
if (challenge_len != MSCHAPV2_CHAL_LEN) {
wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid challenge length "
"%lu", (unsigned long) challenge_len);
ret->ignore = true;
return NULL;
}
if (len < challenge_len) {
wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Too short challenge"
" packet: len=%lu challenge_len=%lu",
(unsigned long) len, (unsigned long) challenge_len);
ret->ignore = true;
return NULL;
}
if (data->passwd_change_challenge_valid) {
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Using challenge from the "
"failure message");
challenge = data->passwd_change_challenge;
} else
challenge = pos;
pos += challenge_len;
len -= challenge_len;
wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Authentication Servername",
pos, len);
ret->ignore = false;
ret->methodState = METHOD_MAY_CONT;
ret->decision = DECISION_FAIL;
ret->allowNotifications = true;
return eap_mschapv2_challenge_reply(sm, data, id, req->mschapv2_id,
challenge);
}
static void
eap_mschapv2_password_changed(struct eap_sm *sm,
struct eap_mschapv2_data *data)
{
struct eap_peer_config *config = eap_get_config(sm);
if (config && config->new_password) {
wpa_msg(sm->msg_ctx, MSG_INFO,
WPA_EVENT_PASSWORD_CHANGED
"EAP-MSCHAPV2: Password changed successfully");
data->prev_error = 0;
bin_clear_free(config->password, config->password_len);
if (config->flags & EAP_CONFIG_FLAGS_EXT_PASSWORD) {
/* TODO: update external storage */
} else if (config->flags & EAP_CONFIG_FLAGS_PASSWORD_NTHASH) {
config->password = os_malloc(16);
config->password_len = 16;
if (config->password) {
nt_password_hash(config->new_password,
config->new_password_len,
config->password);
}
bin_clear_free(config->new_password,
config->new_password_len);
} else {
config->password = config->new_password;
config->password_len = config->new_password_len;
}
config->new_password = NULL;
config->new_password_len = 0;
}
}
static struct wpabuf *
eap_mschapv2_success(struct eap_sm *sm,
struct eap_mschapv2_data *data,
struct eap_method_ret *ret,
const struct eap_mschapv2_hdr *req,
size_t req_len, u8 id)
{
struct wpabuf *resp;
const u8 *pos;
size_t len;
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received success");
len = req_len - sizeof(*req);
pos = (const u8 *) (req + 1);
if (!data->auth_response_valid ||
mschapv2_verify_auth_response(data->auth_response, pos, len)) {
wpa_printf(MSG_WARNING, "EAP-MSCHAPV2: Invalid authenticator "
"response in success request");
ret->methodState = METHOD_DONE;
ret->decision = DECISION_FAIL;
return NULL;
}
pos += 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN;
len -= 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN;
while (len > 0 && *pos == ' ') {
pos++;
len--;
}
wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Success message",
pos, len);
wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Authentication succeeded");
/* Note: Only op_code of the EAP-MSCHAPV2 header is included in success
* message. */
resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, 1,
EAP_CODE_RESPONSE, id);
if (resp == NULL) {
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Failed to allocate "
"buffer for success response");
ret->ignore = true;
return NULL;
}
wpabuf_put_u8(resp, MSCHAPV2_OP_SUCCESS); /* op_code */
ret->methodState = METHOD_DONE;
ret->decision = DECISION_UNCOND_SUCC;
ret->allowNotifications = false;
data->success = 1;
if (data->prev_error == ERROR_PASSWD_EXPIRED)
eap_mschapv2_password_changed(sm, data);
return resp;
}
static int eap_mschapv2_failure_txt(struct eap_sm *sm,
struct eap_mschapv2_data *data, char *txt)
{
char *pos = "";
int retry = 1;
struct eap_peer_config *config = eap_get_config(sm);
/* For example:
* E=691 R=1 C=<32 octets hex challenge> V=3 M=Authentication Failure
*/
pos = txt;
if (pos && os_strncmp(pos, "E=", 2) == 0) {
pos += 2;
data->prev_error = atoi(pos);
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: error %d",
data->prev_error);
pos = (char *)os_strchr(pos, ' ');
if (pos)
pos++;
}
if (pos && os_strncmp(pos, "R=", 2) == 0) {
pos += 2;
retry = atoi(pos);
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: retry is %sallowed",
retry == 1 ? "" : "not ");
pos = (char *)os_strchr(pos, ' ');
if (pos)
pos++;
}
if (pos && os_strncmp(pos, "C=", 2) == 0) {
int hex_len;
pos += 2;
hex_len = (char *)os_strchr(pos, ' ') - (char *)pos;
if (hex_len == PASSWD_CHANGE_CHAL_LEN * 2) {
if (hexstr2bin(pos, data->passwd_change_challenge,
PASSWD_CHANGE_CHAL_LEN)) {
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: invalid "
"failure challenge");
} else {
wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: failure "
"challenge",
data->passwd_change_challenge,
PASSWD_CHANGE_CHAL_LEN);
data->passwd_change_challenge_valid = 1;
}
} else {
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: invalid failure "
"challenge len %d", hex_len);
}
pos = os_strchr(pos, ' ');
if (pos)
pos++;
} else {
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: required challenge field "
"was not present in failure message");
}
if (pos && os_strncmp(pos, "V=", 2) == 0) {
pos += 2;
data->passwd_change_version = atoi(pos);
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: password changing "
"protocol version %d", data->passwd_change_version);
pos = (char *)os_strchr(pos, ' ');
if (pos)
pos++;
}
if (pos && os_strncmp(pos, "M=", 2) == 0) {
pos += 2;
}
if (data->prev_error == ERROR_AUTHENTICATION_FAILURE && retry &&
config && config->phase2 &&
os_strstr(config->phase2, "mschapv2_retry=0")) {
wpa_printf(MSG_DEBUG,
"EAP-MSCHAPV2: mark password retry disabled based on local configuration");
retry = 0;
}
if (data->prev_error == ERROR_PASSWD_EXPIRED &&
data->passwd_change_version == 3 && config) {
if (config->new_password == NULL) {
wpa_msg(sm->msg_ctx, MSG_INFO,
"EAP-MSCHAPV2: Password expired - password "
"change required");
eap_sm_request_new_password(sm);
}
} else if (retry == 1 && config) {
/* TODO: could prevent the current password from being used
* again at least for some period of time */
if (!config->mschapv2_retry)
eap_sm_request_identity(sm);
eap_sm_request_password(sm);
config->mschapv2_retry = 1;
} else if (config) {
/* TODO: prevent retries using same username/password */
config->mschapv2_retry = 0;
}
return retry == 1;
}
static struct wpabuf * eap_mschapv2_change_password(
struct eap_sm *sm, struct eap_mschapv2_data *data,
struct eap_method_ret *ret, const struct eap_mschapv2_hdr *req, u8 id)
{
struct wpabuf *resp;
int ms_len;
const u8 *username, *password, *new_password;
size_t username_len, password_len, new_password_len;
struct eap_mschapv2_hdr *ms;
struct ms_change_password *cp;
u8 password_hash[16], password_hash_hash[16];
int pwhash;
username = eap_get_config_identity(sm, &username_len);
password = eap_get_config_password2(sm, &password_len, &pwhash);
new_password = eap_get_config_new_password(sm, &new_password_len);
if (username == NULL || password == NULL || new_password == NULL)
return NULL;
username = mschapv2_remove_domain(username, &username_len);
ret->ignore = false;
ret->methodState = METHOD_MAY_CONT;
ret->decision = DECISION_COND_SUCC;
ret->allowNotifications = TRUE;
ms_len = sizeof(*ms) + sizeof(*cp);
resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
EAP_CODE_RESPONSE, id);
if (resp == NULL)
return NULL;
ms = wpabuf_put(resp, sizeof(*ms));
ms->op_code = MSCHAPV2_OP_CHANGE_PASSWORD;
ms->mschapv2_id = req->mschapv2_id + 1;
WPA_PUT_BE16(ms->ms_length, ms_len);
cp = wpabuf_put(resp, sizeof(*cp));
/* Encrypted-Password */
if (pwhash) {
if (encrypt_pw_block_with_password_hash(
new_password, new_password_len,
password, cp->encr_password))
goto fail;
} else {
if (new_password_encrypted_with_old_nt_password_hash(
new_password, new_password_len,
password, password_len, cp->encr_password))
goto fail;
}
/* Encrypted-Hash */
if (pwhash) {
u8 new_password_hash[16];
if (nt_password_hash(new_password, new_password_len,
new_password_hash) ||
nt_password_hash_encrypted_with_block(password,
new_password_hash,
cp->encr_hash))
goto fail;
} else {
if (old_nt_password_hash_encrypted_with_new_nt_password_hash(
new_password, new_password_len,
password, password_len, cp->encr_hash))
goto fail;
}
/* Peer-Challenge */
if (random_get_bytes(cp->peer_challenge, MSCHAPV2_CHAL_LEN))
goto fail;
/* Reserved, must be zero */
os_memset(cp->reserved, 0, 8);
/* NT-Response */
wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: auth_challenge",
data->passwd_change_challenge, PASSWD_CHANGE_CHAL_LEN);
wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: peer_challenge",
cp->peer_challenge, MSCHAPV2_CHAL_LEN);
wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: username",
username, username_len);
wpa_hexdump_ascii_key(MSG_DEBUG, "EAP-MSCHAPV2: new password",
new_password, new_password_len);
generate_nt_response(data->passwd_change_challenge, cp->peer_challenge,
username, username_len,
new_password, new_password_len,
cp->nt_response);
wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: NT-Response",
cp->nt_response, MSCHAPV2_NT_RESPONSE_LEN);
/* Authenticator response is not really needed yet, but calculate it
* here so that challenges need not be saved. */
generate_authenticator_response(new_password, new_password_len,
cp->peer_challenge,
data->passwd_change_challenge,
username, username_len,
cp->nt_response, data->auth_response);
data->auth_response_valid = 1;
/* Likewise, generate master_key here since we have the needed data
* available. */
if (nt_password_hash(new_password, new_password_len, password_hash) ||
hash_nt_password_hash(password_hash, password_hash_hash) ||
get_master_key(password_hash_hash, cp->nt_response,
data->master_key)) {
data->auth_response_valid = 0;
goto fail;
}
data->master_key_valid = 1;
/* Flags */
os_memset(cp->flags, 0, 2);
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: TX identifier %d mschapv2_id %d "
"(change pw)", id, ms->mschapv2_id);
return resp;
fail:
wpabuf_free(resp);
return NULL;
}
/**
* eap_mschapv2_process - Process an EAP-MSCHAPv2 failure message
* @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
* @data: Pointer to private EAP method data from eap_mschapv2_init()
* @ret: Return values from EAP request validation and processing
* @req: Pointer to EAP-MSCHAPv2 header from the request
* @req_len: Length of the EAP-MSCHAPv2 data
* @id: EAP identifier used in th erequest
* Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
* no reply available
*/
static struct wpabuf * eap_mschapv2_failure(struct eap_sm *sm,
struct eap_mschapv2_data *data,
struct eap_method_ret *ret,
const struct eap_mschapv2_hdr *req,
size_t req_len, u8 id)
{
struct wpabuf *resp;
const u8 *msdata = (const u8 *) (req + 1);
char *buf;
size_t len = req_len - sizeof(*req);
int retry = 0;
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received failure");
wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Failure data",
msdata, len);
/*
* eap_mschapv2_failure_txt() expects a nul terminated string, so we
* must allocate a large enough temporary buffer to create that since
* the received message does not include nul termination.
*/
buf = (char *)dup_binstr(msdata, len);
if (buf) {
retry = eap_mschapv2_failure_txt(sm, data, buf);
os_free(buf);
}
ret->ignore = false;
ret->methodState = METHOD_DONE;
ret->decision = DECISION_FAIL;
ret->allowNotifications = false;
if (data->prev_error == ERROR_PASSWD_EXPIRED &&
data->passwd_change_version == 3) {
struct eap_peer_config *config = eap_get_config(sm);
if (config && config->new_password)
return eap_mschapv2_change_password(sm, data, ret, req,
id);
if (config && config->pending_req_new_password)
return NULL;
} else if (retry && data->prev_error == ERROR_AUTHENTICATION_FAILURE) {
/* TODO: could try to retry authentication, e.g, after having
* changed the username/password. In this case, EAP MS-CHAP-v2
* Failure Response would not be sent here. */
return NULL;
}
/* Note: Only op_code of the EAP-MSCHAPV2 header is included in failure
* message. */
resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, 1,
EAP_CODE_RESPONSE, id);
if (resp == NULL)
return NULL;
wpabuf_put_u8(resp, MSCHAPV2_OP_FAILURE); /* op_code */
return resp;
}
static int eap_mschapv2_check_config(struct eap_sm *sm)
{
struct eap_peer_config *config = eap_get_config(sm);
if (config == NULL)
return -1;
if (config->identity == NULL ||
config->identity_len == 0) {
wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: idetity not configured");
return -1;
}
if (config->password == NULL ||
config->password_len == 0) {
wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Password not configured");
return -1;
}
return 0;
}
static int eap_mschapv2_check_mslen(struct eap_sm *sm, size_t len,
const struct eap_mschapv2_hdr *ms)
{
size_t ms_len = WPA_GET_BE16(ms->ms_length);
if (ms_len == len)
return 0;
wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid header: len=%lu "
"ms_len=%lu", (unsigned long) len, (unsigned long) ms_len);
if (sm->workaround) {
/* Some authentication servers use invalid ms_len,
* ignore it for interoperability. */
wpa_printf(MSG_INFO, "EAP-MSCHAPV2: workaround, ignore"
" invalid ms_len %lu (len %lu)",
(unsigned long) ms_len,
(unsigned long) len);
return 0;
}
wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Invalid header len=%lu ms_len=%lu",
(unsigned long)len, (unsigned long)ms_len);
return -1;
}
static void eap_mschapv2_copy_challenge(struct eap_mschapv2_data *data,
const struct wpabuf *reqData)
{
/*
* Store a copy of the challenge message, so that it can be processed
* again in case retry is allowed after a possible failure.
*/
wpabuf_free(data->prev_challenge);
data->prev_challenge = wpabuf_dup(reqData);
}
/**
* eap_mschapv2_process - Process an EAP-MSCHAPv2 request
* @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
* @priv: Pointer to private EAP method data from eap_mschapv2_init()
* @ret: Return values from EAP request validation and processing
* @reqData: EAP request to be processed (eapReqData)
* Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if
* no reply available
*/
static struct wpabuf * eap_mschapv2_process(struct eap_sm *sm, void *priv,
struct eap_method_ret *ret,
const struct wpabuf *reqData)
{
u8 id;
size_t len;
const u8 *pos;
int using_prev_challenge = 0;
const struct eap_mschapv2_hdr *ms;
struct eap_mschapv2_data *data = priv;
struct eap_peer_config *config = eap_get_config(sm);
if (eap_mschapv2_check_config(sm)) {
ret->ignore = true;
return NULL;
}
if (config->mschapv2_retry && data->prev_challenge &&
data->prev_error == ERROR_AUTHENTICATION_FAILURE) {
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Replacing pending packet "
"with the previous challenge");
reqData = data->prev_challenge;
using_prev_challenge = 1;
config->mschapv2_retry = 0;
}
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, reqData,
&len);
if (pos == NULL || len < sizeof(*ms) + 1) {
ret->ignore = true;
return NULL;
}
ms = (const struct eap_mschapv2_hdr *) pos;
if (eap_mschapv2_check_mslen(sm, len, ms)) {
ret->ignore = true;
return NULL;
}
id = eap_get_id(reqData);
wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: RX identifier %d mschapv2_id %d",
id, ms->mschapv2_id);
switch (ms->op_code) {
case MSCHAPV2_OP_CHALLENGE:
if (!using_prev_challenge)
eap_mschapv2_copy_challenge(data, reqData);
return eap_mschapv2_challenge(sm, data, ret, ms, len, id);
case MSCHAPV2_OP_SUCCESS:
return eap_mschapv2_success(sm, data, ret, ms, len, id);
case MSCHAPV2_OP_FAILURE:
return eap_mschapv2_failure(sm, data, ret, ms, len, id);
default:
wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Unknown op code %d - ignored",
ms->op_code);
ret->ignore = TRUE;
return NULL;
}
}
static bool eap_mschapv2_isKeyAvailable(struct eap_sm *sm, void *priv)
{
struct eap_mschapv2_data *data = priv;
return data->success && data->master_key_valid;
}
static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
struct eap_mschapv2_data *data = priv;
u8 *key;
int key_len;
if (!data->master_key_valid || !data->success)
return NULL;
key_len = 2 * MSCHAPV2_KEY_LEN;
key = os_malloc(key_len);
if (key == NULL)
return NULL;
/* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key, i.e.,
* peer MS-MPPE-Send-Key | MS-MPPE-Recv-Key */
get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 1, 0);
get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN,
MSCHAPV2_KEY_LEN, 0, 0);
wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key",
key, key_len);
*len = key_len;
return key;
}
/**
* eap_peer_mschapv2_register - Register EAP-MSCHAPv2 peer method
* Returns: 0 on success, -1 on failure
*
* This function is used to register EAP-MSCHAPv2 peer method into the EAP
* method list.
*/
int eap_peer_mschapv2_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_peer_method_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
"MSCHAPV2");
if (eap == NULL)
return -1;
eap->init = eap_mschapv2_init;
eap->deinit = eap_mschapv2_deinit;
eap->process = eap_mschapv2_process;
eap->isKeyAvailable = eap_mschapv2_isKeyAvailable;
eap->getKey = eap_mschapv2_getKey;
ret = eap_peer_method_register(eap);
if (ret)
eap_peer_method_free(eap);
return ret;
}
#endif /* EAP_MSCHAPv2 */
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