mbedtls_mpi_read_string() function

The destination MPI. This must point to an initialized MPI.

The numeric base of the input string.

Null-terminated string buffer.

This function frees the components of an MPI context.

Initialize an MPI context. This makes the MPI ready to be set or freed, but does not define a value for the MPI.

Compare an MPI with an integer.

Make a copy of an MPI.

Compare two MPIs.

Store integer value in MPI.

Enlarge an MPI to the specified number of limbs.

Perform a multiplication of two MPIs: X = A * B

Perform a modular reduction. R = A mod B

Perform a signed subtraction of MPIs: X = A - B

Perform a right-shift on an MPI: X >>= count

Perform a signed subtraction of an MPI and an integer: X = A - b

Return the number of bits up to and including the most significant bit of value \c 1. * \note This is same as the one-based index of the most significant bit of value \c 1.

Perform a signed addition of MPIs: X = A + B

Import an MPI from unsigned big endian binary data.

Export X into unsigned binary data, big endian. Always fills the whole buffer, which will start with zeros if the number is smaller.

Get a specific bit from an MPI.

Modify a specific bit in an MPI.

Montgomery multiplication: A = A * B * R^-1 mod N (HAC 14.36)

Perform an unsigned subtraction of MPIs: X = |A| - |B|

Perform a left-shift on an MPI: X <<= count

Return the total size of an MPI value in bytes.

Compute the modular inverse: X = A^-1 mod N

Perform a sliding-window exponentiation: X = A^E mod N

Perform a multiplication of an MPI with an unsigned integer: X = A * b

Perform a safe conditional copy of MPI which doesn't reveal whether the condition was true or not. \warning If \p assign is neither 0 nor 1, the result of this function is indeterminate, and the resulting value in \p X might be neither its original value nor the value in \p Y.

Fill an MPI with a number of random bytes.

Return the number of bits of value \c 0 before the least significant bit of value \c 1.

This function performs multiplication of a point by an integer: \p R = \p m * \p P in a restartable way. \see mbedtls_ecp_mul()

This function imports a set of core parameters into an RSA context. Any sequence of calls to this function should be followed by a call to mbedtls_rsa_complete(), which checks and completes the provided information to a ready-for-use public or private RSA key.

Perform a safe conditional swap which doesn't reveal whether the condition was true or not. \warning If \p swap is neither 0 nor 1, the result of this function is indeterminate, and both \p X and \p Y might end up with values different to either of the original ones.

Perform an unsigned addition of MPIs: X = |A| + |B|

Perform a division with remainder of two MPIs: A = Q * B + R

Compute the greatest common divisor: G = gcd(A, B)

This function generates a private key.

Select an MPI from a table without leaking the index. This is functionally equivalent to mbedtls_mpi_copy(R, T[idx]) except it reads the entire table in order to avoid leaking the value of idx to an attacker able to observe memory access patterns.

Retrieve an integer ASN.1 tag and its value. Updates the pointer to immediately behind the full tag.

This function resizes an MPI downwards, keeping at least the specified number of limbs. If \c X is smaller than \c nblimbs, it is resized up instead.

Generate a random number uniformly in a range. This function generates a random number between \p min inclusive and \p N exclusive. The procedure complies with RFC 6979 §3.3 (deterministic ECDSA) when the RNG is a suitably parametrized instance of HMAC_DRBG and \p min is \c 1.

Perform a signed addition of an MPI and an integer: X = A + b

Export X into unsigned binary data, little endian. Always fills the whole buffer, which will end with zeros if the number is smaller.

This function performs a scalar multiplication of a point by an integer: \p R = \p m * \p P. It is not thread-safe to use same group in multiple threads.

This function checks that an \c mbedtls_mpi is a valid private key for this curve.

Compare the absolute values of two MPIs.

Check if an MPI is less than the other in constant time.

Import X from unsigned binary data, little endian

Write an arbitrary-precision number (#MBEDTLS_ASN1_INTEGER) in ASN.1 format.

This function generates an ECP keypair.

This function performs multiplication and addition of two points by integers: \p R = \p m * \p P + \p n * \p Q in a restartable way. \see \c mbedtls_ecp_muladd()

This function generates an ECDH keypair on an elliptic curve. This function performs the first of two core computations implemented during the ECDH key exchange. The second core computation is performed by mbedtls_ecdh_compute_shared(). \see ecp.h

Calculate the square of the Montgomery constant. (Needed for conversion and operations in Montgomery form.)

Perform a division with remainder of an MPI by an integer: A = Q * b + R

Perform a modular reduction with respect to an integer. r = A mod b

This function generates a keypair with a configurable base point.

This function exports the core parameters of an RSA key. If this function runs successfully, the non-NULL buffers pointed to by \p N, \p P, \p Q, \p D, and \p E are fully written, with additional unused space filled leading by zero Bytes. Possible reasons for returning #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED: An alternative RSA implementation is in use, which stores the key externally, and either cannot or should not export it into RAM. A SW or HW implementation might not support a certain deduction. For example, \p P, \p Q from \p N, \p D, and \p E if the former are not part of the implementation. If the function fails due to an unsupported operation, the RSA context stays intact and remains usable.

This function computes the shared secret. This function performs the second of two core computations implemented during the ECDH key exchange. The first core computation is performed by mbedtls_ecdh_gen_public(). \see ecp.h

Compute RSA prime moduli P, Q from public modulus N=PQ and a pair of private and public key.

Check validity of RSA CRT parameters

Compute RSA private exponent from prime moduli and public key.

Generate RSA-CRT parameters

Check validity of core RSA parameters

Swap the contents of two MPIs.

Export an MPI to an ASCII string.

This function performs multiplication and addition of two points by integers: \p R = \p m * \p P + \p n * \p Q It is not thread-safe to use same group in multiple threads.

This function exports CRT parameters of a private RSA key.

This function computes the ECDSA signature of a previously-hashed message. \see ecp.h

This function verifies the ECDSA signature of a previously-hashed message. \see ecp.h

Generate a prime number.

Miller-Rabin primality test. \warning If \p X is potentially generated by an adversary, for example when validating cryptographic parameters that you didn't generate yourself and that are supposed to be prime, then \p rounds should be at least the half of the security strength of the cryptographic algorithm. On the other hand, if \p X is chosen uniformly or non-adversarially (as is the case when mbedtls_mpi_gen_prime calls this function), then \p rounds can be much lower.

Print a MPI variable to the debug output. This function is always used through the MBEDTLS_SSL_DEBUG_MPI() macro, which supplies the ssl context, file and line number parameters. \attention This function is intended for INTERNAL usage within the library only.