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Introduce new files rsa_internal.[ch] for RSA helper functions

Browse source 
This commit splits off the RSA helper functions into separate headers and
compilation units to have a clearer separation of the public RSA interface,
intended to be used by end-users, and the helper functions which are publicly
provided only for the benefit of designers of alternative RSA implementations.
This commit is contained in:
Hanno Becker 2017-10-11 11:00:19 +01:00
parent 04877a48d4
commit a565f54c4c
8 changed files with 700 additions and 631 deletions
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2
include/mbedtls/config.h
View file

@ -1650,6 +1650,7 @@
* library/ecp.c * library/ecp.c
* library/ecdsa.c * library/ecdsa.c
* library/rsa.c * library/rsa.c
* library/rsa_internal.c
* library/ssl_tls.c * library/ssl_tls.c
* *
* This module is required for RSA, DHM and ECC (ECDH, ECDSA) support. * This module is required for RSA, DHM and ECC (ECDH, ECDSA) support.
@ -2263,6 +2264,7 @@
* Enable the RSA public-key cryptosystem. * Enable the RSA public-key cryptosystem.
* *
* Module: library/rsa.c * Module: library/rsa.c
* library/rsa_internal.c
* Caller: library/ssl_cli.c * Caller: library/ssl_cli.c
* library/ssl_srv.c * library/ssl_srv.c
* library/ssl_tls.c * library/ssl_tls.c

156
include/mbedtls/rsa.h
View file

@ -74,162 +74,6 @@
extern "C" { extern "C" {
#endif #endif
/**
* Helper functions for RSA-related operations on MPI's.
*/
/**
* \brief Compute RSA prime moduli P, Q from public modulus N=PQ
* and a pair of private and public key.
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param N RSA modulus N = PQ, with P, Q to be found
* \param D RSA private exponent
* \param E RSA public exponent
* \param P Pointer to MPI holding first prime factor of N on success
* \param Q Pointer to MPI holding second prime factor of N on success
*
* \return
* - 0 if successful. In this case, P and Q constitute a
* factorization of N.
* - A non-zero error code otherwise.
*
* \note It is neither checked that P, Q are prime nor that
* D, E are modular inverses wrt. P-1 and Q-1. For that,
* use the helper function \c mbedtls_rsa_validate_params.
*
*/
int mbedtls_rsa_deduce_primes( mbedtls_mpi const *N, mbedtls_mpi const *D,
mbedtls_mpi const *E,
mbedtls_mpi *P, mbedtls_mpi *Q );
/**
* \brief Compute RSA private exponent from
* prime moduli and public key.
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param P First prime factor of RSA modulus
* \param Q Second prime factor of RSA modulus
* \param E RSA public exponent
* \param D Pointer to MPI holding the private exponent on success.
*
* \return
* - 0 if successful. In this case, D is set to a simultaneous
* modular inverse of E modulo both P-1 and Q-1.
* - A non-zero error code otherwise.
*
* \note This function does not check whether P and Q are primes.
*
*/
int mbedtls_rsa_deduce_private_exponent( mbedtls_mpi const *P,
mbedtls_mpi const *Q,
mbedtls_mpi const *E,
mbedtls_mpi *D );
/**
* \brief Generate RSA-CRT parameters
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param P First prime factor of N
* \param Q Second prime factor of N
* \param D RSA private exponent
* \param DP Output variable for D modulo P-1
* \param DQ Output variable for D modulo Q-1
* \param QP Output variable for the modular inverse of Q modulo P.
*
* \return 0 on success, non-zero error code otherwise.
*
* \note This function does not check whether P, Q are
* prime and whether D is a valid private exponent.
*
*/
int mbedtls_rsa_deduce_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
const mbedtls_mpi *D, mbedtls_mpi *DP,
mbedtls_mpi *DQ, mbedtls_mpi *QP );
/**
* \brief Check validity of core RSA parameters
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param N RSA modulus N = PQ
* \param P First prime factor of N
* \param Q Second prime factor of N
* \param D RSA private exponent
* \param E RSA public exponent
* \param f_rng PRNG to be used for primality check, or NULL
* \param p_rng PRNG context for f_rng, or NULL
*
* \return
* - 0 if the following conditions are satisfied
* if all relevant parameters are provided:
* - P prime if f_rng != NULL
* - Q prime if f_rng != NULL
* - 1 < N = PQ
* - 1 < D, E < N
* - D and E are modular inverses modulo P-1 and Q-1
* - A non-zero error code otherwise.
*
* \note The function can be used with a restricted set of arguments
* to perform specific checks only. E.g., calling it with
* (-,P,-,-,-) and a PRNG amounts to a primality check for P.
*/
int mbedtls_rsa_validate_params( const mbedtls_mpi *N, const mbedtls_mpi *P,
const mbedtls_mpi *Q, const mbedtls_mpi *D,
const mbedtls_mpi *E,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng );
/**
* \brief Check validity of RSA CRT parameters
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param P First prime factor of RSA modulus
* \param Q Second prime factor of RSA modulus
* \param D RSA private exponent
* \param DP MPI to check for D modulo P-1
* \param DQ MPI to check for D modulo P-1
* \param QP MPI to check for the modular inverse of Q modulo P.
*
* \return
* - 0 if the following conditions are satisfied:
* - D = DP mod P-1 if P, D, DP != NULL
* - Q = DQ mod P-1 if P, D, DQ != NULL
* - QP = Q^-1 mod P if P, Q, QP != NULL
* - \c MBEDTLS_ERR_RSA_KEY_CHECK_FAILED if check failed,
* potentially including \c MBEDTLS_ERR_MPI_XXX if some
* MPI calculations failed.
* - \c MBEDTLS_ERR_RSA_BAD_INPUT_DATA if insufficient
* data was provided to check DP, DQ or QP.
*
* \note The function can be used with a restricted set of arguments
* to perform specific checks only. E.g., calling it with the
* parameters (P, -, D, DP, -, -) will check DP = D mod P-1.
*/
int mbedtls_rsa_validate_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
const mbedtls_mpi *D, const mbedtls_mpi *DP,
const mbedtls_mpi *DQ, const mbedtls_mpi *QP );
/**
* Implementation of RSA interface
*/
#if !defined(MBEDTLS_RSA_ALT) #if !defined(MBEDTLS_RSA_ALT)
/** /**

219
include/mbedtls/rsa_internal.h Normal file
View file

@ -0,0 +1,219 @@
/**
* \file rsa_internal.h
*
* \brief Context-independent RSA helper functions
*
* Copyright (C) 2006-2017, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*
*
* This file declares some RSA-related helper functions useful when
* implementing the RSA interface. They are public and provided in a
* separate compilation unit in order to make it easy for designers of
* alternative RSA implementations to use them in their code, as it is
* conceived that the functionality they provide will be necessary
* for most complete implementations.
*
* End-users of Mbed TLS not intending to re-implement the RSA functionality
* are not expected to get into the need of making use of these functions directly,
* but instead should be able to make do with the implementation of the RSA module.
*
* There are two classes of helper functions:
* (1) Parameter-generating helpers. These are:
* - mbedtls_rsa_deduce_primes
* - mbedtls_rsa_deduce_private_exponent
* - mbedtls_rsa_deduce_crt
* Each of these functions takes a set of core RSA parameters
* and generates some other, or CRT related parameters.
* (2) Parameter-checking helpers. These are:
* - mbedtls_rsa_validate_params
* - mbedtls_rsa_validate_crt
* They take a set of core or CRT related RSA parameters
* and check their validity.
*
*/
#ifndef MBEDTLS_RSA_INTERNAL_H
#define MBEDTLS_RSA_INTERNAL_H
#if !defined(MBEDTLS_CONFIG_FILE)
#include "config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#include "bignum.h"
#if defined(MBEDTLS_RSA_C)
#ifdef __cplusplus
extern "C" {
#endif
/**
* \brief Compute RSA prime moduli P, Q from public modulus N=PQ
* and a pair of private and public key.
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param N RSA modulus N = PQ, with P, Q to be found
* \param D RSA private exponent
* \param E RSA public exponent
* \param P Pointer to MPI holding first prime factor of N on success
* \param Q Pointer to MPI holding second prime factor of N on success
*
* \return
* - 0 if successful. In this case, P and Q constitute a
* factorization of N.
* - A non-zero error code otherwise.
*
* \note It is neither checked that P, Q are prime nor that
* D, E are modular inverses wrt. P-1 and Q-1. For that,
* use the helper function \c mbedtls_rsa_validate_params.
*
*/
int mbedtls_rsa_deduce_primes( mbedtls_mpi const *N, mbedtls_mpi const *D,
mbedtls_mpi const *E,
mbedtls_mpi *P, mbedtls_mpi *Q );
/**
* \brief Compute RSA private exponent from
* prime moduli and public key.
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param P First prime factor of RSA modulus
* \param Q Second prime factor of RSA modulus
* \param E RSA public exponent
* \param D Pointer to MPI holding the private exponent on success.
*
* \return
* - 0 if successful. In this case, D is set to a simultaneous
* modular inverse of E modulo both P-1 and Q-1.
* - A non-zero error code otherwise.
*
* \note This function does not check whether P and Q are primes.
*
*/
int mbedtls_rsa_deduce_private_exponent( mbedtls_mpi const *P,
mbedtls_mpi const *Q,
mbedtls_mpi const *E,
mbedtls_mpi *D );
/**
* \brief Generate RSA-CRT parameters
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param P First prime factor of N
* \param Q Second prime factor of N
* \param D RSA private exponent
* \param DP Output variable for D modulo P-1
* \param DQ Output variable for D modulo Q-1
* \param QP Output variable for the modular inverse of Q modulo P.
*
* \return 0 on success, non-zero error code otherwise.
*
* \note This function does not check whether P, Q are
* prime and whether D is a valid private exponent.
*
*/
int mbedtls_rsa_deduce_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
const mbedtls_mpi *D, mbedtls_mpi *DP,
mbedtls_mpi *DQ, mbedtls_mpi *QP );
/**
* \brief Check validity of core RSA parameters
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param N RSA modulus N = PQ
* \param P First prime factor of N
* \param Q Second prime factor of N
* \param D RSA private exponent
* \param E RSA public exponent
* \param f_rng PRNG to be used for primality check, or NULL
* \param p_rng PRNG context for f_rng, or NULL
*
* \return
* - 0 if the following conditions are satisfied
* if all relevant parameters are provided:
* - P prime if f_rng != NULL
* - Q prime if f_rng != NULL
* - 1 < N = PQ
* - 1 < D, E < N
* - D and E are modular inverses modulo P-1 and Q-1
* - A non-zero error code otherwise.
*
* \note The function can be used with a restricted set of arguments
* to perform specific checks only. E.g., calling it with
* (-,P,-,-,-) and a PRNG amounts to a primality check for P.
*/
int mbedtls_rsa_validate_params( const mbedtls_mpi *N, const mbedtls_mpi *P,
const mbedtls_mpi *Q, const mbedtls_mpi *D,
const mbedtls_mpi *E,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng );
/**
* \brief Check validity of RSA CRT parameters
*
* \note This is a 'static' helper function not operating on
* an RSA context. Alternative implementations need not
* overwrite it.
*
* \param P First prime factor of RSA modulus
* \param Q Second prime factor of RSA modulus
* \param D RSA private exponent
* \param DP MPI to check for D modulo P-1
* \param DQ MPI to check for D modulo P-1
* \param QP MPI to check for the modular inverse of Q modulo P.
*
* \return
* - 0 if the following conditions are satisfied:
* - D = DP mod P-1 if P, D, DP != NULL
* - Q = DQ mod P-1 if P, D, DQ != NULL
* - QP = Q^-1 mod P if P, Q, QP != NULL
* - \c MBEDTLS_ERR_RSA_KEY_CHECK_FAILED if check failed,
* potentially including \c MBEDTLS_ERR_MPI_XXX if some
* MPI calculations failed.
* - \c MBEDTLS_ERR_RSA_BAD_INPUT_DATA if insufficient
* data was provided to check DP, DQ or QP.
*
* \note The function can be used with a restricted set of arguments
* to perform specific checks only. E.g., calling it with the
* parameters (P, -, D, DP, -, -) will check DP = D mod P-1.
*/
int mbedtls_rsa_validate_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
const mbedtls_mpi *D, const mbedtls_mpi *DP,
const mbedtls_mpi *DQ, const mbedtls_mpi *QP );
#endif /* MBEDTLS_RSA_C */
#endif /* rsa_internal.h */

1
library/CMakeLists.txt
View file

@ -48,6 +48,7 @@ set(src_crypto
platform.c platform.c
ripemd160.c ripemd160.c
rsa.c rsa.c
rsa_internal.c
sha1.c sha1.c
sha256.c sha256.c
sha512.c sha512.c

6
library/Makefile
View file

@ -59,9 +59,9 @@ OBJS_CRYPTO= aes.o aesni.o arc4.o \
padlock.o pem.o pk.o \ padlock.o pem.o pk.o \
pk_wrap.o pkcs12.o pkcs5.o \ pk_wrap.o pkcs12.o pkcs5.o \
pkparse.o pkwrite.o platform.o \ pkparse.o pkwrite.o platform.o \
ripemd160.o rsa.o sha1.o \ ripemd160.o rsa_internal.o rsa.o \
sha256.o sha512.o threading.o \ sha1.o sha256.o sha512.o \
timing.o version.o \ threading.o timing.o version.o \
version_features.o xtea.o version_features.o xtea.o
OBJS_X509= certs.o pkcs11.o x509.o \ OBJS_X509= certs.o pkcs11.o x509.o \

475
library/rsa.c
View file

@ -46,6 +46,7 @@
#if defined(MBEDTLS_RSA_C) #if defined(MBEDTLS_RSA_C)
#include "mbedtls/rsa.h" #include "mbedtls/rsa.h"
#include "mbedtls/rsa_internal.h"
#include "mbedtls/oid.h" #include "mbedtls/oid.h"
#include <string.h> #include <string.h>
@ -67,483 +68,13 @@
#define mbedtls_free free #define mbedtls_free free
#endif #endif
#if !defined(MBEDTLS_RSA_ALT)
/* Implementation that should never be optimized out by the compiler */ /* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) { static void mbedtls_zeroize( void *v, size_t n ) {
volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0; volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
} }
/*
* Context-independent RSA helper functions.
*
* There are two classes of helper functions:
* (1) Parameter-generating helpers. These are:
* - mbedtls_rsa_deduce_primes
* - mbedtls_rsa_deduce_private_exponent
* - mbedtls_rsa_deduce_crt
* Each of these functions takes a set of core RSA parameters
* and generates some other, or CRT related parameters.
* (2) Parameter-checking helpers. These are:
* - mbedtls_rsa_validate_params
* - mbedtls_rsa_validate_crt
* They take a set of core or CRT related RSA parameters
* and check their validity.
*
* The helper functions do not use the RSA context structure
* and therefore do not need to be replaced when providing
* an alternative RSA implementation.
*
* Their main purpose is to provide common MPI operations in the context
* of RSA that can be easily shared across multiple implementations.
*/
/*
*
* Given the modulus N=PQ and a pair of public and private
* exponents E and D, respectively, factor N.
*
* Setting F := lcm(P-1,Q-1), the idea is as follows:
*
* (a) For any 1 <= X < N with gcd(X,N)=1, we have X^F = 1 modulo N, so X^(F/2)
* is a square root of 1 in Z/NZ. Since Z/NZ ~= Z/PZ x Z/QZ by CRT and the
* square roots of 1 in Z/PZ and Z/QZ are +1 and -1, this leaves the four
* possibilities X^(F/2) = (+-1, +-1). If it happens that X^(F/2) = (-1,+1)
* or (+1,-1), then gcd(X^(F/2) + 1, N) will be equal to one of the prime
* factors of N.
*
* (b) If we don't know F/2 but (F/2) * K for some odd (!) K, then the same
* construction still applies since (-)^K is the identity on the set of
* roots of 1 in Z/NZ.
*
* The public and private key primitives (-)^E and (-)^D are mutually inverse
* bijections on Z/NZ if and only if (-)^(DE) is the identity on Z/NZ, i.e.
* if and only if DE - 1 is a multiple of F, say DE - 1 = F * L.
* Splitting L = 2^t * K with K odd, we have
*
* DE - 1 = FL = (F/2) * (2^(t+1)) * K,
*
* so (F / 2) * K is among the numbers
*
* (DE - 1) >> 1, (DE - 1) >> 2, ..., (DE - 1) >> ord
*
* where ord is the order of 2 in (DE - 1).
* We can therefore iterate through these numbers apply the construction
* of (a) and (b) above to attempt to factor N.
*
*/
int mbedtls_rsa_deduce_primes( mbedtls_mpi const *N,
mbedtls_mpi const *D, mbedtls_mpi const *E,
mbedtls_mpi *P, mbedtls_mpi *Q )
{
int ret = 0;
uint16_t attempt; /* Number of current attempt */
uint16_t iter; /* Number of squares computed in the current attempt */
uint16_t order; /* Order of 2 in DE - 1 */
mbedtls_mpi T; /* Holds largest odd divisor of DE - 1 */
mbedtls_mpi K; /* During factorization attempts, stores a random integer
* in the range of [0,..,N] */
const unsigned int primes[] = { 2,
3, 5, 7, 11, 13, 17, 19, 23,
29, 31, 37, 41, 43, 47, 53, 59,
61, 67, 71, 73, 79, 83, 89, 97,
101, 103, 107, 109, 113, 127, 131, 137,
139, 149, 151, 157, 163, 167, 173, 179,
181, 191, 193, 197, 199, 211, 223, 227,
229, 233, 239, 241, 251, 257, 263, 269,
271, 277, 281, 283, 293, 307, 311, 313
};
const size_t num_primes = sizeof( primes ) / sizeof( *primes );
if( P == NULL || Q == NULL || P->p != NULL || Q->p != NULL )
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
if( mbedtls_mpi_cmp_int( N, 0 ) <= 0 ||
mbedtls_mpi_cmp_int( D, 1 ) <= 0 ||
mbedtls_mpi_cmp_mpi( D, N ) >= 0 ||
mbedtls_mpi_cmp_int( E, 1 ) <= 0 ||
mbedtls_mpi_cmp_mpi( E, N ) >= 0 )
{
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
}
/*
* Initializations and temporary changes
*/
mbedtls_mpi_init( &K );
mbedtls_mpi_init( &T );
/* T := DE - 1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, D, E ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &T, &T, 1 ) );
if( ( order = mbedtls_mpi_lsb( &T ) ) == 0 )
{
ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
goto cleanup;
}
/* After this operation, T holds the largest odd divisor of DE - 1. */
MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &T, order ) );
/*
* Actual work
*/
/* Skip trying 2 if N == 1 mod 8 */
attempt = 0;
if( N->p[0] % 8 == 1 )
attempt = 1;
for( ; attempt < num_primes; ++attempt )
{
mbedtls_mpi_lset( &K, primes[attempt] );
/* Check if gcd(K,N) = 1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( P, &K, N ) );
if( mbedtls_mpi_cmp_int( P, 1 ) != 0 )
continue;
/* Go through K^T + 1, K^(2T) + 1, K^(4T) + 1, ...
* and check whether they have nontrivial GCD with N. */
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &K, &K, &T, N,
Q /* temporarily use Q for storing Montgomery
* multiplication helper values */ ) );
for( iter = 1; iter < order; ++iter )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( P, &K, N ) );
if( mbedtls_mpi_cmp_int( P, 1 ) == 1 &&
mbedtls_mpi_cmp_mpi( P, N ) == -1 )
{
/*
* Have found a nontrivial divisor P of N.
* Set Q := N / P.
*/
MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( Q, NULL, N, P ) );
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, &K, &K ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, N ) );
}
}
ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
cleanup:
mbedtls_mpi_free( &K );
mbedtls_mpi_free( &T );
return( ret );
}
/*
* Given P, Q and the public exponent E, deduce D.
* This is essentially a modular inversion.
*/
int mbedtls_rsa_deduce_private_exponent( mbedtls_mpi const *P,
mbedtls_mpi const *Q,
mbedtls_mpi const *E,
mbedtls_mpi *D )
{
int ret = 0;
mbedtls_mpi K, L;
if( D == NULL || mbedtls_mpi_cmp_int( D, 0 ) != 0 )
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
if( mbedtls_mpi_cmp_int( P, 1 ) <= 0 ||
mbedtls_mpi_cmp_int( Q, 1 ) <= 0 ||
mbedtls_mpi_cmp_int( E, 0 ) == 0 )
{
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
}
mbedtls_mpi_init( &K );
mbedtls_mpi_init( &L );
/* Temporarily put K := P-1 and L := Q-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &L, Q, 1 ) );
/* Temporarily put D := gcd(P-1, Q-1) */
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( D, &K, &L ) );
/* K := LCM(P-1, Q-1) */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, &K, &L ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( &K, NULL, &K, D ) );
/* Compute modular inverse of E in LCM(P-1, Q-1) */
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( D, E, &K ) );
cleanup:
mbedtls_mpi_free( &K );
mbedtls_mpi_free( &L );
return( ret );
}
/*
* Check that RSA CRT parameters are in accordance with core parameters.
*/
int mbedtls_rsa_validate_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
const mbedtls_mpi *D, const mbedtls_mpi *DP,
const mbedtls_mpi *DQ, const mbedtls_mpi *QP )
{
int ret = 0;
mbedtls_mpi K, L;
mbedtls_mpi_init( &K );
mbedtls_mpi_init( &L );
/* Check that DP - D == 0 mod P - 1 */
if( DP != NULL )
{
if( P == NULL )
{
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &L, DP, D ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &L, &L, &K ) );
if( mbedtls_mpi_cmp_int( &L, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
/* Check that DQ - D == 0 mod Q - 1 */
if( DQ != NULL )
{
if( Q == NULL )
{
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, Q, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &L, DQ, D ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &L, &L, &K ) );
if( mbedtls_mpi_cmp_int( &L, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
/* Check that QP * Q - 1 == 0 mod P */
if( QP != NULL )
{
if( P == NULL || Q == NULL )
{
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, QP, Q ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, P ) );
if( mbedtls_mpi_cmp_int( &K, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
cleanup:
/* Wrap MPI error codes by RSA check failure error code */
if( ret != 0 &&
ret != MBEDTLS_ERR_RSA_KEY_CHECK_FAILED &&
ret != MBEDTLS_ERR_RSA_BAD_INPUT_DATA )
{
ret += MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
}
mbedtls_mpi_free( &K );
mbedtls_mpi_free( &L );
return( ret );
}
/*
* Check that core RSA parameters are sane.
*/
int mbedtls_rsa_validate_params( const mbedtls_mpi *N, const mbedtls_mpi *P,
const mbedtls_mpi *Q, const mbedtls_mpi *D,
const mbedtls_mpi *E,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
int ret = 0;
mbedtls_mpi K, L;
mbedtls_mpi_init( &K );
mbedtls_mpi_init( &L );
/*
* Step 1: If PRNG provided, check that P and Q are prime
*/
#if defined(MBEDTLS_GENPRIME)
if( f_rng != NULL && P != NULL &&
( ret = mbedtls_mpi_is_prime( P, f_rng, p_rng ) ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
if( f_rng != NULL && Q != NULL &&
( ret = mbedtls_mpi_is_prime( Q, f_rng, p_rng ) ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
#else
((void) f_rng);
((void) p_rng);
#endif /* MBEDTLS_GENPRIME */
/*
* Step 2: Check that 1 < N = PQ
*/
if( P != NULL && Q != NULL && N != NULL )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, P, Q ) );
if( mbedtls_mpi_cmp_int( N, 1 ) <= 0 ||
mbedtls_mpi_cmp_mpi( &K, N ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
/*
* Step 3: Check and 1 < D, E < N if present.
*/
if( N != NULL && D != NULL && E != NULL )
{
if ( mbedtls_mpi_cmp_int( D, 1 ) <= 0 ||
mbedtls_mpi_cmp_int( E, 1 ) <= 0 ||
mbedtls_mpi_cmp_mpi( D, N ) >= 0 ||
mbedtls_mpi_cmp_mpi( E, N ) >= 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
/*
* Step 4: Check that D, E are inverse modulo P-1 and Q-1
*/
if( P != NULL && Q != NULL && D != NULL && E != NULL )
{
if( mbedtls_mpi_cmp_int( P, 1 ) <= 0 ||
mbedtls_mpi_cmp_int( Q, 1 ) <= 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
/* Compute DE-1 mod P-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, D, E ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &L, P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, &L ) );
if( mbedtls_mpi_cmp_int( &K, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
/* Compute DE-1 mod Q-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, D, E ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &L, Q, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, &L ) );
if( mbedtls_mpi_cmp_int( &K, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
cleanup:
mbedtls_mpi_free( &K );
mbedtls_mpi_free( &L );
/* Wrap MPI error codes by RSA check failure error code */
if( ret != 0 && ret != MBEDTLS_ERR_RSA_KEY_CHECK_FAILED )
{
ret += MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
}
return( ret );
}
int mbedtls_rsa_deduce_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
const mbedtls_mpi *D, mbedtls_mpi *DP,
mbedtls_mpi *DQ, mbedtls_mpi *QP )
{
int ret = 0;
mbedtls_mpi K;
mbedtls_mpi_init( &K );
/* DP = D mod P-1 */
if( DP != NULL )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( DP, D, &K ) );
}
/* DQ = D mod Q-1 */
if( DQ != NULL )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, Q, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( DQ, D, &K ) );
}
/* QP = Q^{-1} mod P */
if( QP != NULL )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( QP, Q, P ) );
}
cleanup:
mbedtls_mpi_free( &K );
return( ret );
}
/*
* Default RSA interface implementation
*/
#if !defined(MBEDTLS_RSA_ALT)
int mbedtls_rsa_import( mbedtls_rsa_context *ctx, int mbedtls_rsa_import( mbedtls_rsa_context *ctx,
const mbedtls_mpi *N, const mbedtls_mpi *N,
const mbedtls_mpi *P, const mbedtls_mpi *Q, const mbedtls_mpi *P, const mbedtls_mpi *Q,

471
library/rsa_internal.c Normal file
View file

@ -0,0 +1,471 @@
/*
* Helper functions for the RSA module
*
* Copyright (C) 2006-2017, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_RSA_C)
#include "mbedtls/rsa.h"
#include "mbedtls/bignum.h"
#include "mbedtls/rsa_internal.h"
/*
* Compute RSA prime factors from public and private exponents
*
* Summary of algorithm:
* Setting F := lcm(P-1,Q-1), the idea is as follows:
*
* (a) For any 1 <= X < N with gcd(X,N)=1, we have X^F = 1 modulo N, so X^(F/2)
* is a square root of 1 in Z/NZ. Since Z/NZ ~= Z/PZ x Z/QZ by CRT and the
* square roots of 1 in Z/PZ and Z/QZ are +1 and -1, this leaves the four
* possibilities X^(F/2) = (+-1, +-1). If it happens that X^(F/2) = (-1,+1)
* or (+1,-1), then gcd(X^(F/2) + 1, N) will be equal to one of the prime
* factors of N.
*
* (b) If we don't know F/2 but (F/2) * K for some odd (!) K, then the same
* construction still applies since (-)^K is the identity on the set of
* roots of 1 in Z/NZ.
*
* The public and private key primitives (-)^E and (-)^D are mutually inverse
* bijections on Z/NZ if and only if (-)^(DE) is the identity on Z/NZ, i.e.
* if and only if DE - 1 is a multiple of F, say DE - 1 = F * L.
* Splitting L = 2^t * K with K odd, we have
*
* DE - 1 = FL = (F/2) * (2^(t+1)) * K,
*
* so (F / 2) * K is among the numbers
*
* (DE - 1) >> 1, (DE - 1) >> 2, ..., (DE - 1) >> ord
*
* where ord is the order of 2 in (DE - 1).
* We can therefore iterate through these numbers apply the construction
* of (a) and (b) above to attempt to factor N.
*
*/
int mbedtls_rsa_deduce_primes( mbedtls_mpi const *N,
mbedtls_mpi const *D, mbedtls_mpi const *E,
mbedtls_mpi *P, mbedtls_mpi *Q )
{
int ret = 0;
uint16_t attempt; /* Number of current attempt */
uint16_t iter; /* Number of squares computed in the current attempt */
uint16_t order; /* Order of 2 in DE - 1 */
mbedtls_mpi T; /* Holds largest odd divisor of DE - 1 */
mbedtls_mpi K; /* Temporary holding the current candidate */
const unsigned int primes[] = { 2,
3, 5, 7, 11, 13, 17, 19, 23,
29, 31, 37, 41, 43, 47, 53, 59,
61, 67, 71, 73, 79, 83, 89, 97,
101, 103, 107, 109, 113, 127, 131, 137,
139, 149, 151, 157, 163, 167, 173, 179,
181, 191, 193, 197, 199, 211, 223, 227,
229, 233, 239, 241, 251, 257, 263, 269,
271, 277, 281, 283, 293, 307, 311, 313
};
const size_t num_primes = sizeof( primes ) / sizeof( *primes );
if( P == NULL || Q == NULL || P->p != NULL || Q->p != NULL )
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
if( mbedtls_mpi_cmp_int( N, 0 ) <= 0 ||
mbedtls_mpi_cmp_int( D, 1 ) <= 0 ||
mbedtls_mpi_cmp_mpi( D, N ) >= 0 ||
mbedtls_mpi_cmp_int( E, 1 ) <= 0 ||
mbedtls_mpi_cmp_mpi( E, N ) >= 0 )
{
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
}
/*
* Initializations and temporary changes
*/
mbedtls_mpi_init( &K );
mbedtls_mpi_init( &T );
/* T := DE - 1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, D, E ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &T, &T, 1 ) );
if( ( order = mbedtls_mpi_lsb( &T ) ) == 0 )
{
ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
goto cleanup;
}
/* After this operation, T holds the largest odd divisor of DE - 1. */
MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &T, order ) );
/*
* Actual work
*/
/* Skip trying 2 if N == 1 mod 8 */
attempt = 0;
if( N->p[0] % 8 == 1 )
attempt = 1;
for( ; attempt < num_primes; ++attempt )
{
mbedtls_mpi_lset( &K, primes[attempt] );
/* Check if gcd(K,N) = 1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( P, &K, N ) );
if( mbedtls_mpi_cmp_int( P, 1 ) != 0 )
continue;
/* Go through K^T + 1, K^(2T) + 1, K^(4T) + 1, ...
* and check whether they have nontrivial GCD with N. */
MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &K, &K, &T, N,
Q /* temporarily use Q for storing Montgomery
* multiplication helper values */ ) );
for( iter = 1; iter < order; ++iter )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( P, &K, N ) );
if( mbedtls_mpi_cmp_int( P, 1 ) == 1 &&
mbedtls_mpi_cmp_mpi( P, N ) == -1 )
{
/*
* Have found a nontrivial divisor P of N.
* Set Q := N / P.
*/
MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( Q, NULL, N, P ) );
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, &K, &K ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, N ) );
}
}
ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA;
cleanup:
mbedtls_mpi_free( &K );
mbedtls_mpi_free( &T );
return( ret );
}
/*
* Given P, Q and the public exponent E, deduce D.
* This is essentially a modular inversion.
*/
int mbedtls_rsa_deduce_private_exponent( mbedtls_mpi const *P,
mbedtls_mpi const *Q,
mbedtls_mpi const *E,
mbedtls_mpi *D )
{
int ret = 0;
mbedtls_mpi K, L;
if( D == NULL || mbedtls_mpi_cmp_int( D, 0 ) != 0 )
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
if( mbedtls_mpi_cmp_int( P, 1 ) <= 0 ||
mbedtls_mpi_cmp_int( Q, 1 ) <= 0 ||
mbedtls_mpi_cmp_int( E, 0 ) == 0 )
{
return( MBEDTLS_ERR_MPI_BAD_INPUT_DATA );
}
mbedtls_mpi_init( &K );
mbedtls_mpi_init( &L );
/* Temporarily put K := P-1 and L := Q-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &L, Q, 1 ) );
/* Temporarily put D := gcd(P-1, Q-1) */
MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( D, &K, &L ) );
/* K := LCM(P-1, Q-1) */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, &K, &L ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( &K, NULL, &K, D ) );
/* Compute modular inverse of E in LCM(P-1, Q-1) */
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( D, E, &K ) );
cleanup:
mbedtls_mpi_free( &K );
mbedtls_mpi_free( &L );
return( ret );
}
/*
* Check that RSA CRT parameters are in accordance with core parameters.
*/
int mbedtls_rsa_validate_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
const mbedtls_mpi *D, const mbedtls_mpi *DP,
const mbedtls_mpi *DQ, const mbedtls_mpi *QP )
{
int ret = 0;
mbedtls_mpi K, L;
mbedtls_mpi_init( &K );
mbedtls_mpi_init( &L );
/* Check that DP - D == 0 mod P - 1 */
if( DP != NULL )
{
if( P == NULL )
{
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &L, DP, D ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &L, &L, &K ) );
if( mbedtls_mpi_cmp_int( &L, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
/* Check that DQ - D == 0 mod Q - 1 */
if( DQ != NULL )
{
if( Q == NULL )
{
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, Q, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &L, DQ, D ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &L, &L, &K ) );
if( mbedtls_mpi_cmp_int( &L, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
/* Check that QP * Q - 1 == 0 mod P */
if( QP != NULL )
{
if( P == NULL || Q == NULL )
{
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
goto cleanup;
}
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, QP, Q ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, P ) );
if( mbedtls_mpi_cmp_int( &K, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
cleanup:
/* Wrap MPI error codes by RSA check failure error code */
if( ret != 0 &&
ret != MBEDTLS_ERR_RSA_KEY_CHECK_FAILED &&
ret != MBEDTLS_ERR_RSA_BAD_INPUT_DATA )
{
ret += MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
}
mbedtls_mpi_free( &K );
mbedtls_mpi_free( &L );
return( ret );
}
/*
* Check that core RSA parameters are sane.
*/
int mbedtls_rsa_validate_params( const mbedtls_mpi *N, const mbedtls_mpi *P,
const mbedtls_mpi *Q, const mbedtls_mpi *D,
const mbedtls_mpi *E,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
int ret = 0;
mbedtls_mpi K, L;
mbedtls_mpi_init( &K );
mbedtls_mpi_init( &L );
/*
* Step 1: If PRNG provided, check that P and Q are prime
*/
#if defined(MBEDTLS_GENPRIME)
if( f_rng != NULL && P != NULL &&
( ret = mbedtls_mpi_is_prime( P, f_rng, p_rng ) ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
if( f_rng != NULL && Q != NULL &&
( ret = mbedtls_mpi_is_prime( Q, f_rng, p_rng ) ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
#else
((void) f_rng);
((void) p_rng);
#endif /* MBEDTLS_GENPRIME */
/*
* Step 2: Check that 1 < N = PQ
*/
if( P != NULL && Q != NULL && N != NULL )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, P, Q ) );
if( mbedtls_mpi_cmp_int( N, 1 ) <= 0 ||
mbedtls_mpi_cmp_mpi( &K, N ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
/*
* Step 3: Check and 1 < D, E < N if present.
*/
if( N != NULL && D != NULL && E != NULL )
{
if ( mbedtls_mpi_cmp_int( D, 1 ) <= 0 ||
mbedtls_mpi_cmp_int( E, 1 ) <= 0 ||
mbedtls_mpi_cmp_mpi( D, N ) >= 0 ||
mbedtls_mpi_cmp_mpi( E, N ) >= 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
/*
* Step 4: Check that D, E are inverse modulo P-1 and Q-1
*/
if( P != NULL && Q != NULL && D != NULL && E != NULL )
{
if( mbedtls_mpi_cmp_int( P, 1 ) <= 0 ||
mbedtls_mpi_cmp_int( Q, 1 ) <= 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
/* Compute DE-1 mod P-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, D, E ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &L, P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, &L ) );
if( mbedtls_mpi_cmp_int( &K, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
/* Compute DE-1 mod Q-1 */
MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &K, D, E ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, &K, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &L, Q, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &K, &K, &L ) );
if( mbedtls_mpi_cmp_int( &K, 0 ) != 0 )
{
ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
goto cleanup;
}
}
cleanup:
mbedtls_mpi_free( &K );
mbedtls_mpi_free( &L );
/* Wrap MPI error codes by RSA check failure error code */
if( ret != 0 && ret != MBEDTLS_ERR_RSA_KEY_CHECK_FAILED )
{
ret += MBEDTLS_ERR_RSA_KEY_CHECK_FAILED;
}
return( ret );
}
int mbedtls_rsa_deduce_crt( const mbedtls_mpi *P, const mbedtls_mpi *Q,
const mbedtls_mpi *D, mbedtls_mpi *DP,
mbedtls_mpi *DQ, mbedtls_mpi *QP )
{
int ret = 0;
mbedtls_mpi K;
mbedtls_mpi_init( &K );
/* DP = D mod P-1 */
if( DP != NULL )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, P, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( DP, D, &K ) );
}
/* DQ = D mod Q-1 */
if( DQ != NULL )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &K, Q, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( DQ, D, &K ) );
}
/* QP = Q^{-1} mod P */
if( QP != NULL )
{
MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( QP, Q, P ) );
}
cleanup:
mbedtls_mpi_free( &K );
return( ret );
}
#endif /* MBEDTLS_RSA_C */

1
tests/suites/test_suite_rsa.function
View file

@ -1,5 +1,6 @@
/* BEGIN_HEADER */ /* BEGIN_HEADER */
#include "mbedtls/rsa.h" #include "mbedtls/rsa.h"
#include "mbedtls/rsa_internal.h"
#include "mbedtls/md2.h" #include "mbedtls/md2.h"
#include "mbedtls/md4.h" #include "mbedtls/md4.h"
#include "mbedtls/md5.h" #include "mbedtls/md5.h"