diff options
Diffstat (limited to 'thirdparty/mbedtls/library/rsa.c')
| -rw-r--r-- | thirdparty/mbedtls/library/rsa.c | 2382 |
1 files changed, 2382 insertions, 0 deletions
diff --git a/thirdparty/mbedtls/library/rsa.c b/thirdparty/mbedtls/library/rsa.c new file mode 100644 index 0000000000..c9f7ba91b6 --- /dev/null +++ b/thirdparty/mbedtls/library/rsa.c @@ -0,0 +1,2382 @@ +/* + * The RSA public-key cryptosystem + * + * Copyright (C) 2006-2015, 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) + */ + +/* + * The following sources were referenced in the design of this implementation + * of the RSA algorithm: + * + * [1] A method for obtaining digital signatures and public-key cryptosystems + * R Rivest, A Shamir, and L Adleman + * http://people.csail.mit.edu/rivest/pubs.html#RSA78 + * + * [2] Handbook of Applied Cryptography - 1997, Chapter 8 + * Menezes, van Oorschot and Vanstone + * + * [3] Malware Guard Extension: Using SGX to Conceal Cache Attacks + * Michael Schwarz, Samuel Weiser, Daniel Gruss, Clémentine Maurice and + * Stefan Mangard + * https://arxiv.org/abs/1702.08719v2 + * + */ + +#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/rsa_internal.h" +#include "mbedtls/oid.h" + +#include <string.h> + +#if defined(MBEDTLS_PKCS1_V21) +#include "mbedtls/md.h" +#endif + +#if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__) +#include <stdlib.h> +#endif + +#if defined(MBEDTLS_PLATFORM_C) +#include "mbedtls/platform.h" +#else +#include <stdio.h> +#define mbedtls_printf printf +#define mbedtls_calloc calloc +#define mbedtls_free free +#endif + +#if !defined(MBEDTLS_RSA_ALT) + +/* Implementation that should never be optimized out by the compiler */ +static void mbedtls_zeroize( void *v, size_t n ) { + volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0; +} + +/* constant-time buffer comparison */ +static inline int mbedtls_safer_memcmp( const void *a, const void *b, size_t n ) +{ + size_t i; + const unsigned char *A = (const unsigned char *) a; + const unsigned char *B = (const unsigned char *) b; + unsigned char diff = 0; + + for( i = 0; i < n; i++ ) + diff |= A[i] ^ B[i]; + + return( diff ); +} + +int mbedtls_rsa_import( mbedtls_rsa_context *ctx, + const mbedtls_mpi *N, + const mbedtls_mpi *P, const mbedtls_mpi *Q, + const mbedtls_mpi *D, const mbedtls_mpi *E ) +{ + int ret; + + if( ( N != NULL && ( ret = mbedtls_mpi_copy( &ctx->N, N ) ) != 0 ) || + ( P != NULL && ( ret = mbedtls_mpi_copy( &ctx->P, P ) ) != 0 ) || + ( Q != NULL && ( ret = mbedtls_mpi_copy( &ctx->Q, Q ) ) != 0 ) || + ( D != NULL && ( ret = mbedtls_mpi_copy( &ctx->D, D ) ) != 0 ) || + ( E != NULL && ( ret = mbedtls_mpi_copy( &ctx->E, E ) ) != 0 ) ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret ); + } + + if( N != NULL ) + ctx->len = mbedtls_mpi_size( &ctx->N ); + + return( 0 ); +} + +int mbedtls_rsa_import_raw( mbedtls_rsa_context *ctx, + unsigned char const *N, size_t N_len, + unsigned char const *P, size_t P_len, + unsigned char const *Q, size_t Q_len, + unsigned char const *D, size_t D_len, + unsigned char const *E, size_t E_len ) +{ + int ret = 0; + + if( N != NULL ) + { + MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->N, N, N_len ) ); + ctx->len = mbedtls_mpi_size( &ctx->N ); + } + + if( P != NULL ) + MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->P, P, P_len ) ); + + if( Q != NULL ) + MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->Q, Q, Q_len ) ); + + if( D != NULL ) + MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->D, D, D_len ) ); + + if( E != NULL ) + MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &ctx->E, E, E_len ) ); + +cleanup: + + if( ret != 0 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret ); + + return( 0 ); +} + +/* + * Checks whether the context fields are set in such a way + * that the RSA primitives will be able to execute without error. + * It does *not* make guarantees for consistency of the parameters. + */ +static int rsa_check_context( mbedtls_rsa_context const *ctx, int is_priv, + int blinding_needed ) +{ +#if !defined(MBEDTLS_RSA_NO_CRT) + /* blinding_needed is only used for NO_CRT to decide whether + * P,Q need to be present or not. */ + ((void) blinding_needed); +#endif + + if( ctx->len != mbedtls_mpi_size( &ctx->N ) || + ctx->len > MBEDTLS_MPI_MAX_SIZE ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + } + + /* + * 1. Modular exponentiation needs positive, odd moduli. + */ + + /* Modular exponentiation wrt. N is always used for + * RSA public key operations. */ + if( mbedtls_mpi_cmp_int( &ctx->N, 0 ) <= 0 || + mbedtls_mpi_get_bit( &ctx->N, 0 ) == 0 ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + } + +#if !defined(MBEDTLS_RSA_NO_CRT) + /* Modular exponentiation for P and Q is only + * used for private key operations and if CRT + * is used. */ + if( is_priv && + ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) <= 0 || + mbedtls_mpi_get_bit( &ctx->P, 0 ) == 0 || + mbedtls_mpi_cmp_int( &ctx->Q, 0 ) <= 0 || + mbedtls_mpi_get_bit( &ctx->Q, 0 ) == 0 ) ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + } +#endif /* !MBEDTLS_RSA_NO_CRT */ + + /* + * 2. Exponents must be positive + */ + + /* Always need E for public key operations */ + if( mbedtls_mpi_cmp_int( &ctx->E, 0 ) <= 0 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + +#if defined(MBEDTLS_RSA_NO_CRT) + /* For private key operations, use D or DP & DQ + * as (unblinded) exponents. */ + if( is_priv && mbedtls_mpi_cmp_int( &ctx->D, 0 ) <= 0 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); +#else + if( is_priv && + ( mbedtls_mpi_cmp_int( &ctx->DP, 0 ) <= 0 || + mbedtls_mpi_cmp_int( &ctx->DQ, 0 ) <= 0 ) ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + } +#endif /* MBEDTLS_RSA_NO_CRT */ + + /* Blinding shouldn't make exponents negative either, + * so check that P, Q >= 1 if that hasn't yet been + * done as part of 1. */ +#if defined(MBEDTLS_RSA_NO_CRT) + if( is_priv && blinding_needed && + ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) <= 0 || + mbedtls_mpi_cmp_int( &ctx->Q, 0 ) <= 0 ) ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + } +#endif + + /* It wouldn't lead to an error if it wasn't satisfied, + * but check for QP >= 1 nonetheless. */ +#if !defined(MBEDTLS_RSA_NO_CRT) + if( is_priv && + mbedtls_mpi_cmp_int( &ctx->QP, 0 ) <= 0 ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + } +#endif + + return( 0 ); +} + +int mbedtls_rsa_complete( mbedtls_rsa_context *ctx ) +{ + int ret = 0; + + const int have_N = ( mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 ); + const int have_P = ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 ); + const int have_Q = ( mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 ); + const int have_D = ( mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 ); + const int have_E = ( mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0 ); + + /* + * Check whether provided parameters are enough + * to deduce all others. The following incomplete + * parameter sets for private keys are supported: + * + * (1) P, Q missing. + * (2) D and potentially N missing. + * + */ + + const int n_missing = have_P && have_Q && have_D && have_E; + const int pq_missing = have_N && !have_P && !have_Q && have_D && have_E; + const int d_missing = have_P && have_Q && !have_D && have_E; + const int is_pub = have_N && !have_P && !have_Q && !have_D && have_E; + + /* These three alternatives are mutually exclusive */ + const int is_priv = n_missing || pq_missing || d_missing; + + if( !is_priv && !is_pub ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + /* + * Step 1: Deduce N if P, Q are provided. + */ + + if( !have_N && have_P && have_Q ) + { + if( ( ret = mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P, + &ctx->Q ) ) != 0 ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret ); + } + + ctx->len = mbedtls_mpi_size( &ctx->N ); + } + + /* + * Step 2: Deduce and verify all remaining core parameters. + */ + + if( pq_missing ) + { + ret = mbedtls_rsa_deduce_primes( &ctx->N, &ctx->E, &ctx->D, + &ctx->P, &ctx->Q ); + if( ret != 0 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret ); + + } + else if( d_missing ) + { + if( ( ret = mbedtls_rsa_deduce_private_exponent( &ctx->P, + &ctx->Q, + &ctx->E, + &ctx->D ) ) != 0 ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret ); + } + } + + /* + * Step 3: Deduce all additional parameters specific + * to our current RSA implementation. + */ + +#if !defined(MBEDTLS_RSA_NO_CRT) + if( is_priv ) + { + ret = mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D, + &ctx->DP, &ctx->DQ, &ctx->QP ); + if( ret != 0 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret ); + } +#endif /* MBEDTLS_RSA_NO_CRT */ + + /* + * Step 3: Basic sanity checks + */ + + return( rsa_check_context( ctx, is_priv, 1 ) ); +} + +int mbedtls_rsa_export_raw( const mbedtls_rsa_context *ctx, + unsigned char *N, size_t N_len, + unsigned char *P, size_t P_len, + unsigned char *Q, size_t Q_len, + unsigned char *D, size_t D_len, + unsigned char *E, size_t E_len ) +{ + int ret = 0; + + /* Check if key is private or public */ + const int is_priv = + mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0; + + if( !is_priv ) + { + /* If we're trying to export private parameters for a public key, + * something must be wrong. */ + if( P != NULL || Q != NULL || D != NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + } + + if( N != NULL ) + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->N, N, N_len ) ); + + if( P != NULL ) + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->P, P, P_len ) ); + + if( Q != NULL ) + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->Q, Q, Q_len ) ); + + if( D != NULL ) + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->D, D, D_len ) ); + + if( E != NULL ) + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->E, E, E_len ) ); + +cleanup: + + return( ret ); +} + +int mbedtls_rsa_export( const mbedtls_rsa_context *ctx, + mbedtls_mpi *N, mbedtls_mpi *P, mbedtls_mpi *Q, + mbedtls_mpi *D, mbedtls_mpi *E ) +{ + int ret; + + /* Check if key is private or public */ + int is_priv = + mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0; + + if( !is_priv ) + { + /* If we're trying to export private parameters for a public key, + * something must be wrong. */ + if( P != NULL || Q != NULL || D != NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + } + + /* Export all requested core parameters. */ + + if( ( N != NULL && ( ret = mbedtls_mpi_copy( N, &ctx->N ) ) != 0 ) || + ( P != NULL && ( ret = mbedtls_mpi_copy( P, &ctx->P ) ) != 0 ) || + ( Q != NULL && ( ret = mbedtls_mpi_copy( Q, &ctx->Q ) ) != 0 ) || + ( D != NULL && ( ret = mbedtls_mpi_copy( D, &ctx->D ) ) != 0 ) || + ( E != NULL && ( ret = mbedtls_mpi_copy( E, &ctx->E ) ) != 0 ) ) + { + return( ret ); + } + + return( 0 ); +} + +/* + * Export CRT parameters + * This must also be implemented if CRT is not used, for being able to + * write DER encoded RSA keys. The helper function mbedtls_rsa_deduce_crt + * can be used in this case. + */ +int mbedtls_rsa_export_crt( const mbedtls_rsa_context *ctx, + mbedtls_mpi *DP, mbedtls_mpi *DQ, mbedtls_mpi *QP ) +{ + int ret; + + /* Check if key is private or public */ + int is_priv = + mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 && + mbedtls_mpi_cmp_int( &ctx->E, 0 ) != 0; + + if( !is_priv ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + +#if !defined(MBEDTLS_RSA_NO_CRT) + /* Export all requested blinding parameters. */ + if( ( DP != NULL && ( ret = mbedtls_mpi_copy( DP, &ctx->DP ) ) != 0 ) || + ( DQ != NULL && ( ret = mbedtls_mpi_copy( DQ, &ctx->DQ ) ) != 0 ) || + ( QP != NULL && ( ret = mbedtls_mpi_copy( QP, &ctx->QP ) ) != 0 ) ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret ); + } +#else + if( ( ret = mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D, + DP, DQ, QP ) ) != 0 ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA + ret ); + } +#endif + + return( 0 ); +} + +/* + * Initialize an RSA context + */ +void mbedtls_rsa_init( mbedtls_rsa_context *ctx, + int padding, + int hash_id ) +{ + memset( ctx, 0, sizeof( mbedtls_rsa_context ) ); + + mbedtls_rsa_set_padding( ctx, padding, hash_id ); + +#if defined(MBEDTLS_THREADING_C) + mbedtls_mutex_init( &ctx->mutex ); +#endif +} + +/* + * Set padding for an existing RSA context + */ +void mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding, int hash_id ) +{ + ctx->padding = padding; + ctx->hash_id = hash_id; +} + +/* + * Get length in bytes of RSA modulus + */ + +size_t mbedtls_rsa_get_len( const mbedtls_rsa_context *ctx ) +{ + return( ctx->len ); +} + + +#if defined(MBEDTLS_GENPRIME) + +/* + * Generate an RSA keypair + */ +int mbedtls_rsa_gen_key( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + unsigned int nbits, int exponent ) +{ + int ret; + mbedtls_mpi H, G; + + if( f_rng == NULL || nbits < 128 || exponent < 3 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + if( nbits % 2 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + mbedtls_mpi_init( &H ); + mbedtls_mpi_init( &G ); + + /* + * find primes P and Q with Q < P so that: + * GCD( E, (P-1)*(Q-1) ) == 1 + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->E, exponent ) ); + + do + { + MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->P, nbits >> 1, 0, + f_rng, p_rng ) ); + + MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, nbits >> 1, 0, + f_rng, p_rng ) ); + + if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) == 0 ) + continue; + + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) ); + if( mbedtls_mpi_bitlen( &ctx->N ) != nbits ) + continue; + + if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) < 0 ) + mbedtls_mpi_swap( &ctx->P, &ctx->Q ); + + /* Temporarily replace P,Q by P-1, Q-1 */ + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->P, &ctx->P, 1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &ctx->Q, &ctx->Q, 1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &ctx->P, &ctx->Q ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H ) ); + } + while( mbedtls_mpi_cmp_int( &G, 1 ) != 0 ); + + /* Restore P,Q */ + MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->P, &ctx->P, 1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &ctx->Q, &ctx->Q, 1 ) ); + + ctx->len = mbedtls_mpi_size( &ctx->N ); + + /* + * D = E^-1 mod ((P-1)*(Q-1)) + * DP = D mod (P - 1) + * DQ = D mod (Q - 1) + * QP = Q^-1 mod P + */ + + MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->D, &ctx->E, &H ) ); + +#if !defined(MBEDTLS_RSA_NO_CRT) + MBEDTLS_MPI_CHK( mbedtls_rsa_deduce_crt( &ctx->P, &ctx->Q, &ctx->D, + &ctx->DP, &ctx->DQ, &ctx->QP ) ); +#endif /* MBEDTLS_RSA_NO_CRT */ + + /* Double-check */ + MBEDTLS_MPI_CHK( mbedtls_rsa_check_privkey( ctx ) ); + +cleanup: + + mbedtls_mpi_free( &H ); + mbedtls_mpi_free( &G ); + + if( ret != 0 ) + { + mbedtls_rsa_free( ctx ); + return( MBEDTLS_ERR_RSA_KEY_GEN_FAILED + ret ); + } + + return( 0 ); +} + +#endif /* MBEDTLS_GENPRIME */ + +/* + * Check a public RSA key + */ +int mbedtls_rsa_check_pubkey( const mbedtls_rsa_context *ctx ) +{ + if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) != 0 ) + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + + if( mbedtls_mpi_bitlen( &ctx->N ) < 128 ) + { + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + } + + if( mbedtls_mpi_get_bit( &ctx->E, 0 ) == 0 || + mbedtls_mpi_bitlen( &ctx->E ) < 2 || + mbedtls_mpi_cmp_mpi( &ctx->E, &ctx->N ) >= 0 ) + { + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + } + + return( 0 ); +} + +/* + * Check for the consistency of all fields in an RSA private key context + */ +int mbedtls_rsa_check_privkey( const mbedtls_rsa_context *ctx ) +{ + if( mbedtls_rsa_check_pubkey( ctx ) != 0 || + rsa_check_context( ctx, 1 /* private */, 1 /* blinding */ ) != 0 ) + { + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + } + + if( mbedtls_rsa_validate_params( &ctx->N, &ctx->P, &ctx->Q, + &ctx->D, &ctx->E, NULL, NULL ) != 0 ) + { + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + } + +#if !defined(MBEDTLS_RSA_NO_CRT) + else if( mbedtls_rsa_validate_crt( &ctx->P, &ctx->Q, &ctx->D, + &ctx->DP, &ctx->DQ, &ctx->QP ) != 0 ) + { + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + } +#endif + + return( 0 ); +} + +/* + * Check if contexts holding a public and private key match + */ +int mbedtls_rsa_check_pub_priv( const mbedtls_rsa_context *pub, + const mbedtls_rsa_context *prv ) +{ + if( mbedtls_rsa_check_pubkey( pub ) != 0 || + mbedtls_rsa_check_privkey( prv ) != 0 ) + { + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + } + + if( mbedtls_mpi_cmp_mpi( &pub->N, &prv->N ) != 0 || + mbedtls_mpi_cmp_mpi( &pub->E, &prv->E ) != 0 ) + { + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + } + + return( 0 ); +} + +/* + * Do an RSA public key operation + */ +int mbedtls_rsa_public( mbedtls_rsa_context *ctx, + const unsigned char *input, + unsigned char *output ) +{ + int ret; + size_t olen; + mbedtls_mpi T; + + if( rsa_check_context( ctx, 0 /* public */, 0 /* no blinding */ ) ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + mbedtls_mpi_init( &T ); + +#if defined(MBEDTLS_THREADING_C) + if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 ) + return( ret ); +#endif + + MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) ); + + if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 ) + { + ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA; + goto cleanup; + } + + olen = ctx->len; + MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, &ctx->E, &ctx->N, &ctx->RN ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &T, output, olen ) ); + +cleanup: +#if defined(MBEDTLS_THREADING_C) + if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 ) + return( MBEDTLS_ERR_THREADING_MUTEX_ERROR ); +#endif + + mbedtls_mpi_free( &T ); + + if( ret != 0 ) + return( MBEDTLS_ERR_RSA_PUBLIC_FAILED + ret ); + + return( 0 ); +} + +/* + * Generate or update blinding values, see section 10 of: + * KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA, + * DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer + * Berlin Heidelberg, 1996. p. 104-113. + */ +static int rsa_prepare_blinding( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ) +{ + int ret, count = 0; + + if( ctx->Vf.p != NULL ) + { + /* We already have blinding values, just update them by squaring */ + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->N ) ); + + goto cleanup; + } + + /* Unblinding value: Vf = random number, invertible mod N */ + do { + if( count++ > 10 ) + return( MBEDTLS_ERR_RSA_RNG_FAILED ); + + MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->Vf, ctx->len - 1, f_rng, p_rng ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &ctx->Vi, &ctx->Vf, &ctx->N ) ); + } while( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) != 0 ); + + /* Blinding value: Vi = Vf^(-e) mod N */ + MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vi, &ctx->Vf, &ctx->N ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN ) ); + + +cleanup: + return( ret ); +} + +/* + * Exponent blinding supposed to prevent side-channel attacks using multiple + * traces of measurements to recover the RSA key. The more collisions are there, + * the more bits of the key can be recovered. See [3]. + * + * Collecting n collisions with m bit long blinding value requires 2^(m-m/n) + * observations on avarage. + * + * For example with 28 byte blinding to achieve 2 collisions the adversary has + * to make 2^112 observations on avarage. + * + * (With the currently (as of 2017 April) known best algorithms breaking 2048 + * bit RSA requires approximately as much time as trying out 2^112 random keys. + * Thus in this sense with 28 byte blinding the security is not reduced by + * side-channel attacks like the one in [3]) + * + * This countermeasure does not help if the key recovery is possible with a + * single trace. + */ +#define RSA_EXPONENT_BLINDING 28 + +/* + * Do an RSA private key operation + */ +int mbedtls_rsa_private( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + const unsigned char *input, + unsigned char *output ) +{ + int ret; + size_t olen; + + /* Temporary holding the result */ + mbedtls_mpi T; + + /* Temporaries holding P-1, Q-1 and the + * exponent blinding factor, respectively. */ + mbedtls_mpi P1, Q1, R; + +#if !defined(MBEDTLS_RSA_NO_CRT) + /* Temporaries holding the results mod p resp. mod q. */ + mbedtls_mpi TP, TQ; + + /* Temporaries holding the blinded exponents for + * the mod p resp. mod q computation (if used). */ + mbedtls_mpi DP_blind, DQ_blind; + + /* Pointers to actual exponents to be used - either the unblinded + * or the blinded ones, depending on the presence of a PRNG. */ + mbedtls_mpi *DP = &ctx->DP; + mbedtls_mpi *DQ = &ctx->DQ; +#else + /* Temporary holding the blinded exponent (if used). */ + mbedtls_mpi D_blind; + + /* Pointer to actual exponent to be used - either the unblinded + * or the blinded one, depending on the presence of a PRNG. */ + mbedtls_mpi *D = &ctx->D; +#endif /* MBEDTLS_RSA_NO_CRT */ + + /* Temporaries holding the initial input and the double + * checked result; should be the same in the end. */ + mbedtls_mpi I, C; + + if( rsa_check_context( ctx, 1 /* private key checks */, + f_rng != NULL /* blinding y/n */ ) != 0 ) + { + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + } + +#if defined(MBEDTLS_THREADING_C) + if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 ) + return( ret ); +#endif + + /* MPI Initialization */ + mbedtls_mpi_init( &T ); + + mbedtls_mpi_init( &P1 ); + mbedtls_mpi_init( &Q1 ); + mbedtls_mpi_init( &R ); + + if( f_rng != NULL ) + { +#if defined(MBEDTLS_RSA_NO_CRT) + mbedtls_mpi_init( &D_blind ); +#else + mbedtls_mpi_init( &DP_blind ); + mbedtls_mpi_init( &DQ_blind ); +#endif + } + +#if !defined(MBEDTLS_RSA_NO_CRT) + mbedtls_mpi_init( &TP ); mbedtls_mpi_init( &TQ ); +#endif + + mbedtls_mpi_init( &I ); + mbedtls_mpi_init( &C ); + + /* End of MPI initialization */ + + MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &T, input, ctx->len ) ); + if( mbedtls_mpi_cmp_mpi( &T, &ctx->N ) >= 0 ) + { + ret = MBEDTLS_ERR_MPI_BAD_INPUT_DATA; + goto cleanup; + } + + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &I, &T ) ); + + if( f_rng != NULL ) + { + /* + * Blinding + * T = T * Vi mod N + */ + MBEDTLS_MPI_CHK( rsa_prepare_blinding( ctx, f_rng, p_rng ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vi ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) ); + + /* + * Exponent blinding + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P1, &ctx->P, 1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q1, &ctx->Q, 1 ) ); + +#if defined(MBEDTLS_RSA_NO_CRT) + /* + * D_blind = ( P - 1 ) * ( Q - 1 ) * R + D + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, RSA_EXPONENT_BLINDING, + f_rng, p_rng ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &D_blind, &P1, &Q1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &D_blind, &D_blind, &R ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &D_blind, &D_blind, &ctx->D ) ); + + D = &D_blind; +#else + /* + * DP_blind = ( P - 1 ) * R + DP + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, RSA_EXPONENT_BLINDING, + f_rng, p_rng ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &DP_blind, &P1, &R ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &DP_blind, &DP_blind, + &ctx->DP ) ); + + DP = &DP_blind; + + /* + * DQ_blind = ( Q - 1 ) * R + DQ + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, RSA_EXPONENT_BLINDING, + f_rng, p_rng ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &DQ_blind, &Q1, &R ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &DQ_blind, &DQ_blind, + &ctx->DQ ) ); + + DQ = &DQ_blind; +#endif /* MBEDTLS_RSA_NO_CRT */ + } + +#if defined(MBEDTLS_RSA_NO_CRT) + MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, D, &ctx->N, &ctx->RN ) ); +#else + /* + * Faster decryption using the CRT + * + * TP = input ^ dP mod P + * TQ = input ^ dQ mod Q + */ + + MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &TP, &T, DP, &ctx->P, &ctx->RP ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &TQ, &T, DQ, &ctx->Q, &ctx->RQ ) ); + + /* + * T = (TP - TQ) * (Q^-1 mod P) mod P + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T, &TP, &TQ ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &TP, &T, &ctx->QP ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &TP, &ctx->P ) ); + + /* + * T = TQ + T * Q + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &TP, &T, &ctx->Q ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &T, &TQ, &TP ) ); +#endif /* MBEDTLS_RSA_NO_CRT */ + + if( f_rng != NULL ) + { + /* + * Unblind + * T = T * Vf mod N + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T, &T, &ctx->Vf ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T, &ctx->N ) ); + } + + /* Verify the result to prevent glitching attacks. */ + MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &C, &T, &ctx->E, + &ctx->N, &ctx->RN ) ); + if( mbedtls_mpi_cmp_mpi( &C, &I ) != 0 ) + { + ret = MBEDTLS_ERR_RSA_VERIFY_FAILED; + goto cleanup; + } + + olen = ctx->len; + MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &T, output, olen ) ); + +cleanup: +#if defined(MBEDTLS_THREADING_C) + if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 ) + return( MBEDTLS_ERR_THREADING_MUTEX_ERROR ); +#endif + + mbedtls_mpi_free( &P1 ); + mbedtls_mpi_free( &Q1 ); + mbedtls_mpi_free( &R ); + + if( f_rng != NULL ) + { +#if defined(MBEDTLS_RSA_NO_CRT) + mbedtls_mpi_free( &D_blind ); +#else + mbedtls_mpi_free( &DP_blind ); + mbedtls_mpi_free( &DQ_blind ); +#endif + } + + mbedtls_mpi_free( &T ); + +#if !defined(MBEDTLS_RSA_NO_CRT) + mbedtls_mpi_free( &TP ); mbedtls_mpi_free( &TQ ); +#endif + + mbedtls_mpi_free( &C ); + mbedtls_mpi_free( &I ); + + if( ret != 0 ) + return( MBEDTLS_ERR_RSA_PRIVATE_FAILED + ret ); + + return( 0 ); +} + +#if defined(MBEDTLS_PKCS1_V21) +/** + * Generate and apply the MGF1 operation (from PKCS#1 v2.1) to a buffer. + * + * \param dst buffer to mask + * \param dlen length of destination buffer + * \param src source of the mask generation + * \param slen length of the source buffer + * \param md_ctx message digest context to use + */ +static int mgf_mask( unsigned char *dst, size_t dlen, unsigned char *src, + size_t slen, mbedtls_md_context_t *md_ctx ) +{ + unsigned char mask[MBEDTLS_MD_MAX_SIZE]; + unsigned char counter[4]; + unsigned char *p; + unsigned int hlen; + size_t i, use_len; + int ret = 0; + + memset( mask, 0, MBEDTLS_MD_MAX_SIZE ); + memset( counter, 0, 4 ); + + hlen = mbedtls_md_get_size( md_ctx->md_info ); + + /* Generate and apply dbMask */ + p = dst; + + while( dlen > 0 ) + { + use_len = hlen; + if( dlen < hlen ) + use_len = dlen; + + if( ( ret = mbedtls_md_starts( md_ctx ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md_update( md_ctx, src, slen ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md_update( md_ctx, counter, 4 ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md_finish( md_ctx, mask ) ) != 0 ) + goto exit; + + for( i = 0; i < use_len; ++i ) + *p++ ^= mask[i]; + + counter[3]++; + + dlen -= use_len; + } + +exit: + mbedtls_zeroize( mask, sizeof( mask ) ); + + return( ret ); +} +#endif /* MBEDTLS_PKCS1_V21 */ + +#if defined(MBEDTLS_PKCS1_V21) +/* + * Implementation of the PKCS#1 v2.1 RSAES-OAEP-ENCRYPT function + */ +int mbedtls_rsa_rsaes_oaep_encrypt( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, + const unsigned char *label, size_t label_len, + size_t ilen, + const unsigned char *input, + unsigned char *output ) +{ + size_t olen; + int ret; + unsigned char *p = output; + unsigned int hlen; + const mbedtls_md_info_t *md_info; + mbedtls_md_context_t md_ctx; + + if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + if( f_rng == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id ); + if( md_info == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + olen = ctx->len; + hlen = mbedtls_md_get_size( md_info ); + + /* first comparison checks for overflow */ + if( ilen + 2 * hlen + 2 < ilen || olen < ilen + 2 * hlen + 2 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + memset( output, 0, olen ); + + *p++ = 0; + + /* Generate a random octet string seed */ + if( ( ret = f_rng( p_rng, p, hlen ) ) != 0 ) + return( MBEDTLS_ERR_RSA_RNG_FAILED + ret ); + + p += hlen; + + /* Construct DB */ + if( ( ret = mbedtls_md( md_info, label, label_len, p ) ) != 0 ) + return( ret ); + p += hlen; + p += olen - 2 * hlen - 2 - ilen; + *p++ = 1; + memcpy( p, input, ilen ); + + mbedtls_md_init( &md_ctx ); + if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 ) + goto exit; + + /* maskedDB: Apply dbMask to DB */ + if( ( ret = mgf_mask( output + hlen + 1, olen - hlen - 1, output + 1, hlen, + &md_ctx ) ) != 0 ) + goto exit; + + /* maskedSeed: Apply seedMask to seed */ + if( ( ret = mgf_mask( output + 1, hlen, output + hlen + 1, olen - hlen - 1, + &md_ctx ) ) != 0 ) + goto exit; + +exit: + mbedtls_md_free( &md_ctx ); + + if( ret != 0 ) + return( ret ); + + return( ( mode == MBEDTLS_RSA_PUBLIC ) + ? mbedtls_rsa_public( ctx, output, output ) + : mbedtls_rsa_private( ctx, f_rng, p_rng, output, output ) ); +} +#endif /* MBEDTLS_PKCS1_V21 */ + +#if defined(MBEDTLS_PKCS1_V15) +/* + * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-ENCRYPT function + */ +int mbedtls_rsa_rsaes_pkcs1_v15_encrypt( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, size_t ilen, + const unsigned char *input, + unsigned char *output ) +{ + size_t nb_pad, olen; + int ret; + unsigned char *p = output; + + if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + // We don't check p_rng because it won't be dereferenced here + if( f_rng == NULL || input == NULL || output == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + olen = ctx->len; + + /* first comparison checks for overflow */ + if( ilen + 11 < ilen || olen < ilen + 11 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + nb_pad = olen - 3 - ilen; + + *p++ = 0; + if( mode == MBEDTLS_RSA_PUBLIC ) + { + *p++ = MBEDTLS_RSA_CRYPT; + + while( nb_pad-- > 0 ) + { + int rng_dl = 100; + + do { + ret = f_rng( p_rng, p, 1 ); + } while( *p == 0 && --rng_dl && ret == 0 ); + + /* Check if RNG failed to generate data */ + if( rng_dl == 0 || ret != 0 ) + return( MBEDTLS_ERR_RSA_RNG_FAILED + ret ); + + p++; + } + } + else + { + *p++ = MBEDTLS_RSA_SIGN; + + while( nb_pad-- > 0 ) + *p++ = 0xFF; + } + + *p++ = 0; + memcpy( p, input, ilen ); + + return( ( mode == MBEDTLS_RSA_PUBLIC ) + ? mbedtls_rsa_public( ctx, output, output ) + : mbedtls_rsa_private( ctx, f_rng, p_rng, output, output ) ); +} +#endif /* MBEDTLS_PKCS1_V15 */ + +/* + * Add the message padding, then do an RSA operation + */ +int mbedtls_rsa_pkcs1_encrypt( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, size_t ilen, + const unsigned char *input, + unsigned char *output ) +{ + switch( ctx->padding ) + { +#if defined(MBEDTLS_PKCS1_V15) + case MBEDTLS_RSA_PKCS_V15: + return mbedtls_rsa_rsaes_pkcs1_v15_encrypt( ctx, f_rng, p_rng, mode, ilen, + input, output ); +#endif + +#if defined(MBEDTLS_PKCS1_V21) + case MBEDTLS_RSA_PKCS_V21: + return mbedtls_rsa_rsaes_oaep_encrypt( ctx, f_rng, p_rng, mode, NULL, 0, + ilen, input, output ); +#endif + + default: + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + } +} + +#if defined(MBEDTLS_PKCS1_V21) +/* + * Implementation of the PKCS#1 v2.1 RSAES-OAEP-DECRYPT function + */ +int mbedtls_rsa_rsaes_oaep_decrypt( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, + const unsigned char *label, size_t label_len, + size_t *olen, + const unsigned char *input, + unsigned char *output, + size_t output_max_len ) +{ + int ret; + size_t ilen, i, pad_len; + unsigned char *p, bad, pad_done; + unsigned char buf[MBEDTLS_MPI_MAX_SIZE]; + unsigned char lhash[MBEDTLS_MD_MAX_SIZE]; + unsigned int hlen; + const mbedtls_md_info_t *md_info; + mbedtls_md_context_t md_ctx; + + /* + * Parameters sanity checks + */ + if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + ilen = ctx->len; + + if( ilen < 16 || ilen > sizeof( buf ) ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id ); + if( md_info == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + hlen = mbedtls_md_get_size( md_info ); + + // checking for integer underflow + if( 2 * hlen + 2 > ilen ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + /* + * RSA operation + */ + ret = ( mode == MBEDTLS_RSA_PUBLIC ) + ? mbedtls_rsa_public( ctx, input, buf ) + : mbedtls_rsa_private( ctx, f_rng, p_rng, input, buf ); + + if( ret != 0 ) + goto cleanup; + + /* + * Unmask data and generate lHash + */ + mbedtls_md_init( &md_ctx ); + if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 ) + { + mbedtls_md_free( &md_ctx ); + goto cleanup; + } + + /* seed: Apply seedMask to maskedSeed */ + if( ( ret = mgf_mask( buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1, + &md_ctx ) ) != 0 || + /* DB: Apply dbMask to maskedDB */ + ( ret = mgf_mask( buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen, + &md_ctx ) ) != 0 ) + { + mbedtls_md_free( &md_ctx ); + goto cleanup; + } + + mbedtls_md_free( &md_ctx ); + + /* Generate lHash */ + if( ( ret = mbedtls_md( md_info, label, label_len, lhash ) ) != 0 ) + goto cleanup; + + /* + * Check contents, in "constant-time" + */ + p = buf; + bad = 0; + + bad |= *p++; /* First byte must be 0 */ + + p += hlen; /* Skip seed */ + + /* Check lHash */ + for( i = 0; i < hlen; i++ ) + bad |= lhash[i] ^ *p++; + + /* Get zero-padding len, but always read till end of buffer + * (minus one, for the 01 byte) */ + pad_len = 0; + pad_done = 0; + for( i = 0; i < ilen - 2 * hlen - 2; i++ ) + { + pad_done |= p[i]; + pad_len += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1; + } + + p += pad_len; + bad |= *p++ ^ 0x01; + + /* + * The only information "leaked" is whether the padding was correct or not + * (eg, no data is copied if it was not correct). This meets the + * recommendations in PKCS#1 v2.2: an opponent cannot distinguish between + * the different error conditions. + */ + if( bad != 0 ) + { + ret = MBEDTLS_ERR_RSA_INVALID_PADDING; + goto cleanup; + } + + if( ilen - ( p - buf ) > output_max_len ) + { + ret = MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE; + goto cleanup; + } + + *olen = ilen - (p - buf); + memcpy( output, p, *olen ); + ret = 0; + +cleanup: + mbedtls_zeroize( buf, sizeof( buf ) ); + mbedtls_zeroize( lhash, sizeof( lhash ) ); + + return( ret ); +} +#endif /* MBEDTLS_PKCS1_V21 */ + +#if defined(MBEDTLS_PKCS1_V15) +/* + * Implementation of the PKCS#1 v2.1 RSAES-PKCS1-V1_5-DECRYPT function + */ +int mbedtls_rsa_rsaes_pkcs1_v15_decrypt( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, size_t *olen, + const unsigned char *input, + unsigned char *output, + size_t output_max_len) +{ + int ret; + size_t ilen, pad_count = 0, i; + unsigned char *p, bad, pad_done = 0; + unsigned char buf[MBEDTLS_MPI_MAX_SIZE]; + + if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + ilen = ctx->len; + + if( ilen < 16 || ilen > sizeof( buf ) ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + ret = ( mode == MBEDTLS_RSA_PUBLIC ) + ? mbedtls_rsa_public( ctx, input, buf ) + : mbedtls_rsa_private( ctx, f_rng, p_rng, input, buf ); + + if( ret != 0 ) + goto cleanup; + + p = buf; + bad = 0; + + /* + * Check and get padding len in "constant-time" + */ + bad |= *p++; /* First byte must be 0 */ + + /* This test does not depend on secret data */ + if( mode == MBEDTLS_RSA_PRIVATE ) + { + bad |= *p++ ^ MBEDTLS_RSA_CRYPT; + + /* Get padding len, but always read till end of buffer + * (minus one, for the 00 byte) */ + for( i = 0; i < ilen - 3; i++ ) + { + pad_done |= ((p[i] | (unsigned char)-p[i]) >> 7) ^ 1; + pad_count += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1; + } + + p += pad_count; + bad |= *p++; /* Must be zero */ + } + else + { + bad |= *p++ ^ MBEDTLS_RSA_SIGN; + + /* Get padding len, but always read till end of buffer + * (minus one, for the 00 byte) */ + for( i = 0; i < ilen - 3; i++ ) + { + pad_done |= ( p[i] != 0xFF ); + pad_count += ( pad_done == 0 ); + } + + p += pad_count; + bad |= *p++; /* Must be zero */ + } + + bad |= ( pad_count < 8 ); + + if( bad ) + { + ret = MBEDTLS_ERR_RSA_INVALID_PADDING; + goto cleanup; + } + + if( ilen - ( p - buf ) > output_max_len ) + { + ret = MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE; + goto cleanup; + } + + *olen = ilen - (p - buf); + memcpy( output, p, *olen ); + ret = 0; + +cleanup: + mbedtls_zeroize( buf, sizeof( buf ) ); + + return( ret ); +} +#endif /* MBEDTLS_PKCS1_V15 */ + +/* + * Do an RSA operation, then remove the message padding + */ +int mbedtls_rsa_pkcs1_decrypt( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, size_t *olen, + const unsigned char *input, + unsigned char *output, + size_t output_max_len) +{ + switch( ctx->padding ) + { +#if defined(MBEDTLS_PKCS1_V15) + case MBEDTLS_RSA_PKCS_V15: + return mbedtls_rsa_rsaes_pkcs1_v15_decrypt( ctx, f_rng, p_rng, mode, olen, + input, output, output_max_len ); +#endif + +#if defined(MBEDTLS_PKCS1_V21) + case MBEDTLS_RSA_PKCS_V21: + return mbedtls_rsa_rsaes_oaep_decrypt( ctx, f_rng, p_rng, mode, NULL, 0, + olen, input, output, + output_max_len ); +#endif + + default: + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + } +} + +#if defined(MBEDTLS_PKCS1_V21) +/* + * Implementation of the PKCS#1 v2.1 RSASSA-PSS-SIGN function + */ +int mbedtls_rsa_rsassa_pss_sign( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, + mbedtls_md_type_t md_alg, + unsigned int hashlen, + const unsigned char *hash, + unsigned char *sig ) +{ + size_t olen; + unsigned char *p = sig; + unsigned char salt[MBEDTLS_MD_MAX_SIZE]; + unsigned int slen, hlen, offset = 0; + int ret; + size_t msb; + const mbedtls_md_info_t *md_info; + mbedtls_md_context_t md_ctx; + + if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + if( f_rng == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + olen = ctx->len; + + if( md_alg != MBEDTLS_MD_NONE ) + { + /* Gather length of hash to sign */ + md_info = mbedtls_md_info_from_type( md_alg ); + if( md_info == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + hashlen = mbedtls_md_get_size( md_info ); + } + + md_info = mbedtls_md_info_from_type( (mbedtls_md_type_t) ctx->hash_id ); + if( md_info == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + hlen = mbedtls_md_get_size( md_info ); + slen = hlen; + + if( olen < hlen + slen + 2 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + memset( sig, 0, olen ); + + /* Generate salt of length slen */ + if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 ) + return( MBEDTLS_ERR_RSA_RNG_FAILED + ret ); + + /* Note: EMSA-PSS encoding is over the length of N - 1 bits */ + msb = mbedtls_mpi_bitlen( &ctx->N ) - 1; + p += olen - hlen * 2 - 2; + *p++ = 0x01; + memcpy( p, salt, slen ); + p += slen; + + mbedtls_md_init( &md_ctx ); + if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 ) + goto exit; + + /* Generate H = Hash( M' ) */ + if( ( ret = mbedtls_md_starts( &md_ctx ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md_update( &md_ctx, p, 8 ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md_update( &md_ctx, hash, hashlen ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md_update( &md_ctx, salt, slen ) ) != 0 ) + goto exit; + if( ( ret = mbedtls_md_finish( &md_ctx, p ) ) != 0 ) + goto exit; + + /* Compensate for boundary condition when applying mask */ + if( msb % 8 == 0 ) + offset = 1; + + /* maskedDB: Apply dbMask to DB */ + if( ( ret = mgf_mask( sig + offset, olen - hlen - 1 - offset, p, hlen, + &md_ctx ) ) != 0 ) + goto exit; + + msb = mbedtls_mpi_bitlen( &ctx->N ) - 1; + sig[0] &= 0xFF >> ( olen * 8 - msb ); + + p += hlen; + *p++ = 0xBC; + + mbedtls_zeroize( salt, sizeof( salt ) ); + +exit: + mbedtls_md_free( &md_ctx ); + + if( ret != 0 ) + return( ret ); + + return( ( mode == MBEDTLS_RSA_PUBLIC ) + ? mbedtls_rsa_public( ctx, sig, sig ) + : mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig ) ); +} +#endif /* MBEDTLS_PKCS1_V21 */ + +#if defined(MBEDTLS_PKCS1_V15) +/* + * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-V1_5-SIGN function + */ + +/* Construct a PKCS v1.5 encoding of a hashed message + * + * This is used both for signature generation and verification. + * + * Parameters: + * - md_alg: Identifies the hash algorithm used to generate the given hash; + * MBEDTLS_MD_NONE if raw data is signed. + * - hashlen: Length of hash in case hashlen is MBEDTLS_MD_NONE. + * - hash: Buffer containing the hashed message or the raw data. + * - dst_len: Length of the encoded message. + * - dst: Buffer to hold the encoded message. + * + * Assumptions: + * - hash has size hashlen if md_alg == MBEDTLS_MD_NONE. + * - hash has size corresponding to md_alg if md_alg != MBEDTLS_MD_NONE. + * - dst points to a buffer of size at least dst_len. + * + */ +static int rsa_rsassa_pkcs1_v15_encode( mbedtls_md_type_t md_alg, + unsigned int hashlen, + const unsigned char *hash, + size_t dst_len, + unsigned char *dst ) +{ + size_t oid_size = 0; + size_t nb_pad = dst_len; + unsigned char *p = dst; + const char *oid = NULL; + + /* Are we signing hashed or raw data? */ + if( md_alg != MBEDTLS_MD_NONE ) + { + const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( md_alg ); + if( md_info == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + if( mbedtls_oid_get_oid_by_md( md_alg, &oid, &oid_size ) != 0 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + hashlen = mbedtls_md_get_size( md_info ); + + /* Double-check that 8 + hashlen + oid_size can be used as a + * 1-byte ASN.1 length encoding and that there's no overflow. */ + if( 8 + hashlen + oid_size >= 0x80 || + 10 + hashlen < hashlen || + 10 + hashlen + oid_size < 10 + hashlen ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + /* + * Static bounds check: + * - Need 10 bytes for five tag-length pairs. + * (Insist on 1-byte length encodings to protect against variants of + * Bleichenbacher's forgery attack against lax PKCS#1v1.5 verification) + * - Need hashlen bytes for hash + * - Need oid_size bytes for hash alg OID. + */ + if( nb_pad < 10 + hashlen + oid_size ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + nb_pad -= 10 + hashlen + oid_size; + } + else + { + if( nb_pad < hashlen ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + nb_pad -= hashlen; + } + + /* Need space for signature header and padding delimiter (3 bytes), + * and 8 bytes for the minimal padding */ + if( nb_pad < 3 + 8 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + nb_pad -= 3; + + /* Now nb_pad is the amount of memory to be filled + * with padding, and at least 8 bytes long. */ + + /* Write signature header and padding */ + *p++ = 0; + *p++ = MBEDTLS_RSA_SIGN; + memset( p, 0xFF, nb_pad ); + p += nb_pad; + *p++ = 0; + + /* Are we signing raw data? */ + if( md_alg == MBEDTLS_MD_NONE ) + { + memcpy( p, hash, hashlen ); + return( 0 ); + } + + /* Signing hashed data, add corresponding ASN.1 structure + * + * DigestInfo ::= SEQUENCE { + * digestAlgorithm DigestAlgorithmIdentifier, + * digest Digest } + * DigestAlgorithmIdentifier ::= AlgorithmIdentifier + * Digest ::= OCTET STRING + * + * Schematic: + * TAG-SEQ + LEN [ TAG-SEQ + LEN [ TAG-OID + LEN [ OID ] + * TAG-NULL + LEN [ NULL ] ] + * TAG-OCTET + LEN [ HASH ] ] + */ + *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED; + *p++ = (unsigned char)( 0x08 + oid_size + hashlen ); + *p++ = MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED; + *p++ = (unsigned char)( 0x04 + oid_size ); + *p++ = MBEDTLS_ASN1_OID; + *p++ = (unsigned char) oid_size; + memcpy( p, oid, oid_size ); + p += oid_size; + *p++ = MBEDTLS_ASN1_NULL; + *p++ = 0x00; + *p++ = MBEDTLS_ASN1_OCTET_STRING; + *p++ = (unsigned char) hashlen; + memcpy( p, hash, hashlen ); + p += hashlen; + + /* Just a sanity-check, should be automatic + * after the initial bounds check. */ + if( p != dst + dst_len ) + { + mbedtls_zeroize( dst, dst_len ); + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + } + + return( 0 ); +} + +/* + * Do an RSA operation to sign the message digest + */ +int mbedtls_rsa_rsassa_pkcs1_v15_sign( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, + mbedtls_md_type_t md_alg, + unsigned int hashlen, + const unsigned char *hash, + unsigned char *sig ) +{ + int ret; + unsigned char *sig_try = NULL, *verif = NULL; + + if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + /* + * Prepare PKCS1-v1.5 encoding (padding and hash identifier) + */ + + if( ( ret = rsa_rsassa_pkcs1_v15_encode( md_alg, hashlen, hash, + ctx->len, sig ) ) != 0 ) + return( ret ); + + /* + * Call respective RSA primitive + */ + + if( mode == MBEDTLS_RSA_PUBLIC ) + { + /* Skip verification on a public key operation */ + return( mbedtls_rsa_public( ctx, sig, sig ) ); + } + + /* Private key operation + * + * In order to prevent Lenstra's attack, make the signature in a + * temporary buffer and check it before returning it. + */ + + sig_try = mbedtls_calloc( 1, ctx->len ); + if( sig_try == NULL ) + return( MBEDTLS_ERR_MPI_ALLOC_FAILED ); + + verif = mbedtls_calloc( 1, ctx->len ); + if( verif == NULL ) + { + mbedtls_free( sig_try ); + return( MBEDTLS_ERR_MPI_ALLOC_FAILED ); + } + + MBEDTLS_MPI_CHK( mbedtls_rsa_private( ctx, f_rng, p_rng, sig, sig_try ) ); + MBEDTLS_MPI_CHK( mbedtls_rsa_public( ctx, sig_try, verif ) ); + + if( mbedtls_safer_memcmp( verif, sig, ctx->len ) != 0 ) + { + ret = MBEDTLS_ERR_RSA_PRIVATE_FAILED; + goto cleanup; + } + + memcpy( sig, sig_try, ctx->len ); + +cleanup: + mbedtls_free( sig_try ); + mbedtls_free( verif ); + + return( ret ); +} +#endif /* MBEDTLS_PKCS1_V15 */ + +/* + * Do an RSA operation to sign the message digest + */ +int mbedtls_rsa_pkcs1_sign( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, + mbedtls_md_type_t md_alg, + unsigned int hashlen, + const unsigned char *hash, + unsigned char *sig ) +{ + switch( ctx->padding ) + { +#if defined(MBEDTLS_PKCS1_V15) + case MBEDTLS_RSA_PKCS_V15: + return mbedtls_rsa_rsassa_pkcs1_v15_sign( ctx, f_rng, p_rng, mode, md_alg, + hashlen, hash, sig ); +#endif + +#if defined(MBEDTLS_PKCS1_V21) + case MBEDTLS_RSA_PKCS_V21: + return mbedtls_rsa_rsassa_pss_sign( ctx, f_rng, p_rng, mode, md_alg, + hashlen, hash, sig ); +#endif + + default: + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + } +} + +#if defined(MBEDTLS_PKCS1_V21) +/* + * Implementation of the PKCS#1 v2.1 RSASSA-PSS-VERIFY function + */ +int mbedtls_rsa_rsassa_pss_verify_ext( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, + mbedtls_md_type_t md_alg, + unsigned int hashlen, + const unsigned char *hash, + mbedtls_md_type_t mgf1_hash_id, + int expected_salt_len, + const unsigned char *sig ) +{ + int ret; + size_t siglen; + unsigned char *p; + unsigned char *hash_start; + unsigned char result[MBEDTLS_MD_MAX_SIZE]; + unsigned char zeros[8]; + unsigned int hlen; + size_t observed_salt_len, msb; + const mbedtls_md_info_t *md_info; + mbedtls_md_context_t md_ctx; + unsigned char buf[MBEDTLS_MPI_MAX_SIZE]; + + if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V21 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + siglen = ctx->len; + + if( siglen < 16 || siglen > sizeof( buf ) ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + ret = ( mode == MBEDTLS_RSA_PUBLIC ) + ? mbedtls_rsa_public( ctx, sig, buf ) + : mbedtls_rsa_private( ctx, f_rng, p_rng, sig, buf ); + + if( ret != 0 ) + return( ret ); + + p = buf; + + if( buf[siglen - 1] != 0xBC ) + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + + if( md_alg != MBEDTLS_MD_NONE ) + { + /* Gather length of hash to sign */ + md_info = mbedtls_md_info_from_type( md_alg ); + if( md_info == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + hashlen = mbedtls_md_get_size( md_info ); + } + + md_info = mbedtls_md_info_from_type( mgf1_hash_id ); + if( md_info == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + hlen = mbedtls_md_get_size( md_info ); + + memset( zeros, 0, 8 ); + + /* + * Note: EMSA-PSS verification is over the length of N - 1 bits + */ + msb = mbedtls_mpi_bitlen( &ctx->N ) - 1; + + if( buf[0] >> ( 8 - siglen * 8 + msb ) ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + /* Compensate for boundary condition when applying mask */ + if( msb % 8 == 0 ) + { + p++; + siglen -= 1; + } + + if( siglen < hlen + 2 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + hash_start = p + siglen - hlen - 1; + + mbedtls_md_init( &md_ctx ); + if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 ) + goto exit; + + ret = mgf_mask( p, siglen - hlen - 1, hash_start, hlen, &md_ctx ); + if( ret != 0 ) + goto exit; + + buf[0] &= 0xFF >> ( siglen * 8 - msb ); + + while( p < hash_start - 1 && *p == 0 ) + p++; + + if( *p++ != 0x01 ) + { + ret = MBEDTLS_ERR_RSA_INVALID_PADDING; + goto exit; + } + + observed_salt_len = hash_start - p; + + if( expected_salt_len != MBEDTLS_RSA_SALT_LEN_ANY && + observed_salt_len != (size_t) expected_salt_len ) + { + ret = MBEDTLS_ERR_RSA_INVALID_PADDING; + goto exit; + } + + /* + * Generate H = Hash( M' ) + */ + ret = mbedtls_md_starts( &md_ctx ); + if ( ret != 0 ) + goto exit; + ret = mbedtls_md_update( &md_ctx, zeros, 8 ); + if ( ret != 0 ) + goto exit; + ret = mbedtls_md_update( &md_ctx, hash, hashlen ); + if ( ret != 0 ) + goto exit; + ret = mbedtls_md_update( &md_ctx, p, observed_salt_len ); + if ( ret != 0 ) + goto exit; + ret = mbedtls_md_finish( &md_ctx, result ); + if ( ret != 0 ) + goto exit; + + if( memcmp( hash_start, result, hlen ) != 0 ) + { + ret = MBEDTLS_ERR_RSA_VERIFY_FAILED; + goto exit; + } + +exit: + mbedtls_md_free( &md_ctx ); + + return( ret ); +} + +/* + * Simplified PKCS#1 v2.1 RSASSA-PSS-VERIFY function + */ +int mbedtls_rsa_rsassa_pss_verify( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, + mbedtls_md_type_t md_alg, + unsigned int hashlen, + const unsigned char *hash, + const unsigned char *sig ) +{ + mbedtls_md_type_t mgf1_hash_id = ( ctx->hash_id != MBEDTLS_MD_NONE ) + ? (mbedtls_md_type_t) ctx->hash_id + : md_alg; + + return( mbedtls_rsa_rsassa_pss_verify_ext( ctx, f_rng, p_rng, mode, + md_alg, hashlen, hash, + mgf1_hash_id, MBEDTLS_RSA_SALT_LEN_ANY, + sig ) ); + +} +#endif /* MBEDTLS_PKCS1_V21 */ + +#if defined(MBEDTLS_PKCS1_V15) +/* + * Implementation of the PKCS#1 v2.1 RSASSA-PKCS1-v1_5-VERIFY function + */ +int mbedtls_rsa_rsassa_pkcs1_v15_verify( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, + mbedtls_md_type_t md_alg, + unsigned int hashlen, + const unsigned char *hash, + const unsigned char *sig ) +{ + int ret = 0; + const size_t sig_len = ctx->len; + unsigned char *encoded = NULL, *encoded_expected = NULL; + + if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + /* + * Prepare expected PKCS1 v1.5 encoding of hash. + */ + + if( ( encoded = mbedtls_calloc( 1, sig_len ) ) == NULL || + ( encoded_expected = mbedtls_calloc( 1, sig_len ) ) == NULL ) + { + ret = MBEDTLS_ERR_MPI_ALLOC_FAILED; + goto cleanup; + } + + if( ( ret = rsa_rsassa_pkcs1_v15_encode( md_alg, hashlen, hash, sig_len, + encoded_expected ) ) != 0 ) + goto cleanup; + + /* + * Apply RSA primitive to get what should be PKCS1 encoded hash. + */ + + ret = ( mode == MBEDTLS_RSA_PUBLIC ) + ? mbedtls_rsa_public( ctx, sig, encoded ) + : mbedtls_rsa_private( ctx, f_rng, p_rng, sig, encoded ); + if( ret != 0 ) + goto cleanup; + + /* + * Compare + */ + + if( ( ret = mbedtls_safer_memcmp( encoded, encoded_expected, + sig_len ) ) != 0 ) + { + ret = MBEDTLS_ERR_RSA_VERIFY_FAILED; + goto cleanup; + } + +cleanup: + + if( encoded != NULL ) + { + mbedtls_zeroize( encoded, sig_len ); + mbedtls_free( encoded ); + } + + if( encoded_expected != NULL ) + { + mbedtls_zeroize( encoded_expected, sig_len ); + mbedtls_free( encoded_expected ); + } + + return( ret ); +} +#endif /* MBEDTLS_PKCS1_V15 */ + +/* + * Do an RSA operation and check the message digest + */ +int mbedtls_rsa_pkcs1_verify( mbedtls_rsa_context *ctx, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng, + int mode, + mbedtls_md_type_t md_alg, + unsigned int hashlen, + const unsigned char *hash, + const unsigned char *sig ) +{ + switch( ctx->padding ) + { +#if defined(MBEDTLS_PKCS1_V15) + case MBEDTLS_RSA_PKCS_V15: + return mbedtls_rsa_rsassa_pkcs1_v15_verify( ctx, f_rng, p_rng, mode, md_alg, + hashlen, hash, sig ); +#endif + +#if defined(MBEDTLS_PKCS1_V21) + case MBEDTLS_RSA_PKCS_V21: + return mbedtls_rsa_rsassa_pss_verify( ctx, f_rng, p_rng, mode, md_alg, + hashlen, hash, sig ); +#endif + + default: + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + } +} + +/* + * Copy the components of an RSA key + */ +int mbedtls_rsa_copy( mbedtls_rsa_context *dst, const mbedtls_rsa_context *src ) +{ + int ret; + + dst->ver = src->ver; + dst->len = src->len; + + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->N, &src->N ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->E, &src->E ) ); + + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->D, &src->D ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->P, &src->P ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Q, &src->Q ) ); + +#if !defined(MBEDTLS_RSA_NO_CRT) + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->DP, &src->DP ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->DQ, &src->DQ ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->QP, &src->QP ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RP, &src->RP ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RQ, &src->RQ ) ); +#endif + + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RN, &src->RN ) ); + + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Vi, &src->Vi ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->Vf, &src->Vf ) ); + + dst->padding = src->padding; + dst->hash_id = src->hash_id; + +cleanup: + if( ret != 0 ) + mbedtls_rsa_free( dst ); + + return( ret ); +} + +/* + * Free the components of an RSA key + */ +void mbedtls_rsa_free( mbedtls_rsa_context *ctx ) +{ + mbedtls_mpi_free( &ctx->Vi ); mbedtls_mpi_free( &ctx->Vf ); + mbedtls_mpi_free( &ctx->RN ); mbedtls_mpi_free( &ctx->D ); + mbedtls_mpi_free( &ctx->Q ); mbedtls_mpi_free( &ctx->P ); + mbedtls_mpi_free( &ctx->E ); mbedtls_mpi_free( &ctx->N ); + +#if !defined(MBEDTLS_RSA_NO_CRT) + mbedtls_mpi_free( &ctx->RQ ); mbedtls_mpi_free( &ctx->RP ); + mbedtls_mpi_free( &ctx->QP ); mbedtls_mpi_free( &ctx->DQ ); + mbedtls_mpi_free( &ctx->DP ); +#endif /* MBEDTLS_RSA_NO_CRT */ + +#if defined(MBEDTLS_THREADING_C) + mbedtls_mutex_free( &ctx->mutex ); +#endif +} + +#endif /* !MBEDTLS_RSA_ALT */ + +#if defined(MBEDTLS_SELF_TEST) + +#include "mbedtls/sha1.h" + +/* + * Example RSA-1024 keypair, for test purposes + */ +#define KEY_LEN 128 + +#define RSA_N "9292758453063D803DD603D5E777D788" \ + "8ED1D5BF35786190FA2F23EBC0848AEA" \ + "DDA92CA6C3D80B32C4D109BE0F36D6AE" \ + "7130B9CED7ACDF54CFC7555AC14EEBAB" \ + "93A89813FBF3C4F8066D2D800F7C38A8" \ + "1AE31942917403FF4946B0A83D3D3E05" \ + "EE57C6F5F5606FB5D4BC6CD34EE0801A" \ + "5E94BB77B07507233A0BC7BAC8F90F79" + +#define RSA_E "10001" + +#define RSA_D "24BF6185468786FDD303083D25E64EFC" \ + "66CA472BC44D253102F8B4A9D3BFA750" \ + "91386C0077937FE33FA3252D28855837" \ + "AE1B484A8A9A45F7EE8C0C634F99E8CD" \ + "DF79C5CE07EE72C7F123142198164234" \ + "CABB724CF78B8173B9F880FC86322407" \ + "AF1FEDFDDE2BEB674CA15F3E81A1521E" \ + "071513A1E85B5DFA031F21ECAE91A34D" + +#define RSA_P "C36D0EB7FCD285223CFB5AABA5BDA3D8" \ + "2C01CAD19EA484A87EA4377637E75500" \ + "FCB2005C5C7DD6EC4AC023CDA285D796" \ + "C3D9E75E1EFC42488BB4F1D13AC30A57" + +#define RSA_Q "C000DF51A7C77AE8D7C7370C1FF55B69" \ + "E211C2B9E5DB1ED0BF61D0D9899620F4" \ + "910E4168387E3C30AA1E00C339A79508" \ + "8452DD96A9A5EA5D9DCA68DA636032AF" + +#define PT_LEN 24 +#define RSA_PT "\xAA\xBB\xCC\x03\x02\x01\x00\xFF\xFF\xFF\xFF\xFF" \ + "\x11\x22\x33\x0A\x0B\x0C\xCC\xDD\xDD\xDD\xDD\xDD" + +#if defined(MBEDTLS_PKCS1_V15) +static int myrand( void *rng_state, unsigned char *output, size_t len ) +{ +#if !defined(__OpenBSD__) + size_t i; + + if( rng_state != NULL ) + rng_state = NULL; + + for( i = 0; i < len; ++i ) + output[i] = rand(); +#else + if( rng_state != NULL ) + rng_state = NULL; + + arc4random_buf( output, len ); +#endif /* !OpenBSD */ + + return( 0 ); +} +#endif /* MBEDTLS_PKCS1_V15 */ + +/* + * Checkup routine + */ +int mbedtls_rsa_self_test( int verbose ) +{ + int ret = 0; +#if defined(MBEDTLS_PKCS1_V15) + size_t len; + mbedtls_rsa_context rsa; + unsigned char rsa_plaintext[PT_LEN]; + unsigned char rsa_decrypted[PT_LEN]; + unsigned char rsa_ciphertext[KEY_LEN]; +#if defined(MBEDTLS_SHA1_C) + unsigned char sha1sum[20]; +#endif + + mbedtls_mpi K; + + mbedtls_mpi_init( &K ); + mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 ); + + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_N ) ); + MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, &K, NULL, NULL, NULL, NULL ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_P ) ); + MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, &K, NULL, NULL, NULL ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_Q ) ); + MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, NULL, &K, NULL, NULL ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_D ) ); + MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, NULL, NULL, &K, NULL ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &K, 16, RSA_E ) ); + MBEDTLS_MPI_CHK( mbedtls_rsa_import( &rsa, NULL, NULL, NULL, NULL, &K ) ); + + MBEDTLS_MPI_CHK( mbedtls_rsa_complete( &rsa ) ); + + if( verbose != 0 ) + mbedtls_printf( " RSA key validation: " ); + + if( mbedtls_rsa_check_pubkey( &rsa ) != 0 || + mbedtls_rsa_check_privkey( &rsa ) != 0 ) + { + if( verbose != 0 ) + mbedtls_printf( "failed\n" ); + + ret = 1; + goto cleanup; + } + + if( verbose != 0 ) + mbedtls_printf( "passed\n PKCS#1 encryption : " ); + + memcpy( rsa_plaintext, RSA_PT, PT_LEN ); + + if( mbedtls_rsa_pkcs1_encrypt( &rsa, myrand, NULL, MBEDTLS_RSA_PUBLIC, + PT_LEN, rsa_plaintext, + rsa_ciphertext ) != 0 ) + { + if( verbose != 0 ) + mbedtls_printf( "failed\n" ); + + ret = 1; + goto cleanup; + } + + if( verbose != 0 ) + mbedtls_printf( "passed\n PKCS#1 decryption : " ); + + if( mbedtls_rsa_pkcs1_decrypt( &rsa, myrand, NULL, MBEDTLS_RSA_PRIVATE, + &len, rsa_ciphertext, rsa_decrypted, + sizeof(rsa_decrypted) ) != 0 ) + { + if( verbose != 0 ) + mbedtls_printf( "failed\n" ); + + ret = 1; + goto cleanup; + } + + if( memcmp( rsa_decrypted, rsa_plaintext, len ) != 0 ) + { + if( verbose != 0 ) + mbedtls_printf( "failed\n" ); + + ret = 1; + goto cleanup; + } + + if( verbose != 0 ) + mbedtls_printf( "passed\n" ); + +#if defined(MBEDTLS_SHA1_C) + if( verbose != 0 ) + mbedtls_printf( " PKCS#1 data sign : " ); + + if( mbedtls_sha1_ret( rsa_plaintext, PT_LEN, sha1sum ) != 0 ) + { + if( verbose != 0 ) + mbedtls_printf( "failed\n" ); + + return( 1 ); + } + + if( mbedtls_rsa_pkcs1_sign( &rsa, myrand, NULL, + MBEDTLS_RSA_PRIVATE, MBEDTLS_MD_SHA1, 0, + sha1sum, rsa_ciphertext ) != 0 ) + { + if( verbose != 0 ) + mbedtls_printf( "failed\n" ); + + ret = 1; + goto cleanup; + } + + if( verbose != 0 ) + mbedtls_printf( "passed\n PKCS#1 sig. verify: " ); + + if( mbedtls_rsa_pkcs1_verify( &rsa, NULL, NULL, + MBEDTLS_RSA_PUBLIC, MBEDTLS_MD_SHA1, 0, + sha1sum, rsa_ciphertext ) != 0 ) + { + if( verbose != 0 ) + mbedtls_printf( "failed\n" ); + + ret = 1; + goto cleanup; + } + + if( verbose != 0 ) + mbedtls_printf( "passed\n" ); +#endif /* MBEDTLS_SHA1_C */ + + if( verbose != 0 ) + mbedtls_printf( "\n" ); + +cleanup: + mbedtls_mpi_free( &K ); + mbedtls_rsa_free( &rsa ); +#else /* MBEDTLS_PKCS1_V15 */ + ((void) verbose); +#endif /* MBEDTLS_PKCS1_V15 */ + return( ret ); +} + +#endif /* MBEDTLS_SELF_TEST */ + +#endif /* MBEDTLS_RSA_C */ |