diff options
Diffstat (limited to 'FreeRTOS-Labs/Source/mbedtls/library/rsa.c')
| -rw-r--r-- | FreeRTOS-Labs/Source/mbedtls/library/rsa.c | 2729 |
1 files changed, 2729 insertions, 0 deletions
diff --git a/FreeRTOS-Labs/Source/mbedtls/library/rsa.c b/FreeRTOS-Labs/Source/mbedtls/library/rsa.c new file mode 100644 index 000000000..11a5067b9 --- /dev/null +++ b/FreeRTOS-Labs/Source/mbedtls/library/rsa.c @@ -0,0 +1,2729 @@ +/*
+ * 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 "mbedtls/platform_util.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)
+
+/* Parameter validation macros */
+#define RSA_VALIDATE_RET( cond ) \
+ MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_RSA_BAD_INPUT_DATA )
+#define RSA_VALIDATE( cond ) \
+ MBEDTLS_INTERNAL_VALIDATE( cond )
+
+#if defined(MBEDTLS_PKCS1_V15)
+/* 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 );
+}
+#endif /* MBEDTLS_PKCS1_V15 */
+
+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;
+ RSA_VALIDATE_RET( ctx != NULL );
+
+ 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;
+ RSA_VALIDATE_RET( ctx != NULL );
+
+ 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;
+ int have_N, have_P, have_Q, have_D, have_E;
+ int n_missing, pq_missing, d_missing, is_pub, is_priv;
+
+ RSA_VALIDATE_RET( ctx != NULL );
+
+ have_N = ( mbedtls_mpi_cmp_int( &ctx->N, 0 ) != 0 );
+ have_P = ( mbedtls_mpi_cmp_int( &ctx->P, 0 ) != 0 );
+ have_Q = ( mbedtls_mpi_cmp_int( &ctx->Q, 0 ) != 0 );
+ have_D = ( mbedtls_mpi_cmp_int( &ctx->D, 0 ) != 0 );
+ 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.
+ *
+ */
+
+ n_missing = have_P && have_Q && have_D && have_E;
+ pq_missing = have_N && !have_P && !have_Q && have_D && have_E;
+ d_missing = have_P && have_Q && !have_D && have_E;
+ is_pub = have_N && !have_P && !have_Q && !have_D && have_E;
+
+ /* These three alternatives are mutually exclusive */
+ 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;
+ int is_priv;
+ RSA_VALIDATE_RET( ctx != NULL );
+
+ /* Check if key is private or public */
+ 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;
+ int is_priv;
+ RSA_VALIDATE_RET( ctx != NULL );
+
+ /* Check if key is private or public */
+ 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;
+ int is_priv;
+ RSA_VALIDATE_RET( ctx != NULL );
+
+ /* Check if key is private or public */
+ 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 )
+{
+ RSA_VALIDATE( ctx != NULL );
+ RSA_VALIDATE( padding == MBEDTLS_RSA_PKCS_V15 ||
+ padding == MBEDTLS_RSA_PKCS_V21 );
+
+ 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 )
+{
+ RSA_VALIDATE( ctx != NULL );
+ RSA_VALIDATE( padding == MBEDTLS_RSA_PKCS_V15 ||
+ padding == MBEDTLS_RSA_PKCS_V21 );
+
+ 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
+ *
+ * This generation method follows the RSA key pair generation procedure of
+ * FIPS 186-4 if 2^16 < exponent < 2^256 and nbits = 2048 or nbits = 3072.
+ */
+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, L;
+ int prime_quality = 0;
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( f_rng != NULL );
+
+ if( nbits < 128 || exponent < 3 || nbits % 2 != 0 )
+ return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
+ /*
+ * If the modulus is 1024 bit long or shorter, then the security strength of
+ * the RSA algorithm is less than or equal to 80 bits and therefore an error
+ * rate of 2^-80 is sufficient.
+ */
+ if( nbits > 1024 )
+ prime_quality = MBEDTLS_MPI_GEN_PRIME_FLAG_LOW_ERR;
+
+ mbedtls_mpi_init( &H );
+ mbedtls_mpi_init( &G );
+ mbedtls_mpi_init( &L );
+
+ /*
+ * find primes P and Q with Q < P so that:
+ * 1. |P-Q| > 2^( nbits / 2 - 100 )
+ * 2. GCD( E, (P-1)*(Q-1) ) == 1
+ * 3. E^-1 mod LCM(P-1, Q-1) > 2^( nbits / 2 )
+ */
+ MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->E, exponent ) );
+
+ do
+ {
+ MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->P, nbits >> 1,
+ prime_quality, f_rng, p_rng ) );
+
+ MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, nbits >> 1,
+ prime_quality, f_rng, p_rng ) );
+
+ /* make sure the difference between p and q is not too small (FIPS 186-4 §B.3.3 step 5.4) */
+ MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &H, &ctx->P, &ctx->Q ) );
+ if( mbedtls_mpi_bitlen( &H ) <= ( ( nbits >= 200 ) ? ( ( nbits >> 1 ) - 99 ) : 0 ) )
+ continue;
+
+ /* not required by any standards, but some users rely on the fact that P > Q */
+ if( H.s < 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 ) );
+
+ /* check GCD( E, (P-1)*(Q-1) ) == 1 (FIPS 186-4 §B.3.1 criterion 2(a)) */
+ MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H ) );
+ if( mbedtls_mpi_cmp_int( &G, 1 ) != 0 )
+ continue;
+
+ /* compute smallest possible D = E^-1 mod LCM(P-1, Q-1) (FIPS 186-4 §B.3.1 criterion 3(b)) */
+ MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->P, &ctx->Q ) );
+ MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( &L, NULL, &H, &G ) );
+ MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->D, &ctx->E, &L ) );
+
+ if( mbedtls_mpi_bitlen( &ctx->D ) <= ( ( nbits + 1 ) / 2 ) ) // (FIPS 186-4 §B.3.1 criterion 3(a))
+ continue;
+
+ break;
+ }
+ while( 1 );
+
+ /* 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 ) );
+
+ MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->N, &ctx->P, &ctx->Q ) );
+
+ ctx->len = mbedtls_mpi_size( &ctx->N );
+
+#if !defined(MBEDTLS_RSA_NO_CRT)
+ /*
+ * DP = D mod (P - 1)
+ * DQ = D mod (Q - 1)
+ * QP = Q^-1 mod P
+ */
+ 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 );
+ mbedtls_mpi_free( &L );
+
+ 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 )
+{
+ RSA_VALIDATE_RET( ctx != NULL );
+
+ 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 )
+{
+ RSA_VALIDATE_RET( ctx != NULL );
+
+ 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 )
+{
+ RSA_VALIDATE_RET( pub != NULL );
+ RSA_VALIDATE_RET( prv != NULL );
+
+ 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;
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( input != NULL );
+ RSA_VALIDATE_RET( output != NULL );
+
+ 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;
+
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( input != NULL );
+ RSA_VALIDATE_RET( output != NULL );
+
+ 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_platform_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;
+
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( output != NULL );
+ RSA_VALIDATE_RET( ilen == 0 || input != NULL );
+ RSA_VALIDATE_RET( label_len == 0 || label != NULL );
+
+ 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;
+ if( ilen != 0 )
+ 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;
+
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( output != NULL );
+ RSA_VALIDATE_RET( ilen == 0 || input != NULL );
+
+ if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
+ 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 )
+ {
+ if( f_rng == NULL )
+ return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
+ *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;
+ if( ilen != 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 )
+{
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( output != NULL );
+ RSA_VALIDATE_RET( ilen == 0 || input != NULL );
+
+ 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;
+
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
+ RSA_VALIDATE_RET( label_len == 0 || label != NULL );
+ RSA_VALIDATE_RET( input != NULL );
+ RSA_VALIDATE_RET( olen != NULL );
+
+ /*
+ * 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);
+ if( *olen != 0 )
+ memcpy( output, p, *olen );
+ ret = 0;
+
+cleanup:
+ mbedtls_platform_zeroize( buf, sizeof( buf ) );
+ mbedtls_platform_zeroize( lhash, sizeof( lhash ) );
+
+ return( ret );
+}
+#endif /* MBEDTLS_PKCS1_V21 */
+
+#if defined(MBEDTLS_PKCS1_V15)
+/** Turn zero-or-nonzero into zero-or-all-bits-one, without branches.
+ *
+ * \param value The value to analyze.
+ * \return Zero if \p value is zero, otherwise all-bits-one.
+ */
+static unsigned all_or_nothing_int( unsigned value )
+{
+ /* MSVC has a warning about unary minus on unsigned, but this is
+ * well-defined and precisely what we want to do here */
+#if defined(_MSC_VER)
+#pragma warning( push )
+#pragma warning( disable : 4146 )
+#endif
+ return( - ( ( value | - value ) >> ( sizeof( value ) * 8 - 1 ) ) );
+#if defined(_MSC_VER)
+#pragma warning( pop )
+#endif
+}
+
+/** Check whether a size is out of bounds, without branches.
+ *
+ * This is equivalent to `size > max`, but is likely to be compiled to
+ * to code using bitwise operation rather than a branch.
+ *
+ * \param size Size to check.
+ * \param max Maximum desired value for \p size.
+ * \return \c 0 if `size <= max`.
+ * \return \c 1 if `size > max`.
+ */
+static unsigned size_greater_than( size_t size, size_t max )
+{
+ /* Return the sign bit (1 for negative) of (max - size). */
+ return( ( max - size ) >> ( sizeof( size_t ) * 8 - 1 ) );
+}
+
+/** Choose between two integer values, without branches.
+ *
+ * This is equivalent to `cond ? if1 : if0`, but is likely to be compiled
+ * to code using bitwise operation rather than a branch.
+ *
+ * \param cond Condition to test.
+ * \param if1 Value to use if \p cond is nonzero.
+ * \param if0 Value to use if \p cond is zero.
+ * \return \c if1 if \p cond is nonzero, otherwise \c if0.
+ */
+static unsigned if_int( unsigned cond, unsigned if1, unsigned if0 )
+{
+ unsigned mask = all_or_nothing_int( cond );
+ return( ( mask & if1 ) | (~mask & if0 ) );
+}
+
+/** Shift some data towards the left inside a buffer without leaking
+ * the length of the data through side channels.
+ *
+ * `mem_move_to_left(start, total, offset)` is functionally equivalent to
+ * ```
+ * memmove(start, start + offset, total - offset);
+ * memset(start + offset, 0, total - offset);
+ * ```
+ * but it strives to use a memory access pattern (and thus total timing)
+ * that does not depend on \p offset. This timing independence comes at
+ * the expense of performance.
+ *
+ * \param start Pointer to the start of the buffer.
+ * \param total Total size of the buffer.
+ * \param offset Offset from which to copy \p total - \p offset bytes.
+ */
+static void mem_move_to_left( void *start,
+ size_t total,
+ size_t offset )
+{
+ volatile unsigned char *buf = start;
+ size_t i, n;
+ if( total == 0 )
+ return;
+ for( i = 0; i < total; i++ )
+ {
+ unsigned no_op = size_greater_than( total - offset, i );
+ /* The first `total - offset` passes are a no-op. The last
+ * `offset` passes shift the data one byte to the left and
+ * zero out the last byte. */
+ for( n = 0; n < total - 1; n++ )
+ {
+ unsigned char current = buf[n];
+ unsigned char next = buf[n+1];
+ buf[n] = if_int( no_op, current, next );
+ }
+ buf[total-1] = if_int( no_op, buf[total-1], 0 );
+ }
+}
+
+/*
+ * 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, i, plaintext_max_size;
+ unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
+ /* The following variables take sensitive values: their value must
+ * not leak into the observable behavior of the function other than
+ * the designated outputs (output, olen, return value). Otherwise
+ * this would open the execution of the function to
+ * side-channel-based variants of the Bleichenbacher padding oracle
+ * attack. Potential side channels include overall timing, memory
+ * access patterns (especially visible to an adversary who has access
+ * to a shared memory cache), and branches (especially visible to
+ * an adversary who has access to a shared code cache or to a shared
+ * branch predictor). */
+ size_t pad_count = 0;
+ unsigned bad = 0;
+ unsigned char pad_done = 0;
+ size_t plaintext_size = 0;
+ unsigned output_too_large;
+
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
+ RSA_VALIDATE_RET( input != NULL );
+ RSA_VALIDATE_RET( olen != NULL );
+
+ ilen = ctx->len;
+ plaintext_max_size = ( output_max_len > ilen - 11 ?
+ ilen - 11 :
+ output_max_len );
+
+ if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
+ return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
+ 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;
+
+ /* Check and get padding length in constant time and constant
+ * memory trace. The first byte must be 0. */
+ bad |= buf[0];
+
+ if( mode == MBEDTLS_RSA_PRIVATE )
+ {
+ /* Decode EME-PKCS1-v1_5 padding: 0x00 || 0x02 || PS || 0x00
+ * where PS must be at least 8 nonzero bytes. */
+ bad |= buf[1] ^ MBEDTLS_RSA_CRYPT;
+
+ /* Read the whole buffer. Set pad_done to nonzero if we find
+ * the 0x00 byte and remember the padding length in pad_count. */
+ for( i = 2; i < ilen; i++ )
+ {
+ pad_done |= ((buf[i] | (unsigned char)-buf[i]) >> 7) ^ 1;
+ pad_count += ((pad_done | (unsigned char)-pad_done) >> 7) ^ 1;
+ }
+ }
+ else
+ {
+ /* Decode EMSA-PKCS1-v1_5 padding: 0x00 || 0x01 || PS || 0x00
+ * where PS must be at least 8 bytes with the value 0xFF. */
+ bad |= buf[1] ^ MBEDTLS_RSA_SIGN;
+
+ /* Read the whole buffer. Set pad_done to nonzero if we find
+ * the 0x00 byte and remember the padding length in pad_count.
+ * If there's a non-0xff byte in the padding, the padding is bad. */
+ for( i = 2; i < ilen; i++ )
+ {
+ pad_done |= if_int( buf[i], 0, 1 );
+ pad_count += if_int( pad_done, 0, 1 );
+ bad |= if_int( pad_done, 0, buf[i] ^ 0xFF );
+ }
+ }
+
+ /* If pad_done is still zero, there's no data, only unfinished padding. */
+ bad |= if_int( pad_done, 0, 1 );
+
+ /* There must be at least 8 bytes of padding. */
+ bad |= size_greater_than( 8, pad_count );
+
+ /* If the padding is valid, set plaintext_size to the number of
+ * remaining bytes after stripping the padding. If the padding
+ * is invalid, avoid leaking this fact through the size of the
+ * output: use the maximum message size that fits in the output
+ * buffer. Do it without branches to avoid leaking the padding
+ * validity through timing. RSA keys are small enough that all the
+ * size_t values involved fit in unsigned int. */
+ plaintext_size = if_int( bad,
+ (unsigned) plaintext_max_size,
+ (unsigned) ( ilen - pad_count - 3 ) );
+
+ /* Set output_too_large to 0 if the plaintext fits in the output
+ * buffer and to 1 otherwise. */
+ output_too_large = size_greater_than( plaintext_size,
+ plaintext_max_size );
+
+ /* Set ret without branches to avoid timing attacks. Return:
+ * - INVALID_PADDING if the padding is bad (bad != 0).
+ * - OUTPUT_TOO_LARGE if the padding is good but the decrypted
+ * plaintext does not fit in the output buffer.
+ * - 0 if the padding is correct. */
+ ret = - (int) if_int( bad, - MBEDTLS_ERR_RSA_INVALID_PADDING,
+ if_int( output_too_large, - MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE,
+ 0 ) );
+
+ /* If the padding is bad or the plaintext is too large, zero the
+ * data that we're about to copy to the output buffer.
+ * We need to copy the same amount of data
+ * from the same buffer whether the padding is good or not to
+ * avoid leaking the padding validity through overall timing or
+ * through memory or cache access patterns. */
+ bad = all_or_nothing_int( bad | output_too_large );
+ for( i = 11; i < ilen; i++ )
+ buf[i] &= ~bad;
+
+ /* If the plaintext is too large, truncate it to the buffer size.
+ * Copy anyway to avoid revealing the length through timing, because
+ * revealing the length is as bad as revealing the padding validity
+ * for a Bleichenbacher attack. */
+ plaintext_size = if_int( output_too_large,
+ (unsigned) plaintext_max_size,
+ (unsigned) plaintext_size );
+
+ /* Move the plaintext to the leftmost position where it can start in
+ * the working buffer, i.e. make it start plaintext_max_size from
+ * the end of the buffer. Do this with a memory access trace that
+ * does not depend on the plaintext size. After this move, the
+ * starting location of the plaintext is no longer sensitive
+ * information. */
+ mem_move_to_left( buf + ilen - plaintext_max_size,
+ plaintext_max_size,
+ plaintext_max_size - plaintext_size );
+
+ /* Finally copy the decrypted plaintext plus trailing zeros into the output
+ * buffer. If output_max_len is 0, then output may be an invalid pointer
+ * and the result of memcpy() would be undefined; prevent undefined
+ * behavior making sure to depend only on output_max_len (the size of the
+ * user-provided output buffer), which is independent from plaintext
+ * length, validity of padding, success of the decryption, and other
+ * secrets. */
+ if( output_max_len != 0 )
+ memcpy( output, buf + ilen - plaintext_max_size, plaintext_max_size );
+
+ /* Report the amount of data we copied to the output buffer. In case
+ * of errors (bad padding or output too large), the value of *olen
+ * when this function returns is not specified. Making it equivalent
+ * to the good case limits the risks of leaking the padding validity. */
+ *olen = plaintext_size;
+
+cleanup:
+ mbedtls_platform_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)
+{
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( output_max_len == 0 || output != NULL );
+ RSA_VALIDATE_RET( input != NULL );
+ RSA_VALIDATE_RET( olen != NULL );
+
+ 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];
+ size_t slen, min_slen, hlen, offset = 0;
+ int ret;
+ size_t msb;
+ const mbedtls_md_info_t *md_info;
+ mbedtls_md_context_t md_ctx;
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE &&
+ hashlen == 0 ) ||
+ hash != NULL );
+ RSA_VALIDATE_RET( sig != NULL );
+
+ 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 );
+
+ /* Calculate the largest possible salt length. Normally this is the hash
+ * length, which is the maximum length the salt can have. If there is not
+ * enough room, use the maximum salt length that fits. The constraint is
+ * that the hash length plus the salt length plus 2 bytes must be at most
+ * the key length. This complies with FIPS 186-4 §5.5 (e) and RFC 8017
+ * (PKCS#1 v2.2) §9.1.1 step 3. */
+ min_slen = hlen - 2;
+ if( olen < hlen + min_slen + 2 )
+ return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+ else if( olen >= hlen + hlen + 2 )
+ slen = hlen;
+ else
+ slen = olen - hlen - 2;
+
+ 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 - slen - 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_platform_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_platform_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;
+
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE &&
+ hashlen == 0 ) ||
+ hash != NULL );
+ RSA_VALIDATE_RET( sig != 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 )
+{
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE &&
+ hashlen == 0 ) ||
+ hash != NULL );
+ RSA_VALIDATE_RET( sig != NULL );
+
+ 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];
+
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( sig != NULL );
+ RSA_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE &&
+ hashlen == 0 ) ||
+ hash != NULL );
+
+ 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;
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( sig != NULL );
+ RSA_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE &&
+ hashlen == 0 ) ||
+ hash != NULL );
+
+ 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;
+ size_t sig_len;
+ unsigned char *encoded = NULL, *encoded_expected = NULL;
+
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( sig != NULL );
+ RSA_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE &&
+ hashlen == 0 ) ||
+ hash != NULL );
+
+ sig_len = ctx->len;
+
+ 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_platform_zeroize( encoded, sig_len );
+ mbedtls_free( encoded );
+ }
+
+ if( encoded_expected != NULL )
+ {
+ mbedtls_platform_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 )
+{
+ RSA_VALIDATE_RET( ctx != NULL );
+ RSA_VALIDATE_RET( mode == MBEDTLS_RSA_PRIVATE ||
+ mode == MBEDTLS_RSA_PUBLIC );
+ RSA_VALIDATE_RET( sig != NULL );
+ RSA_VALIDATE_RET( ( md_alg == MBEDTLS_MD_NONE &&
+ hashlen == 0 ) ||
+ hash != NULL );
+
+ 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;
+ RSA_VALIDATE_RET( dst != NULL );
+ RSA_VALIDATE_RET( src != NULL );
+
+ 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 )
+{
+ if( ctx == NULL )
+ return;
+
+ 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 */
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