diff options
Diffstat (limited to 'thirdparty/mbedtls/library/rsa.c')
| -rw-r--r-- | thirdparty/mbedtls/library/rsa.c | 72 |
1 files changed, 61 insertions, 11 deletions
diff --git a/thirdparty/mbedtls/library/rsa.c b/thirdparty/mbedtls/library/rsa.c index 09fd379fdb..a25c633bc6 100644 --- a/thirdparty/mbedtls/library/rsa.c +++ b/thirdparty/mbedtls/library/rsa.c @@ -1,8 +1,14 @@ /* * The RSA public-key cryptosystem * - * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved - * SPDX-License-Identifier: Apache-2.0 + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + * + * This file is provided under the Apache License 2.0, or the + * GNU General Public License v2.0 or later. + * + * ********** + * Apache License 2.0: * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. @@ -16,7 +22,26 @@ * 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) + * ********** + * + * ********** + * GNU General Public License v2.0 or later: + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + * ********** */ /* @@ -56,7 +81,7 @@ #include "mbedtls/md.h" #endif -#if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__) +#if defined(MBEDTLS_PKCS1_V15) && !defined(__OpenBSD__) && !defined(__NetBSD__) #include <stdlib.h> #endif @@ -781,6 +806,9 @@ static int rsa_prepare_blinding( mbedtls_rsa_context *ctx, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ) { int ret, count = 0; + mbedtls_mpi R; + + mbedtls_mpi_init( &R ); if( ctx->Vf.p != NULL ) { @@ -796,18 +824,40 @@ static int rsa_prepare_blinding( mbedtls_rsa_context *ctx, /* Unblinding value: Vf = random number, invertible mod N */ do { if( count++ > 10 ) - return( MBEDTLS_ERR_RSA_RNG_FAILED ); + { + ret = MBEDTLS_ERR_RSA_RNG_FAILED; + goto cleanup; + } 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 ) ); + /* Compute Vf^-1 as R * (R Vf)^-1 to avoid leaks from inv_mod. */ + MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &R, ctx->len - 1, f_rng, p_rng ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vf, &R ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) ); + + /* At this point, Vi is invertible mod N if and only if both Vf and R + * are invertible mod N. If one of them isn't, we don't need to know + * which one, we just loop and choose new values for both of them. + * (Each iteration succeeds with overwhelming probability.) */ + ret = mbedtls_mpi_inv_mod( &ctx->Vi, &ctx->Vi, &ctx->N ); + if( ret != 0 && ret != MBEDTLS_ERR_MPI_NOT_ACCEPTABLE ) + goto cleanup; + + } while( ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE ); + + /* Finish the computation of Vf^-1 = R * (R Vf)^-1 */ + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &R ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->N ) ); + + /* Blinding value: Vi = Vf^(-e) mod N + * (Vi already contains Vf^-1 at this point) */ MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vi, &ctx->Vi, &ctx->E, &ctx->N, &ctx->RN ) ); cleanup: + mbedtls_mpi_free( &R ); + return( ret ); } @@ -2563,7 +2613,7 @@ void mbedtls_rsa_free( mbedtls_rsa_context *ctx ) #if defined(MBEDTLS_PKCS1_V15) static int myrand( void *rng_state, unsigned char *output, size_t len ) { -#if !defined(__OpenBSD__) +#if !defined(__OpenBSD__) && !defined(__NetBSD__) size_t i; if( rng_state != NULL ) @@ -2576,7 +2626,7 @@ static int myrand( void *rng_state, unsigned char *output, size_t len ) rng_state = NULL; arc4random_buf( output, len ); -#endif /* !OpenBSD */ +#endif /* !OpenBSD && !NetBSD */ return( 0 ); } |