mbed TLS Build
Dependents: Encrypt_Decrypt1 mbed_blink_tls encrypt encrypt
Diff: library/rsa.c
- Revision:
- 0:cdf462088d13
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/library/rsa.c Thu Jan 05 00:18:44 2017 +0000 @@ -0,0 +1,1730 @@ +/* + * 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 + * + */ + +#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/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 + +/* + * 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; +} + +#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 P1, Q1, 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( &P1 ); mbedtls_mpi_init( &Q1 ); + 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 ); + + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P1, &ctx->P, 1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q1, &ctx->Q, 1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &P1, &Q1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H ) ); + } + while( mbedtls_mpi_cmp_int( &G, 1 ) != 0 ); + + /* + * 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 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->DP, &ctx->D, &P1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->DQ, &ctx->D, &Q1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->QP, &ctx->Q, &ctx->P ) ); + + ctx->len = ( mbedtls_mpi_bitlen( &ctx->N ) + 7 ) >> 3; + +cleanup: + + mbedtls_mpi_free( &P1 ); mbedtls_mpi_free( &Q1 ); 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( !ctx->N.p || !ctx->E.p ) + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + + if( ( ctx->N.p[0] & 1 ) == 0 || + ( ctx->E.p[0] & 1 ) == 0 ) + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + + if( mbedtls_mpi_bitlen( &ctx->N ) < 128 || + mbedtls_mpi_bitlen( &ctx->N ) > MBEDTLS_MPI_MAX_BITS ) + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + + if( 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 a private RSA key + */ +int mbedtls_rsa_check_privkey( const mbedtls_rsa_context *ctx ) +{ + int ret; + mbedtls_mpi PQ, DE, P1, Q1, H, I, G, G2, L1, L2, DP, DQ, QP; + + if( ( ret = mbedtls_rsa_check_pubkey( ctx ) ) != 0 ) + return( ret ); + + if( !ctx->P.p || !ctx->Q.p || !ctx->D.p ) + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ); + + mbedtls_mpi_init( &PQ ); mbedtls_mpi_init( &DE ); mbedtls_mpi_init( &P1 ); mbedtls_mpi_init( &Q1 ); + mbedtls_mpi_init( &H ); mbedtls_mpi_init( &I ); mbedtls_mpi_init( &G ); mbedtls_mpi_init( &G2 ); + mbedtls_mpi_init( &L1 ); mbedtls_mpi_init( &L2 ); mbedtls_mpi_init( &DP ); mbedtls_mpi_init( &DQ ); + mbedtls_mpi_init( &QP ); + + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &PQ, &ctx->P, &ctx->Q ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &DE, &ctx->D, &ctx->E ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &P1, &ctx->P, 1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &Q1, &ctx->Q, 1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &H, &P1, &Q1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G, &ctx->E, &H ) ); + + MBEDTLS_MPI_CHK( mbedtls_mpi_gcd( &G2, &P1, &Q1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_div_mpi( &L1, &L2, &H, &G2 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &I, &DE, &L1 ) ); + + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &DP, &ctx->D, &P1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &DQ, &ctx->D, &Q1 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &QP, &ctx->Q, &ctx->P ) ); + /* + * Check for a valid PKCS1v2 private key + */ + if( mbedtls_mpi_cmp_mpi( &PQ, &ctx->N ) != 0 || + mbedtls_mpi_cmp_mpi( &DP, &ctx->DP ) != 0 || + mbedtls_mpi_cmp_mpi( &DQ, &ctx->DQ ) != 0 || + mbedtls_mpi_cmp_mpi( &QP, &ctx->QP ) != 0 || + mbedtls_mpi_cmp_int( &L2, 0 ) != 0 || + mbedtls_mpi_cmp_int( &I, 1 ) != 0 || + mbedtls_mpi_cmp_int( &G, 1 ) != 0 ) + { + ret = MBEDTLS_ERR_RSA_KEY_CHECK_FAILED; + } + +cleanup: + mbedtls_mpi_free( &PQ ); mbedtls_mpi_free( &DE ); mbedtls_mpi_free( &P1 ); mbedtls_mpi_free( &Q1 ); + mbedtls_mpi_free( &H ); mbedtls_mpi_free( &I ); mbedtls_mpi_free( &G ); mbedtls_mpi_free( &G2 ); + mbedtls_mpi_free( &L1 ); mbedtls_mpi_free( &L2 ); mbedtls_mpi_free( &DP ); mbedtls_mpi_free( &DQ ); + mbedtls_mpi_free( &QP ); + + if( ret == MBEDTLS_ERR_RSA_KEY_CHECK_FAILED ) + return( ret ); + + if( ret != 0 ) + return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED + ret ); + + 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; + + 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 ); +} + +/* + * 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; + mbedtls_mpi T, T1, T2; + + /* Make sure we have private key info, prevent possible misuse */ + if( ctx->P.p == NULL || ctx->Q.p == NULL || ctx->D.p == NULL ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + mbedtls_mpi_init( &T ); mbedtls_mpi_init( &T1 ); mbedtls_mpi_init( &T2 ); + +#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; + } + + 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 ) ); + } + +#if defined(MBEDTLS_RSA_NO_CRT) + MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T, &T, &ctx->D, &ctx->N, &ctx->RN ) ); +#else + /* + * faster decryption using the CRT + * + * T1 = input ^ dP mod P + * T2 = input ^ dQ mod Q + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T1, &T, &ctx->DP, &ctx->P, &ctx->RP ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &T2, &T, &ctx->DQ, &ctx->Q, &ctx->RQ ) ); + + /* + * T = (T1 - T2) * (Q^-1 mod P) mod P + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_sub_mpi( &T, &T1, &T2 ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T1, &T, &ctx->QP ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &T, &T1, &ctx->P ) ); + + /* + * T = T2 + T * Q + */ + MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &T1, &T, &ctx->Q ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_add_mpi( &T, &T2, &T1 ) ); +#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 ) ); + } + + 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( &T ); mbedtls_mpi_free( &T1 ); mbedtls_mpi_free( &T2 ); + + 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 void 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; + + 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; + + mbedtls_md_starts( md_ctx ); + mbedtls_md_update( md_ctx, src, slen ); + mbedtls_md_update( md_ctx, counter, 4 ); + mbedtls_md_finish( md_ctx, mask ); + + for( i = 0; i < use_len; ++i ) + *p++ ^= mask[i]; + + counter[3]++; + + dlen -= use_len; + } +} +#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 */ + mbedtls_md( md_info, label, label_len, p ); + 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 ) + { + mbedtls_md_free( &md_ctx ); + return( ret ); + } + + /* maskedDB: Apply dbMask to DB */ + mgf_mask( output + hlen + 1, olen - hlen - 1, output + 1, hlen, + &md_ctx ); + + /* maskedSeed: Apply seedMask to seed */ + mgf_mask( output + 1, hlen, output + hlen + 1, olen - hlen - 1, + &md_ctx ); + + mbedtls_md_free( &md_ctx ); + + 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 ) + return( ret ); + + /* + * 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 ); + return( ret ); + } + + + /* Generate lHash */ + mbedtls_md( md_info, label, label_len, lhash ); + + /* seed: Apply seedMask to maskedSeed */ + mgf_mask( buf + 1, hlen, buf + hlen + 1, ilen - hlen - 1, + &md_ctx ); + + /* DB: Apply dbMask to maskedDB */ + mgf_mask( buf + hlen + 1, ilen - hlen - 1, buf + 1, hlen, + &md_ctx ); + + mbedtls_md_free( &md_ctx ); + + /* + * 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 ) + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + + if( ilen - ( p - buf ) > output_max_len ) + return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE ); + + *olen = ilen - (p - buf); + memcpy( output, p, *olen ); + + return( 0 ); +} +#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 ) + return( ret ); + + 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 ) + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + + if( ilen - ( p - buf ) > output_max_len ) + return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE ); + + *olen = ilen - (p - buf); + memcpy( output, p, *olen ); + + return( 0 ); +} +#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 ) + { + mbedtls_md_free( &md_ctx ); + return( ret ); + } + + /* Generate H = Hash( M' ) */ + mbedtls_md_starts( &md_ctx ); + mbedtls_md_update( &md_ctx, p, 8 ); + mbedtls_md_update( &md_ctx, hash, hashlen ); + mbedtls_md_update( &md_ctx, salt, slen ); + mbedtls_md_finish( &md_ctx, p ); + + /* Compensate for boundary condition when applying mask */ + if( msb % 8 == 0 ) + offset = 1; + + /* maskedDB: Apply dbMask to DB */ + mgf_mask( sig + offset, olen - hlen - 1 - offset, p, hlen, &md_ctx ); + + mbedtls_md_free( &md_ctx ); + + msb = mbedtls_mpi_bitlen( &ctx->N ) - 1; + sig[0] &= 0xFF >> ( olen * 8 - msb ); + + p += hlen; + *p++ = 0xBC; + + 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 + */ +/* + * 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 ) +{ + size_t nb_pad, olen, oid_size = 0; + unsigned char *p = sig; + const char *oid = NULL; + unsigned char *sig_try = NULL, *verif = NULL; + size_t i; + unsigned char diff; + volatile unsigned char diff_no_optimize; + int ret; + + if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + olen = ctx->len; + nb_pad = olen - 3; + + 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 ); + + nb_pad -= 10 + oid_size; + + hashlen = mbedtls_md_get_size( md_info ); + } + + nb_pad -= hashlen; + + if( ( nb_pad < 8 ) || ( nb_pad > olen ) ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + *p++ = 0; + *p++ = MBEDTLS_RSA_SIGN; + memset( p, 0xFF, nb_pad ); + p += nb_pad; + *p++ = 0; + + if( md_alg == MBEDTLS_MD_NONE ) + { + memcpy( p, hash, hashlen ); + } + else + { + /* + * DigestInfo ::= SEQUENCE { + * digestAlgorithm DigestAlgorithmIdentifier, + * digest Digest } + * + * DigestAlgorithmIdentifier ::= AlgorithmIdentifier + * + * Digest ::= OCTET STRING + */ + *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++ = oid_size & 0xFF; + memcpy( p, oid, oid_size ); + p += oid_size; + *p++ = MBEDTLS_ASN1_NULL; + *p++ = 0x00; + *p++ = MBEDTLS_ASN1_OCTET_STRING; + *p++ = hashlen; + memcpy( p, hash, hashlen ); + } + + if( mode == MBEDTLS_RSA_PUBLIC ) + return( mbedtls_rsa_public( ctx, sig, sig ) ); + + /* + * 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 ) ); + + /* Compare in constant time just in case */ + for( diff = 0, i = 0; i < ctx->len; i++ ) + diff |= verif[i] ^ sig[i]; + diff_no_optimize = diff; + + if( diff_no_optimize != 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 result[MBEDTLS_MD_MAX_SIZE]; + unsigned char zeros[8]; + unsigned int hlen; + size_t slen, 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 ); + slen = siglen - hlen - 1; /* Currently length of salt + padding */ + + memset( zeros, 0, 8 ); + + /* + * Note: EMSA-PSS verification is over the length of N - 1 bits + */ + msb = mbedtls_mpi_bitlen( &ctx->N ) - 1; + + /* Compensate for boundary condition when applying mask */ + if( msb % 8 == 0 ) + { + p++; + siglen -= 1; + } + if( buf[0] >> ( 8 - siglen * 8 + msb ) ) + return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA ); + + mbedtls_md_init( &md_ctx ); + if( ( ret = mbedtls_md_setup( &md_ctx, md_info, 0 ) ) != 0 ) + { + mbedtls_md_free( &md_ctx ); + return( ret ); + } + + mgf_mask( p, siglen - hlen - 1, p + siglen - hlen - 1, hlen, &md_ctx ); + + buf[0] &= 0xFF >> ( siglen * 8 - msb ); + + while( p < buf + siglen && *p == 0 ) + p++; + + if( p == buf + siglen || + *p++ != 0x01 ) + { + mbedtls_md_free( &md_ctx ); + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + } + + /* Actual salt len */ + slen -= p - buf; + + if( expected_salt_len != MBEDTLS_RSA_SALT_LEN_ANY && + slen != (size_t) expected_salt_len ) + { + mbedtls_md_free( &md_ctx ); + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + } + + /* + * Generate H = Hash( M' ) + */ + mbedtls_md_starts( &md_ctx ); + mbedtls_md_update( &md_ctx, zeros, 8 ); + mbedtls_md_update( &md_ctx, hash, hashlen ); + mbedtls_md_update( &md_ctx, p, slen ); + mbedtls_md_finish( &md_ctx, result ); + + mbedtls_md_free( &md_ctx ); + + if( memcmp( p + slen, result, hlen ) == 0 ) + return( 0 ); + else + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); +} + +/* + * 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; + size_t len, siglen, asn1_len; + unsigned char *p, *end; + mbedtls_md_type_t msg_md_alg; + const mbedtls_md_info_t *md_info; + mbedtls_asn1_buf oid; + 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 ); + + 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( *p++ != 0 || *p++ != MBEDTLS_RSA_SIGN ) + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + + while( *p != 0 ) + { + if( p >= buf + siglen - 1 || *p != 0xFF ) + return( MBEDTLS_ERR_RSA_INVALID_PADDING ); + p++; + } + p++; + + len = siglen - ( p - buf ); + + if( len == hashlen && md_alg == MBEDTLS_MD_NONE ) + { + if( memcmp( p, hash, hashlen ) == 0 ) + return( 0 ); + else + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + } + + 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 ); + + end = p + len; + + /* + * Parse the ASN.1 structure inside the PKCS#1 v1.5 structure + */ + if( ( ret = mbedtls_asn1_get_tag( &p, end, &asn1_len, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + if( asn1_len + 2 != len ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + if( ( ret = mbedtls_asn1_get_tag( &p, end, &asn1_len, + MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + if( asn1_len + 6 + hashlen != len ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + if( ( ret = mbedtls_asn1_get_tag( &p, end, &oid.len, MBEDTLS_ASN1_OID ) ) != 0 ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + oid.p = p; + p += oid.len; + + if( mbedtls_oid_get_md_alg( &oid, &msg_md_alg ) != 0 ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + if( md_alg != msg_md_alg ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + /* + * assume the algorithm parameters must be NULL + */ + if( ( ret = mbedtls_asn1_get_tag( &p, end, &asn1_len, MBEDTLS_ASN1_NULL ) ) != 0 ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + if( ( ret = mbedtls_asn1_get_tag( &p, end, &asn1_len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + if( asn1_len != hashlen ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + if( memcmp( p, hash, hashlen ) != 0 ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + p += hashlen; + + if( p != end ) + return( MBEDTLS_ERR_RSA_VERIFY_FAILED ); + + return( 0 ); +} +#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 ) ); + 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->RN, &src->RN ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RP, &src->RP ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &dst->RQ, &src->RQ ) ); + + 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->RQ ); mbedtls_mpi_free( &ctx->RP ); mbedtls_mpi_free( &ctx->RN ); + mbedtls_mpi_free( &ctx->QP ); mbedtls_mpi_free( &ctx->DQ ); mbedtls_mpi_free( &ctx->DP ); + mbedtls_mpi_free( &ctx->Q ); mbedtls_mpi_free( &ctx->P ); mbedtls_mpi_free( &ctx->D ); + mbedtls_mpi_free( &ctx->E ); mbedtls_mpi_free( &ctx->N ); + +#if defined(MBEDTLS_THREADING_C) + mbedtls_mutex_free( &ctx->mutex ); +#endif +} + +#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 RSA_DP "C1ACF567564274FB07A0BBAD5D26E298" \ + "3C94D22288ACD763FD8E5600ED4A702D" \ + "F84198A5F06C2E72236AE490C93F07F8" \ + "3CC559CD27BC2D1CA488811730BB5725" + +#define RSA_DQ "4959CBF6F8FEF750AEE6977C155579C7" \ + "D8AAEA56749EA28623272E4F7D0592AF" \ + "7C1F1313CAC9471B5C523BFE592F517B" \ + "407A1BD76C164B93DA2D32A383E58357" + +#define RSA_QP "9AE7FBC99546432DF71896FC239EADAE" \ + "F38D18D2B2F0E2DD275AA977E2BF4411" \ + "F5A3B2A5D33605AEBBCCBA7FEB9F2D2F" \ + "A74206CEC169D74BF5A8C50D6F48EA08" + +#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_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 ); + + rsa.len = KEY_LEN; + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.N , 16, RSA_N ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.E , 16, RSA_E ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.D , 16, RSA_D ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.P , 16, RSA_P ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.Q , 16, RSA_Q ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.DP, 16, RSA_DP ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.DQ, 16, RSA_DQ ) ); + MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &rsa.QP, 16, RSA_QP ) ); + + 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" ); + + return( 1 ); + } + + 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" ); + + return( 1 ); + } + + 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" ); + + return( 1 ); + } + + if( memcmp( rsa_decrypted, rsa_plaintext, len ) != 0 ) + { + if( verbose != 0 ) + mbedtls_printf( "failed\n" ); + + return( 1 ); + } + + if( verbose != 0 ) + mbedtls_printf( "passed\n" ); + +#if defined(MBEDTLS_SHA1_C) + if( verbose != 0 ) + mbedtls_printf( " PKCS#1 data sign : " ); + + mbedtls_sha1( rsa_plaintext, PT_LEN, sha1sum ); + + 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" ); + + return( 1 ); + } + + 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" ); + + return( 1 ); + } + + if( verbose != 0 ) + mbedtls_printf( "passed\n" ); +#endif /* MBEDTLS_SHA1_C */ + + if( verbose != 0 ) + mbedtls_printf( "\n" ); + +cleanup: + mbedtls_rsa_free( &rsa ); +#else /* MBEDTLS_PKCS1_V15 */ + ((void) verbose); +#endif /* MBEDTLS_PKCS1_V15 */ + return( ret ); +} + +#endif /* MBEDTLS_SELF_TEST */ + +#endif /* MBEDTLS_RSA_C */