Marco Zecchini / Mbed OS Example_RTOS

Rtos API example

mbed-os/features/mbedtls/src/dhm.c@0:9fca2b23d0ba, 2019-02-23 (annotated)

Committer:
marcozecchini
Date:
Sat Feb 23 12:13:36 2019 +0000
Revision:
0:9fca2b23d0ba
final commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
marcozecchini 0:9fca2b23d0ba 1 /*
marcozecchini 0:9fca2b23d0ba 2 * Diffie-Hellman-Merkle key exchange
marcozecchini 0:9fca2b23d0ba 3 *
marcozecchini 0:9fca2b23d0ba 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
marcozecchini 0:9fca2b23d0ba 5 * SPDX-License-Identifier: Apache-2.0
marcozecchini 0:9fca2b23d0ba 6 *
marcozecchini 0:9fca2b23d0ba 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
marcozecchini 0:9fca2b23d0ba 8 * not use this file except in compliance with the License.
marcozecchini 0:9fca2b23d0ba 9 * You may obtain a copy of the License at
marcozecchini 0:9fca2b23d0ba 10 *
marcozecchini 0:9fca2b23d0ba 11 * http://www.apache.org/licenses/LICENSE-2.0
marcozecchini 0:9fca2b23d0ba 12 *
marcozecchini 0:9fca2b23d0ba 13 * Unless required by applicable law or agreed to in writing, software
marcozecchini 0:9fca2b23d0ba 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
marcozecchini 0:9fca2b23d0ba 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
marcozecchini 0:9fca2b23d0ba 16 * See the License for the specific language governing permissions and
marcozecchini 0:9fca2b23d0ba 17 * limitations under the License.
marcozecchini 0:9fca2b23d0ba 18 *
marcozecchini 0:9fca2b23d0ba 19 * This file is part of mbed TLS (https://tls.mbed.org)
marcozecchini 0:9fca2b23d0ba 20 */
marcozecchini 0:9fca2b23d0ba 21 /*
marcozecchini 0:9fca2b23d0ba 22 * The following sources were referenced in the design of this implementation
marcozecchini 0:9fca2b23d0ba 23 * of the Diffie-Hellman-Merkle algorithm:
marcozecchini 0:9fca2b23d0ba 24 *
marcozecchini 0:9fca2b23d0ba 25 * [1] Handbook of Applied Cryptography - 1997, Chapter 12
marcozecchini 0:9fca2b23d0ba 26 * Menezes, van Oorschot and Vanstone
marcozecchini 0:9fca2b23d0ba 27 *
marcozecchini 0:9fca2b23d0ba 28 */
marcozecchini 0:9fca2b23d0ba 29
marcozecchini 0:9fca2b23d0ba 30 #if !defined(MBEDTLS_CONFIG_FILE)
marcozecchini 0:9fca2b23d0ba 31 #include "mbedtls/config.h"
marcozecchini 0:9fca2b23d0ba 32 #else
marcozecchini 0:9fca2b23d0ba 33 #include MBEDTLS_CONFIG_FILE
marcozecchini 0:9fca2b23d0ba 34 #endif
marcozecchini 0:9fca2b23d0ba 35
marcozecchini 0:9fca2b23d0ba 36 #if defined(MBEDTLS_DHM_C)
marcozecchini 0:9fca2b23d0ba 37
marcozecchini 0:9fca2b23d0ba 38 #include "mbedtls/dhm.h"
marcozecchini 0:9fca2b23d0ba 39
marcozecchini 0:9fca2b23d0ba 40 #include <string.h>
marcozecchini 0:9fca2b23d0ba 41
marcozecchini 0:9fca2b23d0ba 42 #if defined(MBEDTLS_PEM_PARSE_C)
marcozecchini 0:9fca2b23d0ba 43 #include "mbedtls/pem.h"
marcozecchini 0:9fca2b23d0ba 44 #endif
marcozecchini 0:9fca2b23d0ba 45
marcozecchini 0:9fca2b23d0ba 46 #if defined(MBEDTLS_ASN1_PARSE_C)
marcozecchini 0:9fca2b23d0ba 47 #include "mbedtls/asn1.h"
marcozecchini 0:9fca2b23d0ba 48 #endif
marcozecchini 0:9fca2b23d0ba 49
marcozecchini 0:9fca2b23d0ba 50 #if defined(MBEDTLS_PLATFORM_C)
marcozecchini 0:9fca2b23d0ba 51 #include "mbedtls/platform.h"
marcozecchini 0:9fca2b23d0ba 52 #else
marcozecchini 0:9fca2b23d0ba 53 #include <stdlib.h>
marcozecchini 0:9fca2b23d0ba 54 #include <stdio.h>
marcozecchini 0:9fca2b23d0ba 55 #define mbedtls_printf printf
marcozecchini 0:9fca2b23d0ba 56 #define mbedtls_calloc calloc
marcozecchini 0:9fca2b23d0ba 57 #define mbedtls_free free
marcozecchini 0:9fca2b23d0ba 58 #endif
marcozecchini 0:9fca2b23d0ba 59
marcozecchini 0:9fca2b23d0ba 60 /* Implementation that should never be optimized out by the compiler */
marcozecchini 0:9fca2b23d0ba 61 static void mbedtls_zeroize( void *v, size_t n ) {
marcozecchini 0:9fca2b23d0ba 62 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
marcozecchini 0:9fca2b23d0ba 63 }
marcozecchini 0:9fca2b23d0ba 64
marcozecchini 0:9fca2b23d0ba 65 /*
marcozecchini 0:9fca2b23d0ba 66 * helper to validate the mbedtls_mpi size and import it
marcozecchini 0:9fca2b23d0ba 67 */
marcozecchini 0:9fca2b23d0ba 68 static int dhm_read_bignum( mbedtls_mpi *X,
marcozecchini 0:9fca2b23d0ba 69 unsigned char **p,
marcozecchini 0:9fca2b23d0ba 70 const unsigned char *end )
marcozecchini 0:9fca2b23d0ba 71 {
marcozecchini 0:9fca2b23d0ba 72 int ret, n;
marcozecchini 0:9fca2b23d0ba 73
marcozecchini 0:9fca2b23d0ba 74 if( end - *p < 2 )
marcozecchini 0:9fca2b23d0ba 75 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
marcozecchini 0:9fca2b23d0ba 76
marcozecchini 0:9fca2b23d0ba 77 n = ( (*p)[0] << 8 ) | (*p)[1];
marcozecchini 0:9fca2b23d0ba 78 (*p) += 2;
marcozecchini 0:9fca2b23d0ba 79
marcozecchini 0:9fca2b23d0ba 80 if( (int)( end - *p ) < n )
marcozecchini 0:9fca2b23d0ba 81 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
marcozecchini 0:9fca2b23d0ba 82
marcozecchini 0:9fca2b23d0ba 83 if( ( ret = mbedtls_mpi_read_binary( X, *p, n ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 84 return( MBEDTLS_ERR_DHM_READ_PARAMS_FAILED + ret );
marcozecchini 0:9fca2b23d0ba 85
marcozecchini 0:9fca2b23d0ba 86 (*p) += n;
marcozecchini 0:9fca2b23d0ba 87
marcozecchini 0:9fca2b23d0ba 88 return( 0 );
marcozecchini 0:9fca2b23d0ba 89 }
marcozecchini 0:9fca2b23d0ba 90
marcozecchini 0:9fca2b23d0ba 91 /*
marcozecchini 0:9fca2b23d0ba 92 * Verify sanity of parameter with regards to P
marcozecchini 0:9fca2b23d0ba 93 *
marcozecchini 0:9fca2b23d0ba 94 * Parameter should be: 2 <= public_param <= P - 2
marcozecchini 0:9fca2b23d0ba 95 *
marcozecchini 0:9fca2b23d0ba 96 * For more information on the attack, see:
marcozecchini 0:9fca2b23d0ba 97 * http://www.cl.cam.ac.uk/~rja14/Papers/psandqs.pdf
marcozecchini 0:9fca2b23d0ba 98 * http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2005-2643
marcozecchini 0:9fca2b23d0ba 99 */
marcozecchini 0:9fca2b23d0ba 100 static int dhm_check_range( const mbedtls_mpi *param, const mbedtls_mpi *P )
marcozecchini 0:9fca2b23d0ba 101 {
marcozecchini 0:9fca2b23d0ba 102 mbedtls_mpi L, U;
marcozecchini 0:9fca2b23d0ba 103 int ret = MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
marcozecchini 0:9fca2b23d0ba 104
marcozecchini 0:9fca2b23d0ba 105 mbedtls_mpi_init( &L ); mbedtls_mpi_init( &U );
marcozecchini 0:9fca2b23d0ba 106
marcozecchini 0:9fca2b23d0ba 107 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &L, 2 ) );
marcozecchini 0:9fca2b23d0ba 108 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &U, P, 2 ) );
marcozecchini 0:9fca2b23d0ba 109
marcozecchini 0:9fca2b23d0ba 110 if( mbedtls_mpi_cmp_mpi( param, &L ) >= 0 &&
marcozecchini 0:9fca2b23d0ba 111 mbedtls_mpi_cmp_mpi( param, &U ) <= 0 )
marcozecchini 0:9fca2b23d0ba 112 {
marcozecchini 0:9fca2b23d0ba 113 ret = 0;
marcozecchini 0:9fca2b23d0ba 114 }
marcozecchini 0:9fca2b23d0ba 115
marcozecchini 0:9fca2b23d0ba 116 cleanup:
marcozecchini 0:9fca2b23d0ba 117 mbedtls_mpi_free( &L ); mbedtls_mpi_free( &U );
marcozecchini 0:9fca2b23d0ba 118 return( ret );
marcozecchini 0:9fca2b23d0ba 119 }
marcozecchini 0:9fca2b23d0ba 120
marcozecchini 0:9fca2b23d0ba 121 void mbedtls_dhm_init( mbedtls_dhm_context *ctx )
marcozecchini 0:9fca2b23d0ba 122 {
marcozecchini 0:9fca2b23d0ba 123 memset( ctx, 0, sizeof( mbedtls_dhm_context ) );
marcozecchini 0:9fca2b23d0ba 124 }
marcozecchini 0:9fca2b23d0ba 125
marcozecchini 0:9fca2b23d0ba 126 /*
marcozecchini 0:9fca2b23d0ba 127 * Parse the ServerKeyExchange parameters
marcozecchini 0:9fca2b23d0ba 128 */
marcozecchini 0:9fca2b23d0ba 129 int mbedtls_dhm_read_params( mbedtls_dhm_context *ctx,
marcozecchini 0:9fca2b23d0ba 130 unsigned char **p,
marcozecchini 0:9fca2b23d0ba 131 const unsigned char *end )
marcozecchini 0:9fca2b23d0ba 132 {
marcozecchini 0:9fca2b23d0ba 133 int ret;
marcozecchini 0:9fca2b23d0ba 134
marcozecchini 0:9fca2b23d0ba 135 if( ( ret = dhm_read_bignum( &ctx->P, p, end ) ) != 0 ||
marcozecchini 0:9fca2b23d0ba 136 ( ret = dhm_read_bignum( &ctx->G, p, end ) ) != 0 ||
marcozecchini 0:9fca2b23d0ba 137 ( ret = dhm_read_bignum( &ctx->GY, p, end ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 138 return( ret );
marcozecchini 0:9fca2b23d0ba 139
marcozecchini 0:9fca2b23d0ba 140 if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 141 return( ret );
marcozecchini 0:9fca2b23d0ba 142
marcozecchini 0:9fca2b23d0ba 143 ctx->len = mbedtls_mpi_size( &ctx->P );
marcozecchini 0:9fca2b23d0ba 144
marcozecchini 0:9fca2b23d0ba 145 return( 0 );
marcozecchini 0:9fca2b23d0ba 146 }
marcozecchini 0:9fca2b23d0ba 147
marcozecchini 0:9fca2b23d0ba 148 /*
marcozecchini 0:9fca2b23d0ba 149 * Setup and write the ServerKeyExchange parameters
marcozecchini 0:9fca2b23d0ba 150 */
marcozecchini 0:9fca2b23d0ba 151 int mbedtls_dhm_make_params( mbedtls_dhm_context *ctx, int x_size,
marcozecchini 0:9fca2b23d0ba 152 unsigned char *output, size_t *olen,
marcozecchini 0:9fca2b23d0ba 153 int (*f_rng)(void *, unsigned char *, size_t),
marcozecchini 0:9fca2b23d0ba 154 void *p_rng )
marcozecchini 0:9fca2b23d0ba 155 {
marcozecchini 0:9fca2b23d0ba 156 int ret, count = 0;
marcozecchini 0:9fca2b23d0ba 157 size_t n1, n2, n3;
marcozecchini 0:9fca2b23d0ba 158 unsigned char *p;
marcozecchini 0:9fca2b23d0ba 159
marcozecchini 0:9fca2b23d0ba 160 if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
marcozecchini 0:9fca2b23d0ba 161 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
marcozecchini 0:9fca2b23d0ba 162
marcozecchini 0:9fca2b23d0ba 163 /*
marcozecchini 0:9fca2b23d0ba 164 * Generate X as large as possible ( < P )
marcozecchini 0:9fca2b23d0ba 165 */
marcozecchini 0:9fca2b23d0ba 166 do
marcozecchini 0:9fca2b23d0ba 167 {
marcozecchini 0:9fca2b23d0ba 168 MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->X, x_size, f_rng, p_rng ) );
marcozecchini 0:9fca2b23d0ba 169
marcozecchini 0:9fca2b23d0ba 170 while( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 )
marcozecchini 0:9fca2b23d0ba 171 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->X, 1 ) );
marcozecchini 0:9fca2b23d0ba 172
marcozecchini 0:9fca2b23d0ba 173 if( count++ > 10 )
marcozecchini 0:9fca2b23d0ba 174 return( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED );
marcozecchini 0:9fca2b23d0ba 175 }
marcozecchini 0:9fca2b23d0ba 176 while( dhm_check_range( &ctx->X, &ctx->P ) != 0 );
marcozecchini 0:9fca2b23d0ba 177
marcozecchini 0:9fca2b23d0ba 178 /*
marcozecchini 0:9fca2b23d0ba 179 * Calculate GX = G^X mod P
marcozecchini 0:9fca2b23d0ba 180 */
marcozecchini 0:9fca2b23d0ba 181 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X,
marcozecchini 0:9fca2b23d0ba 182 &ctx->P , &ctx->RP ) );
marcozecchini 0:9fca2b23d0ba 183
marcozecchini 0:9fca2b23d0ba 184 if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 185 return( ret );
marcozecchini 0:9fca2b23d0ba 186
marcozecchini 0:9fca2b23d0ba 187 /*
marcozecchini 0:9fca2b23d0ba 188 * export P, G, GX
marcozecchini 0:9fca2b23d0ba 189 */
marcozecchini 0:9fca2b23d0ba 190 #define DHM_MPI_EXPORT(X,n) \
marcozecchini 0:9fca2b23d0ba 191 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, p + 2, n ) ); \
marcozecchini 0:9fca2b23d0ba 192 *p++ = (unsigned char)( n >> 8 ); \
marcozecchini 0:9fca2b23d0ba 193 *p++ = (unsigned char)( n ); p += n;
marcozecchini 0:9fca2b23d0ba 194
marcozecchini 0:9fca2b23d0ba 195 n1 = mbedtls_mpi_size( &ctx->P );
marcozecchini 0:9fca2b23d0ba 196 n2 = mbedtls_mpi_size( &ctx->G );
marcozecchini 0:9fca2b23d0ba 197 n3 = mbedtls_mpi_size( &ctx->GX );
marcozecchini 0:9fca2b23d0ba 198
marcozecchini 0:9fca2b23d0ba 199 p = output;
marcozecchini 0:9fca2b23d0ba 200 DHM_MPI_EXPORT( &ctx->P , n1 );
marcozecchini 0:9fca2b23d0ba 201 DHM_MPI_EXPORT( &ctx->G , n2 );
marcozecchini 0:9fca2b23d0ba 202 DHM_MPI_EXPORT( &ctx->GX, n3 );
marcozecchini 0:9fca2b23d0ba 203
marcozecchini 0:9fca2b23d0ba 204 *olen = p - output;
marcozecchini 0:9fca2b23d0ba 205
marcozecchini 0:9fca2b23d0ba 206 ctx->len = n1;
marcozecchini 0:9fca2b23d0ba 207
marcozecchini 0:9fca2b23d0ba 208 cleanup:
marcozecchini 0:9fca2b23d0ba 209
marcozecchini 0:9fca2b23d0ba 210 if( ret != 0 )
marcozecchini 0:9fca2b23d0ba 211 return( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED + ret );
marcozecchini 0:9fca2b23d0ba 212
marcozecchini 0:9fca2b23d0ba 213 return( 0 );
marcozecchini 0:9fca2b23d0ba 214 }
marcozecchini 0:9fca2b23d0ba 215
marcozecchini 0:9fca2b23d0ba 216 /*
marcozecchini 0:9fca2b23d0ba 217 * Import the peer's public value G^Y
marcozecchini 0:9fca2b23d0ba 218 */
marcozecchini 0:9fca2b23d0ba 219 int mbedtls_dhm_read_public( mbedtls_dhm_context *ctx,
marcozecchini 0:9fca2b23d0ba 220 const unsigned char *input, size_t ilen )
marcozecchini 0:9fca2b23d0ba 221 {
marcozecchini 0:9fca2b23d0ba 222 int ret;
marcozecchini 0:9fca2b23d0ba 223
marcozecchini 0:9fca2b23d0ba 224 if( ctx == NULL || ilen < 1 || ilen > ctx->len )
marcozecchini 0:9fca2b23d0ba 225 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
marcozecchini 0:9fca2b23d0ba 226
marcozecchini 0:9fca2b23d0ba 227 if( ( ret = mbedtls_mpi_read_binary( &ctx->GY, input, ilen ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 228 return( MBEDTLS_ERR_DHM_READ_PUBLIC_FAILED + ret );
marcozecchini 0:9fca2b23d0ba 229
marcozecchini 0:9fca2b23d0ba 230 return( 0 );
marcozecchini 0:9fca2b23d0ba 231 }
marcozecchini 0:9fca2b23d0ba 232
marcozecchini 0:9fca2b23d0ba 233 /*
marcozecchini 0:9fca2b23d0ba 234 * Create own private value X and export G^X
marcozecchini 0:9fca2b23d0ba 235 */
marcozecchini 0:9fca2b23d0ba 236 int mbedtls_dhm_make_public( mbedtls_dhm_context *ctx, int x_size,
marcozecchini 0:9fca2b23d0ba 237 unsigned char *output, size_t olen,
marcozecchini 0:9fca2b23d0ba 238 int (*f_rng)(void *, unsigned char *, size_t),
marcozecchini 0:9fca2b23d0ba 239 void *p_rng )
marcozecchini 0:9fca2b23d0ba 240 {
marcozecchini 0:9fca2b23d0ba 241 int ret, count = 0;
marcozecchini 0:9fca2b23d0ba 242
marcozecchini 0:9fca2b23d0ba 243 if( ctx == NULL || olen < 1 || olen > ctx->len )
marcozecchini 0:9fca2b23d0ba 244 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
marcozecchini 0:9fca2b23d0ba 245
marcozecchini 0:9fca2b23d0ba 246 if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
marcozecchini 0:9fca2b23d0ba 247 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
marcozecchini 0:9fca2b23d0ba 248
marcozecchini 0:9fca2b23d0ba 249 /*
marcozecchini 0:9fca2b23d0ba 250 * generate X and calculate GX = G^X mod P
marcozecchini 0:9fca2b23d0ba 251 */
marcozecchini 0:9fca2b23d0ba 252 do
marcozecchini 0:9fca2b23d0ba 253 {
marcozecchini 0:9fca2b23d0ba 254 MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->X, x_size, f_rng, p_rng ) );
marcozecchini 0:9fca2b23d0ba 255
marcozecchini 0:9fca2b23d0ba 256 while( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 )
marcozecchini 0:9fca2b23d0ba 257 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->X, 1 ) );
marcozecchini 0:9fca2b23d0ba 258
marcozecchini 0:9fca2b23d0ba 259 if( count++ > 10 )
marcozecchini 0:9fca2b23d0ba 260 return( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED );
marcozecchini 0:9fca2b23d0ba 261 }
marcozecchini 0:9fca2b23d0ba 262 while( dhm_check_range( &ctx->X, &ctx->P ) != 0 );
marcozecchini 0:9fca2b23d0ba 263
marcozecchini 0:9fca2b23d0ba 264 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X,
marcozecchini 0:9fca2b23d0ba 265 &ctx->P , &ctx->RP ) );
marcozecchini 0:9fca2b23d0ba 266
marcozecchini 0:9fca2b23d0ba 267 if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 268 return( ret );
marcozecchini 0:9fca2b23d0ba 269
marcozecchini 0:9fca2b23d0ba 270 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->GX, output, olen ) );
marcozecchini 0:9fca2b23d0ba 271
marcozecchini 0:9fca2b23d0ba 272 cleanup:
marcozecchini 0:9fca2b23d0ba 273
marcozecchini 0:9fca2b23d0ba 274 if( ret != 0 )
marcozecchini 0:9fca2b23d0ba 275 return( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED + ret );
marcozecchini 0:9fca2b23d0ba 276
marcozecchini 0:9fca2b23d0ba 277 return( 0 );
marcozecchini 0:9fca2b23d0ba 278 }
marcozecchini 0:9fca2b23d0ba 279
marcozecchini 0:9fca2b23d0ba 280 /*
marcozecchini 0:9fca2b23d0ba 281 * Use the blinding method and optimisation suggested in section 10 of:
marcozecchini 0:9fca2b23d0ba 282 * KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
marcozecchini 0:9fca2b23d0ba 283 * DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
marcozecchini 0:9fca2b23d0ba 284 * Berlin Heidelberg, 1996. p. 104-113.
marcozecchini 0:9fca2b23d0ba 285 */
marcozecchini 0:9fca2b23d0ba 286 static int dhm_update_blinding( mbedtls_dhm_context *ctx,
marcozecchini 0:9fca2b23d0ba 287 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
marcozecchini 0:9fca2b23d0ba 288 {
marcozecchini 0:9fca2b23d0ba 289 int ret, count;
marcozecchini 0:9fca2b23d0ba 290
marcozecchini 0:9fca2b23d0ba 291 /*
marcozecchini 0:9fca2b23d0ba 292 * Don't use any blinding the first time a particular X is used,
marcozecchini 0:9fca2b23d0ba 293 * but remember it to use blinding next time.
marcozecchini 0:9fca2b23d0ba 294 */
marcozecchini 0:9fca2b23d0ba 295 if( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->pX ) != 0 )
marcozecchini 0:9fca2b23d0ba 296 {
marcozecchini 0:9fca2b23d0ba 297 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &ctx->pX, &ctx->X ) );
marcozecchini 0:9fca2b23d0ba 298 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vi, 1 ) );
marcozecchini 0:9fca2b23d0ba 299 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vf, 1 ) );
marcozecchini 0:9fca2b23d0ba 300
marcozecchini 0:9fca2b23d0ba 301 return( 0 );
marcozecchini 0:9fca2b23d0ba 302 }
marcozecchini 0:9fca2b23d0ba 303
marcozecchini 0:9fca2b23d0ba 304 /*
marcozecchini 0:9fca2b23d0ba 305 * Ok, we need blinding. Can we re-use existing values?
marcozecchini 0:9fca2b23d0ba 306 * If yes, just update them by squaring them.
marcozecchini 0:9fca2b23d0ba 307 */
marcozecchini 0:9fca2b23d0ba 308 if( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) != 0 )
marcozecchini 0:9fca2b23d0ba 309 {
marcozecchini 0:9fca2b23d0ba 310 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) );
marcozecchini 0:9fca2b23d0ba 311 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->P ) );
marcozecchini 0:9fca2b23d0ba 312
marcozecchini 0:9fca2b23d0ba 313 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) );
marcozecchini 0:9fca2b23d0ba 314 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->P ) );
marcozecchini 0:9fca2b23d0ba 315
marcozecchini 0:9fca2b23d0ba 316 return( 0 );
marcozecchini 0:9fca2b23d0ba 317 }
marcozecchini 0:9fca2b23d0ba 318
marcozecchini 0:9fca2b23d0ba 319 /*
marcozecchini 0:9fca2b23d0ba 320 * We need to generate blinding values from scratch
marcozecchini 0:9fca2b23d0ba 321 */
marcozecchini 0:9fca2b23d0ba 322
marcozecchini 0:9fca2b23d0ba 323 /* Vi = random( 2, P-1 ) */
marcozecchini 0:9fca2b23d0ba 324 count = 0;
marcozecchini 0:9fca2b23d0ba 325 do
marcozecchini 0:9fca2b23d0ba 326 {
marcozecchini 0:9fca2b23d0ba 327 MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &ctx->Vi, mbedtls_mpi_size( &ctx->P ), f_rng, p_rng ) );
marcozecchini 0:9fca2b23d0ba 328
marcozecchini 0:9fca2b23d0ba 329 while( mbedtls_mpi_cmp_mpi( &ctx->Vi, &ctx->P ) >= 0 )
marcozecchini 0:9fca2b23d0ba 330 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->Vi, 1 ) );
marcozecchini 0:9fca2b23d0ba 331
marcozecchini 0:9fca2b23d0ba 332 if( count++ > 10 )
marcozecchini 0:9fca2b23d0ba 333 return( MBEDTLS_ERR_MPI_NOT_ACCEPTABLE );
marcozecchini 0:9fca2b23d0ba 334 }
marcozecchini 0:9fca2b23d0ba 335 while( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) <= 0 );
marcozecchini 0:9fca2b23d0ba 336
marcozecchini 0:9fca2b23d0ba 337 /* Vf = Vi^-X mod P */
marcozecchini 0:9fca2b23d0ba 338 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vf, &ctx->Vi, &ctx->P ) );
marcozecchini 0:9fca2b23d0ba 339 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vf, &ctx->Vf, &ctx->X, &ctx->P, &ctx->RP ) );
marcozecchini 0:9fca2b23d0ba 340
marcozecchini 0:9fca2b23d0ba 341 cleanup:
marcozecchini 0:9fca2b23d0ba 342 return( ret );
marcozecchini 0:9fca2b23d0ba 343 }
marcozecchini 0:9fca2b23d0ba 344
marcozecchini 0:9fca2b23d0ba 345 /*
marcozecchini 0:9fca2b23d0ba 346 * Derive and export the shared secret (G^Y)^X mod P
marcozecchini 0:9fca2b23d0ba 347 */
marcozecchini 0:9fca2b23d0ba 348 int mbedtls_dhm_calc_secret( mbedtls_dhm_context *ctx,
marcozecchini 0:9fca2b23d0ba 349 unsigned char *output, size_t output_size, size_t *olen,
marcozecchini 0:9fca2b23d0ba 350 int (*f_rng)(void *, unsigned char *, size_t),
marcozecchini 0:9fca2b23d0ba 351 void *p_rng )
marcozecchini 0:9fca2b23d0ba 352 {
marcozecchini 0:9fca2b23d0ba 353 int ret;
marcozecchini 0:9fca2b23d0ba 354 mbedtls_mpi GYb;
marcozecchini 0:9fca2b23d0ba 355
marcozecchini 0:9fca2b23d0ba 356 if( ctx == NULL || output_size < ctx->len )
marcozecchini 0:9fca2b23d0ba 357 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
marcozecchini 0:9fca2b23d0ba 358
marcozecchini 0:9fca2b23d0ba 359 if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 360 return( ret );
marcozecchini 0:9fca2b23d0ba 361
marcozecchini 0:9fca2b23d0ba 362 mbedtls_mpi_init( &GYb );
marcozecchini 0:9fca2b23d0ba 363
marcozecchini 0:9fca2b23d0ba 364 /* Blind peer's value */
marcozecchini 0:9fca2b23d0ba 365 if( f_rng != NULL )
marcozecchini 0:9fca2b23d0ba 366 {
marcozecchini 0:9fca2b23d0ba 367 MBEDTLS_MPI_CHK( dhm_update_blinding( ctx, f_rng, p_rng ) );
marcozecchini 0:9fca2b23d0ba 368 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &GYb, &ctx->GY, &ctx->Vi ) );
marcozecchini 0:9fca2b23d0ba 369 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &GYb, &GYb, &ctx->P ) );
marcozecchini 0:9fca2b23d0ba 370 }
marcozecchini 0:9fca2b23d0ba 371 else
marcozecchini 0:9fca2b23d0ba 372 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &GYb, &ctx->GY ) );
marcozecchini 0:9fca2b23d0ba 373
marcozecchini 0:9fca2b23d0ba 374 /* Do modular exponentiation */
marcozecchini 0:9fca2b23d0ba 375 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->K, &GYb, &ctx->X,
marcozecchini 0:9fca2b23d0ba 376 &ctx->P, &ctx->RP ) );
marcozecchini 0:9fca2b23d0ba 377
marcozecchini 0:9fca2b23d0ba 378 /* Unblind secret value */
marcozecchini 0:9fca2b23d0ba 379 if( f_rng != NULL )
marcozecchini 0:9fca2b23d0ba 380 {
marcozecchini 0:9fca2b23d0ba 381 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->K, &ctx->K, &ctx->Vf ) );
marcozecchini 0:9fca2b23d0ba 382 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->K, &ctx->K, &ctx->P ) );
marcozecchini 0:9fca2b23d0ba 383 }
marcozecchini 0:9fca2b23d0ba 384
marcozecchini 0:9fca2b23d0ba 385 *olen = mbedtls_mpi_size( &ctx->K );
marcozecchini 0:9fca2b23d0ba 386
marcozecchini 0:9fca2b23d0ba 387 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->K, output, *olen ) );
marcozecchini 0:9fca2b23d0ba 388
marcozecchini 0:9fca2b23d0ba 389 cleanup:
marcozecchini 0:9fca2b23d0ba 390 mbedtls_mpi_free( &GYb );
marcozecchini 0:9fca2b23d0ba 391
marcozecchini 0:9fca2b23d0ba 392 if( ret != 0 )
marcozecchini 0:9fca2b23d0ba 393 return( MBEDTLS_ERR_DHM_CALC_SECRET_FAILED + ret );
marcozecchini 0:9fca2b23d0ba 394
marcozecchini 0:9fca2b23d0ba 395 return( 0 );
marcozecchini 0:9fca2b23d0ba 396 }
marcozecchini 0:9fca2b23d0ba 397
marcozecchini 0:9fca2b23d0ba 398 /*
marcozecchini 0:9fca2b23d0ba 399 * Free the components of a DHM key
marcozecchini 0:9fca2b23d0ba 400 */
marcozecchini 0:9fca2b23d0ba 401 void mbedtls_dhm_free( mbedtls_dhm_context *ctx )
marcozecchini 0:9fca2b23d0ba 402 {
marcozecchini 0:9fca2b23d0ba 403 mbedtls_mpi_free( &ctx->pX); mbedtls_mpi_free( &ctx->Vf ); mbedtls_mpi_free( &ctx->Vi );
marcozecchini 0:9fca2b23d0ba 404 mbedtls_mpi_free( &ctx->RP ); mbedtls_mpi_free( &ctx->K ); mbedtls_mpi_free( &ctx->GY );
marcozecchini 0:9fca2b23d0ba 405 mbedtls_mpi_free( &ctx->GX ); mbedtls_mpi_free( &ctx->X ); mbedtls_mpi_free( &ctx->G );
marcozecchini 0:9fca2b23d0ba 406 mbedtls_mpi_free( &ctx->P );
marcozecchini 0:9fca2b23d0ba 407
marcozecchini 0:9fca2b23d0ba 408 mbedtls_zeroize( ctx, sizeof( mbedtls_dhm_context ) );
marcozecchini 0:9fca2b23d0ba 409 }
marcozecchini 0:9fca2b23d0ba 410
marcozecchini 0:9fca2b23d0ba 411 #if defined(MBEDTLS_ASN1_PARSE_C)
marcozecchini 0:9fca2b23d0ba 412 /*
marcozecchini 0:9fca2b23d0ba 413 * Parse DHM parameters
marcozecchini 0:9fca2b23d0ba 414 */
marcozecchini 0:9fca2b23d0ba 415 int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin,
marcozecchini 0:9fca2b23d0ba 416 size_t dhminlen )
marcozecchini 0:9fca2b23d0ba 417 {
marcozecchini 0:9fca2b23d0ba 418 int ret;
marcozecchini 0:9fca2b23d0ba 419 size_t len;
marcozecchini 0:9fca2b23d0ba 420 unsigned char *p, *end;
marcozecchini 0:9fca2b23d0ba 421 #if defined(MBEDTLS_PEM_PARSE_C)
marcozecchini 0:9fca2b23d0ba 422 mbedtls_pem_context pem;
marcozecchini 0:9fca2b23d0ba 423
marcozecchini 0:9fca2b23d0ba 424 mbedtls_pem_init( &pem );
marcozecchini 0:9fca2b23d0ba 425
marcozecchini 0:9fca2b23d0ba 426 /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
marcozecchini 0:9fca2b23d0ba 427 if( dhminlen == 0 || dhmin[dhminlen - 1] != '\0' )
marcozecchini 0:9fca2b23d0ba 428 ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
marcozecchini 0:9fca2b23d0ba 429 else
marcozecchini 0:9fca2b23d0ba 430 ret = mbedtls_pem_read_buffer( &pem,
marcozecchini 0:9fca2b23d0ba 431 "-----BEGIN DH PARAMETERS-----",
marcozecchini 0:9fca2b23d0ba 432 "-----END DH PARAMETERS-----",
marcozecchini 0:9fca2b23d0ba 433 dhmin, NULL, 0, &dhminlen );
marcozecchini 0:9fca2b23d0ba 434
marcozecchini 0:9fca2b23d0ba 435 if( ret == 0 )
marcozecchini 0:9fca2b23d0ba 436 {
marcozecchini 0:9fca2b23d0ba 437 /*
marcozecchini 0:9fca2b23d0ba 438 * Was PEM encoded
marcozecchini 0:9fca2b23d0ba 439 */
marcozecchini 0:9fca2b23d0ba 440 dhminlen = pem.buflen;
marcozecchini 0:9fca2b23d0ba 441 }
marcozecchini 0:9fca2b23d0ba 442 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
marcozecchini 0:9fca2b23d0ba 443 goto exit;
marcozecchini 0:9fca2b23d0ba 444
marcozecchini 0:9fca2b23d0ba 445 p = ( ret == 0 ) ? pem.buf : (unsigned char *) dhmin;
marcozecchini 0:9fca2b23d0ba 446 #else
marcozecchini 0:9fca2b23d0ba 447 p = (unsigned char *) dhmin;
marcozecchini 0:9fca2b23d0ba 448 #endif /* MBEDTLS_PEM_PARSE_C */
marcozecchini 0:9fca2b23d0ba 449 end = p + dhminlen;
marcozecchini 0:9fca2b23d0ba 450
marcozecchini 0:9fca2b23d0ba 451 /*
marcozecchini 0:9fca2b23d0ba 452 * DHParams ::= SEQUENCE {
marcozecchini 0:9fca2b23d0ba 453 * prime INTEGER, -- P
marcozecchini 0:9fca2b23d0ba 454 * generator INTEGER, -- g
marcozecchini 0:9fca2b23d0ba 455 * privateValueLength INTEGER OPTIONAL
marcozecchini 0:9fca2b23d0ba 456 * }
marcozecchini 0:9fca2b23d0ba 457 */
marcozecchini 0:9fca2b23d0ba 458 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
marcozecchini 0:9fca2b23d0ba 459 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 460 {
marcozecchini 0:9fca2b23d0ba 461 ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
marcozecchini 0:9fca2b23d0ba 462 goto exit;
marcozecchini 0:9fca2b23d0ba 463 }
marcozecchini 0:9fca2b23d0ba 464
marcozecchini 0:9fca2b23d0ba 465 end = p + len;
marcozecchini 0:9fca2b23d0ba 466
marcozecchini 0:9fca2b23d0ba 467 if( ( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->P ) ) != 0 ||
marcozecchini 0:9fca2b23d0ba 468 ( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->G ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 469 {
marcozecchini 0:9fca2b23d0ba 470 ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
marcozecchini 0:9fca2b23d0ba 471 goto exit;
marcozecchini 0:9fca2b23d0ba 472 }
marcozecchini 0:9fca2b23d0ba 473
marcozecchini 0:9fca2b23d0ba 474 if( p != end )
marcozecchini 0:9fca2b23d0ba 475 {
marcozecchini 0:9fca2b23d0ba 476 /* This might be the optional privateValueLength.
marcozecchini 0:9fca2b23d0ba 477 * If so, we can cleanly discard it */
marcozecchini 0:9fca2b23d0ba 478 mbedtls_mpi rec;
marcozecchini 0:9fca2b23d0ba 479 mbedtls_mpi_init( &rec );
marcozecchini 0:9fca2b23d0ba 480 ret = mbedtls_asn1_get_mpi( &p, end, &rec );
marcozecchini 0:9fca2b23d0ba 481 mbedtls_mpi_free( &rec );
marcozecchini 0:9fca2b23d0ba 482 if ( ret != 0 )
marcozecchini 0:9fca2b23d0ba 483 {
marcozecchini 0:9fca2b23d0ba 484 ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
marcozecchini 0:9fca2b23d0ba 485 goto exit;
marcozecchini 0:9fca2b23d0ba 486 }
marcozecchini 0:9fca2b23d0ba 487 if ( p != end )
marcozecchini 0:9fca2b23d0ba 488 {
marcozecchini 0:9fca2b23d0ba 489 ret = MBEDTLS_ERR_DHM_INVALID_FORMAT +
marcozecchini 0:9fca2b23d0ba 490 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
marcozecchini 0:9fca2b23d0ba 491 goto exit;
marcozecchini 0:9fca2b23d0ba 492 }
marcozecchini 0:9fca2b23d0ba 493 }
marcozecchini 0:9fca2b23d0ba 494
marcozecchini 0:9fca2b23d0ba 495 ret = 0;
marcozecchini 0:9fca2b23d0ba 496
marcozecchini 0:9fca2b23d0ba 497 dhm->len = mbedtls_mpi_size( &dhm->P );
marcozecchini 0:9fca2b23d0ba 498
marcozecchini 0:9fca2b23d0ba 499 exit:
marcozecchini 0:9fca2b23d0ba 500 #if defined(MBEDTLS_PEM_PARSE_C)
marcozecchini 0:9fca2b23d0ba 501 mbedtls_pem_free( &pem );
marcozecchini 0:9fca2b23d0ba 502 #endif
marcozecchini 0:9fca2b23d0ba 503 if( ret != 0 )
marcozecchini 0:9fca2b23d0ba 504 mbedtls_dhm_free( dhm );
marcozecchini 0:9fca2b23d0ba 505
marcozecchini 0:9fca2b23d0ba 506 return( ret );
marcozecchini 0:9fca2b23d0ba 507 }
marcozecchini 0:9fca2b23d0ba 508
marcozecchini 0:9fca2b23d0ba 509 #if defined(MBEDTLS_FS_IO)
marcozecchini 0:9fca2b23d0ba 510 /*
marcozecchini 0:9fca2b23d0ba 511 * Load all data from a file into a given buffer.
marcozecchini 0:9fca2b23d0ba 512 *
marcozecchini 0:9fca2b23d0ba 513 * The file is expected to contain either PEM or DER encoded data.
marcozecchini 0:9fca2b23d0ba 514 * A terminating null byte is always appended. It is included in the announced
marcozecchini 0:9fca2b23d0ba 515 * length only if the data looks like it is PEM encoded.
marcozecchini 0:9fca2b23d0ba 516 */
marcozecchini 0:9fca2b23d0ba 517 static int load_file( const char *path, unsigned char **buf, size_t *n )
marcozecchini 0:9fca2b23d0ba 518 {
marcozecchini 0:9fca2b23d0ba 519 FILE *f;
marcozecchini 0:9fca2b23d0ba 520 long size;
marcozecchini 0:9fca2b23d0ba 521
marcozecchini 0:9fca2b23d0ba 522 if( ( f = fopen( path, "rb" ) ) == NULL )
marcozecchini 0:9fca2b23d0ba 523 return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
marcozecchini 0:9fca2b23d0ba 524
marcozecchini 0:9fca2b23d0ba 525 fseek( f, 0, SEEK_END );
marcozecchini 0:9fca2b23d0ba 526 if( ( size = ftell( f ) ) == -1 )
marcozecchini 0:9fca2b23d0ba 527 {
marcozecchini 0:9fca2b23d0ba 528 fclose( f );
marcozecchini 0:9fca2b23d0ba 529 return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
marcozecchini 0:9fca2b23d0ba 530 }
marcozecchini 0:9fca2b23d0ba 531 fseek( f, 0, SEEK_SET );
marcozecchini 0:9fca2b23d0ba 532
marcozecchini 0:9fca2b23d0ba 533 *n = (size_t) size;
marcozecchini 0:9fca2b23d0ba 534
marcozecchini 0:9fca2b23d0ba 535 if( *n + 1 == 0 ||
marcozecchini 0:9fca2b23d0ba 536 ( *buf = mbedtls_calloc( 1, *n + 1 ) ) == NULL )
marcozecchini 0:9fca2b23d0ba 537 {
marcozecchini 0:9fca2b23d0ba 538 fclose( f );
marcozecchini 0:9fca2b23d0ba 539 return( MBEDTLS_ERR_DHM_ALLOC_FAILED );
marcozecchini 0:9fca2b23d0ba 540 }
marcozecchini 0:9fca2b23d0ba 541
marcozecchini 0:9fca2b23d0ba 542 if( fread( *buf, 1, *n, f ) != *n )
marcozecchini 0:9fca2b23d0ba 543 {
marcozecchini 0:9fca2b23d0ba 544 fclose( f );
marcozecchini 0:9fca2b23d0ba 545 mbedtls_free( *buf );
marcozecchini 0:9fca2b23d0ba 546 return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
marcozecchini 0:9fca2b23d0ba 547 }
marcozecchini 0:9fca2b23d0ba 548
marcozecchini 0:9fca2b23d0ba 549 fclose( f );
marcozecchini 0:9fca2b23d0ba 550
marcozecchini 0:9fca2b23d0ba 551 (*buf)[*n] = '\0';
marcozecchini 0:9fca2b23d0ba 552
marcozecchini 0:9fca2b23d0ba 553 if( strstr( (const char *) *buf, "-----BEGIN " ) != NULL )
marcozecchini 0:9fca2b23d0ba 554 ++*n;
marcozecchini 0:9fca2b23d0ba 555
marcozecchini 0:9fca2b23d0ba 556 return( 0 );
marcozecchini 0:9fca2b23d0ba 557 }
marcozecchini 0:9fca2b23d0ba 558
marcozecchini 0:9fca2b23d0ba 559 /*
marcozecchini 0:9fca2b23d0ba 560 * Load and parse DHM parameters
marcozecchini 0:9fca2b23d0ba 561 */
marcozecchini 0:9fca2b23d0ba 562 int mbedtls_dhm_parse_dhmfile( mbedtls_dhm_context *dhm, const char *path )
marcozecchini 0:9fca2b23d0ba 563 {
marcozecchini 0:9fca2b23d0ba 564 int ret;
marcozecchini 0:9fca2b23d0ba 565 size_t n;
marcozecchini 0:9fca2b23d0ba 566 unsigned char *buf;
marcozecchini 0:9fca2b23d0ba 567
marcozecchini 0:9fca2b23d0ba 568 if( ( ret = load_file( path, &buf, &n ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 569 return( ret );
marcozecchini 0:9fca2b23d0ba 570
marcozecchini 0:9fca2b23d0ba 571 ret = mbedtls_dhm_parse_dhm( dhm, buf, n );
marcozecchini 0:9fca2b23d0ba 572
marcozecchini 0:9fca2b23d0ba 573 mbedtls_zeroize( buf, n );
marcozecchini 0:9fca2b23d0ba 574 mbedtls_free( buf );
marcozecchini 0:9fca2b23d0ba 575
marcozecchini 0:9fca2b23d0ba 576 return( ret );
marcozecchini 0:9fca2b23d0ba 577 }
marcozecchini 0:9fca2b23d0ba 578 #endif /* MBEDTLS_FS_IO */
marcozecchini 0:9fca2b23d0ba 579 #endif /* MBEDTLS_ASN1_PARSE_C */
marcozecchini 0:9fca2b23d0ba 580
marcozecchini 0:9fca2b23d0ba 581 #if defined(MBEDTLS_SELF_TEST)
marcozecchini 0:9fca2b23d0ba 582
marcozecchini 0:9fca2b23d0ba 583 static const char mbedtls_test_dhm_params[] =
marcozecchini 0:9fca2b23d0ba 584 "-----BEGIN DH PARAMETERS-----\r\n"
marcozecchini 0:9fca2b23d0ba 585 "MIGHAoGBAJ419DBEOgmQTzo5qXl5fQcN9TN455wkOL7052HzxxRVMyhYmwQcgJvh\r\n"
marcozecchini 0:9fca2b23d0ba 586 "1sa18fyfR9OiVEMYglOpkqVoGLN7qd5aQNNi5W7/C+VBdHTBJcGZJyyP5B3qcz32\r\n"
marcozecchini 0:9fca2b23d0ba 587 "9mLJKudlVudV0Qxk5qUJaPZ/xupz0NyoVpviuiBOI1gNi8ovSXWzAgEC\r\n"
marcozecchini 0:9fca2b23d0ba 588 "-----END DH PARAMETERS-----\r\n";
marcozecchini 0:9fca2b23d0ba 589
marcozecchini 0:9fca2b23d0ba 590 static const size_t mbedtls_test_dhm_params_len = sizeof( mbedtls_test_dhm_params );
marcozecchini 0:9fca2b23d0ba 591
marcozecchini 0:9fca2b23d0ba 592 /*
marcozecchini 0:9fca2b23d0ba 593 * Checkup routine
marcozecchini 0:9fca2b23d0ba 594 */
marcozecchini 0:9fca2b23d0ba 595 int mbedtls_dhm_self_test( int verbose )
marcozecchini 0:9fca2b23d0ba 596 {
marcozecchini 0:9fca2b23d0ba 597 int ret;
marcozecchini 0:9fca2b23d0ba 598 mbedtls_dhm_context dhm;
marcozecchini 0:9fca2b23d0ba 599
marcozecchini 0:9fca2b23d0ba 600 mbedtls_dhm_init( &dhm );
marcozecchini 0:9fca2b23d0ba 601
marcozecchini 0:9fca2b23d0ba 602 if( verbose != 0 )
marcozecchini 0:9fca2b23d0ba 603 mbedtls_printf( " DHM parameter load: " );
marcozecchini 0:9fca2b23d0ba 604
marcozecchini 0:9fca2b23d0ba 605 if( ( ret = mbedtls_dhm_parse_dhm( &dhm,
marcozecchini 0:9fca2b23d0ba 606 (const unsigned char *) mbedtls_test_dhm_params,
marcozecchini 0:9fca2b23d0ba 607 mbedtls_test_dhm_params_len ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 608 {
marcozecchini 0:9fca2b23d0ba 609 if( verbose != 0 )
marcozecchini 0:9fca2b23d0ba 610 mbedtls_printf( "failed\n" );
marcozecchini 0:9fca2b23d0ba 611
marcozecchini 0:9fca2b23d0ba 612 ret = 1;
marcozecchini 0:9fca2b23d0ba 613 goto exit;
marcozecchini 0:9fca2b23d0ba 614 }
marcozecchini 0:9fca2b23d0ba 615
marcozecchini 0:9fca2b23d0ba 616 if( verbose != 0 )
marcozecchini 0:9fca2b23d0ba 617 mbedtls_printf( "passed\n\n" );
marcozecchini 0:9fca2b23d0ba 618
marcozecchini 0:9fca2b23d0ba 619 exit:
marcozecchini 0:9fca2b23d0ba 620 mbedtls_dhm_free( &dhm );
marcozecchini 0:9fca2b23d0ba 621
marcozecchini 0:9fca2b23d0ba 622 return( ret );
marcozecchini 0:9fca2b23d0ba 623 }
marcozecchini 0:9fca2b23d0ba 624
marcozecchini 0:9fca2b23d0ba 625 #endif /* MBEDTLS_SELF_TEST */
marcozecchini 0:9fca2b23d0ba 626
marcozecchini 0:9fca2b23d0ba 627 #endif /* MBEDTLS_DHM_C */