Maxim nexpaq / nexpaq_dev

Preliminary main mbed library for nexpaq development

features/mbedtls/src/dhm.c@0:6c56fb4bc5f0, 2016-11-04 (annotated)

Committer:
nexpaq
Date:
Fri Nov 04 20:27:58 2016 +0000
Revision:
0:6c56fb4bc5f0
Moving to library for sharing updates

Who changed what in which revision?

UserRevisionLine numberNew contents of line
nexpaq 0:6c56fb4bc5f0 1 /*
nexpaq 0:6c56fb4bc5f0 2 * Diffie-Hellman-Merkle key exchange
nexpaq 0:6c56fb4bc5f0 3 *
nexpaq 0:6c56fb4bc5f0 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
nexpaq 0:6c56fb4bc5f0 5 * SPDX-License-Identifier: Apache-2.0
nexpaq 0:6c56fb4bc5f0 6 *
nexpaq 0:6c56fb4bc5f0 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
nexpaq 0:6c56fb4bc5f0 8 * not use this file except in compliance with the License.
nexpaq 0:6c56fb4bc5f0 9 * You may obtain a copy of the License at
nexpaq 0:6c56fb4bc5f0 10 *
nexpaq 0:6c56fb4bc5f0 11 * http://www.apache.org/licenses/LICENSE-2.0
nexpaq 0:6c56fb4bc5f0 12 *
nexpaq 0:6c56fb4bc5f0 13 * Unless required by applicable law or agreed to in writing, software
nexpaq 0:6c56fb4bc5f0 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
nexpaq 0:6c56fb4bc5f0 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
nexpaq 0:6c56fb4bc5f0 16 * See the License for the specific language governing permissions and
nexpaq 0:6c56fb4bc5f0 17 * limitations under the License.
nexpaq 0:6c56fb4bc5f0 18 *
nexpaq 0:6c56fb4bc5f0 19 * This file is part of mbed TLS (https://tls.mbed.org)
nexpaq 0:6c56fb4bc5f0 20 */
nexpaq 0:6c56fb4bc5f0 21 /*
nexpaq 0:6c56fb4bc5f0 22 * The following sources were referenced in the design of this implementation
nexpaq 0:6c56fb4bc5f0 23 * of the Diffie-Hellman-Merkle algorithm:
nexpaq 0:6c56fb4bc5f0 24 *
nexpaq 0:6c56fb4bc5f0 25 * [1] Handbook of Applied Cryptography - 1997, Chapter 12
nexpaq 0:6c56fb4bc5f0 26 * Menezes, van Oorschot and Vanstone
nexpaq 0:6c56fb4bc5f0 27 *
nexpaq 0:6c56fb4bc5f0 28 */
nexpaq 0:6c56fb4bc5f0 29
nexpaq 0:6c56fb4bc5f0 30 #if !defined(MBEDTLS_CONFIG_FILE)
nexpaq 0:6c56fb4bc5f0 31 #include "mbedtls/config.h"
nexpaq 0:6c56fb4bc5f0 32 #else
nexpaq 0:6c56fb4bc5f0 33 #include MBEDTLS_CONFIG_FILE
nexpaq 0:6c56fb4bc5f0 34 #endif
nexpaq 0:6c56fb4bc5f0 35
nexpaq 0:6c56fb4bc5f0 36 #if defined(MBEDTLS_DHM_C)
nexpaq 0:6c56fb4bc5f0 37
nexpaq 0:6c56fb4bc5f0 38 #include "mbedtls/dhm.h"
nexpaq 0:6c56fb4bc5f0 39
nexpaq 0:6c56fb4bc5f0 40 #include <string.h>
nexpaq 0:6c56fb4bc5f0 41
nexpaq 0:6c56fb4bc5f0 42 #if defined(MBEDTLS_PEM_PARSE_C)
nexpaq 0:6c56fb4bc5f0 43 #include "mbedtls/pem.h"
nexpaq 0:6c56fb4bc5f0 44 #endif
nexpaq 0:6c56fb4bc5f0 45
nexpaq 0:6c56fb4bc5f0 46 #if defined(MBEDTLS_ASN1_PARSE_C)
nexpaq 0:6c56fb4bc5f0 47 #include "mbedtls/asn1.h"
nexpaq 0:6c56fb4bc5f0 48 #endif
nexpaq 0:6c56fb4bc5f0 49
nexpaq 0:6c56fb4bc5f0 50 #if defined(MBEDTLS_PLATFORM_C)
nexpaq 0:6c56fb4bc5f0 51 #include "mbedtls/platform.h"
nexpaq 0:6c56fb4bc5f0 52 #else
nexpaq 0:6c56fb4bc5f0 53 #include <stdlib.h>
nexpaq 0:6c56fb4bc5f0 54 #include <stdio.h>
nexpaq 0:6c56fb4bc5f0 55 #define mbedtls_printf printf
nexpaq 0:6c56fb4bc5f0 56 #define mbedtls_calloc calloc
nexpaq 0:6c56fb4bc5f0 57 #define mbedtls_free free
nexpaq 0:6c56fb4bc5f0 58 #endif
nexpaq 0:6c56fb4bc5f0 59
nexpaq 0:6c56fb4bc5f0 60 /* Implementation that should never be optimized out by the compiler */
nexpaq 0:6c56fb4bc5f0 61 static void mbedtls_zeroize( void *v, size_t n ) {
nexpaq 0:6c56fb4bc5f0 62 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
nexpaq 0:6c56fb4bc5f0 63 }
nexpaq 0:6c56fb4bc5f0 64
nexpaq 0:6c56fb4bc5f0 65 /*
nexpaq 0:6c56fb4bc5f0 66 * helper to validate the mbedtls_mpi size and import it
nexpaq 0:6c56fb4bc5f0 67 */
nexpaq 0:6c56fb4bc5f0 68 static int dhm_read_bignum( mbedtls_mpi *X,
nexpaq 0:6c56fb4bc5f0 69 unsigned char **p,
nexpaq 0:6c56fb4bc5f0 70 const unsigned char *end )
nexpaq 0:6c56fb4bc5f0 71 {
nexpaq 0:6c56fb4bc5f0 72 int ret, n;
nexpaq 0:6c56fb4bc5f0 73
nexpaq 0:6c56fb4bc5f0 74 if( end - *p < 2 )
nexpaq 0:6c56fb4bc5f0 75 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
nexpaq 0:6c56fb4bc5f0 76
nexpaq 0:6c56fb4bc5f0 77 n = ( (*p)[0] << 8 ) | (*p)[1];
nexpaq 0:6c56fb4bc5f0 78 (*p) += 2;
nexpaq 0:6c56fb4bc5f0 79
nexpaq 0:6c56fb4bc5f0 80 if( (int)( end - *p ) < n )
nexpaq 0:6c56fb4bc5f0 81 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
nexpaq 0:6c56fb4bc5f0 82
nexpaq 0:6c56fb4bc5f0 83 if( ( ret = mbedtls_mpi_read_binary( X, *p, n ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 84 return( MBEDTLS_ERR_DHM_READ_PARAMS_FAILED + ret );
nexpaq 0:6c56fb4bc5f0 85
nexpaq 0:6c56fb4bc5f0 86 (*p) += n;
nexpaq 0:6c56fb4bc5f0 87
nexpaq 0:6c56fb4bc5f0 88 return( 0 );
nexpaq 0:6c56fb4bc5f0 89 }
nexpaq 0:6c56fb4bc5f0 90
nexpaq 0:6c56fb4bc5f0 91 /*
nexpaq 0:6c56fb4bc5f0 92 * Verify sanity of parameter with regards to P
nexpaq 0:6c56fb4bc5f0 93 *
nexpaq 0:6c56fb4bc5f0 94 * Parameter should be: 2 <= public_param <= P - 2
nexpaq 0:6c56fb4bc5f0 95 *
nexpaq 0:6c56fb4bc5f0 96 * For more information on the attack, see:
nexpaq 0:6c56fb4bc5f0 97 * http://www.cl.cam.ac.uk/~rja14/Papers/psandqs.pdf
nexpaq 0:6c56fb4bc5f0 98 * http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2005-2643
nexpaq 0:6c56fb4bc5f0 99 */
nexpaq 0:6c56fb4bc5f0 100 static int dhm_check_range( const mbedtls_mpi *param, const mbedtls_mpi *P )
nexpaq 0:6c56fb4bc5f0 101 {
nexpaq 0:6c56fb4bc5f0 102 mbedtls_mpi L, U;
nexpaq 0:6c56fb4bc5f0 103 int ret = MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
nexpaq 0:6c56fb4bc5f0 104
nexpaq 0:6c56fb4bc5f0 105 mbedtls_mpi_init( &L ); mbedtls_mpi_init( &U );
nexpaq 0:6c56fb4bc5f0 106
nexpaq 0:6c56fb4bc5f0 107 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &L, 2 ) );
nexpaq 0:6c56fb4bc5f0 108 MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &U, P, 2 ) );
nexpaq 0:6c56fb4bc5f0 109
nexpaq 0:6c56fb4bc5f0 110 if( mbedtls_mpi_cmp_mpi( param, &L ) >= 0 &&
nexpaq 0:6c56fb4bc5f0 111 mbedtls_mpi_cmp_mpi( param, &U ) <= 0 )
nexpaq 0:6c56fb4bc5f0 112 {
nexpaq 0:6c56fb4bc5f0 113 ret = 0;
nexpaq 0:6c56fb4bc5f0 114 }
nexpaq 0:6c56fb4bc5f0 115
nexpaq 0:6c56fb4bc5f0 116 cleanup:
nexpaq 0:6c56fb4bc5f0 117 mbedtls_mpi_free( &L ); mbedtls_mpi_free( &U );
nexpaq 0:6c56fb4bc5f0 118 return( ret );
nexpaq 0:6c56fb4bc5f0 119 }
nexpaq 0:6c56fb4bc5f0 120
nexpaq 0:6c56fb4bc5f0 121 void mbedtls_dhm_init( mbedtls_dhm_context *ctx )
nexpaq 0:6c56fb4bc5f0 122 {
nexpaq 0:6c56fb4bc5f0 123 memset( ctx, 0, sizeof( mbedtls_dhm_context ) );
nexpaq 0:6c56fb4bc5f0 124 }
nexpaq 0:6c56fb4bc5f0 125
nexpaq 0:6c56fb4bc5f0 126 /*
nexpaq 0:6c56fb4bc5f0 127 * Parse the ServerKeyExchange parameters
nexpaq 0:6c56fb4bc5f0 128 */
nexpaq 0:6c56fb4bc5f0 129 int mbedtls_dhm_read_params( mbedtls_dhm_context *ctx,
nexpaq 0:6c56fb4bc5f0 130 unsigned char **p,
nexpaq 0:6c56fb4bc5f0 131 const unsigned char *end )
nexpaq 0:6c56fb4bc5f0 132 {
nexpaq 0:6c56fb4bc5f0 133 int ret;
nexpaq 0:6c56fb4bc5f0 134
nexpaq 0:6c56fb4bc5f0 135 if( ( ret = dhm_read_bignum( &ctx->P, p, end ) ) != 0 ||
nexpaq 0:6c56fb4bc5f0 136 ( ret = dhm_read_bignum( &ctx->G, p, end ) ) != 0 ||
nexpaq 0:6c56fb4bc5f0 137 ( ret = dhm_read_bignum( &ctx->GY, p, end ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 138 return( ret );
nexpaq 0:6c56fb4bc5f0 139
nexpaq 0:6c56fb4bc5f0 140 if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 141 return( ret );
nexpaq 0:6c56fb4bc5f0 142
nexpaq 0:6c56fb4bc5f0 143 ctx->len = mbedtls_mpi_size( &ctx->P );
nexpaq 0:6c56fb4bc5f0 144
nexpaq 0:6c56fb4bc5f0 145 return( 0 );
nexpaq 0:6c56fb4bc5f0 146 }
nexpaq 0:6c56fb4bc5f0 147
nexpaq 0:6c56fb4bc5f0 148 /*
nexpaq 0:6c56fb4bc5f0 149 * Setup and write the ServerKeyExchange parameters
nexpaq 0:6c56fb4bc5f0 150 */
nexpaq 0:6c56fb4bc5f0 151 int mbedtls_dhm_make_params( mbedtls_dhm_context *ctx, int x_size,
nexpaq 0:6c56fb4bc5f0 152 unsigned char *output, size_t *olen,
nexpaq 0:6c56fb4bc5f0 153 int (*f_rng)(void *, unsigned char *, size_t),
nexpaq 0:6c56fb4bc5f0 154 void *p_rng )
nexpaq 0:6c56fb4bc5f0 155 {
nexpaq 0:6c56fb4bc5f0 156 int ret, count = 0;
nexpaq 0:6c56fb4bc5f0 157 size_t n1, n2, n3;
nexpaq 0:6c56fb4bc5f0 158 unsigned char *p;
nexpaq 0:6c56fb4bc5f0 159
nexpaq 0:6c56fb4bc5f0 160 if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
nexpaq 0:6c56fb4bc5f0 161 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
nexpaq 0:6c56fb4bc5f0 162
nexpaq 0:6c56fb4bc5f0 163 /*
nexpaq 0:6c56fb4bc5f0 164 * Generate X as large as possible ( < P )
nexpaq 0:6c56fb4bc5f0 165 */
nexpaq 0:6c56fb4bc5f0 166 do
nexpaq 0:6c56fb4bc5f0 167 {
nexpaq 0:6c56fb4bc5f0 168 mbedtls_mpi_fill_random( &ctx->X, x_size, f_rng, p_rng );
nexpaq 0:6c56fb4bc5f0 169
nexpaq 0:6c56fb4bc5f0 170 while( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 )
nexpaq 0:6c56fb4bc5f0 171 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->X, 1 ) );
nexpaq 0:6c56fb4bc5f0 172
nexpaq 0:6c56fb4bc5f0 173 if( count++ > 10 )
nexpaq 0:6c56fb4bc5f0 174 return( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED );
nexpaq 0:6c56fb4bc5f0 175 }
nexpaq 0:6c56fb4bc5f0 176 while( dhm_check_range( &ctx->X, &ctx->P ) != 0 );
nexpaq 0:6c56fb4bc5f0 177
nexpaq 0:6c56fb4bc5f0 178 /*
nexpaq 0:6c56fb4bc5f0 179 * Calculate GX = G^X mod P
nexpaq 0:6c56fb4bc5f0 180 */
nexpaq 0:6c56fb4bc5f0 181 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X,
nexpaq 0:6c56fb4bc5f0 182 &ctx->P , &ctx->RP ) );
nexpaq 0:6c56fb4bc5f0 183
nexpaq 0:6c56fb4bc5f0 184 if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 185 return( ret );
nexpaq 0:6c56fb4bc5f0 186
nexpaq 0:6c56fb4bc5f0 187 /*
nexpaq 0:6c56fb4bc5f0 188 * export P, G, GX
nexpaq 0:6c56fb4bc5f0 189 */
nexpaq 0:6c56fb4bc5f0 190 #define DHM_MPI_EXPORT(X,n) \
nexpaq 0:6c56fb4bc5f0 191 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, p + 2, n ) ); \
nexpaq 0:6c56fb4bc5f0 192 *p++ = (unsigned char)( n >> 8 ); \
nexpaq 0:6c56fb4bc5f0 193 *p++ = (unsigned char)( n ); p += n;
nexpaq 0:6c56fb4bc5f0 194
nexpaq 0:6c56fb4bc5f0 195 n1 = mbedtls_mpi_size( &ctx->P );
nexpaq 0:6c56fb4bc5f0 196 n2 = mbedtls_mpi_size( &ctx->G );
nexpaq 0:6c56fb4bc5f0 197 n3 = mbedtls_mpi_size( &ctx->GX );
nexpaq 0:6c56fb4bc5f0 198
nexpaq 0:6c56fb4bc5f0 199 p = output;
nexpaq 0:6c56fb4bc5f0 200 DHM_MPI_EXPORT( &ctx->P , n1 );
nexpaq 0:6c56fb4bc5f0 201 DHM_MPI_EXPORT( &ctx->G , n2 );
nexpaq 0:6c56fb4bc5f0 202 DHM_MPI_EXPORT( &ctx->GX, n3 );
nexpaq 0:6c56fb4bc5f0 203
nexpaq 0:6c56fb4bc5f0 204 *olen = p - output;
nexpaq 0:6c56fb4bc5f0 205
nexpaq 0:6c56fb4bc5f0 206 ctx->len = n1;
nexpaq 0:6c56fb4bc5f0 207
nexpaq 0:6c56fb4bc5f0 208 cleanup:
nexpaq 0:6c56fb4bc5f0 209
nexpaq 0:6c56fb4bc5f0 210 if( ret != 0 )
nexpaq 0:6c56fb4bc5f0 211 return( MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED + ret );
nexpaq 0:6c56fb4bc5f0 212
nexpaq 0:6c56fb4bc5f0 213 return( 0 );
nexpaq 0:6c56fb4bc5f0 214 }
nexpaq 0:6c56fb4bc5f0 215
nexpaq 0:6c56fb4bc5f0 216 /*
nexpaq 0:6c56fb4bc5f0 217 * Import the peer's public value G^Y
nexpaq 0:6c56fb4bc5f0 218 */
nexpaq 0:6c56fb4bc5f0 219 int mbedtls_dhm_read_public( mbedtls_dhm_context *ctx,
nexpaq 0:6c56fb4bc5f0 220 const unsigned char *input, size_t ilen )
nexpaq 0:6c56fb4bc5f0 221 {
nexpaq 0:6c56fb4bc5f0 222 int ret;
nexpaq 0:6c56fb4bc5f0 223
nexpaq 0:6c56fb4bc5f0 224 if( ctx == NULL || ilen < 1 || ilen > ctx->len )
nexpaq 0:6c56fb4bc5f0 225 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
nexpaq 0:6c56fb4bc5f0 226
nexpaq 0:6c56fb4bc5f0 227 if( ( ret = mbedtls_mpi_read_binary( &ctx->GY, input, ilen ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 228 return( MBEDTLS_ERR_DHM_READ_PUBLIC_FAILED + ret );
nexpaq 0:6c56fb4bc5f0 229
nexpaq 0:6c56fb4bc5f0 230 return( 0 );
nexpaq 0:6c56fb4bc5f0 231 }
nexpaq 0:6c56fb4bc5f0 232
nexpaq 0:6c56fb4bc5f0 233 /*
nexpaq 0:6c56fb4bc5f0 234 * Create own private value X and export G^X
nexpaq 0:6c56fb4bc5f0 235 */
nexpaq 0:6c56fb4bc5f0 236 int mbedtls_dhm_make_public( mbedtls_dhm_context *ctx, int x_size,
nexpaq 0:6c56fb4bc5f0 237 unsigned char *output, size_t olen,
nexpaq 0:6c56fb4bc5f0 238 int (*f_rng)(void *, unsigned char *, size_t),
nexpaq 0:6c56fb4bc5f0 239 void *p_rng )
nexpaq 0:6c56fb4bc5f0 240 {
nexpaq 0:6c56fb4bc5f0 241 int ret, count = 0;
nexpaq 0:6c56fb4bc5f0 242
nexpaq 0:6c56fb4bc5f0 243 if( ctx == NULL || olen < 1 || olen > ctx->len )
nexpaq 0:6c56fb4bc5f0 244 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
nexpaq 0:6c56fb4bc5f0 245
nexpaq 0:6c56fb4bc5f0 246 if( mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 )
nexpaq 0:6c56fb4bc5f0 247 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
nexpaq 0:6c56fb4bc5f0 248
nexpaq 0:6c56fb4bc5f0 249 /*
nexpaq 0:6c56fb4bc5f0 250 * generate X and calculate GX = G^X mod P
nexpaq 0:6c56fb4bc5f0 251 */
nexpaq 0:6c56fb4bc5f0 252 do
nexpaq 0:6c56fb4bc5f0 253 {
nexpaq 0:6c56fb4bc5f0 254 mbedtls_mpi_fill_random( &ctx->X, x_size, f_rng, p_rng );
nexpaq 0:6c56fb4bc5f0 255
nexpaq 0:6c56fb4bc5f0 256 while( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->P ) >= 0 )
nexpaq 0:6c56fb4bc5f0 257 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->X, 1 ) );
nexpaq 0:6c56fb4bc5f0 258
nexpaq 0:6c56fb4bc5f0 259 if( count++ > 10 )
nexpaq 0:6c56fb4bc5f0 260 return( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED );
nexpaq 0:6c56fb4bc5f0 261 }
nexpaq 0:6c56fb4bc5f0 262 while( dhm_check_range( &ctx->X, &ctx->P ) != 0 );
nexpaq 0:6c56fb4bc5f0 263
nexpaq 0:6c56fb4bc5f0 264 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->GX, &ctx->G, &ctx->X,
nexpaq 0:6c56fb4bc5f0 265 &ctx->P , &ctx->RP ) );
nexpaq 0:6c56fb4bc5f0 266
nexpaq 0:6c56fb4bc5f0 267 if( ( ret = dhm_check_range( &ctx->GX, &ctx->P ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 268 return( ret );
nexpaq 0:6c56fb4bc5f0 269
nexpaq 0:6c56fb4bc5f0 270 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->GX, output, olen ) );
nexpaq 0:6c56fb4bc5f0 271
nexpaq 0:6c56fb4bc5f0 272 cleanup:
nexpaq 0:6c56fb4bc5f0 273
nexpaq 0:6c56fb4bc5f0 274 if( ret != 0 )
nexpaq 0:6c56fb4bc5f0 275 return( MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED + ret );
nexpaq 0:6c56fb4bc5f0 276
nexpaq 0:6c56fb4bc5f0 277 return( 0 );
nexpaq 0:6c56fb4bc5f0 278 }
nexpaq 0:6c56fb4bc5f0 279
nexpaq 0:6c56fb4bc5f0 280 /*
nexpaq 0:6c56fb4bc5f0 281 * Use the blinding method and optimisation suggested in section 10 of:
nexpaq 0:6c56fb4bc5f0 282 * KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
nexpaq 0:6c56fb4bc5f0 283 * DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
nexpaq 0:6c56fb4bc5f0 284 * Berlin Heidelberg, 1996. p. 104-113.
nexpaq 0:6c56fb4bc5f0 285 */
nexpaq 0:6c56fb4bc5f0 286 static int dhm_update_blinding( mbedtls_dhm_context *ctx,
nexpaq 0:6c56fb4bc5f0 287 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
nexpaq 0:6c56fb4bc5f0 288 {
nexpaq 0:6c56fb4bc5f0 289 int ret, count;
nexpaq 0:6c56fb4bc5f0 290
nexpaq 0:6c56fb4bc5f0 291 /*
nexpaq 0:6c56fb4bc5f0 292 * Don't use any blinding the first time a particular X is used,
nexpaq 0:6c56fb4bc5f0 293 * but remember it to use blinding next time.
nexpaq 0:6c56fb4bc5f0 294 */
nexpaq 0:6c56fb4bc5f0 295 if( mbedtls_mpi_cmp_mpi( &ctx->X, &ctx->pX ) != 0 )
nexpaq 0:6c56fb4bc5f0 296 {
nexpaq 0:6c56fb4bc5f0 297 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &ctx->pX, &ctx->X ) );
nexpaq 0:6c56fb4bc5f0 298 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vi, 1 ) );
nexpaq 0:6c56fb4bc5f0 299 MBEDTLS_MPI_CHK( mbedtls_mpi_lset( &ctx->Vf, 1 ) );
nexpaq 0:6c56fb4bc5f0 300
nexpaq 0:6c56fb4bc5f0 301 return( 0 );
nexpaq 0:6c56fb4bc5f0 302 }
nexpaq 0:6c56fb4bc5f0 303
nexpaq 0:6c56fb4bc5f0 304 /*
nexpaq 0:6c56fb4bc5f0 305 * Ok, we need blinding. Can we re-use existing values?
nexpaq 0:6c56fb4bc5f0 306 * If yes, just update them by squaring them.
nexpaq 0:6c56fb4bc5f0 307 */
nexpaq 0:6c56fb4bc5f0 308 if( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) != 0 )
nexpaq 0:6c56fb4bc5f0 309 {
nexpaq 0:6c56fb4bc5f0 310 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vi, &ctx->Vi, &ctx->Vi ) );
nexpaq 0:6c56fb4bc5f0 311 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vi, &ctx->Vi, &ctx->P ) );
nexpaq 0:6c56fb4bc5f0 312
nexpaq 0:6c56fb4bc5f0 313 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->Vf, &ctx->Vf, &ctx->Vf ) );
nexpaq 0:6c56fb4bc5f0 314 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->Vf, &ctx->Vf, &ctx->P ) );
nexpaq 0:6c56fb4bc5f0 315
nexpaq 0:6c56fb4bc5f0 316 return( 0 );
nexpaq 0:6c56fb4bc5f0 317 }
nexpaq 0:6c56fb4bc5f0 318
nexpaq 0:6c56fb4bc5f0 319 /*
nexpaq 0:6c56fb4bc5f0 320 * We need to generate blinding values from scratch
nexpaq 0:6c56fb4bc5f0 321 */
nexpaq 0:6c56fb4bc5f0 322
nexpaq 0:6c56fb4bc5f0 323 /* Vi = random( 2, P-1 ) */
nexpaq 0:6c56fb4bc5f0 324 count = 0;
nexpaq 0:6c56fb4bc5f0 325 do
nexpaq 0:6c56fb4bc5f0 326 {
nexpaq 0:6c56fb4bc5f0 327 mbedtls_mpi_fill_random( &ctx->Vi, mbedtls_mpi_size( &ctx->P ), f_rng, p_rng );
nexpaq 0:6c56fb4bc5f0 328
nexpaq 0:6c56fb4bc5f0 329 while( mbedtls_mpi_cmp_mpi( &ctx->Vi, &ctx->P ) >= 0 )
nexpaq 0:6c56fb4bc5f0 330 MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &ctx->Vi, 1 ) );
nexpaq 0:6c56fb4bc5f0 331
nexpaq 0:6c56fb4bc5f0 332 if( count++ > 10 )
nexpaq 0:6c56fb4bc5f0 333 return( MBEDTLS_ERR_MPI_NOT_ACCEPTABLE );
nexpaq 0:6c56fb4bc5f0 334 }
nexpaq 0:6c56fb4bc5f0 335 while( mbedtls_mpi_cmp_int( &ctx->Vi, 1 ) <= 0 );
nexpaq 0:6c56fb4bc5f0 336
nexpaq 0:6c56fb4bc5f0 337 /* Vf = Vi^-X mod P */
nexpaq 0:6c56fb4bc5f0 338 MBEDTLS_MPI_CHK( mbedtls_mpi_inv_mod( &ctx->Vf, &ctx->Vi, &ctx->P ) );
nexpaq 0:6c56fb4bc5f0 339 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->Vf, &ctx->Vf, &ctx->X, &ctx->P, &ctx->RP ) );
nexpaq 0:6c56fb4bc5f0 340
nexpaq 0:6c56fb4bc5f0 341 cleanup:
nexpaq 0:6c56fb4bc5f0 342 return( ret );
nexpaq 0:6c56fb4bc5f0 343 }
nexpaq 0:6c56fb4bc5f0 344
nexpaq 0:6c56fb4bc5f0 345 /*
nexpaq 0:6c56fb4bc5f0 346 * Derive and export the shared secret (G^Y)^X mod P
nexpaq 0:6c56fb4bc5f0 347 */
nexpaq 0:6c56fb4bc5f0 348 int mbedtls_dhm_calc_secret( mbedtls_dhm_context *ctx,
nexpaq 0:6c56fb4bc5f0 349 unsigned char *output, size_t output_size, size_t *olen,
nexpaq 0:6c56fb4bc5f0 350 int (*f_rng)(void *, unsigned char *, size_t),
nexpaq 0:6c56fb4bc5f0 351 void *p_rng )
nexpaq 0:6c56fb4bc5f0 352 {
nexpaq 0:6c56fb4bc5f0 353 int ret;
nexpaq 0:6c56fb4bc5f0 354 mbedtls_mpi GYb;
nexpaq 0:6c56fb4bc5f0 355
nexpaq 0:6c56fb4bc5f0 356 if( ctx == NULL || output_size < ctx->len )
nexpaq 0:6c56fb4bc5f0 357 return( MBEDTLS_ERR_DHM_BAD_INPUT_DATA );
nexpaq 0:6c56fb4bc5f0 358
nexpaq 0:6c56fb4bc5f0 359 if( ( ret = dhm_check_range( &ctx->GY, &ctx->P ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 360 return( ret );
nexpaq 0:6c56fb4bc5f0 361
nexpaq 0:6c56fb4bc5f0 362 mbedtls_mpi_init( &GYb );
nexpaq 0:6c56fb4bc5f0 363
nexpaq 0:6c56fb4bc5f0 364 /* Blind peer's value */
nexpaq 0:6c56fb4bc5f0 365 if( f_rng != NULL )
nexpaq 0:6c56fb4bc5f0 366 {
nexpaq 0:6c56fb4bc5f0 367 MBEDTLS_MPI_CHK( dhm_update_blinding( ctx, f_rng, p_rng ) );
nexpaq 0:6c56fb4bc5f0 368 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &GYb, &ctx->GY, &ctx->Vi ) );
nexpaq 0:6c56fb4bc5f0 369 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &GYb, &GYb, &ctx->P ) );
nexpaq 0:6c56fb4bc5f0 370 }
nexpaq 0:6c56fb4bc5f0 371 else
nexpaq 0:6c56fb4bc5f0 372 MBEDTLS_MPI_CHK( mbedtls_mpi_copy( &GYb, &ctx->GY ) );
nexpaq 0:6c56fb4bc5f0 373
nexpaq 0:6c56fb4bc5f0 374 /* Do modular exponentiation */
nexpaq 0:6c56fb4bc5f0 375 MBEDTLS_MPI_CHK( mbedtls_mpi_exp_mod( &ctx->K, &GYb, &ctx->X,
nexpaq 0:6c56fb4bc5f0 376 &ctx->P, &ctx->RP ) );
nexpaq 0:6c56fb4bc5f0 377
nexpaq 0:6c56fb4bc5f0 378 /* Unblind secret value */
nexpaq 0:6c56fb4bc5f0 379 if( f_rng != NULL )
nexpaq 0:6c56fb4bc5f0 380 {
nexpaq 0:6c56fb4bc5f0 381 MBEDTLS_MPI_CHK( mbedtls_mpi_mul_mpi( &ctx->K, &ctx->K, &ctx->Vf ) );
nexpaq 0:6c56fb4bc5f0 382 MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( &ctx->K, &ctx->K, &ctx->P ) );
nexpaq 0:6c56fb4bc5f0 383 }
nexpaq 0:6c56fb4bc5f0 384
nexpaq 0:6c56fb4bc5f0 385 *olen = mbedtls_mpi_size( &ctx->K );
nexpaq 0:6c56fb4bc5f0 386
nexpaq 0:6c56fb4bc5f0 387 MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &ctx->K, output, *olen ) );
nexpaq 0:6c56fb4bc5f0 388
nexpaq 0:6c56fb4bc5f0 389 cleanup:
nexpaq 0:6c56fb4bc5f0 390 mbedtls_mpi_free( &GYb );
nexpaq 0:6c56fb4bc5f0 391
nexpaq 0:6c56fb4bc5f0 392 if( ret != 0 )
nexpaq 0:6c56fb4bc5f0 393 return( MBEDTLS_ERR_DHM_CALC_SECRET_FAILED + ret );
nexpaq 0:6c56fb4bc5f0 394
nexpaq 0:6c56fb4bc5f0 395 return( 0 );
nexpaq 0:6c56fb4bc5f0 396 }
nexpaq 0:6c56fb4bc5f0 397
nexpaq 0:6c56fb4bc5f0 398 /*
nexpaq 0:6c56fb4bc5f0 399 * Free the components of a DHM key
nexpaq 0:6c56fb4bc5f0 400 */
nexpaq 0:6c56fb4bc5f0 401 void mbedtls_dhm_free( mbedtls_dhm_context *ctx )
nexpaq 0:6c56fb4bc5f0 402 {
nexpaq 0:6c56fb4bc5f0 403 mbedtls_mpi_free( &ctx->pX); mbedtls_mpi_free( &ctx->Vf ); mbedtls_mpi_free( &ctx->Vi );
nexpaq 0:6c56fb4bc5f0 404 mbedtls_mpi_free( &ctx->RP ); mbedtls_mpi_free( &ctx->K ); mbedtls_mpi_free( &ctx->GY );
nexpaq 0:6c56fb4bc5f0 405 mbedtls_mpi_free( &ctx->GX ); mbedtls_mpi_free( &ctx->X ); mbedtls_mpi_free( &ctx->G );
nexpaq 0:6c56fb4bc5f0 406 mbedtls_mpi_free( &ctx->P );
nexpaq 0:6c56fb4bc5f0 407
nexpaq 0:6c56fb4bc5f0 408 mbedtls_zeroize( ctx, sizeof( mbedtls_dhm_context ) );
nexpaq 0:6c56fb4bc5f0 409 }
nexpaq 0:6c56fb4bc5f0 410
nexpaq 0:6c56fb4bc5f0 411 #if defined(MBEDTLS_ASN1_PARSE_C)
nexpaq 0:6c56fb4bc5f0 412 /*
nexpaq 0:6c56fb4bc5f0 413 * Parse DHM parameters
nexpaq 0:6c56fb4bc5f0 414 */
nexpaq 0:6c56fb4bc5f0 415 int mbedtls_dhm_parse_dhm( mbedtls_dhm_context *dhm, const unsigned char *dhmin,
nexpaq 0:6c56fb4bc5f0 416 size_t dhminlen )
nexpaq 0:6c56fb4bc5f0 417 {
nexpaq 0:6c56fb4bc5f0 418 int ret;
nexpaq 0:6c56fb4bc5f0 419 size_t len;
nexpaq 0:6c56fb4bc5f0 420 unsigned char *p, *end;
nexpaq 0:6c56fb4bc5f0 421 #if defined(MBEDTLS_PEM_PARSE_C)
nexpaq 0:6c56fb4bc5f0 422 mbedtls_pem_context pem;
nexpaq 0:6c56fb4bc5f0 423
nexpaq 0:6c56fb4bc5f0 424 mbedtls_pem_init( &pem );
nexpaq 0:6c56fb4bc5f0 425
nexpaq 0:6c56fb4bc5f0 426 /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
nexpaq 0:6c56fb4bc5f0 427 if( dhminlen == 0 || dhmin[dhminlen - 1] != '\0' )
nexpaq 0:6c56fb4bc5f0 428 ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
nexpaq 0:6c56fb4bc5f0 429 else
nexpaq 0:6c56fb4bc5f0 430 ret = mbedtls_pem_read_buffer( &pem,
nexpaq 0:6c56fb4bc5f0 431 "-----BEGIN DH PARAMETERS-----",
nexpaq 0:6c56fb4bc5f0 432 "-----END DH PARAMETERS-----",
nexpaq 0:6c56fb4bc5f0 433 dhmin, NULL, 0, &dhminlen );
nexpaq 0:6c56fb4bc5f0 434
nexpaq 0:6c56fb4bc5f0 435 if( ret == 0 )
nexpaq 0:6c56fb4bc5f0 436 {
nexpaq 0:6c56fb4bc5f0 437 /*
nexpaq 0:6c56fb4bc5f0 438 * Was PEM encoded
nexpaq 0:6c56fb4bc5f0 439 */
nexpaq 0:6c56fb4bc5f0 440 dhminlen = pem.buflen;
nexpaq 0:6c56fb4bc5f0 441 }
nexpaq 0:6c56fb4bc5f0 442 else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
nexpaq 0:6c56fb4bc5f0 443 goto exit;
nexpaq 0:6c56fb4bc5f0 444
nexpaq 0:6c56fb4bc5f0 445 p = ( ret == 0 ) ? pem.buf : (unsigned char *) dhmin;
nexpaq 0:6c56fb4bc5f0 446 #else
nexpaq 0:6c56fb4bc5f0 447 p = (unsigned char *) dhmin;
nexpaq 0:6c56fb4bc5f0 448 #endif /* MBEDTLS_PEM_PARSE_C */
nexpaq 0:6c56fb4bc5f0 449 end = p + dhminlen;
nexpaq 0:6c56fb4bc5f0 450
nexpaq 0:6c56fb4bc5f0 451 /*
nexpaq 0:6c56fb4bc5f0 452 * DHParams ::= SEQUENCE {
nexpaq 0:6c56fb4bc5f0 453 * prime INTEGER, -- P
nexpaq 0:6c56fb4bc5f0 454 * generator INTEGER, -- g
nexpaq 0:6c56fb4bc5f0 455 * privateValueLength INTEGER OPTIONAL
nexpaq 0:6c56fb4bc5f0 456 * }
nexpaq 0:6c56fb4bc5f0 457 */
nexpaq 0:6c56fb4bc5f0 458 if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
nexpaq 0:6c56fb4bc5f0 459 MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 460 {
nexpaq 0:6c56fb4bc5f0 461 ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
nexpaq 0:6c56fb4bc5f0 462 goto exit;
nexpaq 0:6c56fb4bc5f0 463 }
nexpaq 0:6c56fb4bc5f0 464
nexpaq 0:6c56fb4bc5f0 465 end = p + len;
nexpaq 0:6c56fb4bc5f0 466
nexpaq 0:6c56fb4bc5f0 467 if( ( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->P ) ) != 0 ||
nexpaq 0:6c56fb4bc5f0 468 ( ret = mbedtls_asn1_get_mpi( &p, end, &dhm->G ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 469 {
nexpaq 0:6c56fb4bc5f0 470 ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
nexpaq 0:6c56fb4bc5f0 471 goto exit;
nexpaq 0:6c56fb4bc5f0 472 }
nexpaq 0:6c56fb4bc5f0 473
nexpaq 0:6c56fb4bc5f0 474 if( p != end )
nexpaq 0:6c56fb4bc5f0 475 {
nexpaq 0:6c56fb4bc5f0 476 /* This might be the optional privateValueLength.
nexpaq 0:6c56fb4bc5f0 477 * If so, we can cleanly discard it */
nexpaq 0:6c56fb4bc5f0 478 mbedtls_mpi rec;
nexpaq 0:6c56fb4bc5f0 479 mbedtls_mpi_init( &rec );
nexpaq 0:6c56fb4bc5f0 480 ret = mbedtls_asn1_get_mpi( &p, end, &rec );
nexpaq 0:6c56fb4bc5f0 481 mbedtls_mpi_free( &rec );
nexpaq 0:6c56fb4bc5f0 482 if ( ret != 0 )
nexpaq 0:6c56fb4bc5f0 483 {
nexpaq 0:6c56fb4bc5f0 484 ret = MBEDTLS_ERR_DHM_INVALID_FORMAT + ret;
nexpaq 0:6c56fb4bc5f0 485 goto exit;
nexpaq 0:6c56fb4bc5f0 486 }
nexpaq 0:6c56fb4bc5f0 487 if ( p != end )
nexpaq 0:6c56fb4bc5f0 488 {
nexpaq 0:6c56fb4bc5f0 489 ret = MBEDTLS_ERR_DHM_INVALID_FORMAT +
nexpaq 0:6c56fb4bc5f0 490 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
nexpaq 0:6c56fb4bc5f0 491 goto exit;
nexpaq 0:6c56fb4bc5f0 492 }
nexpaq 0:6c56fb4bc5f0 493 }
nexpaq 0:6c56fb4bc5f0 494
nexpaq 0:6c56fb4bc5f0 495 ret = 0;
nexpaq 0:6c56fb4bc5f0 496
nexpaq 0:6c56fb4bc5f0 497 dhm->len = mbedtls_mpi_size( &dhm->P );
nexpaq 0:6c56fb4bc5f0 498
nexpaq 0:6c56fb4bc5f0 499 exit:
nexpaq 0:6c56fb4bc5f0 500 #if defined(MBEDTLS_PEM_PARSE_C)
nexpaq 0:6c56fb4bc5f0 501 mbedtls_pem_free( &pem );
nexpaq 0:6c56fb4bc5f0 502 #endif
nexpaq 0:6c56fb4bc5f0 503 if( ret != 0 )
nexpaq 0:6c56fb4bc5f0 504 mbedtls_dhm_free( dhm );
nexpaq 0:6c56fb4bc5f0 505
nexpaq 0:6c56fb4bc5f0 506 return( ret );
nexpaq 0:6c56fb4bc5f0 507 }
nexpaq 0:6c56fb4bc5f0 508
nexpaq 0:6c56fb4bc5f0 509 #if defined(MBEDTLS_FS_IO)
nexpaq 0:6c56fb4bc5f0 510 /*
nexpaq 0:6c56fb4bc5f0 511 * Load all data from a file into a given buffer.
nexpaq 0:6c56fb4bc5f0 512 *
nexpaq 0:6c56fb4bc5f0 513 * The file is expected to contain either PEM or DER encoded data.
nexpaq 0:6c56fb4bc5f0 514 * A terminating null byte is always appended. It is included in the announced
nexpaq 0:6c56fb4bc5f0 515 * length only if the data looks like it is PEM encoded.
nexpaq 0:6c56fb4bc5f0 516 */
nexpaq 0:6c56fb4bc5f0 517 static int load_file( const char *path, unsigned char **buf, size_t *n )
nexpaq 0:6c56fb4bc5f0 518 {
nexpaq 0:6c56fb4bc5f0 519 FILE *f;
nexpaq 0:6c56fb4bc5f0 520 long size;
nexpaq 0:6c56fb4bc5f0 521
nexpaq 0:6c56fb4bc5f0 522 if( ( f = fopen( path, "rb" ) ) == NULL )
nexpaq 0:6c56fb4bc5f0 523 return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
nexpaq 0:6c56fb4bc5f0 524
nexpaq 0:6c56fb4bc5f0 525 fseek( f, 0, SEEK_END );
nexpaq 0:6c56fb4bc5f0 526 if( ( size = ftell( f ) ) == -1 )
nexpaq 0:6c56fb4bc5f0 527 {
nexpaq 0:6c56fb4bc5f0 528 fclose( f );
nexpaq 0:6c56fb4bc5f0 529 return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
nexpaq 0:6c56fb4bc5f0 530 }
nexpaq 0:6c56fb4bc5f0 531 fseek( f, 0, SEEK_SET );
nexpaq 0:6c56fb4bc5f0 532
nexpaq 0:6c56fb4bc5f0 533 *n = (size_t) size;
nexpaq 0:6c56fb4bc5f0 534
nexpaq 0:6c56fb4bc5f0 535 if( *n + 1 == 0 ||
nexpaq 0:6c56fb4bc5f0 536 ( *buf = mbedtls_calloc( 1, *n + 1 ) ) == NULL )
nexpaq 0:6c56fb4bc5f0 537 {
nexpaq 0:6c56fb4bc5f0 538 fclose( f );
nexpaq 0:6c56fb4bc5f0 539 return( MBEDTLS_ERR_DHM_ALLOC_FAILED );
nexpaq 0:6c56fb4bc5f0 540 }
nexpaq 0:6c56fb4bc5f0 541
nexpaq 0:6c56fb4bc5f0 542 if( fread( *buf, 1, *n, f ) != *n )
nexpaq 0:6c56fb4bc5f0 543 {
nexpaq 0:6c56fb4bc5f0 544 fclose( f );
nexpaq 0:6c56fb4bc5f0 545 mbedtls_free( *buf );
nexpaq 0:6c56fb4bc5f0 546 return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
nexpaq 0:6c56fb4bc5f0 547 }
nexpaq 0:6c56fb4bc5f0 548
nexpaq 0:6c56fb4bc5f0 549 fclose( f );
nexpaq 0:6c56fb4bc5f0 550
nexpaq 0:6c56fb4bc5f0 551 (*buf)[*n] = '\0';
nexpaq 0:6c56fb4bc5f0 552
nexpaq 0:6c56fb4bc5f0 553 if( strstr( (const char *) *buf, "-----BEGIN " ) != NULL )
nexpaq 0:6c56fb4bc5f0 554 ++*n;
nexpaq 0:6c56fb4bc5f0 555
nexpaq 0:6c56fb4bc5f0 556 return( 0 );
nexpaq 0:6c56fb4bc5f0 557 }
nexpaq 0:6c56fb4bc5f0 558
nexpaq 0:6c56fb4bc5f0 559 /*
nexpaq 0:6c56fb4bc5f0 560 * Load and parse DHM parameters
nexpaq 0:6c56fb4bc5f0 561 */
nexpaq 0:6c56fb4bc5f0 562 int mbedtls_dhm_parse_dhmfile( mbedtls_dhm_context *dhm, const char *path )
nexpaq 0:6c56fb4bc5f0 563 {
nexpaq 0:6c56fb4bc5f0 564 int ret;
nexpaq 0:6c56fb4bc5f0 565 size_t n;
nexpaq 0:6c56fb4bc5f0 566 unsigned char *buf;
nexpaq 0:6c56fb4bc5f0 567
nexpaq 0:6c56fb4bc5f0 568 if( ( ret = load_file( path, &buf, &n ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 569 return( ret );
nexpaq 0:6c56fb4bc5f0 570
nexpaq 0:6c56fb4bc5f0 571 ret = mbedtls_dhm_parse_dhm( dhm, buf, n );
nexpaq 0:6c56fb4bc5f0 572
nexpaq 0:6c56fb4bc5f0 573 mbedtls_zeroize( buf, n );
nexpaq 0:6c56fb4bc5f0 574 mbedtls_free( buf );
nexpaq 0:6c56fb4bc5f0 575
nexpaq 0:6c56fb4bc5f0 576 return( ret );
nexpaq 0:6c56fb4bc5f0 577 }
nexpaq 0:6c56fb4bc5f0 578 #endif /* MBEDTLS_FS_IO */
nexpaq 0:6c56fb4bc5f0 579 #endif /* MBEDTLS_ASN1_PARSE_C */
nexpaq 0:6c56fb4bc5f0 580
nexpaq 0:6c56fb4bc5f0 581 #if defined(MBEDTLS_SELF_TEST)
nexpaq 0:6c56fb4bc5f0 582
nexpaq 0:6c56fb4bc5f0 583 static const char mbedtls_test_dhm_params[] =
nexpaq 0:6c56fb4bc5f0 584 "-----BEGIN DH PARAMETERS-----\r\n"
nexpaq 0:6c56fb4bc5f0 585 "MIGHAoGBAJ419DBEOgmQTzo5qXl5fQcN9TN455wkOL7052HzxxRVMyhYmwQcgJvh\r\n"
nexpaq 0:6c56fb4bc5f0 586 "1sa18fyfR9OiVEMYglOpkqVoGLN7qd5aQNNi5W7/C+VBdHTBJcGZJyyP5B3qcz32\r\n"
nexpaq 0:6c56fb4bc5f0 587 "9mLJKudlVudV0Qxk5qUJaPZ/xupz0NyoVpviuiBOI1gNi8ovSXWzAgEC\r\n"
nexpaq 0:6c56fb4bc5f0 588 "-----END DH PARAMETERS-----\r\n";
nexpaq 0:6c56fb4bc5f0 589
nexpaq 0:6c56fb4bc5f0 590 static const size_t mbedtls_test_dhm_params_len = sizeof( mbedtls_test_dhm_params );
nexpaq 0:6c56fb4bc5f0 591
nexpaq 0:6c56fb4bc5f0 592 /*
nexpaq 0:6c56fb4bc5f0 593 * Checkup routine
nexpaq 0:6c56fb4bc5f0 594 */
nexpaq 0:6c56fb4bc5f0 595 int mbedtls_dhm_self_test( int verbose )
nexpaq 0:6c56fb4bc5f0 596 {
nexpaq 0:6c56fb4bc5f0 597 int ret;
nexpaq 0:6c56fb4bc5f0 598 mbedtls_dhm_context dhm;
nexpaq 0:6c56fb4bc5f0 599
nexpaq 0:6c56fb4bc5f0 600 mbedtls_dhm_init( &dhm );
nexpaq 0:6c56fb4bc5f0 601
nexpaq 0:6c56fb4bc5f0 602 if( verbose != 0 )
nexpaq 0:6c56fb4bc5f0 603 mbedtls_printf( " DHM parameter load: " );
nexpaq 0:6c56fb4bc5f0 604
nexpaq 0:6c56fb4bc5f0 605 if( ( ret = mbedtls_dhm_parse_dhm( &dhm,
nexpaq 0:6c56fb4bc5f0 606 (const unsigned char *) mbedtls_test_dhm_params,
nexpaq 0:6c56fb4bc5f0 607 mbedtls_test_dhm_params_len ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 608 {
nexpaq 0:6c56fb4bc5f0 609 if( verbose != 0 )
nexpaq 0:6c56fb4bc5f0 610 mbedtls_printf( "failed\n" );
nexpaq 0:6c56fb4bc5f0 611
nexpaq 0:6c56fb4bc5f0 612 ret = 1;
nexpaq 0:6c56fb4bc5f0 613 goto exit;
nexpaq 0:6c56fb4bc5f0 614 }
nexpaq 0:6c56fb4bc5f0 615
nexpaq 0:6c56fb4bc5f0 616 if( verbose != 0 )
nexpaq 0:6c56fb4bc5f0 617 mbedtls_printf( "passed\n\n" );
nexpaq 0:6c56fb4bc5f0 618
nexpaq 0:6c56fb4bc5f0 619 exit:
nexpaq 0:6c56fb4bc5f0 620 mbedtls_dhm_free( &dhm );
nexpaq 0:6c56fb4bc5f0 621
nexpaq 0:6c56fb4bc5f0 622 return( ret );
nexpaq 0:6c56fb4bc5f0 623 }
nexpaq 0:6c56fb4bc5f0 624
nexpaq 0:6c56fb4bc5f0 625 #endif /* MBEDTLS_SELF_TEST */
nexpaq 0:6c56fb4bc5f0 626
nexpaq 0:6c56fb4bc5f0 627 #endif /* MBEDTLS_DHM_C */