sandbox / mbedtls

mbedtls ported to mbed-classic

Fork of mbedtls by Christopher Haster

source/hmac_drbg.c@4:bef26f687287, 2016-04-07 (annotated)

Committer:
Brian Daniels
Date:
Thu Apr 07 11:11:18 2016 +0100
Revision:
4:bef26f687287
Parent:
1:24750b9ad5ef 
Adding ported selftest test case

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Christopher Haster 1:24750b9ad5ef 1 /*
Christopher Haster 1:24750b9ad5ef 2 * HMAC_DRBG implementation (NIST SP 800-90)
Christopher Haster 1:24750b9ad5ef 3 *
Christopher Haster 1:24750b9ad5ef 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
Christopher Haster 1:24750b9ad5ef 5 * SPDX-License-Identifier: Apache-2.0
Christopher Haster 1:24750b9ad5ef 6 *
Christopher Haster 1:24750b9ad5ef 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
Christopher Haster 1:24750b9ad5ef 8 * not use this file except in compliance with the License.
Christopher Haster 1:24750b9ad5ef 9 * You may obtain a copy of the License at
Christopher Haster 1:24750b9ad5ef 10 *
Christopher Haster 1:24750b9ad5ef 11 * http://www.apache.org/licenses/LICENSE-2.0
Christopher Haster 1:24750b9ad5ef 12 *
Christopher Haster 1:24750b9ad5ef 13 * Unless required by applicable law or agreed to in writing, software
Christopher Haster 1:24750b9ad5ef 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
Christopher Haster 1:24750b9ad5ef 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
Christopher Haster 1:24750b9ad5ef 16 * See the License for the specific language governing permissions and
Christopher Haster 1:24750b9ad5ef 17 * limitations under the License.
Christopher Haster 1:24750b9ad5ef 18 *
Christopher Haster 1:24750b9ad5ef 19 * This file is part of mbed TLS (https://tls.mbed.org)
Christopher Haster 1:24750b9ad5ef 20 */
Christopher Haster 1:24750b9ad5ef 21
Christopher Haster 1:24750b9ad5ef 22 /*
Christopher Haster 1:24750b9ad5ef 23 * The NIST SP 800-90A DRBGs are described in the following publication.
Christopher Haster 1:24750b9ad5ef 24 * http://csrc.nist.gov/publications/nistpubs/800-90A/SP800-90A.pdf
Christopher Haster 1:24750b9ad5ef 25 * References below are based on rev. 1 (January 2012).
Christopher Haster 1:24750b9ad5ef 26 */
Christopher Haster 1:24750b9ad5ef 27
Christopher Haster 1:24750b9ad5ef 28 #if !defined(MBEDTLS_CONFIG_FILE)
Christopher Haster 1:24750b9ad5ef 29 #include "mbedtls/config.h"
Christopher Haster 1:24750b9ad5ef 30 #else
Christopher Haster 1:24750b9ad5ef 31 #include MBEDTLS_CONFIG_FILE
Christopher Haster 1:24750b9ad5ef 32 #endif
Christopher Haster 1:24750b9ad5ef 33
Christopher Haster 1:24750b9ad5ef 34 #if defined(MBEDTLS_HMAC_DRBG_C)
Christopher Haster 1:24750b9ad5ef 35
Christopher Haster 1:24750b9ad5ef 36 #include "mbedtls/hmac_drbg.h"
Christopher Haster 1:24750b9ad5ef 37
Christopher Haster 1:24750b9ad5ef 38 #include <string.h>
Christopher Haster 1:24750b9ad5ef 39
Christopher Haster 1:24750b9ad5ef 40 #if defined(MBEDTLS_FS_IO)
Christopher Haster 1:24750b9ad5ef 41 #include <stdio.h>
Christopher Haster 1:24750b9ad5ef 42 #endif
Christopher Haster 1:24750b9ad5ef 43
Christopher Haster 1:24750b9ad5ef 44 #if defined(MBEDTLS_SELF_TEST)
Christopher Haster 1:24750b9ad5ef 45 #if defined(MBEDTLS_PLATFORM_C)
Christopher Haster 1:24750b9ad5ef 46 #include "mbedtls/platform.h"
Christopher Haster 1:24750b9ad5ef 47 #else
Christopher Haster 1:24750b9ad5ef 48 #include <stdio.h>
Christopher Haster 1:24750b9ad5ef 49 #define mbedtls_printf printf
Christopher Haster 1:24750b9ad5ef 50 #endif /* MBEDTLS_SELF_TEST */
Christopher Haster 1:24750b9ad5ef 51 #endif /* MBEDTLS_PLATFORM_C */
Christopher Haster 1:24750b9ad5ef 52
Christopher Haster 1:24750b9ad5ef 53 /* Implementation that should never be optimized out by the compiler */
Christopher Haster 1:24750b9ad5ef 54 static void mbedtls_zeroize( void *v, size_t n ) {
Christopher Haster 1:24750b9ad5ef 55 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
Christopher Haster 1:24750b9ad5ef 56 }
Christopher Haster 1:24750b9ad5ef 57
Christopher Haster 1:24750b9ad5ef 58 /*
Christopher Haster 1:24750b9ad5ef 59 * HMAC_DRBG context initialization
Christopher Haster 1:24750b9ad5ef 60 */
Christopher Haster 1:24750b9ad5ef 61 void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx )
Christopher Haster 1:24750b9ad5ef 62 {
Christopher Haster 1:24750b9ad5ef 63 memset( ctx, 0, sizeof( mbedtls_hmac_drbg_context ) );
Christopher Haster 1:24750b9ad5ef 64
Christopher Haster 1:24750b9ad5ef 65 #if defined(MBEDTLS_THREADING_C)
Christopher Haster 1:24750b9ad5ef 66 mbedtls_mutex_init( &ctx->mutex );
Christopher Haster 1:24750b9ad5ef 67 #endif
Christopher Haster 1:24750b9ad5ef 68 }
Christopher Haster 1:24750b9ad5ef 69
Christopher Haster 1:24750b9ad5ef 70 /*
Christopher Haster 1:24750b9ad5ef 71 * HMAC_DRBG update, using optional additional data (10.1.2.2)
Christopher Haster 1:24750b9ad5ef 72 */
Christopher Haster 1:24750b9ad5ef 73 void mbedtls_hmac_drbg_update( mbedtls_hmac_drbg_context *ctx,
Christopher Haster 1:24750b9ad5ef 74 const unsigned char *additional, size_t add_len )
Christopher Haster 1:24750b9ad5ef 75 {
Christopher Haster 1:24750b9ad5ef 76 size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
Christopher Haster 1:24750b9ad5ef 77 unsigned char rounds = ( additional != NULL && add_len != 0 ) ? 2 : 1;
Christopher Haster 1:24750b9ad5ef 78 unsigned char sep[1];
Christopher Haster 1:24750b9ad5ef 79 unsigned char K[MBEDTLS_MD_MAX_SIZE];
Christopher Haster 1:24750b9ad5ef 80
Christopher Haster 1:24750b9ad5ef 81 for( sep[0] = 0; sep[0] < rounds; sep[0]++ )
Christopher Haster 1:24750b9ad5ef 82 {
Christopher Haster 1:24750b9ad5ef 83 /* Step 1 or 4 */
Christopher Haster 1:24750b9ad5ef 84 mbedtls_md_hmac_reset( &ctx->md_ctx );
Christopher Haster 1:24750b9ad5ef 85 mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
Christopher Haster 1:24750b9ad5ef 86 mbedtls_md_hmac_update( &ctx->md_ctx, sep, 1 );
Christopher Haster 1:24750b9ad5ef 87 if( rounds == 2 )
Christopher Haster 1:24750b9ad5ef 88 mbedtls_md_hmac_update( &ctx->md_ctx, additional, add_len );
Christopher Haster 1:24750b9ad5ef 89 mbedtls_md_hmac_finish( &ctx->md_ctx, K );
Christopher Haster 1:24750b9ad5ef 90
Christopher Haster 1:24750b9ad5ef 91 /* Step 2 or 5 */
Christopher Haster 1:24750b9ad5ef 92 mbedtls_md_hmac_starts( &ctx->md_ctx, K, md_len );
Christopher Haster 1:24750b9ad5ef 93 mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
Christopher Haster 1:24750b9ad5ef 94 mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V );
Christopher Haster 1:24750b9ad5ef 95 }
Christopher Haster 1:24750b9ad5ef 96 }
Christopher Haster 1:24750b9ad5ef 97
Christopher Haster 1:24750b9ad5ef 98 /*
Christopher Haster 1:24750b9ad5ef 99 * Simplified HMAC_DRBG initialisation (for use with deterministic ECDSA)
Christopher Haster 1:24750b9ad5ef 100 */
Christopher Haster 1:24750b9ad5ef 101 int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
Christopher Haster 1:24750b9ad5ef 102 const mbedtls_md_info_t * md_info,
Christopher Haster 1:24750b9ad5ef 103 const unsigned char *data, size_t data_len )
Christopher Haster 1:24750b9ad5ef 104 {
Christopher Haster 1:24750b9ad5ef 105 int ret;
Christopher Haster 1:24750b9ad5ef 106
Christopher Haster 1:24750b9ad5ef 107 if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
Christopher Haster 1:24750b9ad5ef 108 return( ret );
Christopher Haster 1:24750b9ad5ef 109
Christopher Haster 1:24750b9ad5ef 110 /*
Christopher Haster 1:24750b9ad5ef 111 * Set initial working state.
Christopher Haster 1:24750b9ad5ef 112 * Use the V memory location, which is currently all 0, to initialize the
Christopher Haster 1:24750b9ad5ef 113 * MD context with an all-zero key. Then set V to its initial value.
Christopher Haster 1:24750b9ad5ef 114 */
Christopher Haster 1:24750b9ad5ef 115 mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, mbedtls_md_get_size( md_info ) );
Christopher Haster 1:24750b9ad5ef 116 memset( ctx->V, 0x01, mbedtls_md_get_size( md_info ) );
Christopher Haster 1:24750b9ad5ef 117
Christopher Haster 1:24750b9ad5ef 118 mbedtls_hmac_drbg_update( ctx, data, data_len );
Christopher Haster 1:24750b9ad5ef 119
Christopher Haster 1:24750b9ad5ef 120 return( 0 );
Christopher Haster 1:24750b9ad5ef 121 }
Christopher Haster 1:24750b9ad5ef 122
Christopher Haster 1:24750b9ad5ef 123 /*
Christopher Haster 1:24750b9ad5ef 124 * HMAC_DRBG reseeding: 10.1.2.4 (arabic) + 9.2 (Roman)
Christopher Haster 1:24750b9ad5ef 125 */
Christopher Haster 1:24750b9ad5ef 126 int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
Christopher Haster 1:24750b9ad5ef 127 const unsigned char *additional, size_t len )
Christopher Haster 1:24750b9ad5ef 128 {
Christopher Haster 1:24750b9ad5ef 129 unsigned char seed[MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT];
Christopher Haster 1:24750b9ad5ef 130 size_t seedlen;
Christopher Haster 1:24750b9ad5ef 131
Christopher Haster 1:24750b9ad5ef 132 /* III. Check input length */
Christopher Haster 1:24750b9ad5ef 133 if( len > MBEDTLS_HMAC_DRBG_MAX_INPUT ||
Christopher Haster 1:24750b9ad5ef 134 ctx->entropy_len + len > MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT )
Christopher Haster 1:24750b9ad5ef 135 {
Christopher Haster 1:24750b9ad5ef 136 return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
Christopher Haster 1:24750b9ad5ef 137 }
Christopher Haster 1:24750b9ad5ef 138
Christopher Haster 1:24750b9ad5ef 139 memset( seed, 0, MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT );
Christopher Haster 1:24750b9ad5ef 140
Christopher Haster 1:24750b9ad5ef 141 /* IV. Gather entropy_len bytes of entropy for the seed */
Christopher Haster 1:24750b9ad5ef 142 if( ctx->f_entropy( ctx->p_entropy, seed, ctx->entropy_len ) != 0 )
Christopher Haster 1:24750b9ad5ef 143 return( MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED );
Christopher Haster 1:24750b9ad5ef 144
Christopher Haster 1:24750b9ad5ef 145 seedlen = ctx->entropy_len;
Christopher Haster 1:24750b9ad5ef 146
Christopher Haster 1:24750b9ad5ef 147 /* 1. Concatenate entropy and additional data if any */
Christopher Haster 1:24750b9ad5ef 148 if( additional != NULL && len != 0 )
Christopher Haster 1:24750b9ad5ef 149 {
Christopher Haster 1:24750b9ad5ef 150 memcpy( seed + seedlen, additional, len );
Christopher Haster 1:24750b9ad5ef 151 seedlen += len;
Christopher Haster 1:24750b9ad5ef 152 }
Christopher Haster 1:24750b9ad5ef 153
Christopher Haster 1:24750b9ad5ef 154 /* 2. Update state */
Christopher Haster 1:24750b9ad5ef 155 mbedtls_hmac_drbg_update( ctx, seed, seedlen );
Christopher Haster 1:24750b9ad5ef 156
Christopher Haster 1:24750b9ad5ef 157 /* 3. Reset reseed_counter */
Christopher Haster 1:24750b9ad5ef 158 ctx->reseed_counter = 1;
Christopher Haster 1:24750b9ad5ef 159
Christopher Haster 1:24750b9ad5ef 160 /* 4. Done */
Christopher Haster 1:24750b9ad5ef 161 return( 0 );
Christopher Haster 1:24750b9ad5ef 162 }
Christopher Haster 1:24750b9ad5ef 163
Christopher Haster 1:24750b9ad5ef 164 /*
Christopher Haster 1:24750b9ad5ef 165 * HMAC_DRBG initialisation (10.1.2.3 + 9.1)
Christopher Haster 1:24750b9ad5ef 166 */
Christopher Haster 1:24750b9ad5ef 167 int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
Christopher Haster 1:24750b9ad5ef 168 const mbedtls_md_info_t * md_info,
Christopher Haster 1:24750b9ad5ef 169 int (*f_entropy)(void *, unsigned char *, size_t),
Christopher Haster 1:24750b9ad5ef 170 void *p_entropy,
Christopher Haster 1:24750b9ad5ef 171 const unsigned char *custom,
Christopher Haster 1:24750b9ad5ef 172 size_t len )
Christopher Haster 1:24750b9ad5ef 173 {
Christopher Haster 1:24750b9ad5ef 174 int ret;
Christopher Haster 1:24750b9ad5ef 175 size_t entropy_len, md_size;
Christopher Haster 1:24750b9ad5ef 176
Christopher Haster 1:24750b9ad5ef 177 if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
Christopher Haster 1:24750b9ad5ef 178 return( ret );
Christopher Haster 1:24750b9ad5ef 179
Christopher Haster 1:24750b9ad5ef 180 md_size = mbedtls_md_get_size( md_info );
Christopher Haster 1:24750b9ad5ef 181
Christopher Haster 1:24750b9ad5ef 182 /*
Christopher Haster 1:24750b9ad5ef 183 * Set initial working state.
Christopher Haster 1:24750b9ad5ef 184 * Use the V memory location, which is currently all 0, to initialize the
Christopher Haster 1:24750b9ad5ef 185 * MD context with an all-zero key. Then set V to its initial value.
Christopher Haster 1:24750b9ad5ef 186 */
Christopher Haster 1:24750b9ad5ef 187 mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, md_size );
Christopher Haster 1:24750b9ad5ef 188 memset( ctx->V, 0x01, md_size );
Christopher Haster 1:24750b9ad5ef 189
Christopher Haster 1:24750b9ad5ef 190 ctx->f_entropy = f_entropy;
Christopher Haster 1:24750b9ad5ef 191 ctx->p_entropy = p_entropy;
Christopher Haster 1:24750b9ad5ef 192
Christopher Haster 1:24750b9ad5ef 193 ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
Christopher Haster 1:24750b9ad5ef 194
Christopher Haster 1:24750b9ad5ef 195 /*
Christopher Haster 1:24750b9ad5ef 196 * See SP800-57 5.6.1 (p. 65-66) for the security strength provided by
Christopher Haster 1:24750b9ad5ef 197 * each hash function, then according to SP800-90A rev1 10.1 table 2,
Christopher Haster 1:24750b9ad5ef 198 * min_entropy_len (in bits) is security_strength.
Christopher Haster 1:24750b9ad5ef 199 *
Christopher Haster 1:24750b9ad5ef 200 * (This also matches the sizes used in the NIST test vectors.)
Christopher Haster 1:24750b9ad5ef 201 */
Christopher Haster 1:24750b9ad5ef 202 entropy_len = md_size <= 20 ? 16 : /* 160-bits hash -> 128 bits */
Christopher Haster 1:24750b9ad5ef 203 md_size <= 28 ? 24 : /* 224-bits hash -> 192 bits */
Christopher Haster 1:24750b9ad5ef 204 32; /* better (256+) -> 256 bits */
Christopher Haster 1:24750b9ad5ef 205
Christopher Haster 1:24750b9ad5ef 206 /*
Christopher Haster 1:24750b9ad5ef 207 * For initialisation, use more entropy to emulate a nonce
Christopher Haster 1:24750b9ad5ef 208 * (Again, matches test vectors.)
Christopher Haster 1:24750b9ad5ef 209 */
Christopher Haster 1:24750b9ad5ef 210 ctx->entropy_len = entropy_len * 3 / 2;
Christopher Haster 1:24750b9ad5ef 211
Christopher Haster 1:24750b9ad5ef 212 if( ( ret = mbedtls_hmac_drbg_reseed( ctx, custom, len ) ) != 0 )
Christopher Haster 1:24750b9ad5ef 213 return( ret );
Christopher Haster 1:24750b9ad5ef 214
Christopher Haster 1:24750b9ad5ef 215 ctx->entropy_len = entropy_len;
Christopher Haster 1:24750b9ad5ef 216
Christopher Haster 1:24750b9ad5ef 217 return( 0 );
Christopher Haster 1:24750b9ad5ef 218 }
Christopher Haster 1:24750b9ad5ef 219
Christopher Haster 1:24750b9ad5ef 220 /*
Christopher Haster 1:24750b9ad5ef 221 * Set prediction resistance
Christopher Haster 1:24750b9ad5ef 222 */
Christopher Haster 1:24750b9ad5ef 223 void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx,
Christopher Haster 1:24750b9ad5ef 224 int resistance )
Christopher Haster 1:24750b9ad5ef 225 {
Christopher Haster 1:24750b9ad5ef 226 ctx->prediction_resistance = resistance;
Christopher Haster 1:24750b9ad5ef 227 }
Christopher Haster 1:24750b9ad5ef 228
Christopher Haster 1:24750b9ad5ef 229 /*
Christopher Haster 1:24750b9ad5ef 230 * Set entropy length grabbed for reseeds
Christopher Haster 1:24750b9ad5ef 231 */
Christopher Haster 1:24750b9ad5ef 232 void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx, size_t len )
Christopher Haster 1:24750b9ad5ef 233 {
Christopher Haster 1:24750b9ad5ef 234 ctx->entropy_len = len;
Christopher Haster 1:24750b9ad5ef 235 }
Christopher Haster 1:24750b9ad5ef 236
Christopher Haster 1:24750b9ad5ef 237 /*
Christopher Haster 1:24750b9ad5ef 238 * Set reseed interval
Christopher Haster 1:24750b9ad5ef 239 */
Christopher Haster 1:24750b9ad5ef 240 void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx, int interval )
Christopher Haster 1:24750b9ad5ef 241 {
Christopher Haster 1:24750b9ad5ef 242 ctx->reseed_interval = interval;
Christopher Haster 1:24750b9ad5ef 243 }
Christopher Haster 1:24750b9ad5ef 244
Christopher Haster 1:24750b9ad5ef 245 /*
Christopher Haster 1:24750b9ad5ef 246 * HMAC_DRBG random function with optional additional data:
Christopher Haster 1:24750b9ad5ef 247 * 10.1.2.5 (arabic) + 9.3 (Roman)
Christopher Haster 1:24750b9ad5ef 248 */
Christopher Haster 1:24750b9ad5ef 249 int mbedtls_hmac_drbg_random_with_add( void *p_rng,
Christopher Haster 1:24750b9ad5ef 250 unsigned char *output, size_t out_len,
Christopher Haster 1:24750b9ad5ef 251 const unsigned char *additional, size_t add_len )
Christopher Haster 1:24750b9ad5ef 252 {
Christopher Haster 1:24750b9ad5ef 253 int ret;
Christopher Haster 1:24750b9ad5ef 254 mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
Christopher Haster 1:24750b9ad5ef 255 size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
Christopher Haster 1:24750b9ad5ef 256 size_t left = out_len;
Christopher Haster 1:24750b9ad5ef 257 unsigned char *out = output;
Christopher Haster 1:24750b9ad5ef 258
Christopher Haster 1:24750b9ad5ef 259 /* II. Check request length */
Christopher Haster 1:24750b9ad5ef 260 if( out_len > MBEDTLS_HMAC_DRBG_MAX_REQUEST )
Christopher Haster 1:24750b9ad5ef 261 return( MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG );
Christopher Haster 1:24750b9ad5ef 262
Christopher Haster 1:24750b9ad5ef 263 /* III. Check input length */
Christopher Haster 1:24750b9ad5ef 264 if( add_len > MBEDTLS_HMAC_DRBG_MAX_INPUT )
Christopher Haster 1:24750b9ad5ef 265 return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
Christopher Haster 1:24750b9ad5ef 266
Christopher Haster 1:24750b9ad5ef 267 /* 1. (aka VII and IX) Check reseed counter and PR */
Christopher Haster 1:24750b9ad5ef 268 if( ctx->f_entropy != NULL && /* For no-reseeding instances */
Christopher Haster 1:24750b9ad5ef 269 ( ctx->prediction_resistance == MBEDTLS_HMAC_DRBG_PR_ON ||
Christopher Haster 1:24750b9ad5ef 270 ctx->reseed_counter > ctx->reseed_interval ) )
Christopher Haster 1:24750b9ad5ef 271 {
Christopher Haster 1:24750b9ad5ef 272 if( ( ret = mbedtls_hmac_drbg_reseed( ctx, additional, add_len ) ) != 0 )
Christopher Haster 1:24750b9ad5ef 273 return( ret );
Christopher Haster 1:24750b9ad5ef 274
Christopher Haster 1:24750b9ad5ef 275 add_len = 0; /* VII.4 */
Christopher Haster 1:24750b9ad5ef 276 }
Christopher Haster 1:24750b9ad5ef 277
Christopher Haster 1:24750b9ad5ef 278 /* 2. Use additional data if any */
Christopher Haster 1:24750b9ad5ef 279 if( additional != NULL && add_len != 0 )
Christopher Haster 1:24750b9ad5ef 280 mbedtls_hmac_drbg_update( ctx, additional, add_len );
Christopher Haster 1:24750b9ad5ef 281
Christopher Haster 1:24750b9ad5ef 282 /* 3, 4, 5. Generate bytes */
Christopher Haster 1:24750b9ad5ef 283 while( left != 0 )
Christopher Haster 1:24750b9ad5ef 284 {
Christopher Haster 1:24750b9ad5ef 285 size_t use_len = left > md_len ? md_len : left;
Christopher Haster 1:24750b9ad5ef 286
Christopher Haster 1:24750b9ad5ef 287 mbedtls_md_hmac_reset( &ctx->md_ctx );
Christopher Haster 1:24750b9ad5ef 288 mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
Christopher Haster 1:24750b9ad5ef 289 mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V );
Christopher Haster 1:24750b9ad5ef 290
Christopher Haster 1:24750b9ad5ef 291 memcpy( out, ctx->V, use_len );
Christopher Haster 1:24750b9ad5ef 292 out += use_len;
Christopher Haster 1:24750b9ad5ef 293 left -= use_len;
Christopher Haster 1:24750b9ad5ef 294 }
Christopher Haster 1:24750b9ad5ef 295
Christopher Haster 1:24750b9ad5ef 296 /* 6. Update */
Christopher Haster 1:24750b9ad5ef 297 mbedtls_hmac_drbg_update( ctx, additional, add_len );
Christopher Haster 1:24750b9ad5ef 298
Christopher Haster 1:24750b9ad5ef 299 /* 7. Update reseed counter */
Christopher Haster 1:24750b9ad5ef 300 ctx->reseed_counter++;
Christopher Haster 1:24750b9ad5ef 301
Christopher Haster 1:24750b9ad5ef 302 /* 8. Done */
Christopher Haster 1:24750b9ad5ef 303 return( 0 );
Christopher Haster 1:24750b9ad5ef 304 }
Christopher Haster 1:24750b9ad5ef 305
Christopher Haster 1:24750b9ad5ef 306 /*
Christopher Haster 1:24750b9ad5ef 307 * HMAC_DRBG random function
Christopher Haster 1:24750b9ad5ef 308 */
Christopher Haster 1:24750b9ad5ef 309 int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len )
Christopher Haster 1:24750b9ad5ef 310 {
Christopher Haster 1:24750b9ad5ef 311 int ret;
Christopher Haster 1:24750b9ad5ef 312 mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
Christopher Haster 1:24750b9ad5ef 313
Christopher Haster 1:24750b9ad5ef 314 #if defined(MBEDTLS_THREADING_C)
Christopher Haster 1:24750b9ad5ef 315 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
Christopher Haster 1:24750b9ad5ef 316 return( ret );
Christopher Haster 1:24750b9ad5ef 317 #endif
Christopher Haster 1:24750b9ad5ef 318
Christopher Haster 1:24750b9ad5ef 319 ret = mbedtls_hmac_drbg_random_with_add( ctx, output, out_len, NULL, 0 );
Christopher Haster 1:24750b9ad5ef 320
Christopher Haster 1:24750b9ad5ef 321 #if defined(MBEDTLS_THREADING_C)
Christopher Haster 1:24750b9ad5ef 322 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
Christopher Haster 1:24750b9ad5ef 323 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
Christopher Haster 1:24750b9ad5ef 324 #endif
Christopher Haster 1:24750b9ad5ef 325
Christopher Haster 1:24750b9ad5ef 326 return( ret );
Christopher Haster 1:24750b9ad5ef 327 }
Christopher Haster 1:24750b9ad5ef 328
Christopher Haster 1:24750b9ad5ef 329 /*
Christopher Haster 1:24750b9ad5ef 330 * Free an HMAC_DRBG context
Christopher Haster 1:24750b9ad5ef 331 */
Christopher Haster 1:24750b9ad5ef 332 void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx )
Christopher Haster 1:24750b9ad5ef 333 {
Christopher Haster 1:24750b9ad5ef 334 if( ctx == NULL )
Christopher Haster 1:24750b9ad5ef 335 return;
Christopher Haster 1:24750b9ad5ef 336
Christopher Haster 1:24750b9ad5ef 337 #if defined(MBEDTLS_THREADING_C)
Christopher Haster 1:24750b9ad5ef 338 mbedtls_mutex_free( &ctx->mutex );
Christopher Haster 1:24750b9ad5ef 339 #endif
Christopher Haster 1:24750b9ad5ef 340 mbedtls_md_free( &ctx->md_ctx );
Christopher Haster 1:24750b9ad5ef 341 mbedtls_zeroize( ctx, sizeof( mbedtls_hmac_drbg_context ) );
Christopher Haster 1:24750b9ad5ef 342 }
Christopher Haster 1:24750b9ad5ef 343
Christopher Haster 1:24750b9ad5ef 344 #if defined(MBEDTLS_FS_IO)
Christopher Haster 1:24750b9ad5ef 345 int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
Christopher Haster 1:24750b9ad5ef 346 {
Christopher Haster 1:24750b9ad5ef 347 int ret;
Christopher Haster 1:24750b9ad5ef 348 FILE *f;
Christopher Haster 1:24750b9ad5ef 349 unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];
Christopher Haster 1:24750b9ad5ef 350
Christopher Haster 1:24750b9ad5ef 351 if( ( f = fopen( path, "wb" ) ) == NULL )
Christopher Haster 1:24750b9ad5ef 352 return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
Christopher Haster 1:24750b9ad5ef 353
Christopher Haster 1:24750b9ad5ef 354 if( ( ret = mbedtls_hmac_drbg_random( ctx, buf, sizeof( buf ) ) ) != 0 )
Christopher Haster 1:24750b9ad5ef 355 goto exit;
Christopher Haster 1:24750b9ad5ef 356
Christopher Haster 1:24750b9ad5ef 357 if( fwrite( buf, 1, sizeof( buf ), f ) != sizeof( buf ) )
Christopher Haster 1:24750b9ad5ef 358 {
Christopher Haster 1:24750b9ad5ef 359 ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
Christopher Haster 1:24750b9ad5ef 360 goto exit;
Christopher Haster 1:24750b9ad5ef 361 }
Christopher Haster 1:24750b9ad5ef 362
Christopher Haster 1:24750b9ad5ef 363 ret = 0;
Christopher Haster 1:24750b9ad5ef 364
Christopher Haster 1:24750b9ad5ef 365 exit:
Christopher Haster 1:24750b9ad5ef 366 fclose( f );
Christopher Haster 1:24750b9ad5ef 367 return( ret );
Christopher Haster 1:24750b9ad5ef 368 }
Christopher Haster 1:24750b9ad5ef 369
Christopher Haster 1:24750b9ad5ef 370 int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
Christopher Haster 1:24750b9ad5ef 371 {
Christopher Haster 1:24750b9ad5ef 372 FILE *f;
Christopher Haster 1:24750b9ad5ef 373 size_t n;
Christopher Haster 1:24750b9ad5ef 374 unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];
Christopher Haster 1:24750b9ad5ef 375
Christopher Haster 1:24750b9ad5ef 376 if( ( f = fopen( path, "rb" ) ) == NULL )
Christopher Haster 1:24750b9ad5ef 377 return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
Christopher Haster 1:24750b9ad5ef 378
Christopher Haster 1:24750b9ad5ef 379 fseek( f, 0, SEEK_END );
Christopher Haster 1:24750b9ad5ef 380 n = (size_t) ftell( f );
Christopher Haster 1:24750b9ad5ef 381 fseek( f, 0, SEEK_SET );
Christopher Haster 1:24750b9ad5ef 382
Christopher Haster 1:24750b9ad5ef 383 if( n > MBEDTLS_HMAC_DRBG_MAX_INPUT )
Christopher Haster 1:24750b9ad5ef 384 {
Christopher Haster 1:24750b9ad5ef 385 fclose( f );
Christopher Haster 1:24750b9ad5ef 386 return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
Christopher Haster 1:24750b9ad5ef 387 }
Christopher Haster 1:24750b9ad5ef 388
Christopher Haster 1:24750b9ad5ef 389 if( fread( buf, 1, n, f ) != n )
Christopher Haster 1:24750b9ad5ef 390 {
Christopher Haster 1:24750b9ad5ef 391 fclose( f );
Christopher Haster 1:24750b9ad5ef 392 return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
Christopher Haster 1:24750b9ad5ef 393 }
Christopher Haster 1:24750b9ad5ef 394
Christopher Haster 1:24750b9ad5ef 395 fclose( f );
Christopher Haster 1:24750b9ad5ef 396
Christopher Haster 1:24750b9ad5ef 397 mbedtls_hmac_drbg_update( ctx, buf, n );
Christopher Haster 1:24750b9ad5ef 398
Christopher Haster 1:24750b9ad5ef 399 return( mbedtls_hmac_drbg_write_seed_file( ctx, path ) );
Christopher Haster 1:24750b9ad5ef 400 }
Christopher Haster 1:24750b9ad5ef 401 #endif /* MBEDTLS_FS_IO */
Christopher Haster 1:24750b9ad5ef 402
Christopher Haster 1:24750b9ad5ef 403
Christopher Haster 1:24750b9ad5ef 404 #if defined(MBEDTLS_SELF_TEST)
Christopher Haster 1:24750b9ad5ef 405
Christopher Haster 1:24750b9ad5ef 406 #if !defined(MBEDTLS_SHA1_C)
Christopher Haster 1:24750b9ad5ef 407 /* Dummy checkup routine */
Christopher Haster 1:24750b9ad5ef 408 int mbedtls_hmac_drbg_self_test( int verbose )
Christopher Haster 1:24750b9ad5ef 409 {
Christopher Haster 1:24750b9ad5ef 410 (void) verbose;
Christopher Haster 1:24750b9ad5ef 411 return( 0 );
Christopher Haster 1:24750b9ad5ef 412 }
Christopher Haster 1:24750b9ad5ef 413 #else
Christopher Haster 1:24750b9ad5ef 414
Christopher Haster 1:24750b9ad5ef 415 #define OUTPUT_LEN 80
Christopher Haster 1:24750b9ad5ef 416
Christopher Haster 1:24750b9ad5ef 417 /* From a NIST PR=true test vector */
Christopher Haster 1:24750b9ad5ef 418 static const unsigned char entropy_pr[] = {
Christopher Haster 1:24750b9ad5ef 419 0xa0, 0xc9, 0xab, 0x58, 0xf1, 0xe2, 0xe5, 0xa4, 0xde, 0x3e, 0xbd, 0x4f,
Christopher Haster 1:24750b9ad5ef 420 0xf7, 0x3e, 0x9c, 0x5b, 0x64, 0xef, 0xd8, 0xca, 0x02, 0x8c, 0xf8, 0x11,
Christopher Haster 1:24750b9ad5ef 421 0x48, 0xa5, 0x84, 0xfe, 0x69, 0xab, 0x5a, 0xee, 0x42, 0xaa, 0x4d, 0x42,
Christopher Haster 1:24750b9ad5ef 422 0x17, 0x60, 0x99, 0xd4, 0x5e, 0x13, 0x97, 0xdc, 0x40, 0x4d, 0x86, 0xa3,
Christopher Haster 1:24750b9ad5ef 423 0x7b, 0xf5, 0x59, 0x54, 0x75, 0x69, 0x51, 0xe4 };
Christopher Haster 1:24750b9ad5ef 424 static const unsigned char result_pr[OUTPUT_LEN] = {
Christopher Haster 1:24750b9ad5ef 425 0x9a, 0x00, 0xa2, 0xd0, 0x0e, 0xd5, 0x9b, 0xfe, 0x31, 0xec, 0xb1, 0x39,
Christopher Haster 1:24750b9ad5ef 426 0x9b, 0x60, 0x81, 0x48, 0xd1, 0x96, 0x9d, 0x25, 0x0d, 0x3c, 0x1e, 0x94,
Christopher Haster 1:24750b9ad5ef 427 0x10, 0x10, 0x98, 0x12, 0x93, 0x25, 0xca, 0xb8, 0xfc, 0xcc, 0x2d, 0x54,
Christopher Haster 1:24750b9ad5ef 428 0x73, 0x19, 0x70, 0xc0, 0x10, 0x7a, 0xa4, 0x89, 0x25, 0x19, 0x95, 0x5e,
Christopher Haster 1:24750b9ad5ef 429 0x4b, 0xc6, 0x00, 0x1d, 0x7f, 0x4e, 0x6a, 0x2b, 0xf8, 0xa3, 0x01, 0xab,
Christopher Haster 1:24750b9ad5ef 430 0x46, 0x05, 0x5c, 0x09, 0xa6, 0x71, 0x88, 0xf1, 0xa7, 0x40, 0xee, 0xf3,
Christopher Haster 1:24750b9ad5ef 431 0xe1, 0x5c, 0x02, 0x9b, 0x44, 0xaf, 0x03, 0x44 };
Christopher Haster 1:24750b9ad5ef 432
Christopher Haster 1:24750b9ad5ef 433 /* From a NIST PR=false test vector */
Christopher Haster 1:24750b9ad5ef 434 static const unsigned char entropy_nopr[] = {
Christopher Haster 1:24750b9ad5ef 435 0x79, 0x34, 0x9b, 0xbf, 0x7c, 0xdd, 0xa5, 0x79, 0x95, 0x57, 0x86, 0x66,
Christopher Haster 1:24750b9ad5ef 436 0x21, 0xc9, 0x13, 0x83, 0x11, 0x46, 0x73, 0x3a, 0xbf, 0x8c, 0x35, 0xc8,
Christopher Haster 1:24750b9ad5ef 437 0xc7, 0x21, 0x5b, 0x5b, 0x96, 0xc4, 0x8e, 0x9b, 0x33, 0x8c, 0x74, 0xe3,
Christopher Haster 1:24750b9ad5ef 438 0xe9, 0x9d, 0xfe, 0xdf };
Christopher Haster 1:24750b9ad5ef 439 static const unsigned char result_nopr[OUTPUT_LEN] = {
Christopher Haster 1:24750b9ad5ef 440 0xc6, 0xa1, 0x6a, 0xb8, 0xd4, 0x20, 0x70, 0x6f, 0x0f, 0x34, 0xab, 0x7f,
Christopher Haster 1:24750b9ad5ef 441 0xec, 0x5a, 0xdc, 0xa9, 0xd8, 0xca, 0x3a, 0x13, 0x3e, 0x15, 0x9c, 0xa6,
Christopher Haster 1:24750b9ad5ef 442 0xac, 0x43, 0xc6, 0xf8, 0xa2, 0xbe, 0x22, 0x83, 0x4a, 0x4c, 0x0a, 0x0a,
Christopher Haster 1:24750b9ad5ef 443 0xff, 0xb1, 0x0d, 0x71, 0x94, 0xf1, 0xc1, 0xa5, 0xcf, 0x73, 0x22, 0xec,
Christopher Haster 1:24750b9ad5ef 444 0x1a, 0xe0, 0x96, 0x4e, 0xd4, 0xbf, 0x12, 0x27, 0x46, 0xe0, 0x87, 0xfd,
Christopher Haster 1:24750b9ad5ef 445 0xb5, 0xb3, 0xe9, 0x1b, 0x34, 0x93, 0xd5, 0xbb, 0x98, 0xfa, 0xed, 0x49,
Christopher Haster 1:24750b9ad5ef 446 0xe8, 0x5f, 0x13, 0x0f, 0xc8, 0xa4, 0x59, 0xb7 };
Christopher Haster 1:24750b9ad5ef 447
Christopher Haster 1:24750b9ad5ef 448 /* "Entropy" from buffer */
Christopher Haster 1:24750b9ad5ef 449 static size_t test_offset;
Christopher Haster 1:24750b9ad5ef 450 static int hmac_drbg_self_test_entropy( void *data,
Christopher Haster 1:24750b9ad5ef 451 unsigned char *buf, size_t len )
Christopher Haster 1:24750b9ad5ef 452 {
Christopher Haster 1:24750b9ad5ef 453 const unsigned char *p = data;
Christopher Haster 1:24750b9ad5ef 454 memcpy( buf, p + test_offset, len );
Christopher Haster 1:24750b9ad5ef 455 test_offset += len;
Christopher Haster 1:24750b9ad5ef 456 return( 0 );
Christopher Haster 1:24750b9ad5ef 457 }
Christopher Haster 1:24750b9ad5ef 458
Christopher Haster 1:24750b9ad5ef 459 #define CHK( c ) if( (c) != 0 ) \
Christopher Haster 1:24750b9ad5ef 460 { \
Christopher Haster 1:24750b9ad5ef 461 if( verbose != 0 ) \
Christopher Haster 1:24750b9ad5ef 462 mbedtls_printf( "failed\n" ); \
Christopher Haster 1:24750b9ad5ef 463 return( 1 ); \
Christopher Haster 1:24750b9ad5ef 464 }
Christopher Haster 1:24750b9ad5ef 465
Christopher Haster 1:24750b9ad5ef 466 /*
Christopher Haster 1:24750b9ad5ef 467 * Checkup routine for HMAC_DRBG with SHA-1
Christopher Haster 1:24750b9ad5ef 468 */
Christopher Haster 1:24750b9ad5ef 469 int mbedtls_hmac_drbg_self_test( int verbose )
Christopher Haster 1:24750b9ad5ef 470 {
Christopher Haster 1:24750b9ad5ef 471 mbedtls_hmac_drbg_context ctx;
Christopher Haster 1:24750b9ad5ef 472 unsigned char buf[OUTPUT_LEN];
Christopher Haster 1:24750b9ad5ef 473 const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 );
Christopher Haster 1:24750b9ad5ef 474
Christopher Haster 1:24750b9ad5ef 475 mbedtls_hmac_drbg_init( &ctx );
Christopher Haster 1:24750b9ad5ef 476
Christopher Haster 1:24750b9ad5ef 477 /*
Christopher Haster 1:24750b9ad5ef 478 * PR = True
Christopher Haster 1:24750b9ad5ef 479 */
Christopher Haster 1:24750b9ad5ef 480 if( verbose != 0 )
Christopher Haster 1:24750b9ad5ef 481 mbedtls_printf( " HMAC_DRBG (PR = True) : " );
Christopher Haster 1:24750b9ad5ef 482
Christopher Haster 1:24750b9ad5ef 483 test_offset = 0;
Christopher Haster 1:24750b9ad5ef 484 CHK( mbedtls_hmac_drbg_seed( &ctx, md_info,
Christopher Haster 1:24750b9ad5ef 485 hmac_drbg_self_test_entropy, (void *) entropy_pr,
Christopher Haster 1:24750b9ad5ef 486 NULL, 0 ) );
Christopher Haster 1:24750b9ad5ef 487 mbedtls_hmac_drbg_set_prediction_resistance( &ctx, MBEDTLS_HMAC_DRBG_PR_ON );
Christopher Haster 1:24750b9ad5ef 488 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
Christopher Haster 1:24750b9ad5ef 489 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
Christopher Haster 1:24750b9ad5ef 490 CHK( memcmp( buf, result_pr, OUTPUT_LEN ) );
Christopher Haster 1:24750b9ad5ef 491 mbedtls_hmac_drbg_free( &ctx );
Christopher Haster 1:24750b9ad5ef 492
Christopher Haster 1:24750b9ad5ef 493 mbedtls_hmac_drbg_free( &ctx );
Christopher Haster 1:24750b9ad5ef 494
Christopher Haster 1:24750b9ad5ef 495 if( verbose != 0 )
Christopher Haster 1:24750b9ad5ef 496 mbedtls_printf( "passed\n" );
Christopher Haster 1:24750b9ad5ef 497
Christopher Haster 1:24750b9ad5ef 498 /*
Christopher Haster 1:24750b9ad5ef 499 * PR = False
Christopher Haster 1:24750b9ad5ef 500 */
Christopher Haster 1:24750b9ad5ef 501 if( verbose != 0 )
Christopher Haster 1:24750b9ad5ef 502 mbedtls_printf( " HMAC_DRBG (PR = False) : " );
Christopher Haster 1:24750b9ad5ef 503
Christopher Haster 1:24750b9ad5ef 504 mbedtls_hmac_drbg_init( &ctx );
Christopher Haster 1:24750b9ad5ef 505
Christopher Haster 1:24750b9ad5ef 506 test_offset = 0;
Christopher Haster 1:24750b9ad5ef 507 CHK( mbedtls_hmac_drbg_seed( &ctx, md_info,
Christopher Haster 1:24750b9ad5ef 508 hmac_drbg_self_test_entropy, (void *) entropy_nopr,
Christopher Haster 1:24750b9ad5ef 509 NULL, 0 ) );
Christopher Haster 1:24750b9ad5ef 510 CHK( mbedtls_hmac_drbg_reseed( &ctx, NULL, 0 ) );
Christopher Haster 1:24750b9ad5ef 511 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
Christopher Haster 1:24750b9ad5ef 512 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
Christopher Haster 1:24750b9ad5ef 513 CHK( memcmp( buf, result_nopr, OUTPUT_LEN ) );
Christopher Haster 1:24750b9ad5ef 514 mbedtls_hmac_drbg_free( &ctx );
Christopher Haster 1:24750b9ad5ef 515
Christopher Haster 1:24750b9ad5ef 516 mbedtls_hmac_drbg_free( &ctx );
Christopher Haster 1:24750b9ad5ef 517
Christopher Haster 1:24750b9ad5ef 518 if( verbose != 0 )
Christopher Haster 1:24750b9ad5ef 519 mbedtls_printf( "passed\n" );
Christopher Haster 1:24750b9ad5ef 520
Christopher Haster 1:24750b9ad5ef 521 if( verbose != 0 )
Christopher Haster 1:24750b9ad5ef 522 mbedtls_printf( "\n" );
Christopher Haster 1:24750b9ad5ef 523
Christopher Haster 1:24750b9ad5ef 524 return( 0 );
Christopher Haster 1:24750b9ad5ef 525 }
Christopher Haster 1:24750b9ad5ef 526 #endif /* MBEDTLS_SHA1_C */
Christopher Haster 1:24750b9ad5ef 527 #endif /* MBEDTLS_SELF_TEST */
Christopher Haster 1:24750b9ad5ef 528
Christopher Haster 1:24750b9ad5ef 529 #endif /* MBEDTLS_HMAC_DRBG_C */