erkin yucel / mbed-os

mbed os with nrf51 internal bandgap enabled to read battery level

Dependents:   BLE_file_test BLE_Blink ExternalEncoder

features/mbedtls/src/hmac_drbg.c@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
elessair 0:f269e3021894 1 /*
elessair 0:f269e3021894 2 * HMAC_DRBG implementation (NIST SP 800-90)
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
elessair 0:f269e3021894 5 * SPDX-License-Identifier: Apache-2.0
elessair 0:f269e3021894 6 *
elessair 0:f269e3021894 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
elessair 0:f269e3021894 8 * not use this file except in compliance with the License.
elessair 0:f269e3021894 9 * You may obtain a copy of the License at
elessair 0:f269e3021894 10 *
elessair 0:f269e3021894 11 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 12 *
elessair 0:f269e3021894 13 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
elessair 0:f269e3021894 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 16 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 17 * limitations under the License.
elessair 0:f269e3021894 18 *
elessair 0:f269e3021894 19 * This file is part of mbed TLS (https://tls.mbed.org)
elessair 0:f269e3021894 20 */
elessair 0:f269e3021894 21
elessair 0:f269e3021894 22 /*
elessair 0:f269e3021894 23 * The NIST SP 800-90A DRBGs are described in the following publication.
elessair 0:f269e3021894 24 * http://csrc.nist.gov/publications/nistpubs/800-90A/SP800-90A.pdf
elessair 0:f269e3021894 25 * References below are based on rev. 1 (January 2012).
elessair 0:f269e3021894 26 */
elessair 0:f269e3021894 27
elessair 0:f269e3021894 28 #if !defined(MBEDTLS_CONFIG_FILE)
elessair 0:f269e3021894 29 #include "mbedtls/config.h"
elessair 0:f269e3021894 30 #else
elessair 0:f269e3021894 31 #include MBEDTLS_CONFIG_FILE
elessair 0:f269e3021894 32 #endif
elessair 0:f269e3021894 33
elessair 0:f269e3021894 34 #if defined(MBEDTLS_HMAC_DRBG_C)
elessair 0:f269e3021894 35
elessair 0:f269e3021894 36 #include "mbedtls/hmac_drbg.h"
elessair 0:f269e3021894 37
elessair 0:f269e3021894 38 #include <string.h>
elessair 0:f269e3021894 39
elessair 0:f269e3021894 40 #if defined(MBEDTLS_FS_IO)
elessair 0:f269e3021894 41 #include <stdio.h>
elessair 0:f269e3021894 42 #endif
elessair 0:f269e3021894 43
elessair 0:f269e3021894 44 #if defined(MBEDTLS_SELF_TEST)
elessair 0:f269e3021894 45 #if defined(MBEDTLS_PLATFORM_C)
elessair 0:f269e3021894 46 #include "mbedtls/platform.h"
elessair 0:f269e3021894 47 #else
elessair 0:f269e3021894 48 #include <stdio.h>
elessair 0:f269e3021894 49 #define mbedtls_printf printf
elessair 0:f269e3021894 50 #endif /* MBEDTLS_SELF_TEST */
elessair 0:f269e3021894 51 #endif /* MBEDTLS_PLATFORM_C */
elessair 0:f269e3021894 52
elessair 0:f269e3021894 53 /* Implementation that should never be optimized out by the compiler */
elessair 0:f269e3021894 54 static void mbedtls_zeroize( void *v, size_t n ) {
elessair 0:f269e3021894 55 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
elessair 0:f269e3021894 56 }
elessair 0:f269e3021894 57
elessair 0:f269e3021894 58 /*
elessair 0:f269e3021894 59 * HMAC_DRBG context initialization
elessair 0:f269e3021894 60 */
elessair 0:f269e3021894 61 void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx )
elessair 0:f269e3021894 62 {
elessair 0:f269e3021894 63 memset( ctx, 0, sizeof( mbedtls_hmac_drbg_context ) );
elessair 0:f269e3021894 64
elessair 0:f269e3021894 65 #if defined(MBEDTLS_THREADING_C)
elessair 0:f269e3021894 66 mbedtls_mutex_init( &ctx->mutex );
elessair 0:f269e3021894 67 #endif
elessair 0:f269e3021894 68 }
elessair 0:f269e3021894 69
elessair 0:f269e3021894 70 /*
elessair 0:f269e3021894 71 * HMAC_DRBG update, using optional additional data (10.1.2.2)
elessair 0:f269e3021894 72 */
elessair 0:f269e3021894 73 void mbedtls_hmac_drbg_update( mbedtls_hmac_drbg_context *ctx,
elessair 0:f269e3021894 74 const unsigned char *additional, size_t add_len )
elessair 0:f269e3021894 75 {
elessair 0:f269e3021894 76 size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
elessair 0:f269e3021894 77 unsigned char rounds = ( additional != NULL && add_len != 0 ) ? 2 : 1;
elessair 0:f269e3021894 78 unsigned char sep[1];
elessair 0:f269e3021894 79 unsigned char K[MBEDTLS_MD_MAX_SIZE];
elessair 0:f269e3021894 80
elessair 0:f269e3021894 81 for( sep[0] = 0; sep[0] < rounds; sep[0]++ )
elessair 0:f269e3021894 82 {
elessair 0:f269e3021894 83 /* Step 1 or 4 */
elessair 0:f269e3021894 84 mbedtls_md_hmac_reset( &ctx->md_ctx );
elessair 0:f269e3021894 85 mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
elessair 0:f269e3021894 86 mbedtls_md_hmac_update( &ctx->md_ctx, sep, 1 );
elessair 0:f269e3021894 87 if( rounds == 2 )
elessair 0:f269e3021894 88 mbedtls_md_hmac_update( &ctx->md_ctx, additional, add_len );
elessair 0:f269e3021894 89 mbedtls_md_hmac_finish( &ctx->md_ctx, K );
elessair 0:f269e3021894 90
elessair 0:f269e3021894 91 /* Step 2 or 5 */
elessair 0:f269e3021894 92 mbedtls_md_hmac_starts( &ctx->md_ctx, K, md_len );
elessair 0:f269e3021894 93 mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
elessair 0:f269e3021894 94 mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V );
elessair 0:f269e3021894 95 }
elessair 0:f269e3021894 96 }
elessair 0:f269e3021894 97
elessair 0:f269e3021894 98 /*
elessair 0:f269e3021894 99 * Simplified HMAC_DRBG initialisation (for use with deterministic ECDSA)
elessair 0:f269e3021894 100 */
elessair 0:f269e3021894 101 int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
elessair 0:f269e3021894 102 const mbedtls_md_info_t * md_info,
elessair 0:f269e3021894 103 const unsigned char *data, size_t data_len )
elessair 0:f269e3021894 104 {
elessair 0:f269e3021894 105 int ret;
elessair 0:f269e3021894 106
elessair 0:f269e3021894 107 if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
elessair 0:f269e3021894 108 return( ret );
elessair 0:f269e3021894 109
elessair 0:f269e3021894 110 /*
elessair 0:f269e3021894 111 * Set initial working state.
elessair 0:f269e3021894 112 * Use the V memory location, which is currently all 0, to initialize the
elessair 0:f269e3021894 113 * MD context with an all-zero key. Then set V to its initial value.
elessair 0:f269e3021894 114 */
elessair 0:f269e3021894 115 mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, mbedtls_md_get_size( md_info ) );
elessair 0:f269e3021894 116 memset( ctx->V, 0x01, mbedtls_md_get_size( md_info ) );
elessair 0:f269e3021894 117
elessair 0:f269e3021894 118 mbedtls_hmac_drbg_update( ctx, data, data_len );
elessair 0:f269e3021894 119
elessair 0:f269e3021894 120 return( 0 );
elessair 0:f269e3021894 121 }
elessair 0:f269e3021894 122
elessair 0:f269e3021894 123 /*
elessair 0:f269e3021894 124 * HMAC_DRBG reseeding: 10.1.2.4 (arabic) + 9.2 (Roman)
elessair 0:f269e3021894 125 */
elessair 0:f269e3021894 126 int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
elessair 0:f269e3021894 127 const unsigned char *additional, size_t len )
elessair 0:f269e3021894 128 {
elessair 0:f269e3021894 129 unsigned char seed[MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT];
elessair 0:f269e3021894 130 size_t seedlen;
elessair 0:f269e3021894 131
elessair 0:f269e3021894 132 /* III. Check input length */
elessair 0:f269e3021894 133 if( len > MBEDTLS_HMAC_DRBG_MAX_INPUT ||
elessair 0:f269e3021894 134 ctx->entropy_len + len > MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT )
elessair 0:f269e3021894 135 {
elessair 0:f269e3021894 136 return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
elessair 0:f269e3021894 137 }
elessair 0:f269e3021894 138
elessair 0:f269e3021894 139 memset( seed, 0, MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT );
elessair 0:f269e3021894 140
elessair 0:f269e3021894 141 /* IV. Gather entropy_len bytes of entropy for the seed */
elessair 0:f269e3021894 142 if( ctx->f_entropy( ctx->p_entropy, seed, ctx->entropy_len ) != 0 )
elessair 0:f269e3021894 143 return( MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED );
elessair 0:f269e3021894 144
elessair 0:f269e3021894 145 seedlen = ctx->entropy_len;
elessair 0:f269e3021894 146
elessair 0:f269e3021894 147 /* 1. Concatenate entropy and additional data if any */
elessair 0:f269e3021894 148 if( additional != NULL && len != 0 )
elessair 0:f269e3021894 149 {
elessair 0:f269e3021894 150 memcpy( seed + seedlen, additional, len );
elessair 0:f269e3021894 151 seedlen += len;
elessair 0:f269e3021894 152 }
elessair 0:f269e3021894 153
elessair 0:f269e3021894 154 /* 2. Update state */
elessair 0:f269e3021894 155 mbedtls_hmac_drbg_update( ctx, seed, seedlen );
elessair 0:f269e3021894 156
elessair 0:f269e3021894 157 /* 3. Reset reseed_counter */
elessair 0:f269e3021894 158 ctx->reseed_counter = 1;
elessair 0:f269e3021894 159
elessair 0:f269e3021894 160 /* 4. Done */
elessair 0:f269e3021894 161 return( 0 );
elessair 0:f269e3021894 162 }
elessair 0:f269e3021894 163
elessair 0:f269e3021894 164 /*
elessair 0:f269e3021894 165 * HMAC_DRBG initialisation (10.1.2.3 + 9.1)
elessair 0:f269e3021894 166 */
elessair 0:f269e3021894 167 int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
elessair 0:f269e3021894 168 const mbedtls_md_info_t * md_info,
elessair 0:f269e3021894 169 int (*f_entropy)(void *, unsigned char *, size_t),
elessair 0:f269e3021894 170 void *p_entropy,
elessair 0:f269e3021894 171 const unsigned char *custom,
elessair 0:f269e3021894 172 size_t len )
elessair 0:f269e3021894 173 {
elessair 0:f269e3021894 174 int ret;
elessair 0:f269e3021894 175 size_t entropy_len, md_size;
elessair 0:f269e3021894 176
elessair 0:f269e3021894 177 if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
elessair 0:f269e3021894 178 return( ret );
elessair 0:f269e3021894 179
elessair 0:f269e3021894 180 md_size = mbedtls_md_get_size( md_info );
elessair 0:f269e3021894 181
elessair 0:f269e3021894 182 /*
elessair 0:f269e3021894 183 * Set initial working state.
elessair 0:f269e3021894 184 * Use the V memory location, which is currently all 0, to initialize the
elessair 0:f269e3021894 185 * MD context with an all-zero key. Then set V to its initial value.
elessair 0:f269e3021894 186 */
elessair 0:f269e3021894 187 mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, md_size );
elessair 0:f269e3021894 188 memset( ctx->V, 0x01, md_size );
elessair 0:f269e3021894 189
elessair 0:f269e3021894 190 ctx->f_entropy = f_entropy;
elessair 0:f269e3021894 191 ctx->p_entropy = p_entropy;
elessair 0:f269e3021894 192
elessair 0:f269e3021894 193 ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
elessair 0:f269e3021894 194
elessair 0:f269e3021894 195 /*
elessair 0:f269e3021894 196 * See SP800-57 5.6.1 (p. 65-66) for the security strength provided by
elessair 0:f269e3021894 197 * each hash function, then according to SP800-90A rev1 10.1 table 2,
elessair 0:f269e3021894 198 * min_entropy_len (in bits) is security_strength.
elessair 0:f269e3021894 199 *
elessair 0:f269e3021894 200 * (This also matches the sizes used in the NIST test vectors.)
elessair 0:f269e3021894 201 */
elessair 0:f269e3021894 202 entropy_len = md_size <= 20 ? 16 : /* 160-bits hash -> 128 bits */
elessair 0:f269e3021894 203 md_size <= 28 ? 24 : /* 224-bits hash -> 192 bits */
elessair 0:f269e3021894 204 32; /* better (256+) -> 256 bits */
elessair 0:f269e3021894 205
elessair 0:f269e3021894 206 /*
elessair 0:f269e3021894 207 * For initialisation, use more entropy to emulate a nonce
elessair 0:f269e3021894 208 * (Again, matches test vectors.)
elessair 0:f269e3021894 209 */
elessair 0:f269e3021894 210 ctx->entropy_len = entropy_len * 3 / 2;
elessair 0:f269e3021894 211
elessair 0:f269e3021894 212 if( ( ret = mbedtls_hmac_drbg_reseed( ctx, custom, len ) ) != 0 )
elessair 0:f269e3021894 213 return( ret );
elessair 0:f269e3021894 214
elessair 0:f269e3021894 215 ctx->entropy_len = entropy_len;
elessair 0:f269e3021894 216
elessair 0:f269e3021894 217 return( 0 );
elessair 0:f269e3021894 218 }
elessair 0:f269e3021894 219
elessair 0:f269e3021894 220 /*
elessair 0:f269e3021894 221 * Set prediction resistance
elessair 0:f269e3021894 222 */
elessair 0:f269e3021894 223 void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx,
elessair 0:f269e3021894 224 int resistance )
elessair 0:f269e3021894 225 {
elessair 0:f269e3021894 226 ctx->prediction_resistance = resistance;
elessair 0:f269e3021894 227 }
elessair 0:f269e3021894 228
elessair 0:f269e3021894 229 /*
elessair 0:f269e3021894 230 * Set entropy length grabbed for reseeds
elessair 0:f269e3021894 231 */
elessair 0:f269e3021894 232 void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx, size_t len )
elessair 0:f269e3021894 233 {
elessair 0:f269e3021894 234 ctx->entropy_len = len;
elessair 0:f269e3021894 235 }
elessair 0:f269e3021894 236
elessair 0:f269e3021894 237 /*
elessair 0:f269e3021894 238 * Set reseed interval
elessair 0:f269e3021894 239 */
elessair 0:f269e3021894 240 void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx, int interval )
elessair 0:f269e3021894 241 {
elessair 0:f269e3021894 242 ctx->reseed_interval = interval;
elessair 0:f269e3021894 243 }
elessair 0:f269e3021894 244
elessair 0:f269e3021894 245 /*
elessair 0:f269e3021894 246 * HMAC_DRBG random function with optional additional data:
elessair 0:f269e3021894 247 * 10.1.2.5 (arabic) + 9.3 (Roman)
elessair 0:f269e3021894 248 */
elessair 0:f269e3021894 249 int mbedtls_hmac_drbg_random_with_add( void *p_rng,
elessair 0:f269e3021894 250 unsigned char *output, size_t out_len,
elessair 0:f269e3021894 251 const unsigned char *additional, size_t add_len )
elessair 0:f269e3021894 252 {
elessair 0:f269e3021894 253 int ret;
elessair 0:f269e3021894 254 mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
elessair 0:f269e3021894 255 size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
elessair 0:f269e3021894 256 size_t left = out_len;
elessair 0:f269e3021894 257 unsigned char *out = output;
elessair 0:f269e3021894 258
elessair 0:f269e3021894 259 /* II. Check request length */
elessair 0:f269e3021894 260 if( out_len > MBEDTLS_HMAC_DRBG_MAX_REQUEST )
elessair 0:f269e3021894 261 return( MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG );
elessair 0:f269e3021894 262
elessair 0:f269e3021894 263 /* III. Check input length */
elessair 0:f269e3021894 264 if( add_len > MBEDTLS_HMAC_DRBG_MAX_INPUT )
elessair 0:f269e3021894 265 return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
elessair 0:f269e3021894 266
elessair 0:f269e3021894 267 /* 1. (aka VII and IX) Check reseed counter and PR */
elessair 0:f269e3021894 268 if( ctx->f_entropy != NULL && /* For no-reseeding instances */
elessair 0:f269e3021894 269 ( ctx->prediction_resistance == MBEDTLS_HMAC_DRBG_PR_ON ||
elessair 0:f269e3021894 270 ctx->reseed_counter > ctx->reseed_interval ) )
elessair 0:f269e3021894 271 {
elessair 0:f269e3021894 272 if( ( ret = mbedtls_hmac_drbg_reseed( ctx, additional, add_len ) ) != 0 )
elessair 0:f269e3021894 273 return( ret );
elessair 0:f269e3021894 274
elessair 0:f269e3021894 275 add_len = 0; /* VII.4 */
elessair 0:f269e3021894 276 }
elessair 0:f269e3021894 277
elessair 0:f269e3021894 278 /* 2. Use additional data if any */
elessair 0:f269e3021894 279 if( additional != NULL && add_len != 0 )
elessair 0:f269e3021894 280 mbedtls_hmac_drbg_update( ctx, additional, add_len );
elessair 0:f269e3021894 281
elessair 0:f269e3021894 282 /* 3, 4, 5. Generate bytes */
elessair 0:f269e3021894 283 while( left != 0 )
elessair 0:f269e3021894 284 {
elessair 0:f269e3021894 285 size_t use_len = left > md_len ? md_len : left;
elessair 0:f269e3021894 286
elessair 0:f269e3021894 287 mbedtls_md_hmac_reset( &ctx->md_ctx );
elessair 0:f269e3021894 288 mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
elessair 0:f269e3021894 289 mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V );
elessair 0:f269e3021894 290
elessair 0:f269e3021894 291 memcpy( out, ctx->V, use_len );
elessair 0:f269e3021894 292 out += use_len;
elessair 0:f269e3021894 293 left -= use_len;
elessair 0:f269e3021894 294 }
elessair 0:f269e3021894 295
elessair 0:f269e3021894 296 /* 6. Update */
elessair 0:f269e3021894 297 mbedtls_hmac_drbg_update( ctx, additional, add_len );
elessair 0:f269e3021894 298
elessair 0:f269e3021894 299 /* 7. Update reseed counter */
elessair 0:f269e3021894 300 ctx->reseed_counter++;
elessair 0:f269e3021894 301
elessair 0:f269e3021894 302 /* 8. Done */
elessair 0:f269e3021894 303 return( 0 );
elessair 0:f269e3021894 304 }
elessair 0:f269e3021894 305
elessair 0:f269e3021894 306 /*
elessair 0:f269e3021894 307 * HMAC_DRBG random function
elessair 0:f269e3021894 308 */
elessair 0:f269e3021894 309 int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len )
elessair 0:f269e3021894 310 {
elessair 0:f269e3021894 311 int ret;
elessair 0:f269e3021894 312 mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
elessair 0:f269e3021894 313
elessair 0:f269e3021894 314 #if defined(MBEDTLS_THREADING_C)
elessair 0:f269e3021894 315 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
elessair 0:f269e3021894 316 return( ret );
elessair 0:f269e3021894 317 #endif
elessair 0:f269e3021894 318
elessair 0:f269e3021894 319 ret = mbedtls_hmac_drbg_random_with_add( ctx, output, out_len, NULL, 0 );
elessair 0:f269e3021894 320
elessair 0:f269e3021894 321 #if defined(MBEDTLS_THREADING_C)
elessair 0:f269e3021894 322 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
elessair 0:f269e3021894 323 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
elessair 0:f269e3021894 324 #endif
elessair 0:f269e3021894 325
elessair 0:f269e3021894 326 return( ret );
elessair 0:f269e3021894 327 }
elessair 0:f269e3021894 328
elessair 0:f269e3021894 329 /*
elessair 0:f269e3021894 330 * Free an HMAC_DRBG context
elessair 0:f269e3021894 331 */
elessair 0:f269e3021894 332 void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx )
elessair 0:f269e3021894 333 {
elessair 0:f269e3021894 334 if( ctx == NULL )
elessair 0:f269e3021894 335 return;
elessair 0:f269e3021894 336
elessair 0:f269e3021894 337 #if defined(MBEDTLS_THREADING_C)
elessair 0:f269e3021894 338 mbedtls_mutex_free( &ctx->mutex );
elessair 0:f269e3021894 339 #endif
elessair 0:f269e3021894 340 mbedtls_md_free( &ctx->md_ctx );
elessair 0:f269e3021894 341 mbedtls_zeroize( ctx, sizeof( mbedtls_hmac_drbg_context ) );
elessair 0:f269e3021894 342 }
elessair 0:f269e3021894 343
elessair 0:f269e3021894 344 #if defined(MBEDTLS_FS_IO)
elessair 0:f269e3021894 345 int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
elessair 0:f269e3021894 346 {
elessair 0:f269e3021894 347 int ret;
elessair 0:f269e3021894 348 FILE *f;
elessair 0:f269e3021894 349 unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];
elessair 0:f269e3021894 350
elessair 0:f269e3021894 351 if( ( f = fopen( path, "wb" ) ) == NULL )
elessair 0:f269e3021894 352 return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
elessair 0:f269e3021894 353
elessair 0:f269e3021894 354 if( ( ret = mbedtls_hmac_drbg_random( ctx, buf, sizeof( buf ) ) ) != 0 )
elessair 0:f269e3021894 355 goto exit;
elessair 0:f269e3021894 356
elessair 0:f269e3021894 357 if( fwrite( buf, 1, sizeof( buf ), f ) != sizeof( buf ) )
elessair 0:f269e3021894 358 {
elessair 0:f269e3021894 359 ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
elessair 0:f269e3021894 360 goto exit;
elessair 0:f269e3021894 361 }
elessair 0:f269e3021894 362
elessair 0:f269e3021894 363 ret = 0;
elessair 0:f269e3021894 364
elessair 0:f269e3021894 365 exit:
elessair 0:f269e3021894 366 fclose( f );
elessair 0:f269e3021894 367 return( ret );
elessair 0:f269e3021894 368 }
elessair 0:f269e3021894 369
elessair 0:f269e3021894 370 int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
elessair 0:f269e3021894 371 {
elessair 0:f269e3021894 372 FILE *f;
elessair 0:f269e3021894 373 size_t n;
elessair 0:f269e3021894 374 unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];
elessair 0:f269e3021894 375
elessair 0:f269e3021894 376 if( ( f = fopen( path, "rb" ) ) == NULL )
elessair 0:f269e3021894 377 return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
elessair 0:f269e3021894 378
elessair 0:f269e3021894 379 fseek( f, 0, SEEK_END );
elessair 0:f269e3021894 380 n = (size_t) ftell( f );
elessair 0:f269e3021894 381 fseek( f, 0, SEEK_SET );
elessair 0:f269e3021894 382
elessair 0:f269e3021894 383 if( n > MBEDTLS_HMAC_DRBG_MAX_INPUT )
elessair 0:f269e3021894 384 {
elessair 0:f269e3021894 385 fclose( f );
elessair 0:f269e3021894 386 return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
elessair 0:f269e3021894 387 }
elessair 0:f269e3021894 388
elessair 0:f269e3021894 389 if( fread( buf, 1, n, f ) != n )
elessair 0:f269e3021894 390 {
elessair 0:f269e3021894 391 fclose( f );
elessair 0:f269e3021894 392 return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
elessair 0:f269e3021894 393 }
elessair 0:f269e3021894 394
elessair 0:f269e3021894 395 fclose( f );
elessair 0:f269e3021894 396
elessair 0:f269e3021894 397 mbedtls_hmac_drbg_update( ctx, buf, n );
elessair 0:f269e3021894 398
elessair 0:f269e3021894 399 return( mbedtls_hmac_drbg_write_seed_file( ctx, path ) );
elessair 0:f269e3021894 400 }
elessair 0:f269e3021894 401 #endif /* MBEDTLS_FS_IO */
elessair 0:f269e3021894 402
elessair 0:f269e3021894 403
elessair 0:f269e3021894 404 #if defined(MBEDTLS_SELF_TEST)
elessair 0:f269e3021894 405
elessair 0:f269e3021894 406 #if !defined(MBEDTLS_SHA1_C)
elessair 0:f269e3021894 407 /* Dummy checkup routine */
elessair 0:f269e3021894 408 int mbedtls_hmac_drbg_self_test( int verbose )
elessair 0:f269e3021894 409 {
elessair 0:f269e3021894 410 (void) verbose;
elessair 0:f269e3021894 411 return( 0 );
elessair 0:f269e3021894 412 }
elessair 0:f269e3021894 413 #else
elessair 0:f269e3021894 414
elessair 0:f269e3021894 415 #define OUTPUT_LEN 80
elessair 0:f269e3021894 416
elessair 0:f269e3021894 417 /* From a NIST PR=true test vector */
elessair 0:f269e3021894 418 static const unsigned char entropy_pr[] = {
elessair 0:f269e3021894 419 0xa0, 0xc9, 0xab, 0x58, 0xf1, 0xe2, 0xe5, 0xa4, 0xde, 0x3e, 0xbd, 0x4f,
elessair 0:f269e3021894 420 0xf7, 0x3e, 0x9c, 0x5b, 0x64, 0xef, 0xd8, 0xca, 0x02, 0x8c, 0xf8, 0x11,
elessair 0:f269e3021894 421 0x48, 0xa5, 0x84, 0xfe, 0x69, 0xab, 0x5a, 0xee, 0x42, 0xaa, 0x4d, 0x42,
elessair 0:f269e3021894 422 0x17, 0x60, 0x99, 0xd4, 0x5e, 0x13, 0x97, 0xdc, 0x40, 0x4d, 0x86, 0xa3,
elessair 0:f269e3021894 423 0x7b, 0xf5, 0x59, 0x54, 0x75, 0x69, 0x51, 0xe4 };
elessair 0:f269e3021894 424 static const unsigned char result_pr[OUTPUT_LEN] = {
elessair 0:f269e3021894 425 0x9a, 0x00, 0xa2, 0xd0, 0x0e, 0xd5, 0x9b, 0xfe, 0x31, 0xec, 0xb1, 0x39,
elessair 0:f269e3021894 426 0x9b, 0x60, 0x81, 0x48, 0xd1, 0x96, 0x9d, 0x25, 0x0d, 0x3c, 0x1e, 0x94,
elessair 0:f269e3021894 427 0x10, 0x10, 0x98, 0x12, 0x93, 0x25, 0xca, 0xb8, 0xfc, 0xcc, 0x2d, 0x54,
elessair 0:f269e3021894 428 0x73, 0x19, 0x70, 0xc0, 0x10, 0x7a, 0xa4, 0x89, 0x25, 0x19, 0x95, 0x5e,
elessair 0:f269e3021894 429 0x4b, 0xc6, 0x00, 0x1d, 0x7f, 0x4e, 0x6a, 0x2b, 0xf8, 0xa3, 0x01, 0xab,
elessair 0:f269e3021894 430 0x46, 0x05, 0x5c, 0x09, 0xa6, 0x71, 0x88, 0xf1, 0xa7, 0x40, 0xee, 0xf3,
elessair 0:f269e3021894 431 0xe1, 0x5c, 0x02, 0x9b, 0x44, 0xaf, 0x03, 0x44 };
elessair 0:f269e3021894 432
elessair 0:f269e3021894 433 /* From a NIST PR=false test vector */
elessair 0:f269e3021894 434 static const unsigned char entropy_nopr[] = {
elessair 0:f269e3021894 435 0x79, 0x34, 0x9b, 0xbf, 0x7c, 0xdd, 0xa5, 0x79, 0x95, 0x57, 0x86, 0x66,
elessair 0:f269e3021894 436 0x21, 0xc9, 0x13, 0x83, 0x11, 0x46, 0x73, 0x3a, 0xbf, 0x8c, 0x35, 0xc8,
elessair 0:f269e3021894 437 0xc7, 0x21, 0x5b, 0x5b, 0x96, 0xc4, 0x8e, 0x9b, 0x33, 0x8c, 0x74, 0xe3,
elessair 0:f269e3021894 438 0xe9, 0x9d, 0xfe, 0xdf };
elessair 0:f269e3021894 439 static const unsigned char result_nopr[OUTPUT_LEN] = {
elessair 0:f269e3021894 440 0xc6, 0xa1, 0x6a, 0xb8, 0xd4, 0x20, 0x70, 0x6f, 0x0f, 0x34, 0xab, 0x7f,
elessair 0:f269e3021894 441 0xec, 0x5a, 0xdc, 0xa9, 0xd8, 0xca, 0x3a, 0x13, 0x3e, 0x15, 0x9c, 0xa6,
elessair 0:f269e3021894 442 0xac, 0x43, 0xc6, 0xf8, 0xa2, 0xbe, 0x22, 0x83, 0x4a, 0x4c, 0x0a, 0x0a,
elessair 0:f269e3021894 443 0xff, 0xb1, 0x0d, 0x71, 0x94, 0xf1, 0xc1, 0xa5, 0xcf, 0x73, 0x22, 0xec,
elessair 0:f269e3021894 444 0x1a, 0xe0, 0x96, 0x4e, 0xd4, 0xbf, 0x12, 0x27, 0x46, 0xe0, 0x87, 0xfd,
elessair 0:f269e3021894 445 0xb5, 0xb3, 0xe9, 0x1b, 0x34, 0x93, 0xd5, 0xbb, 0x98, 0xfa, 0xed, 0x49,
elessair 0:f269e3021894 446 0xe8, 0x5f, 0x13, 0x0f, 0xc8, 0xa4, 0x59, 0xb7 };
elessair 0:f269e3021894 447
elessair 0:f269e3021894 448 /* "Entropy" from buffer */
elessair 0:f269e3021894 449 static size_t test_offset;
elessair 0:f269e3021894 450 static int hmac_drbg_self_test_entropy( void *data,
elessair 0:f269e3021894 451 unsigned char *buf, size_t len )
elessair 0:f269e3021894 452 {
elessair 0:f269e3021894 453 const unsigned char *p = data;
elessair 0:f269e3021894 454 memcpy( buf, p + test_offset, len );
elessair 0:f269e3021894 455 test_offset += len;
elessair 0:f269e3021894 456 return( 0 );
elessair 0:f269e3021894 457 }
elessair 0:f269e3021894 458
elessair 0:f269e3021894 459 #define CHK( c ) if( (c) != 0 ) \
elessair 0:f269e3021894 460 { \
elessair 0:f269e3021894 461 if( verbose != 0 ) \
elessair 0:f269e3021894 462 mbedtls_printf( "failed\n" ); \
elessair 0:f269e3021894 463 return( 1 ); \
elessair 0:f269e3021894 464 }
elessair 0:f269e3021894 465
elessair 0:f269e3021894 466 /*
elessair 0:f269e3021894 467 * Checkup routine for HMAC_DRBG with SHA-1
elessair 0:f269e3021894 468 */
elessair 0:f269e3021894 469 int mbedtls_hmac_drbg_self_test( int verbose )
elessair 0:f269e3021894 470 {
elessair 0:f269e3021894 471 mbedtls_hmac_drbg_context ctx;
elessair 0:f269e3021894 472 unsigned char buf[OUTPUT_LEN];
elessair 0:f269e3021894 473 const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 );
elessair 0:f269e3021894 474
elessair 0:f269e3021894 475 mbedtls_hmac_drbg_init( &ctx );
elessair 0:f269e3021894 476
elessair 0:f269e3021894 477 /*
elessair 0:f269e3021894 478 * PR = True
elessair 0:f269e3021894 479 */
elessair 0:f269e3021894 480 if( verbose != 0 )
elessair 0:f269e3021894 481 mbedtls_printf( " HMAC_DRBG (PR = True) : " );
elessair 0:f269e3021894 482
elessair 0:f269e3021894 483 test_offset = 0;
elessair 0:f269e3021894 484 CHK( mbedtls_hmac_drbg_seed( &ctx, md_info,
elessair 0:f269e3021894 485 hmac_drbg_self_test_entropy, (void *) entropy_pr,
elessair 0:f269e3021894 486 NULL, 0 ) );
elessair 0:f269e3021894 487 mbedtls_hmac_drbg_set_prediction_resistance( &ctx, MBEDTLS_HMAC_DRBG_PR_ON );
elessair 0:f269e3021894 488 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
elessair 0:f269e3021894 489 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
elessair 0:f269e3021894 490 CHK( memcmp( buf, result_pr, OUTPUT_LEN ) );
elessair 0:f269e3021894 491 mbedtls_hmac_drbg_free( &ctx );
elessair 0:f269e3021894 492
elessair 0:f269e3021894 493 mbedtls_hmac_drbg_free( &ctx );
elessair 0:f269e3021894 494
elessair 0:f269e3021894 495 if( verbose != 0 )
elessair 0:f269e3021894 496 mbedtls_printf( "passed\n" );
elessair 0:f269e3021894 497
elessair 0:f269e3021894 498 /*
elessair 0:f269e3021894 499 * PR = False
elessair 0:f269e3021894 500 */
elessair 0:f269e3021894 501 if( verbose != 0 )
elessair 0:f269e3021894 502 mbedtls_printf( " HMAC_DRBG (PR = False) : " );
elessair 0:f269e3021894 503
elessair 0:f269e3021894 504 mbedtls_hmac_drbg_init( &ctx );
elessair 0:f269e3021894 505
elessair 0:f269e3021894 506 test_offset = 0;
elessair 0:f269e3021894 507 CHK( mbedtls_hmac_drbg_seed( &ctx, md_info,
elessair 0:f269e3021894 508 hmac_drbg_self_test_entropy, (void *) entropy_nopr,
elessair 0:f269e3021894 509 NULL, 0 ) );
elessair 0:f269e3021894 510 CHK( mbedtls_hmac_drbg_reseed( &ctx, NULL, 0 ) );
elessair 0:f269e3021894 511 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
elessair 0:f269e3021894 512 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
elessair 0:f269e3021894 513 CHK( memcmp( buf, result_nopr, OUTPUT_LEN ) );
elessair 0:f269e3021894 514 mbedtls_hmac_drbg_free( &ctx );
elessair 0:f269e3021894 515
elessair 0:f269e3021894 516 mbedtls_hmac_drbg_free( &ctx );
elessair 0:f269e3021894 517
elessair 0:f269e3021894 518 if( verbose != 0 )
elessair 0:f269e3021894 519 mbedtls_printf( "passed\n" );
elessair 0:f269e3021894 520
elessair 0:f269e3021894 521 if( verbose != 0 )
elessair 0:f269e3021894 522 mbedtls_printf( "\n" );
elessair 0:f269e3021894 523
elessair 0:f269e3021894 524 return( 0 );
elessair 0:f269e3021894 525 }
elessair 0:f269e3021894 526 #endif /* MBEDTLS_SHA1_C */
elessair 0:f269e3021894 527 #endif /* MBEDTLS_SELF_TEST */
elessair 0:f269e3021894 528
elessair 0:f269e3021894 529 #endif /* MBEDTLS_HMAC_DRBG_C */