Marco Zecchini / Mbed OS Example_RTOS

Rtos API example

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

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

Who changed what in which revision?

UserRevisionLine numberNew contents of line
marcozecchini 0:9fca2b23d0ba 1 /*
marcozecchini 0:9fca2b23d0ba 2 * HMAC_DRBG implementation (NIST SP 800-90)
marcozecchini 0:9fca2b23d0ba 3 *
marcozecchini 0:9fca2b23d0ba 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
marcozecchini 0:9fca2b23d0ba 5 * SPDX-License-Identifier: Apache-2.0
marcozecchini 0:9fca2b23d0ba 6 *
marcozecchini 0:9fca2b23d0ba 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
marcozecchini 0:9fca2b23d0ba 8 * not use this file except in compliance with the License.
marcozecchini 0:9fca2b23d0ba 9 * You may obtain a copy of the License at
marcozecchini 0:9fca2b23d0ba 10 *
marcozecchini 0:9fca2b23d0ba 11 * http://www.apache.org/licenses/LICENSE-2.0
marcozecchini 0:9fca2b23d0ba 12 *
marcozecchini 0:9fca2b23d0ba 13 * Unless required by applicable law or agreed to in writing, software
marcozecchini 0:9fca2b23d0ba 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
marcozecchini 0:9fca2b23d0ba 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
marcozecchini 0:9fca2b23d0ba 16 * See the License for the specific language governing permissions and
marcozecchini 0:9fca2b23d0ba 17 * limitations under the License.
marcozecchini 0:9fca2b23d0ba 18 *
marcozecchini 0:9fca2b23d0ba 19 * This file is part of mbed TLS (https://tls.mbed.org)
marcozecchini 0:9fca2b23d0ba 20 */
marcozecchini 0:9fca2b23d0ba 21
marcozecchini 0:9fca2b23d0ba 22 /*
marcozecchini 0:9fca2b23d0ba 23 * The NIST SP 800-90A DRBGs are described in the following publication.
marcozecchini 0:9fca2b23d0ba 24 * http://csrc.nist.gov/publications/nistpubs/800-90A/SP800-90A.pdf
marcozecchini 0:9fca2b23d0ba 25 * References below are based on rev. 1 (January 2012).
marcozecchini 0:9fca2b23d0ba 26 */
marcozecchini 0:9fca2b23d0ba 27
marcozecchini 0:9fca2b23d0ba 28 #if !defined(MBEDTLS_CONFIG_FILE)
marcozecchini 0:9fca2b23d0ba 29 #include "mbedtls/config.h"
marcozecchini 0:9fca2b23d0ba 30 #else
marcozecchini 0:9fca2b23d0ba 31 #include MBEDTLS_CONFIG_FILE
marcozecchini 0:9fca2b23d0ba 32 #endif
marcozecchini 0:9fca2b23d0ba 33
marcozecchini 0:9fca2b23d0ba 34 #if defined(MBEDTLS_HMAC_DRBG_C)
marcozecchini 0:9fca2b23d0ba 35
marcozecchini 0:9fca2b23d0ba 36 #include "mbedtls/hmac_drbg.h"
marcozecchini 0:9fca2b23d0ba 37
marcozecchini 0:9fca2b23d0ba 38 #include <string.h>
marcozecchini 0:9fca2b23d0ba 39
marcozecchini 0:9fca2b23d0ba 40 #if defined(MBEDTLS_FS_IO)
marcozecchini 0:9fca2b23d0ba 41 #include <stdio.h>
marcozecchini 0:9fca2b23d0ba 42 #endif
marcozecchini 0:9fca2b23d0ba 43
marcozecchini 0:9fca2b23d0ba 44 #if defined(MBEDTLS_SELF_TEST)
marcozecchini 0:9fca2b23d0ba 45 #if defined(MBEDTLS_PLATFORM_C)
marcozecchini 0:9fca2b23d0ba 46 #include "mbedtls/platform.h"
marcozecchini 0:9fca2b23d0ba 47 #else
marcozecchini 0:9fca2b23d0ba 48 #include <stdio.h>
marcozecchini 0:9fca2b23d0ba 49 #define mbedtls_printf printf
marcozecchini 0:9fca2b23d0ba 50 #endif /* MBEDTLS_SELF_TEST */
marcozecchini 0:9fca2b23d0ba 51 #endif /* MBEDTLS_PLATFORM_C */
marcozecchini 0:9fca2b23d0ba 52
marcozecchini 0:9fca2b23d0ba 53 /* Implementation that should never be optimized out by the compiler */
marcozecchini 0:9fca2b23d0ba 54 static void mbedtls_zeroize( void *v, size_t n ) {
marcozecchini 0:9fca2b23d0ba 55 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
marcozecchini 0:9fca2b23d0ba 56 }
marcozecchini 0:9fca2b23d0ba 57
marcozecchini 0:9fca2b23d0ba 58 /*
marcozecchini 0:9fca2b23d0ba 59 * HMAC_DRBG context initialization
marcozecchini 0:9fca2b23d0ba 60 */
marcozecchini 0:9fca2b23d0ba 61 void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx )
marcozecchini 0:9fca2b23d0ba 62 {
marcozecchini 0:9fca2b23d0ba 63 memset( ctx, 0, sizeof( mbedtls_hmac_drbg_context ) );
marcozecchini 0:9fca2b23d0ba 64
marcozecchini 0:9fca2b23d0ba 65 #if defined(MBEDTLS_THREADING_C)
marcozecchini 0:9fca2b23d0ba 66 mbedtls_mutex_init( &ctx->mutex );
marcozecchini 0:9fca2b23d0ba 67 #endif
marcozecchini 0:9fca2b23d0ba 68 }
marcozecchini 0:9fca2b23d0ba 69
marcozecchini 0:9fca2b23d0ba 70 /*
marcozecchini 0:9fca2b23d0ba 71 * HMAC_DRBG update, using optional additional data (10.1.2.2)
marcozecchini 0:9fca2b23d0ba 72 */
marcozecchini 0:9fca2b23d0ba 73 void mbedtls_hmac_drbg_update( mbedtls_hmac_drbg_context *ctx,
marcozecchini 0:9fca2b23d0ba 74 const unsigned char *additional, size_t add_len )
marcozecchini 0:9fca2b23d0ba 75 {
marcozecchini 0:9fca2b23d0ba 76 size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
marcozecchini 0:9fca2b23d0ba 77 unsigned char rounds = ( additional != NULL && add_len != 0 ) ? 2 : 1;
marcozecchini 0:9fca2b23d0ba 78 unsigned char sep[1];
marcozecchini 0:9fca2b23d0ba 79 unsigned char K[MBEDTLS_MD_MAX_SIZE];
marcozecchini 0:9fca2b23d0ba 80
marcozecchini 0:9fca2b23d0ba 81 for( sep[0] = 0; sep[0] < rounds; sep[0]++ )
marcozecchini 0:9fca2b23d0ba 82 {
marcozecchini 0:9fca2b23d0ba 83 /* Step 1 or 4 */
marcozecchini 0:9fca2b23d0ba 84 mbedtls_md_hmac_reset( &ctx->md_ctx );
marcozecchini 0:9fca2b23d0ba 85 mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
marcozecchini 0:9fca2b23d0ba 86 mbedtls_md_hmac_update( &ctx->md_ctx, sep, 1 );
marcozecchini 0:9fca2b23d0ba 87 if( rounds == 2 )
marcozecchini 0:9fca2b23d0ba 88 mbedtls_md_hmac_update( &ctx->md_ctx, additional, add_len );
marcozecchini 0:9fca2b23d0ba 89 mbedtls_md_hmac_finish( &ctx->md_ctx, K );
marcozecchini 0:9fca2b23d0ba 90
marcozecchini 0:9fca2b23d0ba 91 /* Step 2 or 5 */
marcozecchini 0:9fca2b23d0ba 92 mbedtls_md_hmac_starts( &ctx->md_ctx, K, md_len );
marcozecchini 0:9fca2b23d0ba 93 mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
marcozecchini 0:9fca2b23d0ba 94 mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V );
marcozecchini 0:9fca2b23d0ba 95 }
marcozecchini 0:9fca2b23d0ba 96 }
marcozecchini 0:9fca2b23d0ba 97
marcozecchini 0:9fca2b23d0ba 98 /*
marcozecchini 0:9fca2b23d0ba 99 * Simplified HMAC_DRBG initialisation (for use with deterministic ECDSA)
marcozecchini 0:9fca2b23d0ba 100 */
marcozecchini 0:9fca2b23d0ba 101 int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
marcozecchini 0:9fca2b23d0ba 102 const mbedtls_md_info_t * md_info,
marcozecchini 0:9fca2b23d0ba 103 const unsigned char *data, size_t data_len )
marcozecchini 0:9fca2b23d0ba 104 {
marcozecchini 0:9fca2b23d0ba 105 int ret;
marcozecchini 0:9fca2b23d0ba 106
marcozecchini 0:9fca2b23d0ba 107 if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 108 return( ret );
marcozecchini 0:9fca2b23d0ba 109
marcozecchini 0:9fca2b23d0ba 110 /*
marcozecchini 0:9fca2b23d0ba 111 * Set initial working state.
marcozecchini 0:9fca2b23d0ba 112 * Use the V memory location, which is currently all 0, to initialize the
marcozecchini 0:9fca2b23d0ba 113 * MD context with an all-zero key. Then set V to its initial value.
marcozecchini 0:9fca2b23d0ba 114 */
marcozecchini 0:9fca2b23d0ba 115 mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, mbedtls_md_get_size( md_info ) );
marcozecchini 0:9fca2b23d0ba 116 memset( ctx->V, 0x01, mbedtls_md_get_size( md_info ) );
marcozecchini 0:9fca2b23d0ba 117
marcozecchini 0:9fca2b23d0ba 118 mbedtls_hmac_drbg_update( ctx, data, data_len );
marcozecchini 0:9fca2b23d0ba 119
marcozecchini 0:9fca2b23d0ba 120 return( 0 );
marcozecchini 0:9fca2b23d0ba 121 }
marcozecchini 0:9fca2b23d0ba 122
marcozecchini 0:9fca2b23d0ba 123 /*
marcozecchini 0:9fca2b23d0ba 124 * HMAC_DRBG reseeding: 10.1.2.4 (arabic) + 9.2 (Roman)
marcozecchini 0:9fca2b23d0ba 125 */
marcozecchini 0:9fca2b23d0ba 126 int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
marcozecchini 0:9fca2b23d0ba 127 const unsigned char *additional, size_t len )
marcozecchini 0:9fca2b23d0ba 128 {
marcozecchini 0:9fca2b23d0ba 129 unsigned char seed[MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT];
marcozecchini 0:9fca2b23d0ba 130 size_t seedlen;
marcozecchini 0:9fca2b23d0ba 131
marcozecchini 0:9fca2b23d0ba 132 /* III. Check input length */
marcozecchini 0:9fca2b23d0ba 133 if( len > MBEDTLS_HMAC_DRBG_MAX_INPUT ||
marcozecchini 0:9fca2b23d0ba 134 ctx->entropy_len + len > MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT )
marcozecchini 0:9fca2b23d0ba 135 {
marcozecchini 0:9fca2b23d0ba 136 return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
marcozecchini 0:9fca2b23d0ba 137 }
marcozecchini 0:9fca2b23d0ba 138
marcozecchini 0:9fca2b23d0ba 139 memset( seed, 0, MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT );
marcozecchini 0:9fca2b23d0ba 140
marcozecchini 0:9fca2b23d0ba 141 /* IV. Gather entropy_len bytes of entropy for the seed */
marcozecchini 0:9fca2b23d0ba 142 if( ctx->f_entropy( ctx->p_entropy, seed, ctx->entropy_len ) != 0 )
marcozecchini 0:9fca2b23d0ba 143 return( MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED );
marcozecchini 0:9fca2b23d0ba 144
marcozecchini 0:9fca2b23d0ba 145 seedlen = ctx->entropy_len;
marcozecchini 0:9fca2b23d0ba 146
marcozecchini 0:9fca2b23d0ba 147 /* 1. Concatenate entropy and additional data if any */
marcozecchini 0:9fca2b23d0ba 148 if( additional != NULL && len != 0 )
marcozecchini 0:9fca2b23d0ba 149 {
marcozecchini 0:9fca2b23d0ba 150 memcpy( seed + seedlen, additional, len );
marcozecchini 0:9fca2b23d0ba 151 seedlen += len;
marcozecchini 0:9fca2b23d0ba 152 }
marcozecchini 0:9fca2b23d0ba 153
marcozecchini 0:9fca2b23d0ba 154 /* 2. Update state */
marcozecchini 0:9fca2b23d0ba 155 mbedtls_hmac_drbg_update( ctx, seed, seedlen );
marcozecchini 0:9fca2b23d0ba 156
marcozecchini 0:9fca2b23d0ba 157 /* 3. Reset reseed_counter */
marcozecchini 0:9fca2b23d0ba 158 ctx->reseed_counter = 1;
marcozecchini 0:9fca2b23d0ba 159
marcozecchini 0:9fca2b23d0ba 160 /* 4. Done */
marcozecchini 0:9fca2b23d0ba 161 return( 0 );
marcozecchini 0:9fca2b23d0ba 162 }
marcozecchini 0:9fca2b23d0ba 163
marcozecchini 0:9fca2b23d0ba 164 /*
marcozecchini 0:9fca2b23d0ba 165 * HMAC_DRBG initialisation (10.1.2.3 + 9.1)
marcozecchini 0:9fca2b23d0ba 166 */
marcozecchini 0:9fca2b23d0ba 167 int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
marcozecchini 0:9fca2b23d0ba 168 const mbedtls_md_info_t * md_info,
marcozecchini 0:9fca2b23d0ba 169 int (*f_entropy)(void *, unsigned char *, size_t),
marcozecchini 0:9fca2b23d0ba 170 void *p_entropy,
marcozecchini 0:9fca2b23d0ba 171 const unsigned char *custom,
marcozecchini 0:9fca2b23d0ba 172 size_t len )
marcozecchini 0:9fca2b23d0ba 173 {
marcozecchini 0:9fca2b23d0ba 174 int ret;
marcozecchini 0:9fca2b23d0ba 175 size_t entropy_len, md_size;
marcozecchini 0:9fca2b23d0ba 176
marcozecchini 0:9fca2b23d0ba 177 if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 178 return( ret );
marcozecchini 0:9fca2b23d0ba 179
marcozecchini 0:9fca2b23d0ba 180 md_size = mbedtls_md_get_size( md_info );
marcozecchini 0:9fca2b23d0ba 181
marcozecchini 0:9fca2b23d0ba 182 /*
marcozecchini 0:9fca2b23d0ba 183 * Set initial working state.
marcozecchini 0:9fca2b23d0ba 184 * Use the V memory location, which is currently all 0, to initialize the
marcozecchini 0:9fca2b23d0ba 185 * MD context with an all-zero key. Then set V to its initial value.
marcozecchini 0:9fca2b23d0ba 186 */
marcozecchini 0:9fca2b23d0ba 187 mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, md_size );
marcozecchini 0:9fca2b23d0ba 188 memset( ctx->V, 0x01, md_size );
marcozecchini 0:9fca2b23d0ba 189
marcozecchini 0:9fca2b23d0ba 190 ctx->f_entropy = f_entropy;
marcozecchini 0:9fca2b23d0ba 191 ctx->p_entropy = p_entropy;
marcozecchini 0:9fca2b23d0ba 192
marcozecchini 0:9fca2b23d0ba 193 ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
marcozecchini 0:9fca2b23d0ba 194
marcozecchini 0:9fca2b23d0ba 195 /*
marcozecchini 0:9fca2b23d0ba 196 * See SP800-57 5.6.1 (p. 65-66) for the security strength provided by
marcozecchini 0:9fca2b23d0ba 197 * each hash function, then according to SP800-90A rev1 10.1 table 2,
marcozecchini 0:9fca2b23d0ba 198 * min_entropy_len (in bits) is security_strength.
marcozecchini 0:9fca2b23d0ba 199 *
marcozecchini 0:9fca2b23d0ba 200 * (This also matches the sizes used in the NIST test vectors.)
marcozecchini 0:9fca2b23d0ba 201 */
marcozecchini 0:9fca2b23d0ba 202 entropy_len = md_size <= 20 ? 16 : /* 160-bits hash -> 128 bits */
marcozecchini 0:9fca2b23d0ba 203 md_size <= 28 ? 24 : /* 224-bits hash -> 192 bits */
marcozecchini 0:9fca2b23d0ba 204 32; /* better (256+) -> 256 bits */
marcozecchini 0:9fca2b23d0ba 205
marcozecchini 0:9fca2b23d0ba 206 /*
marcozecchini 0:9fca2b23d0ba 207 * For initialisation, use more entropy to emulate a nonce
marcozecchini 0:9fca2b23d0ba 208 * (Again, matches test vectors.)
marcozecchini 0:9fca2b23d0ba 209 */
marcozecchini 0:9fca2b23d0ba 210 ctx->entropy_len = entropy_len * 3 / 2;
marcozecchini 0:9fca2b23d0ba 211
marcozecchini 0:9fca2b23d0ba 212 if( ( ret = mbedtls_hmac_drbg_reseed( ctx, custom, len ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 213 return( ret );
marcozecchini 0:9fca2b23d0ba 214
marcozecchini 0:9fca2b23d0ba 215 ctx->entropy_len = entropy_len;
marcozecchini 0:9fca2b23d0ba 216
marcozecchini 0:9fca2b23d0ba 217 return( 0 );
marcozecchini 0:9fca2b23d0ba 218 }
marcozecchini 0:9fca2b23d0ba 219
marcozecchini 0:9fca2b23d0ba 220 /*
marcozecchini 0:9fca2b23d0ba 221 * Set prediction resistance
marcozecchini 0:9fca2b23d0ba 222 */
marcozecchini 0:9fca2b23d0ba 223 void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx,
marcozecchini 0:9fca2b23d0ba 224 int resistance )
marcozecchini 0:9fca2b23d0ba 225 {
marcozecchini 0:9fca2b23d0ba 226 ctx->prediction_resistance = resistance;
marcozecchini 0:9fca2b23d0ba 227 }
marcozecchini 0:9fca2b23d0ba 228
marcozecchini 0:9fca2b23d0ba 229 /*
marcozecchini 0:9fca2b23d0ba 230 * Set entropy length grabbed for reseeds
marcozecchini 0:9fca2b23d0ba 231 */
marcozecchini 0:9fca2b23d0ba 232 void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx, size_t len )
marcozecchini 0:9fca2b23d0ba 233 {
marcozecchini 0:9fca2b23d0ba 234 ctx->entropy_len = len;
marcozecchini 0:9fca2b23d0ba 235 }
marcozecchini 0:9fca2b23d0ba 236
marcozecchini 0:9fca2b23d0ba 237 /*
marcozecchini 0:9fca2b23d0ba 238 * Set reseed interval
marcozecchini 0:9fca2b23d0ba 239 */
marcozecchini 0:9fca2b23d0ba 240 void mbedtls_hmac_drbg_set_reseed_interval( mbedtls_hmac_drbg_context *ctx, int interval )
marcozecchini 0:9fca2b23d0ba 241 {
marcozecchini 0:9fca2b23d0ba 242 ctx->reseed_interval = interval;
marcozecchini 0:9fca2b23d0ba 243 }
marcozecchini 0:9fca2b23d0ba 244
marcozecchini 0:9fca2b23d0ba 245 /*
marcozecchini 0:9fca2b23d0ba 246 * HMAC_DRBG random function with optional additional data:
marcozecchini 0:9fca2b23d0ba 247 * 10.1.2.5 (arabic) + 9.3 (Roman)
marcozecchini 0:9fca2b23d0ba 248 */
marcozecchini 0:9fca2b23d0ba 249 int mbedtls_hmac_drbg_random_with_add( void *p_rng,
marcozecchini 0:9fca2b23d0ba 250 unsigned char *output, size_t out_len,
marcozecchini 0:9fca2b23d0ba 251 const unsigned char *additional, size_t add_len )
marcozecchini 0:9fca2b23d0ba 252 {
marcozecchini 0:9fca2b23d0ba 253 int ret;
marcozecchini 0:9fca2b23d0ba 254 mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
marcozecchini 0:9fca2b23d0ba 255 size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
marcozecchini 0:9fca2b23d0ba 256 size_t left = out_len;
marcozecchini 0:9fca2b23d0ba 257 unsigned char *out = output;
marcozecchini 0:9fca2b23d0ba 258
marcozecchini 0:9fca2b23d0ba 259 /* II. Check request length */
marcozecchini 0:9fca2b23d0ba 260 if( out_len > MBEDTLS_HMAC_DRBG_MAX_REQUEST )
marcozecchini 0:9fca2b23d0ba 261 return( MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG );
marcozecchini 0:9fca2b23d0ba 262
marcozecchini 0:9fca2b23d0ba 263 /* III. Check input length */
marcozecchini 0:9fca2b23d0ba 264 if( add_len > MBEDTLS_HMAC_DRBG_MAX_INPUT )
marcozecchini 0:9fca2b23d0ba 265 return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
marcozecchini 0:9fca2b23d0ba 266
marcozecchini 0:9fca2b23d0ba 267 /* 1. (aka VII and IX) Check reseed counter and PR */
marcozecchini 0:9fca2b23d0ba 268 if( ctx->f_entropy != NULL && /* For no-reseeding instances */
marcozecchini 0:9fca2b23d0ba 269 ( ctx->prediction_resistance == MBEDTLS_HMAC_DRBG_PR_ON ||
marcozecchini 0:9fca2b23d0ba 270 ctx->reseed_counter > ctx->reseed_interval ) )
marcozecchini 0:9fca2b23d0ba 271 {
marcozecchini 0:9fca2b23d0ba 272 if( ( ret = mbedtls_hmac_drbg_reseed( ctx, additional, add_len ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 273 return( ret );
marcozecchini 0:9fca2b23d0ba 274
marcozecchini 0:9fca2b23d0ba 275 add_len = 0; /* VII.4 */
marcozecchini 0:9fca2b23d0ba 276 }
marcozecchini 0:9fca2b23d0ba 277
marcozecchini 0:9fca2b23d0ba 278 /* 2. Use additional data if any */
marcozecchini 0:9fca2b23d0ba 279 if( additional != NULL && add_len != 0 )
marcozecchini 0:9fca2b23d0ba 280 mbedtls_hmac_drbg_update( ctx, additional, add_len );
marcozecchini 0:9fca2b23d0ba 281
marcozecchini 0:9fca2b23d0ba 282 /* 3, 4, 5. Generate bytes */
marcozecchini 0:9fca2b23d0ba 283 while( left != 0 )
marcozecchini 0:9fca2b23d0ba 284 {
marcozecchini 0:9fca2b23d0ba 285 size_t use_len = left > md_len ? md_len : left;
marcozecchini 0:9fca2b23d0ba 286
marcozecchini 0:9fca2b23d0ba 287 mbedtls_md_hmac_reset( &ctx->md_ctx );
marcozecchini 0:9fca2b23d0ba 288 mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
marcozecchini 0:9fca2b23d0ba 289 mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V );
marcozecchini 0:9fca2b23d0ba 290
marcozecchini 0:9fca2b23d0ba 291 memcpy( out, ctx->V, use_len );
marcozecchini 0:9fca2b23d0ba 292 out += use_len;
marcozecchini 0:9fca2b23d0ba 293 left -= use_len;
marcozecchini 0:9fca2b23d0ba 294 }
marcozecchini 0:9fca2b23d0ba 295
marcozecchini 0:9fca2b23d0ba 296 /* 6. Update */
marcozecchini 0:9fca2b23d0ba 297 mbedtls_hmac_drbg_update( ctx, additional, add_len );
marcozecchini 0:9fca2b23d0ba 298
marcozecchini 0:9fca2b23d0ba 299 /* 7. Update reseed counter */
marcozecchini 0:9fca2b23d0ba 300 ctx->reseed_counter++;
marcozecchini 0:9fca2b23d0ba 301
marcozecchini 0:9fca2b23d0ba 302 /* 8. Done */
marcozecchini 0:9fca2b23d0ba 303 return( 0 );
marcozecchini 0:9fca2b23d0ba 304 }
marcozecchini 0:9fca2b23d0ba 305
marcozecchini 0:9fca2b23d0ba 306 /*
marcozecchini 0:9fca2b23d0ba 307 * HMAC_DRBG random function
marcozecchini 0:9fca2b23d0ba 308 */
marcozecchini 0:9fca2b23d0ba 309 int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len )
marcozecchini 0:9fca2b23d0ba 310 {
marcozecchini 0:9fca2b23d0ba 311 int ret;
marcozecchini 0:9fca2b23d0ba 312 mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
marcozecchini 0:9fca2b23d0ba 313
marcozecchini 0:9fca2b23d0ba 314 #if defined(MBEDTLS_THREADING_C)
marcozecchini 0:9fca2b23d0ba 315 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 316 return( ret );
marcozecchini 0:9fca2b23d0ba 317 #endif
marcozecchini 0:9fca2b23d0ba 318
marcozecchini 0:9fca2b23d0ba 319 ret = mbedtls_hmac_drbg_random_with_add( ctx, output, out_len, NULL, 0 );
marcozecchini 0:9fca2b23d0ba 320
marcozecchini 0:9fca2b23d0ba 321 #if defined(MBEDTLS_THREADING_C)
marcozecchini 0:9fca2b23d0ba 322 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
marcozecchini 0:9fca2b23d0ba 323 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
marcozecchini 0:9fca2b23d0ba 324 #endif
marcozecchini 0:9fca2b23d0ba 325
marcozecchini 0:9fca2b23d0ba 326 return( ret );
marcozecchini 0:9fca2b23d0ba 327 }
marcozecchini 0:9fca2b23d0ba 328
marcozecchini 0:9fca2b23d0ba 329 /*
marcozecchini 0:9fca2b23d0ba 330 * Free an HMAC_DRBG context
marcozecchini 0:9fca2b23d0ba 331 */
marcozecchini 0:9fca2b23d0ba 332 void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx )
marcozecchini 0:9fca2b23d0ba 333 {
marcozecchini 0:9fca2b23d0ba 334 if( ctx == NULL )
marcozecchini 0:9fca2b23d0ba 335 return;
marcozecchini 0:9fca2b23d0ba 336
marcozecchini 0:9fca2b23d0ba 337 #if defined(MBEDTLS_THREADING_C)
marcozecchini 0:9fca2b23d0ba 338 mbedtls_mutex_free( &ctx->mutex );
marcozecchini 0:9fca2b23d0ba 339 #endif
marcozecchini 0:9fca2b23d0ba 340 mbedtls_md_free( &ctx->md_ctx );
marcozecchini 0:9fca2b23d0ba 341 mbedtls_zeroize( ctx, sizeof( mbedtls_hmac_drbg_context ) );
marcozecchini 0:9fca2b23d0ba 342 }
marcozecchini 0:9fca2b23d0ba 343
marcozecchini 0:9fca2b23d0ba 344 #if defined(MBEDTLS_FS_IO)
marcozecchini 0:9fca2b23d0ba 345 int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
marcozecchini 0:9fca2b23d0ba 346 {
marcozecchini 0:9fca2b23d0ba 347 int ret;
marcozecchini 0:9fca2b23d0ba 348 FILE *f;
marcozecchini 0:9fca2b23d0ba 349 unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];
marcozecchini 0:9fca2b23d0ba 350
marcozecchini 0:9fca2b23d0ba 351 if( ( f = fopen( path, "wb" ) ) == NULL )
marcozecchini 0:9fca2b23d0ba 352 return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
marcozecchini 0:9fca2b23d0ba 353
marcozecchini 0:9fca2b23d0ba 354 if( ( ret = mbedtls_hmac_drbg_random( ctx, buf, sizeof( buf ) ) ) != 0 )
marcozecchini 0:9fca2b23d0ba 355 goto exit;
marcozecchini 0:9fca2b23d0ba 356
marcozecchini 0:9fca2b23d0ba 357 if( fwrite( buf, 1, sizeof( buf ), f ) != sizeof( buf ) )
marcozecchini 0:9fca2b23d0ba 358 {
marcozecchini 0:9fca2b23d0ba 359 ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
marcozecchini 0:9fca2b23d0ba 360 goto exit;
marcozecchini 0:9fca2b23d0ba 361 }
marcozecchini 0:9fca2b23d0ba 362
marcozecchini 0:9fca2b23d0ba 363 ret = 0;
marcozecchini 0:9fca2b23d0ba 364
marcozecchini 0:9fca2b23d0ba 365 exit:
marcozecchini 0:9fca2b23d0ba 366 fclose( f );
marcozecchini 0:9fca2b23d0ba 367 return( ret );
marcozecchini 0:9fca2b23d0ba 368 }
marcozecchini 0:9fca2b23d0ba 369
marcozecchini 0:9fca2b23d0ba 370 int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
marcozecchini 0:9fca2b23d0ba 371 {
marcozecchini 0:9fca2b23d0ba 372 FILE *f;
marcozecchini 0:9fca2b23d0ba 373 size_t n;
marcozecchini 0:9fca2b23d0ba 374 unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];
marcozecchini 0:9fca2b23d0ba 375
marcozecchini 0:9fca2b23d0ba 376 if( ( f = fopen( path, "rb" ) ) == NULL )
marcozecchini 0:9fca2b23d0ba 377 return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
marcozecchini 0:9fca2b23d0ba 378
marcozecchini 0:9fca2b23d0ba 379 fseek( f, 0, SEEK_END );
marcozecchini 0:9fca2b23d0ba 380 n = (size_t) ftell( f );
marcozecchini 0:9fca2b23d0ba 381 fseek( f, 0, SEEK_SET );
marcozecchini 0:9fca2b23d0ba 382
marcozecchini 0:9fca2b23d0ba 383 if( n > MBEDTLS_HMAC_DRBG_MAX_INPUT )
marcozecchini 0:9fca2b23d0ba 384 {
marcozecchini 0:9fca2b23d0ba 385 fclose( f );
marcozecchini 0:9fca2b23d0ba 386 return( MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG );
marcozecchini 0:9fca2b23d0ba 387 }
marcozecchini 0:9fca2b23d0ba 388
marcozecchini 0:9fca2b23d0ba 389 if( fread( buf, 1, n, f ) != n )
marcozecchini 0:9fca2b23d0ba 390 {
marcozecchini 0:9fca2b23d0ba 391 fclose( f );
marcozecchini 0:9fca2b23d0ba 392 return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
marcozecchini 0:9fca2b23d0ba 393 }
marcozecchini 0:9fca2b23d0ba 394
marcozecchini 0:9fca2b23d0ba 395 fclose( f );
marcozecchini 0:9fca2b23d0ba 396
marcozecchini 0:9fca2b23d0ba 397 mbedtls_hmac_drbg_update( ctx, buf, n );
marcozecchini 0:9fca2b23d0ba 398
marcozecchini 0:9fca2b23d0ba 399 return( mbedtls_hmac_drbg_write_seed_file( ctx, path ) );
marcozecchini 0:9fca2b23d0ba 400 }
marcozecchini 0:9fca2b23d0ba 401 #endif /* MBEDTLS_FS_IO */
marcozecchini 0:9fca2b23d0ba 402
marcozecchini 0:9fca2b23d0ba 403
marcozecchini 0:9fca2b23d0ba 404 #if defined(MBEDTLS_SELF_TEST)
marcozecchini 0:9fca2b23d0ba 405
marcozecchini 0:9fca2b23d0ba 406 #if !defined(MBEDTLS_SHA1_C)
marcozecchini 0:9fca2b23d0ba 407 /* Dummy checkup routine */
marcozecchini 0:9fca2b23d0ba 408 int mbedtls_hmac_drbg_self_test( int verbose )
marcozecchini 0:9fca2b23d0ba 409 {
marcozecchini 0:9fca2b23d0ba 410 (void) verbose;
marcozecchini 0:9fca2b23d0ba 411 return( 0 );
marcozecchini 0:9fca2b23d0ba 412 }
marcozecchini 0:9fca2b23d0ba 413 #else
marcozecchini 0:9fca2b23d0ba 414
marcozecchini 0:9fca2b23d0ba 415 #define OUTPUT_LEN 80
marcozecchini 0:9fca2b23d0ba 416
marcozecchini 0:9fca2b23d0ba 417 /* From a NIST PR=true test vector */
marcozecchini 0:9fca2b23d0ba 418 static const unsigned char entropy_pr[] = {
marcozecchini 0:9fca2b23d0ba 419 0xa0, 0xc9, 0xab, 0x58, 0xf1, 0xe2, 0xe5, 0xa4, 0xde, 0x3e, 0xbd, 0x4f,
marcozecchini 0:9fca2b23d0ba 420 0xf7, 0x3e, 0x9c, 0x5b, 0x64, 0xef, 0xd8, 0xca, 0x02, 0x8c, 0xf8, 0x11,
marcozecchini 0:9fca2b23d0ba 421 0x48, 0xa5, 0x84, 0xfe, 0x69, 0xab, 0x5a, 0xee, 0x42, 0xaa, 0x4d, 0x42,
marcozecchini 0:9fca2b23d0ba 422 0x17, 0x60, 0x99, 0xd4, 0x5e, 0x13, 0x97, 0xdc, 0x40, 0x4d, 0x86, 0xa3,
marcozecchini 0:9fca2b23d0ba 423 0x7b, 0xf5, 0x59, 0x54, 0x75, 0x69, 0x51, 0xe4 };
marcozecchini 0:9fca2b23d0ba 424 static const unsigned char result_pr[OUTPUT_LEN] = {
marcozecchini 0:9fca2b23d0ba 425 0x9a, 0x00, 0xa2, 0xd0, 0x0e, 0xd5, 0x9b, 0xfe, 0x31, 0xec, 0xb1, 0x39,
marcozecchini 0:9fca2b23d0ba 426 0x9b, 0x60, 0x81, 0x48, 0xd1, 0x96, 0x9d, 0x25, 0x0d, 0x3c, 0x1e, 0x94,
marcozecchini 0:9fca2b23d0ba 427 0x10, 0x10, 0x98, 0x12, 0x93, 0x25, 0xca, 0xb8, 0xfc, 0xcc, 0x2d, 0x54,
marcozecchini 0:9fca2b23d0ba 428 0x73, 0x19, 0x70, 0xc0, 0x10, 0x7a, 0xa4, 0x89, 0x25, 0x19, 0x95, 0x5e,
marcozecchini 0:9fca2b23d0ba 429 0x4b, 0xc6, 0x00, 0x1d, 0x7f, 0x4e, 0x6a, 0x2b, 0xf8, 0xa3, 0x01, 0xab,
marcozecchini 0:9fca2b23d0ba 430 0x46, 0x05, 0x5c, 0x09, 0xa6, 0x71, 0x88, 0xf1, 0xa7, 0x40, 0xee, 0xf3,
marcozecchini 0:9fca2b23d0ba 431 0xe1, 0x5c, 0x02, 0x9b, 0x44, 0xaf, 0x03, 0x44 };
marcozecchini 0:9fca2b23d0ba 432
marcozecchini 0:9fca2b23d0ba 433 /* From a NIST PR=false test vector */
marcozecchini 0:9fca2b23d0ba 434 static const unsigned char entropy_nopr[] = {
marcozecchini 0:9fca2b23d0ba 435 0x79, 0x34, 0x9b, 0xbf, 0x7c, 0xdd, 0xa5, 0x79, 0x95, 0x57, 0x86, 0x66,
marcozecchini 0:9fca2b23d0ba 436 0x21, 0xc9, 0x13, 0x83, 0x11, 0x46, 0x73, 0x3a, 0xbf, 0x8c, 0x35, 0xc8,
marcozecchini 0:9fca2b23d0ba 437 0xc7, 0x21, 0x5b, 0x5b, 0x96, 0xc4, 0x8e, 0x9b, 0x33, 0x8c, 0x74, 0xe3,
marcozecchini 0:9fca2b23d0ba 438 0xe9, 0x9d, 0xfe, 0xdf };
marcozecchini 0:9fca2b23d0ba 439 static const unsigned char result_nopr[OUTPUT_LEN] = {
marcozecchini 0:9fca2b23d0ba 440 0xc6, 0xa1, 0x6a, 0xb8, 0xd4, 0x20, 0x70, 0x6f, 0x0f, 0x34, 0xab, 0x7f,
marcozecchini 0:9fca2b23d0ba 441 0xec, 0x5a, 0xdc, 0xa9, 0xd8, 0xca, 0x3a, 0x13, 0x3e, 0x15, 0x9c, 0xa6,
marcozecchini 0:9fca2b23d0ba 442 0xac, 0x43, 0xc6, 0xf8, 0xa2, 0xbe, 0x22, 0x83, 0x4a, 0x4c, 0x0a, 0x0a,
marcozecchini 0:9fca2b23d0ba 443 0xff, 0xb1, 0x0d, 0x71, 0x94, 0xf1, 0xc1, 0xa5, 0xcf, 0x73, 0x22, 0xec,
marcozecchini 0:9fca2b23d0ba 444 0x1a, 0xe0, 0x96, 0x4e, 0xd4, 0xbf, 0x12, 0x27, 0x46, 0xe0, 0x87, 0xfd,
marcozecchini 0:9fca2b23d0ba 445 0xb5, 0xb3, 0xe9, 0x1b, 0x34, 0x93, 0xd5, 0xbb, 0x98, 0xfa, 0xed, 0x49,
marcozecchini 0:9fca2b23d0ba 446 0xe8, 0x5f, 0x13, 0x0f, 0xc8, 0xa4, 0x59, 0xb7 };
marcozecchini 0:9fca2b23d0ba 447
marcozecchini 0:9fca2b23d0ba 448 /* "Entropy" from buffer */
marcozecchini 0:9fca2b23d0ba 449 static size_t test_offset;
marcozecchini 0:9fca2b23d0ba 450 static int hmac_drbg_self_test_entropy( void *data,
marcozecchini 0:9fca2b23d0ba 451 unsigned char *buf, size_t len )
marcozecchini 0:9fca2b23d0ba 452 {
marcozecchini 0:9fca2b23d0ba 453 const unsigned char *p = data;
marcozecchini 0:9fca2b23d0ba 454 memcpy( buf, p + test_offset, len );
marcozecchini 0:9fca2b23d0ba 455 test_offset += len;
marcozecchini 0:9fca2b23d0ba 456 return( 0 );
marcozecchini 0:9fca2b23d0ba 457 }
marcozecchini 0:9fca2b23d0ba 458
marcozecchini 0:9fca2b23d0ba 459 #define CHK( c ) if( (c) != 0 ) \
marcozecchini 0:9fca2b23d0ba 460 { \
marcozecchini 0:9fca2b23d0ba 461 if( verbose != 0 ) \
marcozecchini 0:9fca2b23d0ba 462 mbedtls_printf( "failed\n" ); \
marcozecchini 0:9fca2b23d0ba 463 return( 1 ); \
marcozecchini 0:9fca2b23d0ba 464 }
marcozecchini 0:9fca2b23d0ba 465
marcozecchini 0:9fca2b23d0ba 466 /*
marcozecchini 0:9fca2b23d0ba 467 * Checkup routine for HMAC_DRBG with SHA-1
marcozecchini 0:9fca2b23d0ba 468 */
marcozecchini 0:9fca2b23d0ba 469 int mbedtls_hmac_drbg_self_test( int verbose )
marcozecchini 0:9fca2b23d0ba 470 {
marcozecchini 0:9fca2b23d0ba 471 mbedtls_hmac_drbg_context ctx;
marcozecchini 0:9fca2b23d0ba 472 unsigned char buf[OUTPUT_LEN];
marcozecchini 0:9fca2b23d0ba 473 const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA1 );
marcozecchini 0:9fca2b23d0ba 474
marcozecchini 0:9fca2b23d0ba 475 mbedtls_hmac_drbg_init( &ctx );
marcozecchini 0:9fca2b23d0ba 476
marcozecchini 0:9fca2b23d0ba 477 /*
marcozecchini 0:9fca2b23d0ba 478 * PR = True
marcozecchini 0:9fca2b23d0ba 479 */
marcozecchini 0:9fca2b23d0ba 480 if( verbose != 0 )
marcozecchini 0:9fca2b23d0ba 481 mbedtls_printf( " HMAC_DRBG (PR = True) : " );
marcozecchini 0:9fca2b23d0ba 482
marcozecchini 0:9fca2b23d0ba 483 test_offset = 0;
marcozecchini 0:9fca2b23d0ba 484 CHK( mbedtls_hmac_drbg_seed( &ctx, md_info,
marcozecchini 0:9fca2b23d0ba 485 hmac_drbg_self_test_entropy, (void *) entropy_pr,
marcozecchini 0:9fca2b23d0ba 486 NULL, 0 ) );
marcozecchini 0:9fca2b23d0ba 487 mbedtls_hmac_drbg_set_prediction_resistance( &ctx, MBEDTLS_HMAC_DRBG_PR_ON );
marcozecchini 0:9fca2b23d0ba 488 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
marcozecchini 0:9fca2b23d0ba 489 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
marcozecchini 0:9fca2b23d0ba 490 CHK( memcmp( buf, result_pr, OUTPUT_LEN ) );
marcozecchini 0:9fca2b23d0ba 491 mbedtls_hmac_drbg_free( &ctx );
marcozecchini 0:9fca2b23d0ba 492
marcozecchini 0:9fca2b23d0ba 493 mbedtls_hmac_drbg_free( &ctx );
marcozecchini 0:9fca2b23d0ba 494
marcozecchini 0:9fca2b23d0ba 495 if( verbose != 0 )
marcozecchini 0:9fca2b23d0ba 496 mbedtls_printf( "passed\n" );
marcozecchini 0:9fca2b23d0ba 497
marcozecchini 0:9fca2b23d0ba 498 /*
marcozecchini 0:9fca2b23d0ba 499 * PR = False
marcozecchini 0:9fca2b23d0ba 500 */
marcozecchini 0:9fca2b23d0ba 501 if( verbose != 0 )
marcozecchini 0:9fca2b23d0ba 502 mbedtls_printf( " HMAC_DRBG (PR = False) : " );
marcozecchini 0:9fca2b23d0ba 503
marcozecchini 0:9fca2b23d0ba 504 mbedtls_hmac_drbg_init( &ctx );
marcozecchini 0:9fca2b23d0ba 505
marcozecchini 0:9fca2b23d0ba 506 test_offset = 0;
marcozecchini 0:9fca2b23d0ba 507 CHK( mbedtls_hmac_drbg_seed( &ctx, md_info,
marcozecchini 0:9fca2b23d0ba 508 hmac_drbg_self_test_entropy, (void *) entropy_nopr,
marcozecchini 0:9fca2b23d0ba 509 NULL, 0 ) );
marcozecchini 0:9fca2b23d0ba 510 CHK( mbedtls_hmac_drbg_reseed( &ctx, NULL, 0 ) );
marcozecchini 0:9fca2b23d0ba 511 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
marcozecchini 0:9fca2b23d0ba 512 CHK( mbedtls_hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
marcozecchini 0:9fca2b23d0ba 513 CHK( memcmp( buf, result_nopr, OUTPUT_LEN ) );
marcozecchini 0:9fca2b23d0ba 514 mbedtls_hmac_drbg_free( &ctx );
marcozecchini 0:9fca2b23d0ba 515
marcozecchini 0:9fca2b23d0ba 516 mbedtls_hmac_drbg_free( &ctx );
marcozecchini 0:9fca2b23d0ba 517
marcozecchini 0:9fca2b23d0ba 518 if( verbose != 0 )
marcozecchini 0:9fca2b23d0ba 519 mbedtls_printf( "passed\n" );
marcozecchini 0:9fca2b23d0ba 520
marcozecchini 0:9fca2b23d0ba 521 if( verbose != 0 )
marcozecchini 0:9fca2b23d0ba 522 mbedtls_printf( "\n" );
marcozecchini 0:9fca2b23d0ba 523
marcozecchini 0:9fca2b23d0ba 524 return( 0 );
marcozecchini 0:9fca2b23d0ba 525 }
marcozecchini 0:9fca2b23d0ba 526 #endif /* MBEDTLS_SHA1_C */
marcozecchini 0:9fca2b23d0ba 527 #endif /* MBEDTLS_SELF_TEST */
marcozecchini 0:9fca2b23d0ba 528
marcozecchini 0:9fca2b23d0ba 529 #endif /* MBEDTLS_HMAC_DRBG_C */