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/ctr_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 * CTR_DRBG implementation based on AES-256 (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 * The NIST SP 800-90 DRBGs are described in the following publucation.
elessair 0:f269e3021894 23 *
elessair 0:f269e3021894 24 * http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf
elessair 0:f269e3021894 25 */
elessair 0:f269e3021894 26
elessair 0:f269e3021894 27 #if !defined(MBEDTLS_CONFIG_FILE)
elessair 0:f269e3021894 28 #include "mbedtls/config.h"
elessair 0:f269e3021894 29 #else
elessair 0:f269e3021894 30 #include MBEDTLS_CONFIG_FILE
elessair 0:f269e3021894 31 #endif
elessair 0:f269e3021894 32
elessair 0:f269e3021894 33 #if defined(MBEDTLS_CTR_DRBG_C)
elessair 0:f269e3021894 34
elessair 0:f269e3021894 35 #include "mbedtls/ctr_drbg.h"
elessair 0:f269e3021894 36
elessair 0:f269e3021894 37 #include <string.h>
elessair 0:f269e3021894 38
elessair 0:f269e3021894 39 #if defined(MBEDTLS_FS_IO)
elessair 0:f269e3021894 40 #include <stdio.h>
elessair 0:f269e3021894 41 #endif
elessair 0:f269e3021894 42
elessair 0:f269e3021894 43 #if defined(MBEDTLS_SELF_TEST)
elessair 0:f269e3021894 44 #if defined(MBEDTLS_PLATFORM_C)
elessair 0:f269e3021894 45 #include "mbedtls/platform.h"
elessair 0:f269e3021894 46 #else
elessair 0:f269e3021894 47 #include <stdio.h>
elessair 0:f269e3021894 48 #define mbedtls_printf printf
elessair 0:f269e3021894 49 #endif /* MBEDTLS_PLATFORM_C */
elessair 0:f269e3021894 50 #endif /* MBEDTLS_SELF_TEST */
elessair 0:f269e3021894 51
elessair 0:f269e3021894 52 /* Implementation that should never be optimized out by the compiler */
elessair 0:f269e3021894 53 static void mbedtls_zeroize( void *v, size_t n ) {
elessair 0:f269e3021894 54 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
elessair 0:f269e3021894 55 }
elessair 0:f269e3021894 56
elessair 0:f269e3021894 57 /*
elessair 0:f269e3021894 58 * CTR_DRBG context initialization
elessair 0:f269e3021894 59 */
elessair 0:f269e3021894 60 void mbedtls_ctr_drbg_init( mbedtls_ctr_drbg_context *ctx )
elessair 0:f269e3021894 61 {
elessair 0:f269e3021894 62 memset( ctx, 0, sizeof( mbedtls_ctr_drbg_context ) );
elessair 0:f269e3021894 63
elessair 0:f269e3021894 64 #if defined(MBEDTLS_THREADING_C)
elessair 0:f269e3021894 65 mbedtls_mutex_init( &ctx->mutex );
elessair 0:f269e3021894 66 #endif
elessair 0:f269e3021894 67 }
elessair 0:f269e3021894 68
elessair 0:f269e3021894 69 /*
elessair 0:f269e3021894 70 * Non-public function wrapped by mbedtls_ctr_drbg_seed(). Necessary to allow
elessair 0:f269e3021894 71 * NIST tests to succeed (which require known length fixed entropy)
elessair 0:f269e3021894 72 */
elessair 0:f269e3021894 73 int mbedtls_ctr_drbg_seed_entropy_len(
elessair 0:f269e3021894 74 mbedtls_ctr_drbg_context *ctx,
elessair 0:f269e3021894 75 int (*f_entropy)(void *, unsigned char *, size_t),
elessair 0:f269e3021894 76 void *p_entropy,
elessair 0:f269e3021894 77 const unsigned char *custom,
elessair 0:f269e3021894 78 size_t len,
elessair 0:f269e3021894 79 size_t entropy_len )
elessair 0:f269e3021894 80 {
elessair 0:f269e3021894 81 int ret;
elessair 0:f269e3021894 82 unsigned char key[MBEDTLS_CTR_DRBG_KEYSIZE];
elessair 0:f269e3021894 83
elessair 0:f269e3021894 84 memset( key, 0, MBEDTLS_CTR_DRBG_KEYSIZE );
elessair 0:f269e3021894 85
elessair 0:f269e3021894 86 mbedtls_aes_init( &ctx->aes_ctx );
elessair 0:f269e3021894 87
elessair 0:f269e3021894 88 ctx->f_entropy = f_entropy;
elessair 0:f269e3021894 89 ctx->p_entropy = p_entropy;
elessair 0:f269e3021894 90
elessair 0:f269e3021894 91 ctx->entropy_len = entropy_len;
elessair 0:f269e3021894 92 ctx->reseed_interval = MBEDTLS_CTR_DRBG_RESEED_INTERVAL;
elessair 0:f269e3021894 93
elessair 0:f269e3021894 94 /*
elessair 0:f269e3021894 95 * Initialize with an empty key
elessair 0:f269e3021894 96 */
elessair 0:f269e3021894 97 mbedtls_aes_setkey_enc( &ctx->aes_ctx, key, MBEDTLS_CTR_DRBG_KEYBITS );
elessair 0:f269e3021894 98
elessair 0:f269e3021894 99 if( ( ret = mbedtls_ctr_drbg_reseed( ctx, custom, len ) ) != 0 )
elessair 0:f269e3021894 100 return( ret );
elessair 0:f269e3021894 101
elessair 0:f269e3021894 102 return( 0 );
elessair 0:f269e3021894 103 }
elessair 0:f269e3021894 104
elessair 0:f269e3021894 105 int mbedtls_ctr_drbg_seed( mbedtls_ctr_drbg_context *ctx,
elessair 0:f269e3021894 106 int (*f_entropy)(void *, unsigned char *, size_t),
elessair 0:f269e3021894 107 void *p_entropy,
elessair 0:f269e3021894 108 const unsigned char *custom,
elessair 0:f269e3021894 109 size_t len )
elessair 0:f269e3021894 110 {
elessair 0:f269e3021894 111 return( mbedtls_ctr_drbg_seed_entropy_len( ctx, f_entropy, p_entropy, custom, len,
elessair 0:f269e3021894 112 MBEDTLS_CTR_DRBG_ENTROPY_LEN ) );
elessair 0:f269e3021894 113 }
elessair 0:f269e3021894 114
elessair 0:f269e3021894 115 void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx )
elessair 0:f269e3021894 116 {
elessair 0:f269e3021894 117 if( ctx == NULL )
elessair 0:f269e3021894 118 return;
elessair 0:f269e3021894 119
elessair 0:f269e3021894 120 #if defined(MBEDTLS_THREADING_C)
elessair 0:f269e3021894 121 mbedtls_mutex_free( &ctx->mutex );
elessair 0:f269e3021894 122 #endif
elessair 0:f269e3021894 123 mbedtls_aes_free( &ctx->aes_ctx );
elessair 0:f269e3021894 124 mbedtls_zeroize( ctx, sizeof( mbedtls_ctr_drbg_context ) );
elessair 0:f269e3021894 125 }
elessair 0:f269e3021894 126
elessair 0:f269e3021894 127 void mbedtls_ctr_drbg_set_prediction_resistance( mbedtls_ctr_drbg_context *ctx, int resistance )
elessair 0:f269e3021894 128 {
elessair 0:f269e3021894 129 ctx->prediction_resistance = resistance;
elessair 0:f269e3021894 130 }
elessair 0:f269e3021894 131
elessair 0:f269e3021894 132 void mbedtls_ctr_drbg_set_entropy_len( mbedtls_ctr_drbg_context *ctx, size_t len )
elessair 0:f269e3021894 133 {
elessair 0:f269e3021894 134 ctx->entropy_len = len;
elessair 0:f269e3021894 135 }
elessair 0:f269e3021894 136
elessair 0:f269e3021894 137 void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx, int interval )
elessair 0:f269e3021894 138 {
elessair 0:f269e3021894 139 ctx->reseed_interval = interval;
elessair 0:f269e3021894 140 }
elessair 0:f269e3021894 141
elessair 0:f269e3021894 142 static int block_cipher_df( unsigned char *output,
elessair 0:f269e3021894 143 const unsigned char *data, size_t data_len )
elessair 0:f269e3021894 144 {
elessair 0:f269e3021894 145 unsigned char buf[MBEDTLS_CTR_DRBG_MAX_SEED_INPUT + MBEDTLS_CTR_DRBG_BLOCKSIZE + 16];
elessair 0:f269e3021894 146 unsigned char tmp[MBEDTLS_CTR_DRBG_SEEDLEN];
elessair 0:f269e3021894 147 unsigned char key[MBEDTLS_CTR_DRBG_KEYSIZE];
elessair 0:f269e3021894 148 unsigned char chain[MBEDTLS_CTR_DRBG_BLOCKSIZE];
elessair 0:f269e3021894 149 unsigned char *p, *iv;
elessair 0:f269e3021894 150 mbedtls_aes_context aes_ctx;
elessair 0:f269e3021894 151
elessair 0:f269e3021894 152 int i, j;
elessair 0:f269e3021894 153 size_t buf_len, use_len;
elessair 0:f269e3021894 154
elessair 0:f269e3021894 155 if( data_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
elessair 0:f269e3021894 156 return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
elessair 0:f269e3021894 157
elessair 0:f269e3021894 158 memset( buf, 0, MBEDTLS_CTR_DRBG_MAX_SEED_INPUT + MBEDTLS_CTR_DRBG_BLOCKSIZE + 16 );
elessair 0:f269e3021894 159 mbedtls_aes_init( &aes_ctx );
elessair 0:f269e3021894 160
elessair 0:f269e3021894 161 /*
elessair 0:f269e3021894 162 * Construct IV (16 bytes) and S in buffer
elessair 0:f269e3021894 163 * IV = Counter (in 32-bits) padded to 16 with zeroes
elessair 0:f269e3021894 164 * S = Length input string (in 32-bits) || Length of output (in 32-bits) ||
elessair 0:f269e3021894 165 * data || 0x80
elessair 0:f269e3021894 166 * (Total is padded to a multiple of 16-bytes with zeroes)
elessair 0:f269e3021894 167 */
elessair 0:f269e3021894 168 p = buf + MBEDTLS_CTR_DRBG_BLOCKSIZE;
elessair 0:f269e3021894 169 *p++ = ( data_len >> 24 ) & 0xff;
elessair 0:f269e3021894 170 *p++ = ( data_len >> 16 ) & 0xff;
elessair 0:f269e3021894 171 *p++ = ( data_len >> 8 ) & 0xff;
elessair 0:f269e3021894 172 *p++ = ( data_len ) & 0xff;
elessair 0:f269e3021894 173 p += 3;
elessair 0:f269e3021894 174 *p++ = MBEDTLS_CTR_DRBG_SEEDLEN;
elessair 0:f269e3021894 175 memcpy( p, data, data_len );
elessair 0:f269e3021894 176 p[data_len] = 0x80;
elessair 0:f269e3021894 177
elessair 0:f269e3021894 178 buf_len = MBEDTLS_CTR_DRBG_BLOCKSIZE + 8 + data_len + 1;
elessair 0:f269e3021894 179
elessair 0:f269e3021894 180 for( i = 0; i < MBEDTLS_CTR_DRBG_KEYSIZE; i++ )
elessair 0:f269e3021894 181 key[i] = i;
elessair 0:f269e3021894 182
elessair 0:f269e3021894 183 mbedtls_aes_setkey_enc( &aes_ctx, key, MBEDTLS_CTR_DRBG_KEYBITS );
elessair 0:f269e3021894 184
elessair 0:f269e3021894 185 /*
elessair 0:f269e3021894 186 * Reduce data to MBEDTLS_CTR_DRBG_SEEDLEN bytes of data
elessair 0:f269e3021894 187 */
elessair 0:f269e3021894 188 for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
elessair 0:f269e3021894 189 {
elessair 0:f269e3021894 190 p = buf;
elessair 0:f269e3021894 191 memset( chain, 0, MBEDTLS_CTR_DRBG_BLOCKSIZE );
elessair 0:f269e3021894 192 use_len = buf_len;
elessair 0:f269e3021894 193
elessair 0:f269e3021894 194 while( use_len > 0 )
elessair 0:f269e3021894 195 {
elessair 0:f269e3021894 196 for( i = 0; i < MBEDTLS_CTR_DRBG_BLOCKSIZE; i++ )
elessair 0:f269e3021894 197 chain[i] ^= p[i];
elessair 0:f269e3021894 198 p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
elessair 0:f269e3021894 199 use_len -= ( use_len >= MBEDTLS_CTR_DRBG_BLOCKSIZE ) ?
elessair 0:f269e3021894 200 MBEDTLS_CTR_DRBG_BLOCKSIZE : use_len;
elessair 0:f269e3021894 201
elessair 0:f269e3021894 202 mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT, chain, chain );
elessair 0:f269e3021894 203 }
elessair 0:f269e3021894 204
elessair 0:f269e3021894 205 memcpy( tmp + j, chain, MBEDTLS_CTR_DRBG_BLOCKSIZE );
elessair 0:f269e3021894 206
elessair 0:f269e3021894 207 /*
elessair 0:f269e3021894 208 * Update IV
elessair 0:f269e3021894 209 */
elessair 0:f269e3021894 210 buf[3]++;
elessair 0:f269e3021894 211 }
elessair 0:f269e3021894 212
elessair 0:f269e3021894 213 /*
elessair 0:f269e3021894 214 * Do final encryption with reduced data
elessair 0:f269e3021894 215 */
elessair 0:f269e3021894 216 mbedtls_aes_setkey_enc( &aes_ctx, tmp, MBEDTLS_CTR_DRBG_KEYBITS );
elessair 0:f269e3021894 217 iv = tmp + MBEDTLS_CTR_DRBG_KEYSIZE;
elessair 0:f269e3021894 218 p = output;
elessair 0:f269e3021894 219
elessair 0:f269e3021894 220 for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
elessair 0:f269e3021894 221 {
elessair 0:f269e3021894 222 mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT, iv, iv );
elessair 0:f269e3021894 223 memcpy( p, iv, MBEDTLS_CTR_DRBG_BLOCKSIZE );
elessair 0:f269e3021894 224 p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
elessair 0:f269e3021894 225 }
elessair 0:f269e3021894 226
elessair 0:f269e3021894 227 mbedtls_aes_free( &aes_ctx );
elessair 0:f269e3021894 228
elessair 0:f269e3021894 229 return( 0 );
elessair 0:f269e3021894 230 }
elessair 0:f269e3021894 231
elessair 0:f269e3021894 232 static int ctr_drbg_update_internal( mbedtls_ctr_drbg_context *ctx,
elessair 0:f269e3021894 233 const unsigned char data[MBEDTLS_CTR_DRBG_SEEDLEN] )
elessair 0:f269e3021894 234 {
elessair 0:f269e3021894 235 unsigned char tmp[MBEDTLS_CTR_DRBG_SEEDLEN];
elessair 0:f269e3021894 236 unsigned char *p = tmp;
elessair 0:f269e3021894 237 int i, j;
elessair 0:f269e3021894 238
elessair 0:f269e3021894 239 memset( tmp, 0, MBEDTLS_CTR_DRBG_SEEDLEN );
elessair 0:f269e3021894 240
elessair 0:f269e3021894 241 for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
elessair 0:f269e3021894 242 {
elessair 0:f269e3021894 243 /*
elessair 0:f269e3021894 244 * Increase counter
elessair 0:f269e3021894 245 */
elessair 0:f269e3021894 246 for( i = MBEDTLS_CTR_DRBG_BLOCKSIZE; i > 0; i-- )
elessair 0:f269e3021894 247 if( ++ctx->counter[i - 1] != 0 )
elessair 0:f269e3021894 248 break;
elessair 0:f269e3021894 249
elessair 0:f269e3021894 250 /*
elessair 0:f269e3021894 251 * Crypt counter block
elessair 0:f269e3021894 252 */
elessair 0:f269e3021894 253 mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT, ctx->counter, p );
elessair 0:f269e3021894 254
elessair 0:f269e3021894 255 p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
elessair 0:f269e3021894 256 }
elessair 0:f269e3021894 257
elessair 0:f269e3021894 258 for( i = 0; i < MBEDTLS_CTR_DRBG_SEEDLEN; i++ )
elessair 0:f269e3021894 259 tmp[i] ^= data[i];
elessair 0:f269e3021894 260
elessair 0:f269e3021894 261 /*
elessair 0:f269e3021894 262 * Update key and counter
elessair 0:f269e3021894 263 */
elessair 0:f269e3021894 264 mbedtls_aes_setkey_enc( &ctx->aes_ctx, tmp, MBEDTLS_CTR_DRBG_KEYBITS );
elessair 0:f269e3021894 265 memcpy( ctx->counter, tmp + MBEDTLS_CTR_DRBG_KEYSIZE, MBEDTLS_CTR_DRBG_BLOCKSIZE );
elessair 0:f269e3021894 266
elessair 0:f269e3021894 267 return( 0 );
elessair 0:f269e3021894 268 }
elessair 0:f269e3021894 269
elessair 0:f269e3021894 270 void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx,
elessair 0:f269e3021894 271 const unsigned char *additional, size_t add_len )
elessair 0:f269e3021894 272 {
elessair 0:f269e3021894 273 unsigned char add_input[MBEDTLS_CTR_DRBG_SEEDLEN];
elessair 0:f269e3021894 274
elessair 0:f269e3021894 275 if( add_len > 0 )
elessair 0:f269e3021894 276 {
elessair 0:f269e3021894 277 /* MAX_INPUT would be more logical here, but we have to match
elessair 0:f269e3021894 278 * block_cipher_df()'s limits since we can't propagate errors */
elessair 0:f269e3021894 279 if( add_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
elessair 0:f269e3021894 280 add_len = MBEDTLS_CTR_DRBG_MAX_SEED_INPUT;
elessair 0:f269e3021894 281
elessair 0:f269e3021894 282 block_cipher_df( add_input, additional, add_len );
elessair 0:f269e3021894 283 ctr_drbg_update_internal( ctx, add_input );
elessair 0:f269e3021894 284 }
elessair 0:f269e3021894 285 }
elessair 0:f269e3021894 286
elessair 0:f269e3021894 287 int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx,
elessair 0:f269e3021894 288 const unsigned char *additional, size_t len )
elessair 0:f269e3021894 289 {
elessair 0:f269e3021894 290 unsigned char seed[MBEDTLS_CTR_DRBG_MAX_SEED_INPUT];
elessair 0:f269e3021894 291 size_t seedlen = 0;
elessair 0:f269e3021894 292
elessair 0:f269e3021894 293 if( ctx->entropy_len + len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
elessair 0:f269e3021894 294 return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
elessair 0:f269e3021894 295
elessair 0:f269e3021894 296 memset( seed, 0, MBEDTLS_CTR_DRBG_MAX_SEED_INPUT );
elessair 0:f269e3021894 297
elessair 0:f269e3021894 298 /*
elessair 0:f269e3021894 299 * Gather entropy_len bytes of entropy to seed state
elessair 0:f269e3021894 300 */
elessair 0:f269e3021894 301 if( 0 != ctx->f_entropy( ctx->p_entropy, seed,
elessair 0:f269e3021894 302 ctx->entropy_len ) )
elessair 0:f269e3021894 303 {
elessair 0:f269e3021894 304 return( MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED );
elessair 0:f269e3021894 305 }
elessair 0:f269e3021894 306
elessair 0:f269e3021894 307 seedlen += ctx->entropy_len;
elessair 0:f269e3021894 308
elessair 0:f269e3021894 309 /*
elessair 0:f269e3021894 310 * Add additional data
elessair 0:f269e3021894 311 */
elessair 0:f269e3021894 312 if( additional && len )
elessair 0:f269e3021894 313 {
elessair 0:f269e3021894 314 memcpy( seed + seedlen, additional, len );
elessair 0:f269e3021894 315 seedlen += len;
elessair 0:f269e3021894 316 }
elessair 0:f269e3021894 317
elessair 0:f269e3021894 318 /*
elessair 0:f269e3021894 319 * Reduce to 384 bits
elessair 0:f269e3021894 320 */
elessair 0:f269e3021894 321 block_cipher_df( seed, seed, seedlen );
elessair 0:f269e3021894 322
elessair 0:f269e3021894 323 /*
elessair 0:f269e3021894 324 * Update state
elessair 0:f269e3021894 325 */
elessair 0:f269e3021894 326 ctr_drbg_update_internal( ctx, seed );
elessair 0:f269e3021894 327 ctx->reseed_counter = 1;
elessair 0:f269e3021894 328
elessair 0:f269e3021894 329 return( 0 );
elessair 0:f269e3021894 330 }
elessair 0:f269e3021894 331
elessair 0:f269e3021894 332 int mbedtls_ctr_drbg_random_with_add( void *p_rng,
elessair 0:f269e3021894 333 unsigned char *output, size_t output_len,
elessair 0:f269e3021894 334 const unsigned char *additional, size_t add_len )
elessair 0:f269e3021894 335 {
elessair 0:f269e3021894 336 int ret = 0;
elessair 0:f269e3021894 337 mbedtls_ctr_drbg_context *ctx = (mbedtls_ctr_drbg_context *) p_rng;
elessair 0:f269e3021894 338 unsigned char add_input[MBEDTLS_CTR_DRBG_SEEDLEN];
elessair 0:f269e3021894 339 unsigned char *p = output;
elessair 0:f269e3021894 340 unsigned char tmp[MBEDTLS_CTR_DRBG_BLOCKSIZE];
elessair 0:f269e3021894 341 int i;
elessair 0:f269e3021894 342 size_t use_len;
elessair 0:f269e3021894 343
elessair 0:f269e3021894 344 if( output_len > MBEDTLS_CTR_DRBG_MAX_REQUEST )
elessair 0:f269e3021894 345 return( MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG );
elessair 0:f269e3021894 346
elessair 0:f269e3021894 347 if( add_len > MBEDTLS_CTR_DRBG_MAX_INPUT )
elessair 0:f269e3021894 348 return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
elessair 0:f269e3021894 349
elessair 0:f269e3021894 350 memset( add_input, 0, MBEDTLS_CTR_DRBG_SEEDLEN );
elessair 0:f269e3021894 351
elessair 0:f269e3021894 352 if( ctx->reseed_counter > ctx->reseed_interval ||
elessair 0:f269e3021894 353 ctx->prediction_resistance )
elessair 0:f269e3021894 354 {
elessair 0:f269e3021894 355 if( ( ret = mbedtls_ctr_drbg_reseed( ctx, additional, add_len ) ) != 0 )
elessair 0:f269e3021894 356 return( ret );
elessair 0:f269e3021894 357
elessair 0:f269e3021894 358 add_len = 0;
elessair 0:f269e3021894 359 }
elessair 0:f269e3021894 360
elessair 0:f269e3021894 361 if( add_len > 0 )
elessair 0:f269e3021894 362 {
elessair 0:f269e3021894 363 block_cipher_df( add_input, additional, add_len );
elessair 0:f269e3021894 364 ctr_drbg_update_internal( ctx, add_input );
elessair 0:f269e3021894 365 }
elessair 0:f269e3021894 366
elessair 0:f269e3021894 367 while( output_len > 0 )
elessair 0:f269e3021894 368 {
elessair 0:f269e3021894 369 /*
elessair 0:f269e3021894 370 * Increase counter
elessair 0:f269e3021894 371 */
elessair 0:f269e3021894 372 for( i = MBEDTLS_CTR_DRBG_BLOCKSIZE; i > 0; i-- )
elessair 0:f269e3021894 373 if( ++ctx->counter[i - 1] != 0 )
elessair 0:f269e3021894 374 break;
elessair 0:f269e3021894 375
elessair 0:f269e3021894 376 /*
elessair 0:f269e3021894 377 * Crypt counter block
elessair 0:f269e3021894 378 */
elessair 0:f269e3021894 379 mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT, ctx->counter, tmp );
elessair 0:f269e3021894 380
elessair 0:f269e3021894 381 use_len = ( output_len > MBEDTLS_CTR_DRBG_BLOCKSIZE ) ? MBEDTLS_CTR_DRBG_BLOCKSIZE :
elessair 0:f269e3021894 382 output_len;
elessair 0:f269e3021894 383 /*
elessair 0:f269e3021894 384 * Copy random block to destination
elessair 0:f269e3021894 385 */
elessair 0:f269e3021894 386 memcpy( p, tmp, use_len );
elessair 0:f269e3021894 387 p += use_len;
elessair 0:f269e3021894 388 output_len -= use_len;
elessair 0:f269e3021894 389 }
elessair 0:f269e3021894 390
elessair 0:f269e3021894 391 ctr_drbg_update_internal( ctx, add_input );
elessair 0:f269e3021894 392
elessair 0:f269e3021894 393 ctx->reseed_counter++;
elessair 0:f269e3021894 394
elessair 0:f269e3021894 395 return( 0 );
elessair 0:f269e3021894 396 }
elessair 0:f269e3021894 397
elessair 0:f269e3021894 398 int mbedtls_ctr_drbg_random( void *p_rng, unsigned char *output, size_t output_len )
elessair 0:f269e3021894 399 {
elessair 0:f269e3021894 400 int ret;
elessair 0:f269e3021894 401 mbedtls_ctr_drbg_context *ctx = (mbedtls_ctr_drbg_context *) p_rng;
elessair 0:f269e3021894 402
elessair 0:f269e3021894 403 #if defined(MBEDTLS_THREADING_C)
elessair 0:f269e3021894 404 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
elessair 0:f269e3021894 405 return( ret );
elessair 0:f269e3021894 406 #endif
elessair 0:f269e3021894 407
elessair 0:f269e3021894 408 ret = mbedtls_ctr_drbg_random_with_add( ctx, output, output_len, NULL, 0 );
elessair 0:f269e3021894 409
elessair 0:f269e3021894 410 #if defined(MBEDTLS_THREADING_C)
elessair 0:f269e3021894 411 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
elessair 0:f269e3021894 412 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
elessair 0:f269e3021894 413 #endif
elessair 0:f269e3021894 414
elessair 0:f269e3021894 415 return( ret );
elessair 0:f269e3021894 416 }
elessair 0:f269e3021894 417
elessair 0:f269e3021894 418 #if defined(MBEDTLS_FS_IO)
elessair 0:f269e3021894 419 int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path )
elessair 0:f269e3021894 420 {
elessair 0:f269e3021894 421 int ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
elessair 0:f269e3021894 422 FILE *f;
elessair 0:f269e3021894 423 unsigned char buf[ MBEDTLS_CTR_DRBG_MAX_INPUT ];
elessair 0:f269e3021894 424
elessair 0:f269e3021894 425 if( ( f = fopen( path, "wb" ) ) == NULL )
elessair 0:f269e3021894 426 return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
elessair 0:f269e3021894 427
elessair 0:f269e3021894 428 if( ( ret = mbedtls_ctr_drbg_random( ctx, buf, MBEDTLS_CTR_DRBG_MAX_INPUT ) ) != 0 )
elessair 0:f269e3021894 429 goto exit;
elessair 0:f269e3021894 430
elessair 0:f269e3021894 431 if( fwrite( buf, 1, MBEDTLS_CTR_DRBG_MAX_INPUT, f ) != MBEDTLS_CTR_DRBG_MAX_INPUT )
elessair 0:f269e3021894 432 {
elessair 0:f269e3021894 433 ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
elessair 0:f269e3021894 434 goto exit;
elessair 0:f269e3021894 435 }
elessair 0:f269e3021894 436
elessair 0:f269e3021894 437 ret = 0;
elessair 0:f269e3021894 438
elessair 0:f269e3021894 439 exit:
elessair 0:f269e3021894 440 fclose( f );
elessair 0:f269e3021894 441 return( ret );
elessair 0:f269e3021894 442 }
elessair 0:f269e3021894 443
elessair 0:f269e3021894 444 int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path )
elessair 0:f269e3021894 445 {
elessair 0:f269e3021894 446 FILE *f;
elessair 0:f269e3021894 447 size_t n;
elessair 0:f269e3021894 448 unsigned char buf[ MBEDTLS_CTR_DRBG_MAX_INPUT ];
elessair 0:f269e3021894 449
elessair 0:f269e3021894 450 if( ( f = fopen( path, "rb" ) ) == NULL )
elessair 0:f269e3021894 451 return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
elessair 0:f269e3021894 452
elessair 0:f269e3021894 453 fseek( f, 0, SEEK_END );
elessair 0:f269e3021894 454 n = (size_t) ftell( f );
elessair 0:f269e3021894 455 fseek( f, 0, SEEK_SET );
elessair 0:f269e3021894 456
elessair 0:f269e3021894 457 if( n > MBEDTLS_CTR_DRBG_MAX_INPUT )
elessair 0:f269e3021894 458 {
elessair 0:f269e3021894 459 fclose( f );
elessair 0:f269e3021894 460 return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
elessair 0:f269e3021894 461 }
elessair 0:f269e3021894 462
elessair 0:f269e3021894 463 if( fread( buf, 1, n, f ) != n )
elessair 0:f269e3021894 464 {
elessair 0:f269e3021894 465 fclose( f );
elessair 0:f269e3021894 466 return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
elessair 0:f269e3021894 467 }
elessair 0:f269e3021894 468
elessair 0:f269e3021894 469 fclose( f );
elessair 0:f269e3021894 470
elessair 0:f269e3021894 471 mbedtls_ctr_drbg_update( ctx, buf, n );
elessair 0:f269e3021894 472
elessair 0:f269e3021894 473 return( mbedtls_ctr_drbg_write_seed_file( ctx, path ) );
elessair 0:f269e3021894 474 }
elessair 0:f269e3021894 475 #endif /* MBEDTLS_FS_IO */
elessair 0:f269e3021894 476
elessair 0:f269e3021894 477 #if defined(MBEDTLS_SELF_TEST)
elessair 0:f269e3021894 478
elessair 0:f269e3021894 479 static const unsigned char entropy_source_pr[96] =
elessair 0:f269e3021894 480 { 0xc1, 0x80, 0x81, 0xa6, 0x5d, 0x44, 0x02, 0x16,
elessair 0:f269e3021894 481 0x19, 0xb3, 0xf1, 0x80, 0xb1, 0xc9, 0x20, 0x02,
elessair 0:f269e3021894 482 0x6a, 0x54, 0x6f, 0x0c, 0x70, 0x81, 0x49, 0x8b,
elessair 0:f269e3021894 483 0x6e, 0xa6, 0x62, 0x52, 0x6d, 0x51, 0xb1, 0xcb,
elessair 0:f269e3021894 484 0x58, 0x3b, 0xfa, 0xd5, 0x37, 0x5f, 0xfb, 0xc9,
elessair 0:f269e3021894 485 0xff, 0x46, 0xd2, 0x19, 0xc7, 0x22, 0x3e, 0x95,
elessair 0:f269e3021894 486 0x45, 0x9d, 0x82, 0xe1, 0xe7, 0x22, 0x9f, 0x63,
elessair 0:f269e3021894 487 0x31, 0x69, 0xd2, 0x6b, 0x57, 0x47, 0x4f, 0xa3,
elessair 0:f269e3021894 488 0x37, 0xc9, 0x98, 0x1c, 0x0b, 0xfb, 0x91, 0x31,
elessair 0:f269e3021894 489 0x4d, 0x55, 0xb9, 0xe9, 0x1c, 0x5a, 0x5e, 0xe4,
elessair 0:f269e3021894 490 0x93, 0x92, 0xcf, 0xc5, 0x23, 0x12, 0xd5, 0x56,
elessair 0:f269e3021894 491 0x2c, 0x4a, 0x6e, 0xff, 0xdc, 0x10, 0xd0, 0x68 };
elessair 0:f269e3021894 492
elessair 0:f269e3021894 493 static const unsigned char entropy_source_nopr[64] =
elessair 0:f269e3021894 494 { 0x5a, 0x19, 0x4d, 0x5e, 0x2b, 0x31, 0x58, 0x14,
elessair 0:f269e3021894 495 0x54, 0xde, 0xf6, 0x75, 0xfb, 0x79, 0x58, 0xfe,
elessair 0:f269e3021894 496 0xc7, 0xdb, 0x87, 0x3e, 0x56, 0x89, 0xfc, 0x9d,
elessair 0:f269e3021894 497 0x03, 0x21, 0x7c, 0x68, 0xd8, 0x03, 0x38, 0x20,
elessair 0:f269e3021894 498 0xf9, 0xe6, 0x5e, 0x04, 0xd8, 0x56, 0xf3, 0xa9,
elessair 0:f269e3021894 499 0xc4, 0x4a, 0x4c, 0xbd, 0xc1, 0xd0, 0x08, 0x46,
elessair 0:f269e3021894 500 0xf5, 0x98, 0x3d, 0x77, 0x1c, 0x1b, 0x13, 0x7e,
elessair 0:f269e3021894 501 0x4e, 0x0f, 0x9d, 0x8e, 0xf4, 0x09, 0xf9, 0x2e };
elessair 0:f269e3021894 502
elessair 0:f269e3021894 503 static const unsigned char nonce_pers_pr[16] =
elessair 0:f269e3021894 504 { 0xd2, 0x54, 0xfc, 0xff, 0x02, 0x1e, 0x69, 0xd2,
elessair 0:f269e3021894 505 0x29, 0xc9, 0xcf, 0xad, 0x85, 0xfa, 0x48, 0x6c };
elessair 0:f269e3021894 506
elessair 0:f269e3021894 507 static const unsigned char nonce_pers_nopr[16] =
elessair 0:f269e3021894 508 { 0x1b, 0x54, 0xb8, 0xff, 0x06, 0x42, 0xbf, 0xf5,
elessair 0:f269e3021894 509 0x21, 0xf1, 0x5c, 0x1c, 0x0b, 0x66, 0x5f, 0x3f };
elessair 0:f269e3021894 510
elessair 0:f269e3021894 511 static const unsigned char result_pr[16] =
elessair 0:f269e3021894 512 { 0x34, 0x01, 0x16, 0x56, 0xb4, 0x29, 0x00, 0x8f,
elessair 0:f269e3021894 513 0x35, 0x63, 0xec, 0xb5, 0xf2, 0x59, 0x07, 0x23 };
elessair 0:f269e3021894 514
elessair 0:f269e3021894 515 static const unsigned char result_nopr[16] =
elessair 0:f269e3021894 516 { 0xa0, 0x54, 0x30, 0x3d, 0x8a, 0x7e, 0xa9, 0x88,
elessair 0:f269e3021894 517 0x9d, 0x90, 0x3e, 0x07, 0x7c, 0x6f, 0x21, 0x8f };
elessair 0:f269e3021894 518
elessair 0:f269e3021894 519 static size_t test_offset;
elessair 0:f269e3021894 520 static int ctr_drbg_self_test_entropy( void *data, unsigned char *buf,
elessair 0:f269e3021894 521 size_t len )
elessair 0:f269e3021894 522 {
elessair 0:f269e3021894 523 const unsigned char *p = data;
elessair 0:f269e3021894 524 memcpy( buf, p + test_offset, len );
elessair 0:f269e3021894 525 test_offset += len;
elessair 0:f269e3021894 526 return( 0 );
elessair 0:f269e3021894 527 }
elessair 0:f269e3021894 528
elessair 0:f269e3021894 529 #define CHK( c ) if( (c) != 0 ) \
elessair 0:f269e3021894 530 { \
elessair 0:f269e3021894 531 if( verbose != 0 ) \
elessair 0:f269e3021894 532 mbedtls_printf( "failed\n" ); \
elessair 0:f269e3021894 533 return( 1 ); \
elessair 0:f269e3021894 534 }
elessair 0:f269e3021894 535
elessair 0:f269e3021894 536 /*
elessair 0:f269e3021894 537 * Checkup routine
elessair 0:f269e3021894 538 */
elessair 0:f269e3021894 539 int mbedtls_ctr_drbg_self_test( int verbose )
elessair 0:f269e3021894 540 {
elessair 0:f269e3021894 541 mbedtls_ctr_drbg_context ctx;
elessair 0:f269e3021894 542 unsigned char buf[16];
elessair 0:f269e3021894 543
elessair 0:f269e3021894 544 mbedtls_ctr_drbg_init( &ctx );
elessair 0:f269e3021894 545
elessair 0:f269e3021894 546 /*
elessair 0:f269e3021894 547 * Based on a NIST CTR_DRBG test vector (PR = True)
elessair 0:f269e3021894 548 */
elessair 0:f269e3021894 549 if( verbose != 0 )
elessair 0:f269e3021894 550 mbedtls_printf( " CTR_DRBG (PR = TRUE) : " );
elessair 0:f269e3021894 551
elessair 0:f269e3021894 552 test_offset = 0;
elessair 0:f269e3021894 553 CHK( mbedtls_ctr_drbg_seed_entropy_len( &ctx, ctr_drbg_self_test_entropy,
elessair 0:f269e3021894 554 (void *) entropy_source_pr, nonce_pers_pr, 16, 32 ) );
elessair 0:f269e3021894 555 mbedtls_ctr_drbg_set_prediction_resistance( &ctx, MBEDTLS_CTR_DRBG_PR_ON );
elessair 0:f269e3021894 556 CHK( mbedtls_ctr_drbg_random( &ctx, buf, MBEDTLS_CTR_DRBG_BLOCKSIZE ) );
elessair 0:f269e3021894 557 CHK( mbedtls_ctr_drbg_random( &ctx, buf, MBEDTLS_CTR_DRBG_BLOCKSIZE ) );
elessair 0:f269e3021894 558 CHK( memcmp( buf, result_pr, MBEDTLS_CTR_DRBG_BLOCKSIZE ) );
elessair 0:f269e3021894 559
elessair 0:f269e3021894 560 mbedtls_ctr_drbg_free( &ctx );
elessair 0:f269e3021894 561
elessair 0:f269e3021894 562 if( verbose != 0 )
elessair 0:f269e3021894 563 mbedtls_printf( "passed\n" );
elessair 0:f269e3021894 564
elessair 0:f269e3021894 565 /*
elessair 0:f269e3021894 566 * Based on a NIST CTR_DRBG test vector (PR = FALSE)
elessair 0:f269e3021894 567 */
elessair 0:f269e3021894 568 if( verbose != 0 )
elessair 0:f269e3021894 569 mbedtls_printf( " CTR_DRBG (PR = FALSE): " );
elessair 0:f269e3021894 570
elessair 0:f269e3021894 571 mbedtls_ctr_drbg_init( &ctx );
elessair 0:f269e3021894 572
elessair 0:f269e3021894 573 test_offset = 0;
elessair 0:f269e3021894 574 CHK( mbedtls_ctr_drbg_seed_entropy_len( &ctx, ctr_drbg_self_test_entropy,
elessair 0:f269e3021894 575 (void *) entropy_source_nopr, nonce_pers_nopr, 16, 32 ) );
elessair 0:f269e3021894 576 CHK( mbedtls_ctr_drbg_random( &ctx, buf, 16 ) );
elessair 0:f269e3021894 577 CHK( mbedtls_ctr_drbg_reseed( &ctx, NULL, 0 ) );
elessair 0:f269e3021894 578 CHK( mbedtls_ctr_drbg_random( &ctx, buf, 16 ) );
elessair 0:f269e3021894 579 CHK( memcmp( buf, result_nopr, 16 ) );
elessair 0:f269e3021894 580
elessair 0:f269e3021894 581 mbedtls_ctr_drbg_free( &ctx );
elessair 0:f269e3021894 582
elessair 0:f269e3021894 583 if( verbose != 0 )
elessair 0:f269e3021894 584 mbedtls_printf( "passed\n" );
elessair 0:f269e3021894 585
elessair 0:f269e3021894 586 if( verbose != 0 )
elessair 0:f269e3021894 587 mbedtls_printf( "\n" );
elessair 0:f269e3021894 588
elessair 0:f269e3021894 589 return( 0 );
elessair 0:f269e3021894 590 }
elessair 0:f269e3021894 591 #endif /* MBEDTLS_SELF_TEST */
elessair 0:f269e3021894 592
elessair 0:f269e3021894 593 #endif /* MBEDTLS_CTR_DRBG_C */