Nitin Shukla / LED_Demo

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Dependencies:   MAX44000 nexpaq_mdk

Fork of LED_Demo by Maxim nexpaq

mbd_os/features/mbedtls/src/entropy.c@7:3a65ef12ba31, 2016-11-04 (annotated)

Committer:
nitsshukla
Date:
Fri Nov 04 12:06:04 2016 +0000
Revision:
7:3a65ef12ba31
Parent:
1:55a6170b404f 
kghj;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
nexpaq 1:55a6170b404f 1 /*
nexpaq 1:55a6170b404f 2 * Entropy accumulator implementation
nexpaq 1:55a6170b404f 3 *
nexpaq 1:55a6170b404f 4 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
nexpaq 1:55a6170b404f 5 * SPDX-License-Identifier: Apache-2.0
nexpaq 1:55a6170b404f 6 *
nexpaq 1:55a6170b404f 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
nexpaq 1:55a6170b404f 8 * not use this file except in compliance with the License.
nexpaq 1:55a6170b404f 9 * You may obtain a copy of the License at
nexpaq 1:55a6170b404f 10 *
nexpaq 1:55a6170b404f 11 * http://www.apache.org/licenses/LICENSE-2.0
nexpaq 1:55a6170b404f 12 *
nexpaq 1:55a6170b404f 13 * Unless required by applicable law or agreed to in writing, software
nexpaq 1:55a6170b404f 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
nexpaq 1:55a6170b404f 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
nexpaq 1:55a6170b404f 16 * See the License for the specific language governing permissions and
nexpaq 1:55a6170b404f 17 * limitations under the License.
nexpaq 1:55a6170b404f 18 *
nexpaq 1:55a6170b404f 19 * This file is part of mbed TLS (https://tls.mbed.org)
nexpaq 1:55a6170b404f 20 */
nexpaq 1:55a6170b404f 21
nexpaq 1:55a6170b404f 22 #if !defined(MBEDTLS_CONFIG_FILE)
nexpaq 1:55a6170b404f 23 #include "mbedtls/config.h"
nexpaq 1:55a6170b404f 24 #else
nexpaq 1:55a6170b404f 25 #include MBEDTLS_CONFIG_FILE
nexpaq 1:55a6170b404f 26 #endif
nexpaq 1:55a6170b404f 27
nexpaq 1:55a6170b404f 28 #if defined(MBEDTLS_ENTROPY_C)
nexpaq 1:55a6170b404f 29
nexpaq 1:55a6170b404f 30 #if defined(MBEDTLS_TEST_NULL_ENTROPY)
nexpaq 1:55a6170b404f 31 #warning "**** WARNING! MBEDTLS_TEST_NULL_ENTROPY defined! "
nexpaq 1:55a6170b404f 32 #warning "**** THIS BUILD HAS NO DEFINED ENTROPY SOURCES "
nexpaq 1:55a6170b404f 33 #warning "**** THIS BUILD IS *NOT* SUITABLE FOR PRODUCTION USE "
nexpaq 1:55a6170b404f 34 #endif
nexpaq 1:55a6170b404f 35
nexpaq 1:55a6170b404f 36 #include "mbedtls/entropy.h"
nexpaq 1:55a6170b404f 37 #include "mbedtls/entropy_poll.h"
nexpaq 1:55a6170b404f 38
nexpaq 1:55a6170b404f 39 #include <string.h>
nexpaq 1:55a6170b404f 40
nexpaq 1:55a6170b404f 41 #if defined(MBEDTLS_FS_IO)
nexpaq 1:55a6170b404f 42 #include <stdio.h>
nexpaq 1:55a6170b404f 43 #endif
nexpaq 1:55a6170b404f 44
nexpaq 1:55a6170b404f 45 #if defined(MBEDTLS_SELF_TEST)
nexpaq 1:55a6170b404f 46 #if defined(MBEDTLS_PLATFORM_C)
nexpaq 1:55a6170b404f 47 #include "mbedtls/platform.h"
nexpaq 1:55a6170b404f 48 #else
nexpaq 1:55a6170b404f 49 #include <stdio.h>
nexpaq 1:55a6170b404f 50 #define mbedtls_printf printf
nexpaq 1:55a6170b404f 51 #endif /* MBEDTLS_PLATFORM_C */
nexpaq 1:55a6170b404f 52 #endif /* MBEDTLS_SELF_TEST */
nexpaq 1:55a6170b404f 53
nexpaq 1:55a6170b404f 54 #if defined(MBEDTLS_HAVEGE_C)
nexpaq 1:55a6170b404f 55 #include "mbedtls/havege.h"
nexpaq 1:55a6170b404f 56 #endif
nexpaq 1:55a6170b404f 57
nexpaq 1:55a6170b404f 58 /* Implementation that should never be optimized out by the compiler */
nexpaq 1:55a6170b404f 59 static void mbedtls_zeroize( void *v, size_t n ) {
nexpaq 1:55a6170b404f 60 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
nexpaq 1:55a6170b404f 61 }
nexpaq 1:55a6170b404f 62
nexpaq 1:55a6170b404f 63 #define ENTROPY_MAX_LOOP 256 /**< Maximum amount to loop before error */
nexpaq 1:55a6170b404f 64
nexpaq 1:55a6170b404f 65 void mbedtls_entropy_init( mbedtls_entropy_context *ctx )
nexpaq 1:55a6170b404f 66 {
nexpaq 1:55a6170b404f 67 memset( ctx, 0, sizeof(mbedtls_entropy_context) );
nexpaq 1:55a6170b404f 68
nexpaq 1:55a6170b404f 69 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 70 mbedtls_mutex_init( &ctx->mutex );
nexpaq 1:55a6170b404f 71 #endif
nexpaq 1:55a6170b404f 72
nexpaq 1:55a6170b404f 73 #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
nexpaq 1:55a6170b404f 74 mbedtls_sha512_starts( &ctx->accumulator, 0 );
nexpaq 1:55a6170b404f 75 #else
nexpaq 1:55a6170b404f 76 mbedtls_sha256_starts( &ctx->accumulator, 0 );
nexpaq 1:55a6170b404f 77 #endif
nexpaq 1:55a6170b404f 78 #if defined(MBEDTLS_HAVEGE_C)
nexpaq 1:55a6170b404f 79 mbedtls_havege_init( &ctx->havege_data );
nexpaq 1:55a6170b404f 80 #endif
nexpaq 1:55a6170b404f 81
nexpaq 1:55a6170b404f 82 #if defined(MBEDTLS_TEST_NULL_ENTROPY)
nexpaq 1:55a6170b404f 83 mbedtls_entropy_add_source( ctx, mbedtls_null_entropy_poll, NULL,
nexpaq 1:55a6170b404f 84 1, MBEDTLS_ENTROPY_SOURCE_STRONG );
nexpaq 1:55a6170b404f 85 #endif
nexpaq 1:55a6170b404f 86
nexpaq 1:55a6170b404f 87 #if !defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES)
nexpaq 1:55a6170b404f 88 #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
nexpaq 1:55a6170b404f 89 mbedtls_entropy_add_source( ctx, mbedtls_platform_entropy_poll, NULL,
nexpaq 1:55a6170b404f 90 MBEDTLS_ENTROPY_MIN_PLATFORM,
nexpaq 1:55a6170b404f 91 MBEDTLS_ENTROPY_SOURCE_STRONG );
nexpaq 1:55a6170b404f 92 #endif
nexpaq 1:55a6170b404f 93 #if defined(MBEDTLS_TIMING_C)
nexpaq 1:55a6170b404f 94 mbedtls_entropy_add_source( ctx, mbedtls_hardclock_poll, NULL,
nexpaq 1:55a6170b404f 95 MBEDTLS_ENTROPY_MIN_HARDCLOCK,
nexpaq 1:55a6170b404f 96 MBEDTLS_ENTROPY_SOURCE_WEAK );
nexpaq 1:55a6170b404f 97 #endif
nexpaq 1:55a6170b404f 98 #if defined(MBEDTLS_HAVEGE_C)
nexpaq 1:55a6170b404f 99 mbedtls_entropy_add_source( ctx, mbedtls_havege_poll, &ctx->havege_data,
nexpaq 1:55a6170b404f 100 MBEDTLS_ENTROPY_MIN_HAVEGE,
nexpaq 1:55a6170b404f 101 MBEDTLS_ENTROPY_SOURCE_STRONG );
nexpaq 1:55a6170b404f 102 #endif
nexpaq 1:55a6170b404f 103 #if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
nexpaq 1:55a6170b404f 104 mbedtls_entropy_add_source( ctx, mbedtls_hardware_poll, NULL,
nexpaq 1:55a6170b404f 105 MBEDTLS_ENTROPY_MIN_HARDWARE,
nexpaq 1:55a6170b404f 106 MBEDTLS_ENTROPY_SOURCE_STRONG );
nexpaq 1:55a6170b404f 107 #endif
nexpaq 1:55a6170b404f 108 #if defined(MBEDTLS_ENTROPY_NV_SEED)
nexpaq 1:55a6170b404f 109 mbedtls_entropy_add_source( ctx, mbedtls_nv_seed_poll, NULL,
nexpaq 1:55a6170b404f 110 MBEDTLS_ENTROPY_BLOCK_SIZE,
nexpaq 1:55a6170b404f 111 MBEDTLS_ENTROPY_SOURCE_STRONG );
nexpaq 1:55a6170b404f 112 #endif
nexpaq 1:55a6170b404f 113 #endif /* MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES */
nexpaq 1:55a6170b404f 114 }
nexpaq 1:55a6170b404f 115
nexpaq 1:55a6170b404f 116 void mbedtls_entropy_free( mbedtls_entropy_context *ctx )
nexpaq 1:55a6170b404f 117 {
nexpaq 1:55a6170b404f 118 #if defined(MBEDTLS_HAVEGE_C)
nexpaq 1:55a6170b404f 119 mbedtls_havege_free( &ctx->havege_data );
nexpaq 1:55a6170b404f 120 #endif
nexpaq 1:55a6170b404f 121 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 122 mbedtls_mutex_free( &ctx->mutex );
nexpaq 1:55a6170b404f 123 #endif
nexpaq 1:55a6170b404f 124 mbedtls_zeroize( ctx, sizeof( mbedtls_entropy_context ) );
nexpaq 1:55a6170b404f 125 }
nexpaq 1:55a6170b404f 126
nexpaq 1:55a6170b404f 127 int mbedtls_entropy_add_source( mbedtls_entropy_context *ctx,
nexpaq 1:55a6170b404f 128 mbedtls_entropy_f_source_ptr f_source, void *p_source,
nexpaq 1:55a6170b404f 129 size_t threshold, int strong )
nexpaq 1:55a6170b404f 130 {
nexpaq 1:55a6170b404f 131 int index, ret = 0;
nexpaq 1:55a6170b404f 132
nexpaq 1:55a6170b404f 133 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 134 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
nexpaq 1:55a6170b404f 135 return( ret );
nexpaq 1:55a6170b404f 136 #endif
nexpaq 1:55a6170b404f 137
nexpaq 1:55a6170b404f 138 index = ctx->source_count;
nexpaq 1:55a6170b404f 139 if( index >= MBEDTLS_ENTROPY_MAX_SOURCES )
nexpaq 1:55a6170b404f 140 {
nexpaq 1:55a6170b404f 141 ret = MBEDTLS_ERR_ENTROPY_MAX_SOURCES;
nexpaq 1:55a6170b404f 142 goto exit;
nexpaq 1:55a6170b404f 143 }
nexpaq 1:55a6170b404f 144
nexpaq 1:55a6170b404f 145 ctx->source[index].f_source = f_source;
nexpaq 1:55a6170b404f 146 ctx->source[index].p_source = p_source;
nexpaq 1:55a6170b404f 147 ctx->source[index].threshold = threshold;
nexpaq 1:55a6170b404f 148 ctx->source[index].strong = strong;
nexpaq 1:55a6170b404f 149
nexpaq 1:55a6170b404f 150 ctx->source_count++;
nexpaq 1:55a6170b404f 151
nexpaq 1:55a6170b404f 152 exit:
nexpaq 1:55a6170b404f 153 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 154 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
nexpaq 1:55a6170b404f 155 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
nexpaq 1:55a6170b404f 156 #endif
nexpaq 1:55a6170b404f 157
nexpaq 1:55a6170b404f 158 return( ret );
nexpaq 1:55a6170b404f 159 }
nexpaq 1:55a6170b404f 160
nexpaq 1:55a6170b404f 161 /*
nexpaq 1:55a6170b404f 162 * Entropy accumulator update
nexpaq 1:55a6170b404f 163 */
nexpaq 1:55a6170b404f 164 static int entropy_update( mbedtls_entropy_context *ctx, unsigned char source_id,
nexpaq 1:55a6170b404f 165 const unsigned char *data, size_t len )
nexpaq 1:55a6170b404f 166 {
nexpaq 1:55a6170b404f 167 unsigned char header[2];
nexpaq 1:55a6170b404f 168 unsigned char tmp[MBEDTLS_ENTROPY_BLOCK_SIZE];
nexpaq 1:55a6170b404f 169 size_t use_len = len;
nexpaq 1:55a6170b404f 170 const unsigned char *p = data;
nexpaq 1:55a6170b404f 171
nexpaq 1:55a6170b404f 172 if( use_len > MBEDTLS_ENTROPY_BLOCK_SIZE )
nexpaq 1:55a6170b404f 173 {
nexpaq 1:55a6170b404f 174 #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
nexpaq 1:55a6170b404f 175 mbedtls_sha512( data, len, tmp, 0 );
nexpaq 1:55a6170b404f 176 #else
nexpaq 1:55a6170b404f 177 mbedtls_sha256( data, len, tmp, 0 );
nexpaq 1:55a6170b404f 178 #endif
nexpaq 1:55a6170b404f 179 p = tmp;
nexpaq 1:55a6170b404f 180 use_len = MBEDTLS_ENTROPY_BLOCK_SIZE;
nexpaq 1:55a6170b404f 181 }
nexpaq 1:55a6170b404f 182
nexpaq 1:55a6170b404f 183 header[0] = source_id;
nexpaq 1:55a6170b404f 184 header[1] = use_len & 0xFF;
nexpaq 1:55a6170b404f 185
nexpaq 1:55a6170b404f 186 #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
nexpaq 1:55a6170b404f 187 mbedtls_sha512_update( &ctx->accumulator, header, 2 );
nexpaq 1:55a6170b404f 188 mbedtls_sha512_update( &ctx->accumulator, p, use_len );
nexpaq 1:55a6170b404f 189 #else
nexpaq 1:55a6170b404f 190 mbedtls_sha256_update( &ctx->accumulator, header, 2 );
nexpaq 1:55a6170b404f 191 mbedtls_sha256_update( &ctx->accumulator, p, use_len );
nexpaq 1:55a6170b404f 192 #endif
nexpaq 1:55a6170b404f 193
nexpaq 1:55a6170b404f 194 return( 0 );
nexpaq 1:55a6170b404f 195 }
nexpaq 1:55a6170b404f 196
nexpaq 1:55a6170b404f 197 int mbedtls_entropy_update_manual( mbedtls_entropy_context *ctx,
nexpaq 1:55a6170b404f 198 const unsigned char *data, size_t len )
nexpaq 1:55a6170b404f 199 {
nexpaq 1:55a6170b404f 200 int ret;
nexpaq 1:55a6170b404f 201
nexpaq 1:55a6170b404f 202 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 203 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
nexpaq 1:55a6170b404f 204 return( ret );
nexpaq 1:55a6170b404f 205 #endif
nexpaq 1:55a6170b404f 206
nexpaq 1:55a6170b404f 207 ret = entropy_update( ctx, MBEDTLS_ENTROPY_SOURCE_MANUAL, data, len );
nexpaq 1:55a6170b404f 208
nexpaq 1:55a6170b404f 209 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 210 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
nexpaq 1:55a6170b404f 211 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
nexpaq 1:55a6170b404f 212 #endif
nexpaq 1:55a6170b404f 213
nexpaq 1:55a6170b404f 214 return( ret );
nexpaq 1:55a6170b404f 215 }
nexpaq 1:55a6170b404f 216
nexpaq 1:55a6170b404f 217 /*
nexpaq 1:55a6170b404f 218 * Run through the different sources to add entropy to our accumulator
nexpaq 1:55a6170b404f 219 */
nexpaq 1:55a6170b404f 220 static int entropy_gather_internal( mbedtls_entropy_context *ctx )
nexpaq 1:55a6170b404f 221 {
nexpaq 1:55a6170b404f 222 int ret, i, have_one_strong = 0;
nexpaq 1:55a6170b404f 223 unsigned char buf[MBEDTLS_ENTROPY_MAX_GATHER];
nexpaq 1:55a6170b404f 224 size_t olen;
nexpaq 1:55a6170b404f 225
nexpaq 1:55a6170b404f 226 if( ctx->source_count == 0 )
nexpaq 1:55a6170b404f 227 return( MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED );
nexpaq 1:55a6170b404f 228
nexpaq 1:55a6170b404f 229 /*
nexpaq 1:55a6170b404f 230 * Run through our entropy sources
nexpaq 1:55a6170b404f 231 */
nexpaq 1:55a6170b404f 232 for( i = 0; i < ctx->source_count; i++ )
nexpaq 1:55a6170b404f 233 {
nexpaq 1:55a6170b404f 234 if( ctx->source[i].strong == MBEDTLS_ENTROPY_SOURCE_STRONG )
nexpaq 1:55a6170b404f 235 have_one_strong = 1;
nexpaq 1:55a6170b404f 236
nexpaq 1:55a6170b404f 237 olen = 0;
nexpaq 1:55a6170b404f 238 if( ( ret = ctx->source[i].f_source( ctx->source[i].p_source,
nexpaq 1:55a6170b404f 239 buf, MBEDTLS_ENTROPY_MAX_GATHER, &olen ) ) != 0 )
nexpaq 1:55a6170b404f 240 {
nexpaq 1:55a6170b404f 241 return( ret );
nexpaq 1:55a6170b404f 242 }
nexpaq 1:55a6170b404f 243
nexpaq 1:55a6170b404f 244 /*
nexpaq 1:55a6170b404f 245 * Add if we actually gathered something
nexpaq 1:55a6170b404f 246 */
nexpaq 1:55a6170b404f 247 if( olen > 0 )
nexpaq 1:55a6170b404f 248 {
nexpaq 1:55a6170b404f 249 entropy_update( ctx, (unsigned char) i, buf, olen );
nexpaq 1:55a6170b404f 250 ctx->source[i].size += olen;
nexpaq 1:55a6170b404f 251 }
nexpaq 1:55a6170b404f 252 }
nexpaq 1:55a6170b404f 253
nexpaq 1:55a6170b404f 254 if( have_one_strong == 0 )
nexpaq 1:55a6170b404f 255 return( MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE );
nexpaq 1:55a6170b404f 256
nexpaq 1:55a6170b404f 257 return( 0 );
nexpaq 1:55a6170b404f 258 }
nexpaq 1:55a6170b404f 259
nexpaq 1:55a6170b404f 260 /*
nexpaq 1:55a6170b404f 261 * Thread-safe wrapper for entropy_gather_internal()
nexpaq 1:55a6170b404f 262 */
nexpaq 1:55a6170b404f 263 int mbedtls_entropy_gather( mbedtls_entropy_context *ctx )
nexpaq 1:55a6170b404f 264 {
nexpaq 1:55a6170b404f 265 int ret;
nexpaq 1:55a6170b404f 266
nexpaq 1:55a6170b404f 267 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 268 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
nexpaq 1:55a6170b404f 269 return( ret );
nexpaq 1:55a6170b404f 270 #endif
nexpaq 1:55a6170b404f 271
nexpaq 1:55a6170b404f 272 ret = entropy_gather_internal( ctx );
nexpaq 1:55a6170b404f 273
nexpaq 1:55a6170b404f 274 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 275 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
nexpaq 1:55a6170b404f 276 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
nexpaq 1:55a6170b404f 277 #endif
nexpaq 1:55a6170b404f 278
nexpaq 1:55a6170b404f 279 return( ret );
nexpaq 1:55a6170b404f 280 }
nexpaq 1:55a6170b404f 281
nexpaq 1:55a6170b404f 282 int mbedtls_entropy_func( void *data, unsigned char *output, size_t len )
nexpaq 1:55a6170b404f 283 {
nexpaq 1:55a6170b404f 284 int ret, count = 0, i, done;
nexpaq 1:55a6170b404f 285 mbedtls_entropy_context *ctx = (mbedtls_entropy_context *) data;
nexpaq 1:55a6170b404f 286 unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
nexpaq 1:55a6170b404f 287
nexpaq 1:55a6170b404f 288 if( len > MBEDTLS_ENTROPY_BLOCK_SIZE )
nexpaq 1:55a6170b404f 289 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
nexpaq 1:55a6170b404f 290
nexpaq 1:55a6170b404f 291 #if defined(MBEDTLS_ENTROPY_NV_SEED)
nexpaq 1:55a6170b404f 292 /* Update the NV entropy seed before generating any entropy for outside
nexpaq 1:55a6170b404f 293 * use.
nexpaq 1:55a6170b404f 294 */
nexpaq 1:55a6170b404f 295 if( ctx->initial_entropy_run == 0 )
nexpaq 1:55a6170b404f 296 {
nexpaq 1:55a6170b404f 297 ctx->initial_entropy_run = 1;
nexpaq 1:55a6170b404f 298 if( ( ret = mbedtls_entropy_update_nv_seed( ctx ) ) != 0 )
nexpaq 1:55a6170b404f 299 return( ret );
nexpaq 1:55a6170b404f 300 }
nexpaq 1:55a6170b404f 301 #endif
nexpaq 1:55a6170b404f 302
nexpaq 1:55a6170b404f 303 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 304 if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
nexpaq 1:55a6170b404f 305 return( ret );
nexpaq 1:55a6170b404f 306 #endif
nexpaq 1:55a6170b404f 307
nexpaq 1:55a6170b404f 308 /*
nexpaq 1:55a6170b404f 309 * Always gather extra entropy before a call
nexpaq 1:55a6170b404f 310 */
nexpaq 1:55a6170b404f 311 do
nexpaq 1:55a6170b404f 312 {
nexpaq 1:55a6170b404f 313 if( count++ > ENTROPY_MAX_LOOP )
nexpaq 1:55a6170b404f 314 {
nexpaq 1:55a6170b404f 315 ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
nexpaq 1:55a6170b404f 316 goto exit;
nexpaq 1:55a6170b404f 317 }
nexpaq 1:55a6170b404f 318
nexpaq 1:55a6170b404f 319 if( ( ret = entropy_gather_internal( ctx ) ) != 0 )
nexpaq 1:55a6170b404f 320 goto exit;
nexpaq 1:55a6170b404f 321
nexpaq 1:55a6170b404f 322 done = 1;
nexpaq 1:55a6170b404f 323 for( i = 0; i < ctx->source_count; i++ )
nexpaq 1:55a6170b404f 324 if( ctx->source[i].size < ctx->source[i].threshold )
nexpaq 1:55a6170b404f 325 done = 0;
nexpaq 1:55a6170b404f 326 }
nexpaq 1:55a6170b404f 327 while( ! done );
nexpaq 1:55a6170b404f 328
nexpaq 1:55a6170b404f 329 memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
nexpaq 1:55a6170b404f 330
nexpaq 1:55a6170b404f 331 #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
nexpaq 1:55a6170b404f 332 mbedtls_sha512_finish( &ctx->accumulator, buf );
nexpaq 1:55a6170b404f 333
nexpaq 1:55a6170b404f 334 /*
nexpaq 1:55a6170b404f 335 * Reset accumulator and counters and recycle existing entropy
nexpaq 1:55a6170b404f 336 */
nexpaq 1:55a6170b404f 337 memset( &ctx->accumulator, 0, sizeof( mbedtls_sha512_context ) );
nexpaq 1:55a6170b404f 338 mbedtls_sha512_starts( &ctx->accumulator, 0 );
nexpaq 1:55a6170b404f 339 mbedtls_sha512_update( &ctx->accumulator, buf, MBEDTLS_ENTROPY_BLOCK_SIZE );
nexpaq 1:55a6170b404f 340
nexpaq 1:55a6170b404f 341 /*
nexpaq 1:55a6170b404f 342 * Perform second SHA-512 on entropy
nexpaq 1:55a6170b404f 343 */
nexpaq 1:55a6170b404f 344 mbedtls_sha512( buf, MBEDTLS_ENTROPY_BLOCK_SIZE, buf, 0 );
nexpaq 1:55a6170b404f 345 #else /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
nexpaq 1:55a6170b404f 346 mbedtls_sha256_finish( &ctx->accumulator, buf );
nexpaq 1:55a6170b404f 347
nexpaq 1:55a6170b404f 348 /*
nexpaq 1:55a6170b404f 349 * Reset accumulator and counters and recycle existing entropy
nexpaq 1:55a6170b404f 350 */
nexpaq 1:55a6170b404f 351 memset( &ctx->accumulator, 0, sizeof( mbedtls_sha256_context ) );
nexpaq 1:55a6170b404f 352 mbedtls_sha256_starts( &ctx->accumulator, 0 );
nexpaq 1:55a6170b404f 353 mbedtls_sha256_update( &ctx->accumulator, buf, MBEDTLS_ENTROPY_BLOCK_SIZE );
nexpaq 1:55a6170b404f 354
nexpaq 1:55a6170b404f 355 /*
nexpaq 1:55a6170b404f 356 * Perform second SHA-256 on entropy
nexpaq 1:55a6170b404f 357 */
nexpaq 1:55a6170b404f 358 mbedtls_sha256( buf, MBEDTLS_ENTROPY_BLOCK_SIZE, buf, 0 );
nexpaq 1:55a6170b404f 359 #endif /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
nexpaq 1:55a6170b404f 360
nexpaq 1:55a6170b404f 361 for( i = 0; i < ctx->source_count; i++ )
nexpaq 1:55a6170b404f 362 ctx->source[i].size = 0;
nexpaq 1:55a6170b404f 363
nexpaq 1:55a6170b404f 364 memcpy( output, buf, len );
nexpaq 1:55a6170b404f 365
nexpaq 1:55a6170b404f 366 ret = 0;
nexpaq 1:55a6170b404f 367
nexpaq 1:55a6170b404f 368 exit:
nexpaq 1:55a6170b404f 369 #if defined(MBEDTLS_THREADING_C)
nexpaq 1:55a6170b404f 370 if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
nexpaq 1:55a6170b404f 371 return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
nexpaq 1:55a6170b404f 372 #endif
nexpaq 1:55a6170b404f 373
nexpaq 1:55a6170b404f 374 return( ret );
nexpaq 1:55a6170b404f 375 }
nexpaq 1:55a6170b404f 376
nexpaq 1:55a6170b404f 377 #if defined(MBEDTLS_ENTROPY_NV_SEED)
nexpaq 1:55a6170b404f 378 int mbedtls_entropy_update_nv_seed( mbedtls_entropy_context *ctx )
nexpaq 1:55a6170b404f 379 {
nexpaq 1:55a6170b404f 380 int ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
nexpaq 1:55a6170b404f 381 unsigned char buf[ MBEDTLS_ENTROPY_MAX_SEED_SIZE ];
nexpaq 1:55a6170b404f 382
nexpaq 1:55a6170b404f 383 /* Read new seed and write it to NV */
nexpaq 1:55a6170b404f 384 if( ( ret = mbedtls_entropy_func( ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) ) != 0 )
nexpaq 1:55a6170b404f 385 return( ret );
nexpaq 1:55a6170b404f 386
nexpaq 1:55a6170b404f 387 if( mbedtls_nv_seed_write( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 )
nexpaq 1:55a6170b404f 388 return( MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR );
nexpaq 1:55a6170b404f 389
nexpaq 1:55a6170b404f 390 /* Manually update the remaining stream with a separator value to diverge */
nexpaq 1:55a6170b404f 391 memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
nexpaq 1:55a6170b404f 392 mbedtls_entropy_update_manual( ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE );
nexpaq 1:55a6170b404f 393
nexpaq 1:55a6170b404f 394 return( 0 );
nexpaq 1:55a6170b404f 395 }
nexpaq 1:55a6170b404f 396 #endif /* MBEDTLS_ENTROPY_NV_SEED */
nexpaq 1:55a6170b404f 397
nexpaq 1:55a6170b404f 398 #if defined(MBEDTLS_FS_IO)
nexpaq 1:55a6170b404f 399 int mbedtls_entropy_write_seed_file( mbedtls_entropy_context *ctx, const char *path )
nexpaq 1:55a6170b404f 400 {
nexpaq 1:55a6170b404f 401 int ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
nexpaq 1:55a6170b404f 402 FILE *f;
nexpaq 1:55a6170b404f 403 unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
nexpaq 1:55a6170b404f 404
nexpaq 1:55a6170b404f 405 if( ( f = fopen( path, "wb" ) ) == NULL )
nexpaq 1:55a6170b404f 406 return( MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR );
nexpaq 1:55a6170b404f 407
nexpaq 1:55a6170b404f 408 if( ( ret = mbedtls_entropy_func( ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) ) != 0 )
nexpaq 1:55a6170b404f 409 goto exit;
nexpaq 1:55a6170b404f 410
nexpaq 1:55a6170b404f 411 if( fwrite( buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f ) != MBEDTLS_ENTROPY_BLOCK_SIZE )
nexpaq 1:55a6170b404f 412 {
nexpaq 1:55a6170b404f 413 ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
nexpaq 1:55a6170b404f 414 goto exit;
nexpaq 1:55a6170b404f 415 }
nexpaq 1:55a6170b404f 416
nexpaq 1:55a6170b404f 417 ret = 0;
nexpaq 1:55a6170b404f 418
nexpaq 1:55a6170b404f 419 exit:
nexpaq 1:55a6170b404f 420 fclose( f );
nexpaq 1:55a6170b404f 421 return( ret );
nexpaq 1:55a6170b404f 422 }
nexpaq 1:55a6170b404f 423
nexpaq 1:55a6170b404f 424 int mbedtls_entropy_update_seed_file( mbedtls_entropy_context *ctx, const char *path )
nexpaq 1:55a6170b404f 425 {
nexpaq 1:55a6170b404f 426 FILE *f;
nexpaq 1:55a6170b404f 427 size_t n;
nexpaq 1:55a6170b404f 428 unsigned char buf[ MBEDTLS_ENTROPY_MAX_SEED_SIZE ];
nexpaq 1:55a6170b404f 429
nexpaq 1:55a6170b404f 430 if( ( f = fopen( path, "rb" ) ) == NULL )
nexpaq 1:55a6170b404f 431 return( MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR );
nexpaq 1:55a6170b404f 432
nexpaq 1:55a6170b404f 433 fseek( f, 0, SEEK_END );
nexpaq 1:55a6170b404f 434 n = (size_t) ftell( f );
nexpaq 1:55a6170b404f 435 fseek( f, 0, SEEK_SET );
nexpaq 1:55a6170b404f 436
nexpaq 1:55a6170b404f 437 if( n > MBEDTLS_ENTROPY_MAX_SEED_SIZE )
nexpaq 1:55a6170b404f 438 n = MBEDTLS_ENTROPY_MAX_SEED_SIZE;
nexpaq 1:55a6170b404f 439
nexpaq 1:55a6170b404f 440 if( fread( buf, 1, n, f ) != n )
nexpaq 1:55a6170b404f 441 {
nexpaq 1:55a6170b404f 442 fclose( f );
nexpaq 1:55a6170b404f 443 return( MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR );
nexpaq 1:55a6170b404f 444 }
nexpaq 1:55a6170b404f 445
nexpaq 1:55a6170b404f 446 fclose( f );
nexpaq 1:55a6170b404f 447
nexpaq 1:55a6170b404f 448 mbedtls_entropy_update_manual( ctx, buf, n );
nexpaq 1:55a6170b404f 449
nexpaq 1:55a6170b404f 450 return( mbedtls_entropy_write_seed_file( ctx, path ) );
nexpaq 1:55a6170b404f 451 }
nexpaq 1:55a6170b404f 452 #endif /* MBEDTLS_FS_IO */
nexpaq 1:55a6170b404f 453
nexpaq 1:55a6170b404f 454 #if defined(MBEDTLS_SELF_TEST)
nexpaq 1:55a6170b404f 455 /*
nexpaq 1:55a6170b404f 456 * Dummy source function
nexpaq 1:55a6170b404f 457 */
nexpaq 1:55a6170b404f 458 static int entropy_dummy_source( void *data, unsigned char *output,
nexpaq 1:55a6170b404f 459 size_t len, size_t *olen )
nexpaq 1:55a6170b404f 460 {
nexpaq 1:55a6170b404f 461 ((void) data);
nexpaq 1:55a6170b404f 462
nexpaq 1:55a6170b404f 463 memset( output, 0x2a, len );
nexpaq 1:55a6170b404f 464 *olen = len;
nexpaq 1:55a6170b404f 465
nexpaq 1:55a6170b404f 466 return( 0 );
nexpaq 1:55a6170b404f 467 }
nexpaq 1:55a6170b404f 468
nexpaq 1:55a6170b404f 469 /*
nexpaq 1:55a6170b404f 470 * The actual entropy quality is hard to test, but we can at least
nexpaq 1:55a6170b404f 471 * test that the functions don't cause errors and write the correct
nexpaq 1:55a6170b404f 472 * amount of data to buffers.
nexpaq 1:55a6170b404f 473 */
nexpaq 1:55a6170b404f 474 int mbedtls_entropy_self_test( int verbose )
nexpaq 1:55a6170b404f 475 {
nexpaq 1:55a6170b404f 476 int ret = 0;
nexpaq 1:55a6170b404f 477 mbedtls_entropy_context ctx;
nexpaq 1:55a6170b404f 478 unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
nexpaq 1:55a6170b404f 479 unsigned char acc[MBEDTLS_ENTROPY_BLOCK_SIZE] = { 0 };
nexpaq 1:55a6170b404f 480 size_t i, j;
nexpaq 1:55a6170b404f 481
nexpaq 1:55a6170b404f 482 if( verbose != 0 )
nexpaq 1:55a6170b404f 483 mbedtls_printf( " ENTROPY test: " );
nexpaq 1:55a6170b404f 484
nexpaq 1:55a6170b404f 485 mbedtls_entropy_init( &ctx );
nexpaq 1:55a6170b404f 486
nexpaq 1:55a6170b404f 487 /* First do a gather to make sure we have default sources */
nexpaq 1:55a6170b404f 488 if( ( ret = mbedtls_entropy_gather( &ctx ) ) != 0 )
nexpaq 1:55a6170b404f 489 goto cleanup;
nexpaq 1:55a6170b404f 490
nexpaq 1:55a6170b404f 491 ret = mbedtls_entropy_add_source( &ctx, entropy_dummy_source, NULL, 16,
nexpaq 1:55a6170b404f 492 MBEDTLS_ENTROPY_SOURCE_WEAK );
nexpaq 1:55a6170b404f 493 if( ret != 0 )
nexpaq 1:55a6170b404f 494 goto cleanup;
nexpaq 1:55a6170b404f 495
nexpaq 1:55a6170b404f 496 if( ( ret = mbedtls_entropy_update_manual( &ctx, buf, sizeof buf ) ) != 0 )
nexpaq 1:55a6170b404f 497 goto cleanup;
nexpaq 1:55a6170b404f 498
nexpaq 1:55a6170b404f 499 /*
nexpaq 1:55a6170b404f 500 * To test that mbedtls_entropy_func writes correct number of bytes:
nexpaq 1:55a6170b404f 501 * - use the whole buffer and rely on ASan to detect overruns
nexpaq 1:55a6170b404f 502 * - collect entropy 8 times and OR the result in an accumulator:
nexpaq 1:55a6170b404f 503 * any byte should then be 0 with probably 2^(-64), so requiring
nexpaq 1:55a6170b404f 504 * each of the 32 or 64 bytes to be non-zero has a false failure rate
nexpaq 1:55a6170b404f 505 * of at most 2^(-58) which is acceptable.
nexpaq 1:55a6170b404f 506 */
nexpaq 1:55a6170b404f 507 for( i = 0; i < 8; i++ )
nexpaq 1:55a6170b404f 508 {
nexpaq 1:55a6170b404f 509 if( ( ret = mbedtls_entropy_func( &ctx, buf, sizeof( buf ) ) ) != 0 )
nexpaq 1:55a6170b404f 510 goto cleanup;
nexpaq 1:55a6170b404f 511
nexpaq 1:55a6170b404f 512 for( j = 0; j < sizeof( buf ); j++ )
nexpaq 1:55a6170b404f 513 acc[j] |= buf[j];
nexpaq 1:55a6170b404f 514 }
nexpaq 1:55a6170b404f 515
nexpaq 1:55a6170b404f 516 for( j = 0; j < sizeof( buf ); j++ )
nexpaq 1:55a6170b404f 517 {
nexpaq 1:55a6170b404f 518 if( acc[j] == 0 )
nexpaq 1:55a6170b404f 519 {
nexpaq 1:55a6170b404f 520 ret = 1;
nexpaq 1:55a6170b404f 521 goto cleanup;
nexpaq 1:55a6170b404f 522 }
nexpaq 1:55a6170b404f 523 }
nexpaq 1:55a6170b404f 524
nexpaq 1:55a6170b404f 525 cleanup:
nexpaq 1:55a6170b404f 526 mbedtls_entropy_free( &ctx );
nexpaq 1:55a6170b404f 527
nexpaq 1:55a6170b404f 528 if( verbose != 0 )
nexpaq 1:55a6170b404f 529 {
nexpaq 1:55a6170b404f 530 if( ret != 0 )
nexpaq 1:55a6170b404f 531 mbedtls_printf( "failed\n" );
nexpaq 1:55a6170b404f 532 else
nexpaq 1:55a6170b404f 533 mbedtls_printf( "passed\n" );
nexpaq 1:55a6170b404f 534
nexpaq 1:55a6170b404f 535 mbedtls_printf( "\n" );
nexpaq 1:55a6170b404f 536 }
nexpaq 1:55a6170b404f 537
nexpaq 1:55a6170b404f 538 return( ret != 0 );
nexpaq 1:55a6170b404f 539 }
nexpaq 1:55a6170b404f 540 #endif /* MBEDTLS_SELF_TEST */
nexpaq 1:55a6170b404f 541
nexpaq 1:55a6170b404f 542 #endif /* MBEDTLS_ENTROPY_C */