1 | /*
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2 | * CTR_DRBG implementation based on AES-256 (NIST SP 800-90)
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3 | *
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4 | * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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5 | * SPDX-License-Identifier: Apache-2.0
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6 | *
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7 | * Licensed under the Apache License, Version 2.0 (the "License"); you may
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8 | * not use this file except in compliance with the License.
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9 | * You may obtain a copy of the License at
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10 | *
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11 | * http://www.apache.org/licenses/LICENSE-2.0
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12 | *
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13 | * Unless required by applicable law or agreed to in writing, software
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14 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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15 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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16 | * See the License for the specific language governing permissions and
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17 | * limitations under the License.
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18 | *
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19 | * This file is part of mbed TLS (https://tls.mbed.org)
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20 | */
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21 | /*
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22 | * The NIST SP 800-90 DRBGs are described in the following publication.
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23 | *
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24 | * http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf
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25 | */
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26 |
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27 | #if !defined(MBEDTLS_CONFIG_FILE)
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28 | #include "mbedtls/config.h"
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29 | #else
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30 | #include MBEDTLS_CONFIG_FILE
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31 | #endif
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32 |
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33 | #if defined(MBEDTLS_CTR_DRBG_C)
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34 |
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35 | #include "mbedtls/ctr_drbg.h"
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36 | #include "mbedtls/platform_util.h"
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37 |
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38 | #include <string.h>
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39 |
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40 | #if defined(MBEDTLS_FS_IO)
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41 | #include <stdio.h>
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42 | #endif
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43 |
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44 | #if defined(MBEDTLS_SELF_TEST)
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45 | #if defined(MBEDTLS_PLATFORM_C)
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46 | #include "mbedtls/platform.h"
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47 | #else
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48 | #include <stdio.h>
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49 | #define mbedtls_printf printf
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50 | #endif /* MBEDTLS_PLATFORM_C */
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51 | #endif /* MBEDTLS_SELF_TEST */
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52 |
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53 | /*
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54 | * CTR_DRBG context initialization
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55 | */
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56 | void mbedtls_ctr_drbg_init( mbedtls_ctr_drbg_context *ctx )
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57 | {
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58 | memset( ctx, 0, sizeof( mbedtls_ctr_drbg_context ) );
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59 |
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60 | #if defined(MBEDTLS_THREADING_C)
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61 | mbedtls_mutex_init( &ctx->mutex );
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62 | #endif
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63 | }
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64 |
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65 | /*
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66 | * Non-public function wrapped by mbedtls_ctr_drbg_seed(). Necessary to allow
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67 | * NIST tests to succeed (which require known length fixed entropy)
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68 | */
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69 | /* CTR_DRBG_Instantiate with derivation function (SP 800-90A §10.2.1.3.2)
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70 | * mbedtls_ctr_drbg_seed_entropy_len(ctx, f_entropy, p_entropy,
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71 | * custom, len, entropy_len)
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72 | * implements
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73 | * CTR_DRBG_Instantiate(entropy_input, nonce, personalization_string,
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74 | * security_strength) -> initial_working_state
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75 | * with inputs
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76 | * custom[:len] = nonce || personalization_string
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77 | * where entropy_input comes from f_entropy for entropy_len bytes
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78 | * and with outputs
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79 | * ctx = initial_working_state
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80 | */
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81 | int mbedtls_ctr_drbg_seed_entropy_len(
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82 | mbedtls_ctr_drbg_context *ctx,
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83 | int (*f_entropy)(void *, unsigned char *, size_t),
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84 | void *p_entropy,
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85 | const unsigned char *custom,
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86 | size_t len,
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87 | size_t entropy_len )
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88 | {
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89 | int ret;
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90 | unsigned char key[MBEDTLS_CTR_DRBG_KEYSIZE];
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91 |
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92 | memset( key, 0, MBEDTLS_CTR_DRBG_KEYSIZE );
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93 |
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94 | mbedtls_aes_init( &ctx->aes_ctx );
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95 |
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96 | ctx->f_entropy = f_entropy;
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97 | ctx->p_entropy = p_entropy;
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98 |
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99 | ctx->entropy_len = entropy_len;
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100 | ctx->reseed_interval = MBEDTLS_CTR_DRBG_RESEED_INTERVAL;
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101 |
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102 | /*
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103 | * Initialize with an empty key
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104 | */
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105 | if( ( ret = mbedtls_aes_setkey_enc( &ctx->aes_ctx, key, MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
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106 | {
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107 | return( ret );
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108 | }
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109 |
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110 | if( ( ret = mbedtls_ctr_drbg_reseed( ctx, custom, len ) ) != 0 )
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111 | {
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112 | return( ret );
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113 | }
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114 | return( 0 );
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115 | }
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116 |
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117 | int mbedtls_ctr_drbg_seed( mbedtls_ctr_drbg_context *ctx,
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118 | int (*f_entropy)(void *, unsigned char *, size_t),
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119 | void *p_entropy,
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120 | const unsigned char *custom,
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121 | size_t len )
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122 | {
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123 | return( mbedtls_ctr_drbg_seed_entropy_len( ctx, f_entropy, p_entropy, custom, len,
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124 | MBEDTLS_CTR_DRBG_ENTROPY_LEN ) );
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125 | }
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126 |
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127 | void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx )
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128 | {
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129 | if( ctx == NULL )
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130 | return;
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131 |
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132 | #if defined(MBEDTLS_THREADING_C)
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133 | mbedtls_mutex_free( &ctx->mutex );
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134 | #endif
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135 | mbedtls_aes_free( &ctx->aes_ctx );
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136 | mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ctr_drbg_context ) );
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137 | }
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138 |
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139 | void mbedtls_ctr_drbg_set_prediction_resistance( mbedtls_ctr_drbg_context *ctx, int resistance )
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140 | {
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141 | ctx->prediction_resistance = resistance;
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142 | }
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143 |
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144 | void mbedtls_ctr_drbg_set_entropy_len( mbedtls_ctr_drbg_context *ctx, size_t len )
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145 | {
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146 | ctx->entropy_len = len;
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147 | }
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148 |
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149 | void mbedtls_ctr_drbg_set_reseed_interval( mbedtls_ctr_drbg_context *ctx, int interval )
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150 | {
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151 | ctx->reseed_interval = interval;
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152 | }
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153 |
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154 | static int block_cipher_df( unsigned char *output,
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155 | const unsigned char *data, size_t data_len )
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156 | {
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157 | unsigned char buf[MBEDTLS_CTR_DRBG_MAX_SEED_INPUT + MBEDTLS_CTR_DRBG_BLOCKSIZE + 16];
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158 | unsigned char tmp[MBEDTLS_CTR_DRBG_SEEDLEN];
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159 | unsigned char key[MBEDTLS_CTR_DRBG_KEYSIZE];
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160 | unsigned char chain[MBEDTLS_CTR_DRBG_BLOCKSIZE];
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161 | unsigned char *p, *iv;
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162 | mbedtls_aes_context aes_ctx;
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163 | int ret = 0;
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164 |
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165 | int i, j;
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166 | size_t buf_len, use_len;
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167 |
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168 | if( data_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
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169 | return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
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170 |
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171 | memset( buf, 0, MBEDTLS_CTR_DRBG_MAX_SEED_INPUT + MBEDTLS_CTR_DRBG_BLOCKSIZE + 16 );
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172 | mbedtls_aes_init( &aes_ctx );
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173 |
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174 | /*
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175 | * Construct IV (16 bytes) and S in buffer
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176 | * IV = Counter (in 32-bits) padded to 16 with zeroes
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177 | * S = Length input string (in 32-bits) || Length of output (in 32-bits) ||
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178 | * data || 0x80
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179 | * (Total is padded to a multiple of 16-bytes with zeroes)
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180 | */
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181 | p = buf + MBEDTLS_CTR_DRBG_BLOCKSIZE;
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182 | *p++ = ( data_len >> 24 ) & 0xff;
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183 | *p++ = ( data_len >> 16 ) & 0xff;
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184 | *p++ = ( data_len >> 8 ) & 0xff;
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185 | *p++ = ( data_len ) & 0xff;
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186 | p += 3;
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187 | *p++ = MBEDTLS_CTR_DRBG_SEEDLEN;
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188 | memcpy( p, data, data_len );
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189 | p[data_len] = 0x80;
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190 |
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191 | buf_len = MBEDTLS_CTR_DRBG_BLOCKSIZE + 8 + data_len + 1;
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192 |
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193 | for( i = 0; i < MBEDTLS_CTR_DRBG_KEYSIZE; i++ )
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194 | key[i] = i;
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195 |
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196 | if( ( ret = mbedtls_aes_setkey_enc( &aes_ctx, key, MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
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197 | {
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198 | goto exit;
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199 | }
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200 |
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201 | /*
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202 | * Reduce data to MBEDTLS_CTR_DRBG_SEEDLEN bytes of data
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203 | */
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204 | for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
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205 | {
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206 | p = buf;
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207 | memset( chain, 0, MBEDTLS_CTR_DRBG_BLOCKSIZE );
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208 | use_len = buf_len;
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209 |
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210 | while( use_len > 0 )
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211 | {
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212 | for( i = 0; i < MBEDTLS_CTR_DRBG_BLOCKSIZE; i++ )
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213 | chain[i] ^= p[i];
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214 | p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
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215 | use_len -= ( use_len >= MBEDTLS_CTR_DRBG_BLOCKSIZE ) ?
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216 | MBEDTLS_CTR_DRBG_BLOCKSIZE : use_len;
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217 |
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218 | if( ( ret = mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT, chain, chain ) ) != 0 )
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219 | {
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220 | goto exit;
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221 | }
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222 | }
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223 |
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224 | memcpy( tmp + j, chain, MBEDTLS_CTR_DRBG_BLOCKSIZE );
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225 |
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226 | /*
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227 | * Update IV
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228 | */
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229 | buf[3]++;
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230 | }
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231 |
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232 | /*
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233 | * Do final encryption with reduced data
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234 | */
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235 | if( ( ret = mbedtls_aes_setkey_enc( &aes_ctx, tmp, MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
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236 | {
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237 | goto exit;
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238 | }
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239 | iv = tmp + MBEDTLS_CTR_DRBG_KEYSIZE;
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240 | p = output;
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241 |
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242 | for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
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243 | {
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244 | if( ( ret = mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT, iv, iv ) ) != 0 )
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245 | {
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246 | goto exit;
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247 | }
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248 | memcpy( p, iv, MBEDTLS_CTR_DRBG_BLOCKSIZE );
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249 | p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
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250 | }
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251 | exit:
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252 | mbedtls_aes_free( &aes_ctx );
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253 | /*
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254 | * tidy up the stack
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255 | */
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256 | mbedtls_platform_zeroize( buf, sizeof( buf ) );
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257 | mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
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258 | mbedtls_platform_zeroize( key, sizeof( key ) );
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259 | mbedtls_platform_zeroize( chain, sizeof( chain ) );
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260 | if( 0 != ret )
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261 | {
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262 | /*
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263 | * wipe partial seed from memory
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264 | */
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265 | mbedtls_platform_zeroize( output, MBEDTLS_CTR_DRBG_SEEDLEN );
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266 | }
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267 |
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268 | return( ret );
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269 | }
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270 |
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271 | /* CTR_DRBG_Update (SP 800-90A §10.2.1.2)
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272 | * ctr_drbg_update_internal(ctx, provided_data)
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273 | * implements
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274 | * CTR_DRBG_Update(provided_data, Key, V)
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275 | * with inputs and outputs
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276 | * ctx->aes_ctx = Key
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277 | * ctx->counter = V
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278 | */
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279 | static int ctr_drbg_update_internal( mbedtls_ctr_drbg_context *ctx,
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280 | const unsigned char data[MBEDTLS_CTR_DRBG_SEEDLEN] )
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281 | {
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282 | unsigned char tmp[MBEDTLS_CTR_DRBG_SEEDLEN];
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283 | unsigned char *p = tmp;
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284 | int i, j;
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285 | int ret = 0;
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286 |
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287 | memset( tmp, 0, MBEDTLS_CTR_DRBG_SEEDLEN );
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288 |
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289 | for( j = 0; j < MBEDTLS_CTR_DRBG_SEEDLEN; j += MBEDTLS_CTR_DRBG_BLOCKSIZE )
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290 | {
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291 | /*
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292 | * Increase counter
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293 | */
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294 | for( i = MBEDTLS_CTR_DRBG_BLOCKSIZE; i > 0; i-- )
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295 | if( ++ctx->counter[i - 1] != 0 )
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296 | break;
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297 |
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298 | /*
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299 | * Crypt counter block
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300 | */
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301 | if( ( ret = mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT, ctx->counter, p ) ) != 0 )
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302 | goto exit;
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303 |
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304 | p += MBEDTLS_CTR_DRBG_BLOCKSIZE;
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305 | }
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306 |
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307 | for( i = 0; i < MBEDTLS_CTR_DRBG_SEEDLEN; i++ )
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308 | tmp[i] ^= data[i];
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309 |
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310 | /*
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311 | * Update key and counter
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312 | */
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313 | if( ( ret = mbedtls_aes_setkey_enc( &ctx->aes_ctx, tmp, MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )
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314 | goto exit;
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315 | memcpy( ctx->counter, tmp + MBEDTLS_CTR_DRBG_KEYSIZE, MBEDTLS_CTR_DRBG_BLOCKSIZE );
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316 |
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317 | exit:
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318 | mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
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319 | return( ret );
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320 | }
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321 |
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322 | /* CTR_DRBG_Instantiate with derivation function (SP 800-90A §10.2.1.3.2)
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323 | * mbedtls_ctr_drbg_update(ctx, additional, add_len)
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324 | * implements
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325 | * CTR_DRBG_Instantiate(entropy_input, nonce, personalization_string,
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326 | * security_strength) -> initial_working_state
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327 | * with inputs
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328 | * ctx->counter = all-bits-0
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329 | * ctx->aes_ctx = context from all-bits-0 key
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330 | * additional[:add_len] = entropy_input || nonce || personalization_string
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331 | * and with outputs
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332 | * ctx = initial_working_state
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333 | */
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334 | int mbedtls_ctr_drbg_update_ret( mbedtls_ctr_drbg_context *ctx,
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335 | const unsigned char *additional,
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336 | size_t add_len )
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337 | {
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338 | unsigned char add_input[MBEDTLS_CTR_DRBG_SEEDLEN];
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339 | int ret;
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340 |
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341 | if( add_len == 0 )
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342 | return( 0 );
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343 |
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344 | if( ( ret = block_cipher_df( add_input, additional, add_len ) ) != 0 )
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345 | goto exit;
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346 | if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
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347 | goto exit;
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348 |
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349 | exit:
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350 | mbedtls_platform_zeroize( add_input, sizeof( add_input ) );
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351 | return( ret );
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352 | }
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353 |
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354 | #if !defined(MBEDTLS_DEPRECATED_REMOVED)
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355 | void mbedtls_ctr_drbg_update( mbedtls_ctr_drbg_context *ctx,
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356 | const unsigned char *additional,
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357 | size_t add_len )
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358 | {
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359 | /* MAX_INPUT would be more logical here, but we have to match
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360 | * block_cipher_df()'s limits since we can't propagate errors */
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361 | if( add_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT )
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362 | add_len = MBEDTLS_CTR_DRBG_MAX_SEED_INPUT;
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363 | (void) mbedtls_ctr_drbg_update_ret( ctx, additional, add_len );
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364 | }
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365 | #endif /* MBEDTLS_DEPRECATED_REMOVED */
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366 |
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367 | /* CTR_DRBG_Reseed with derivation function (SP 800-90A §10.2.1.4.2)
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368 | * mbedtls_ctr_drbg_reseed(ctx, additional, len)
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369 | * implements
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370 | * CTR_DRBG_Reseed(working_state, entropy_input, additional_input)
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371 | * -> new_working_state
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372 | * with inputs
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373 | * ctx contains working_state
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374 | * additional[:len] = additional_input
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375 | * and entropy_input comes from calling ctx->f_entropy
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376 | * and with output
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377 | * ctx contains new_working_state
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378 | */
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379 | int mbedtls_ctr_drbg_reseed( mbedtls_ctr_drbg_context *ctx,
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380 | const unsigned char *additional, size_t len )
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381 | {
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382 | unsigned char seed[MBEDTLS_CTR_DRBG_MAX_SEED_INPUT];
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383 | size_t seedlen = 0;
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384 | int ret;
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385 |
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386 | if( ctx->entropy_len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT ||
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387 | len > MBEDTLS_CTR_DRBG_MAX_SEED_INPUT - ctx->entropy_len )
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388 | return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
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389 |
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390 | memset( seed, 0, MBEDTLS_CTR_DRBG_MAX_SEED_INPUT );
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391 |
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392 | /*
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393 | * Gather entropy_len bytes of entropy to seed state
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394 | */
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395 | if( 0 != ctx->f_entropy( ctx->p_entropy, seed,
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396 | ctx->entropy_len ) )
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397 | {
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398 | return( MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED );
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399 | }
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400 |
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401 | seedlen += ctx->entropy_len;
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402 |
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403 | /*
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404 | * Add additional data
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405 | */
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406 | if( additional && len )
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407 | {
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408 | memcpy( seed + seedlen, additional, len );
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409 | seedlen += len;
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410 | }
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411 |
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412 | /*
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413 | * Reduce to 384 bits
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414 | */
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415 | if( ( ret = block_cipher_df( seed, seed, seedlen ) ) != 0 )
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416 | goto exit;
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417 |
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418 | /*
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419 | * Update state
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420 | */
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421 | if( ( ret = ctr_drbg_update_internal( ctx, seed ) ) != 0 )
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422 | goto exit;
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423 | ctx->reseed_counter = 1;
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424 |
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425 | exit:
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426 | mbedtls_platform_zeroize( seed, sizeof( seed ) );
|
---|
427 | return( ret );
|
---|
428 | }
|
---|
429 |
|
---|
430 | /* CTR_DRBG_Generate with derivation function (SP 800-90A §10.2.1.5.2)
|
---|
431 | * mbedtls_ctr_drbg_random_with_add(ctx, output, output_len, additional, add_len)
|
---|
432 | * implements
|
---|
433 | * CTR_DRBG_Reseed(working_state, entropy_input, additional[:add_len])
|
---|
434 | * -> working_state_after_reseed
|
---|
435 | * if required, then
|
---|
436 | * CTR_DRBG_Generate(working_state_after_reseed,
|
---|
437 | * requested_number_of_bits, additional_input)
|
---|
438 | * -> status, returned_bits, new_working_state
|
---|
439 | * with inputs
|
---|
440 | * ctx contains working_state
|
---|
441 | * requested_number_of_bits = 8 * output_len
|
---|
442 | * additional[:add_len] = additional_input
|
---|
443 | * and entropy_input comes from calling ctx->f_entropy
|
---|
444 | * and with outputs
|
---|
445 | * status = SUCCESS (this function does the reseed internally)
|
---|
446 | * returned_bits = output[:output_len]
|
---|
447 | * ctx contains new_working_state
|
---|
448 | */
|
---|
449 | int mbedtls_ctr_drbg_random_with_add( void *p_rng,
|
---|
450 | unsigned char *output, size_t output_len,
|
---|
451 | const unsigned char *additional, size_t add_len )
|
---|
452 | {
|
---|
453 | int ret = 0;
|
---|
454 | mbedtls_ctr_drbg_context *ctx = (mbedtls_ctr_drbg_context *) p_rng;
|
---|
455 | unsigned char add_input[MBEDTLS_CTR_DRBG_SEEDLEN];
|
---|
456 | unsigned char *p = output;
|
---|
457 | unsigned char tmp[MBEDTLS_CTR_DRBG_BLOCKSIZE];
|
---|
458 | int i;
|
---|
459 | size_t use_len;
|
---|
460 |
|
---|
461 | if( output_len > MBEDTLS_CTR_DRBG_MAX_REQUEST )
|
---|
462 | return( MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG );
|
---|
463 |
|
---|
464 | if( add_len > MBEDTLS_CTR_DRBG_MAX_INPUT )
|
---|
465 | return( MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG );
|
---|
466 |
|
---|
467 | memset( add_input, 0, MBEDTLS_CTR_DRBG_SEEDLEN );
|
---|
468 |
|
---|
469 | if( ctx->reseed_counter > ctx->reseed_interval ||
|
---|
470 | ctx->prediction_resistance )
|
---|
471 | {
|
---|
472 | if( ( ret = mbedtls_ctr_drbg_reseed( ctx, additional, add_len ) ) != 0 )
|
---|
473 | {
|
---|
474 | return( ret );
|
---|
475 | }
|
---|
476 | add_len = 0;
|
---|
477 | }
|
---|
478 |
|
---|
479 | if( add_len > 0 )
|
---|
480 | {
|
---|
481 | if( ( ret = block_cipher_df( add_input, additional, add_len ) ) != 0 )
|
---|
482 | goto exit;
|
---|
483 | if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
|
---|
484 | goto exit;
|
---|
485 | }
|
---|
486 |
|
---|
487 | while( output_len > 0 )
|
---|
488 | {
|
---|
489 | /*
|
---|
490 | * Increase counter
|
---|
491 | */
|
---|
492 | for( i = MBEDTLS_CTR_DRBG_BLOCKSIZE; i > 0; i-- )
|
---|
493 | if( ++ctx->counter[i - 1] != 0 )
|
---|
494 | break;
|
---|
495 |
|
---|
496 | /*
|
---|
497 | * Crypt counter block
|
---|
498 | */
|
---|
499 | if( ( ret = mbedtls_aes_crypt_ecb( &ctx->aes_ctx, MBEDTLS_AES_ENCRYPT, ctx->counter, tmp ) ) != 0 )
|
---|
500 | goto exit;
|
---|
501 |
|
---|
502 | use_len = ( output_len > MBEDTLS_CTR_DRBG_BLOCKSIZE ) ? MBEDTLS_CTR_DRBG_BLOCKSIZE :
|
---|
503 | output_len;
|
---|
504 | /*
|
---|
505 | * Copy random block to destination
|
---|
506 | */
|
---|
507 | memcpy( p, tmp, use_len );
|
---|
508 | p += use_len;
|
---|
509 | output_len -= use_len;
|
---|
510 | }
|
---|
511 |
|
---|
512 | if( ( ret = ctr_drbg_update_internal( ctx, add_input ) ) != 0 )
|
---|
513 | goto exit;
|
---|
514 |
|
---|
515 | ctx->reseed_counter++;
|
---|
516 |
|
---|
517 | exit:
|
---|
518 | mbedtls_platform_zeroize( add_input, sizeof( add_input ) );
|
---|
519 | mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
|
---|
520 | return( 0 );
|
---|
521 | }
|
---|
522 |
|
---|
523 | int mbedtls_ctr_drbg_random( void *p_rng, unsigned char *output, size_t output_len )
|
---|
524 | {
|
---|
525 | int ret;
|
---|
526 | mbedtls_ctr_drbg_context *ctx = (mbedtls_ctr_drbg_context *) p_rng;
|
---|
527 |
|
---|
528 | #if defined(MBEDTLS_THREADING_C)
|
---|
529 | if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
|
---|
530 | return( ret );
|
---|
531 | #endif
|
---|
532 |
|
---|
533 | ret = mbedtls_ctr_drbg_random_with_add( ctx, output, output_len, NULL, 0 );
|
---|
534 |
|
---|
535 | #if defined(MBEDTLS_THREADING_C)
|
---|
536 | if( mbedtls_mutex_unlock( &ctx->mutex ) != 0 )
|
---|
537 | return( MBEDTLS_ERR_THREADING_MUTEX_ERROR );
|
---|
538 | #endif
|
---|
539 |
|
---|
540 | return( ret );
|
---|
541 | }
|
---|
542 |
|
---|
543 | #if defined(MBEDTLS_FS_IO)
|
---|
544 | int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path )
|
---|
545 | {
|
---|
546 | int ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
|
---|
547 | FILE *f;
|
---|
548 | unsigned char buf[ MBEDTLS_CTR_DRBG_MAX_INPUT ];
|
---|
549 |
|
---|
550 | if( ( f = fopen( path, "wb" ) ) == NULL )
|
---|
551 | return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
|
---|
552 |
|
---|
553 | if( ( ret = mbedtls_ctr_drbg_random( ctx, buf, MBEDTLS_CTR_DRBG_MAX_INPUT ) ) != 0 )
|
---|
554 | goto exit;
|
---|
555 |
|
---|
556 | if( fwrite( buf, 1, MBEDTLS_CTR_DRBG_MAX_INPUT, f ) != MBEDTLS_CTR_DRBG_MAX_INPUT )
|
---|
557 | ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
|
---|
558 | else
|
---|
559 | ret = 0;
|
---|
560 |
|
---|
561 | exit:
|
---|
562 | mbedtls_platform_zeroize( buf, sizeof( buf ) );
|
---|
563 |
|
---|
564 | fclose( f );
|
---|
565 | return( ret );
|
---|
566 | }
|
---|
567 |
|
---|
568 | int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path )
|
---|
569 | {
|
---|
570 | int ret = 0;
|
---|
571 | FILE *f = NULL;
|
---|
572 | size_t n;
|
---|
573 | unsigned char buf[ MBEDTLS_CTR_DRBG_MAX_INPUT ];
|
---|
574 | unsigned char c;
|
---|
575 |
|
---|
576 | if( ( f = fopen( path, "rb" ) ) == NULL )
|
---|
577 | return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
|
---|
578 |
|
---|
579 | n = fread( buf, 1, sizeof( buf ), f );
|
---|
580 | if( fread( &c, 1, 1, f ) != 0 )
|
---|
581 | {
|
---|
582 | ret = MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG;
|
---|
583 | goto exit;
|
---|
584 | }
|
---|
585 | if( n == 0 || ferror( f ) )
|
---|
586 | {
|
---|
587 | ret = MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR;
|
---|
588 | goto exit;
|
---|
589 | }
|
---|
590 | fclose( f );
|
---|
591 | f = NULL;
|
---|
592 |
|
---|
593 | ret = mbedtls_ctr_drbg_update_ret( ctx, buf, n );
|
---|
594 |
|
---|
595 | exit:
|
---|
596 | mbedtls_platform_zeroize( buf, sizeof( buf ) );
|
---|
597 | if( f != NULL )
|
---|
598 | fclose( f );
|
---|
599 | if( ret != 0 )
|
---|
600 | return( ret );
|
---|
601 | return( mbedtls_ctr_drbg_write_seed_file( ctx, path ) );
|
---|
602 | }
|
---|
603 | #endif /* MBEDTLS_FS_IO */
|
---|
604 |
|
---|
605 | #if defined(MBEDTLS_SELF_TEST)
|
---|
606 |
|
---|
607 | static const unsigned char entropy_source_pr[96] =
|
---|
608 | { 0xc1, 0x80, 0x81, 0xa6, 0x5d, 0x44, 0x02, 0x16,
|
---|
609 | 0x19, 0xb3, 0xf1, 0x80, 0xb1, 0xc9, 0x20, 0x02,
|
---|
610 | 0x6a, 0x54, 0x6f, 0x0c, 0x70, 0x81, 0x49, 0x8b,
|
---|
611 | 0x6e, 0xa6, 0x62, 0x52, 0x6d, 0x51, 0xb1, 0xcb,
|
---|
612 | 0x58, 0x3b, 0xfa, 0xd5, 0x37, 0x5f, 0xfb, 0xc9,
|
---|
613 | 0xff, 0x46, 0xd2, 0x19, 0xc7, 0x22, 0x3e, 0x95,
|
---|
614 | 0x45, 0x9d, 0x82, 0xe1, 0xe7, 0x22, 0x9f, 0x63,
|
---|
615 | 0x31, 0x69, 0xd2, 0x6b, 0x57, 0x47, 0x4f, 0xa3,
|
---|
616 | 0x37, 0xc9, 0x98, 0x1c, 0x0b, 0xfb, 0x91, 0x31,
|
---|
617 | 0x4d, 0x55, 0xb9, 0xe9, 0x1c, 0x5a, 0x5e, 0xe4,
|
---|
618 | 0x93, 0x92, 0xcf, 0xc5, 0x23, 0x12, 0xd5, 0x56,
|
---|
619 | 0x2c, 0x4a, 0x6e, 0xff, 0xdc, 0x10, 0xd0, 0x68 };
|
---|
620 |
|
---|
621 | static const unsigned char entropy_source_nopr[64] =
|
---|
622 | { 0x5a, 0x19, 0x4d, 0x5e, 0x2b, 0x31, 0x58, 0x14,
|
---|
623 | 0x54, 0xde, 0xf6, 0x75, 0xfb, 0x79, 0x58, 0xfe,
|
---|
624 | 0xc7, 0xdb, 0x87, 0x3e, 0x56, 0x89, 0xfc, 0x9d,
|
---|
625 | 0x03, 0x21, 0x7c, 0x68, 0xd8, 0x03, 0x38, 0x20,
|
---|
626 | 0xf9, 0xe6, 0x5e, 0x04, 0xd8, 0x56, 0xf3, 0xa9,
|
---|
627 | 0xc4, 0x4a, 0x4c, 0xbd, 0xc1, 0xd0, 0x08, 0x46,
|
---|
628 | 0xf5, 0x98, 0x3d, 0x77, 0x1c, 0x1b, 0x13, 0x7e,
|
---|
629 | 0x4e, 0x0f, 0x9d, 0x8e, 0xf4, 0x09, 0xf9, 0x2e };
|
---|
630 |
|
---|
631 | static const unsigned char nonce_pers_pr[16] =
|
---|
632 | { 0xd2, 0x54, 0xfc, 0xff, 0x02, 0x1e, 0x69, 0xd2,
|
---|
633 | 0x29, 0xc9, 0xcf, 0xad, 0x85, 0xfa, 0x48, 0x6c };
|
---|
634 |
|
---|
635 | static const unsigned char nonce_pers_nopr[16] =
|
---|
636 | { 0x1b, 0x54, 0xb8, 0xff, 0x06, 0x42, 0xbf, 0xf5,
|
---|
637 | 0x21, 0xf1, 0x5c, 0x1c, 0x0b, 0x66, 0x5f, 0x3f };
|
---|
638 |
|
---|
639 | static const unsigned char result_pr[16] =
|
---|
640 | { 0x34, 0x01, 0x16, 0x56, 0xb4, 0x29, 0x00, 0x8f,
|
---|
641 | 0x35, 0x63, 0xec, 0xb5, 0xf2, 0x59, 0x07, 0x23 };
|
---|
642 |
|
---|
643 | static const unsigned char result_nopr[16] =
|
---|
644 | { 0xa0, 0x54, 0x30, 0x3d, 0x8a, 0x7e, 0xa9, 0x88,
|
---|
645 | 0x9d, 0x90, 0x3e, 0x07, 0x7c, 0x6f, 0x21, 0x8f };
|
---|
646 |
|
---|
647 | static size_t test_offset;
|
---|
648 | static int ctr_drbg_self_test_entropy( void *data, unsigned char *buf,
|
---|
649 | size_t len )
|
---|
650 | {
|
---|
651 | const unsigned char *p = data;
|
---|
652 | memcpy( buf, p + test_offset, len );
|
---|
653 | test_offset += len;
|
---|
654 | return( 0 );
|
---|
655 | }
|
---|
656 |
|
---|
657 | #define CHK( c ) if( (c) != 0 ) \
|
---|
658 | { \
|
---|
659 | if( verbose != 0 ) \
|
---|
660 | mbedtls_printf( "failed\n" ); \
|
---|
661 | return( 1 ); \
|
---|
662 | }
|
---|
663 |
|
---|
664 | /*
|
---|
665 | * Checkup routine
|
---|
666 | */
|
---|
667 | int mbedtls_ctr_drbg_self_test( int verbose )
|
---|
668 | {
|
---|
669 | mbedtls_ctr_drbg_context ctx;
|
---|
670 | unsigned char buf[16];
|
---|
671 |
|
---|
672 | mbedtls_ctr_drbg_init( &ctx );
|
---|
673 |
|
---|
674 | /*
|
---|
675 | * Based on a NIST CTR_DRBG test vector (PR = True)
|
---|
676 | */
|
---|
677 | if( verbose != 0 )
|
---|
678 | mbedtls_printf( " CTR_DRBG (PR = TRUE) : " );
|
---|
679 |
|
---|
680 | test_offset = 0;
|
---|
681 | CHK( mbedtls_ctr_drbg_seed_entropy_len( &ctx, ctr_drbg_self_test_entropy,
|
---|
682 | (void *) entropy_source_pr, nonce_pers_pr, 16, 32 ) );
|
---|
683 | mbedtls_ctr_drbg_set_prediction_resistance( &ctx, MBEDTLS_CTR_DRBG_PR_ON );
|
---|
684 | CHK( mbedtls_ctr_drbg_random( &ctx, buf, MBEDTLS_CTR_DRBG_BLOCKSIZE ) );
|
---|
685 | CHK( mbedtls_ctr_drbg_random( &ctx, buf, MBEDTLS_CTR_DRBG_BLOCKSIZE ) );
|
---|
686 | CHK( memcmp( buf, result_pr, MBEDTLS_CTR_DRBG_BLOCKSIZE ) );
|
---|
687 |
|
---|
688 | mbedtls_ctr_drbg_free( &ctx );
|
---|
689 |
|
---|
690 | if( verbose != 0 )
|
---|
691 | mbedtls_printf( "passed\n" );
|
---|
692 |
|
---|
693 | /*
|
---|
694 | * Based on a NIST CTR_DRBG test vector (PR = FALSE)
|
---|
695 | */
|
---|
696 | if( verbose != 0 )
|
---|
697 | mbedtls_printf( " CTR_DRBG (PR = FALSE): " );
|
---|
698 |
|
---|
699 | mbedtls_ctr_drbg_init( &ctx );
|
---|
700 |
|
---|
701 | test_offset = 0;
|
---|
702 | CHK( mbedtls_ctr_drbg_seed_entropy_len( &ctx, ctr_drbg_self_test_entropy,
|
---|
703 | (void *) entropy_source_nopr, nonce_pers_nopr, 16, 32 ) );
|
---|
704 | CHK( mbedtls_ctr_drbg_random( &ctx, buf, 16 ) );
|
---|
705 | CHK( mbedtls_ctr_drbg_reseed( &ctx, NULL, 0 ) );
|
---|
706 | CHK( mbedtls_ctr_drbg_random( &ctx, buf, 16 ) );
|
---|
707 | CHK( memcmp( buf, result_nopr, 16 ) );
|
---|
708 |
|
---|
709 | mbedtls_ctr_drbg_free( &ctx );
|
---|
710 |
|
---|
711 | if( verbose != 0 )
|
---|
712 | mbedtls_printf( "passed\n" );
|
---|
713 |
|
---|
714 | if( verbose != 0 )
|
---|
715 | mbedtls_printf( "\n" );
|
---|
716 |
|
---|
717 | return( 0 );
|
---|
718 | }
|
---|
719 | #endif /* MBEDTLS_SELF_TEST */
|
---|
720 |
|
---|
721 | #endif /* MBEDTLS_CTR_DRBG_C */
|
---|