Kev Mann / mbed-dev-OS5_10_4

RTC auf true

features/mbedtls/src/ccm.c@0:38ceb79fef03, 2018-11-28 (annotated)

Committer:
kevman
Date:
Wed Nov 28 15:10:15 2018 +0000
Revision:
0:38ceb79fef03
RTC modified

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kevman 0:38ceb79fef03 1 /*
kevman 0:38ceb79fef03 2 * NIST SP800-38C compliant CCM implementation
kevman 0:38ceb79fef03 3 *
kevman 0:38ceb79fef03 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
kevman 0:38ceb79fef03 5 * SPDX-License-Identifier: Apache-2.0
kevman 0:38ceb79fef03 6 *
kevman 0:38ceb79fef03 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
kevman 0:38ceb79fef03 8 * not use this file except in compliance with the License.
kevman 0:38ceb79fef03 9 * You may obtain a copy of the License at
kevman 0:38ceb79fef03 10 *
kevman 0:38ceb79fef03 11 * http://www.apache.org/licenses/LICENSE-2.0
kevman 0:38ceb79fef03 12 *
kevman 0:38ceb79fef03 13 * Unless required by applicable law or agreed to in writing, software
kevman 0:38ceb79fef03 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
kevman 0:38ceb79fef03 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
kevman 0:38ceb79fef03 16 * See the License for the specific language governing permissions and
kevman 0:38ceb79fef03 17 * limitations under the License.
kevman 0:38ceb79fef03 18 *
kevman 0:38ceb79fef03 19 * This file is part of mbed TLS (https://tls.mbed.org)
kevman 0:38ceb79fef03 20 */
kevman 0:38ceb79fef03 21
kevman 0:38ceb79fef03 22 /*
kevman 0:38ceb79fef03 23 * Definition of CCM:
kevman 0:38ceb79fef03 24 * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
kevman 0:38ceb79fef03 25 * RFC 3610 "Counter with CBC-MAC (CCM)"
kevman 0:38ceb79fef03 26 *
kevman 0:38ceb79fef03 27 * Related:
kevman 0:38ceb79fef03 28 * RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
kevman 0:38ceb79fef03 29 */
kevman 0:38ceb79fef03 30
kevman 0:38ceb79fef03 31 #if !defined(MBEDTLS_CONFIG_FILE)
kevman 0:38ceb79fef03 32 #include "mbedtls/config.h"
kevman 0:38ceb79fef03 33 #else
kevman 0:38ceb79fef03 34 #include MBEDTLS_CONFIG_FILE
kevman 0:38ceb79fef03 35 #endif
kevman 0:38ceb79fef03 36
kevman 0:38ceb79fef03 37 #if defined(MBEDTLS_CCM_C)
kevman 0:38ceb79fef03 38
kevman 0:38ceb79fef03 39 #include "mbedtls/ccm.h"
kevman 0:38ceb79fef03 40 #include "mbedtls/platform_util.h"
kevman 0:38ceb79fef03 41
kevman 0:38ceb79fef03 42 #include <string.h>
kevman 0:38ceb79fef03 43
kevman 0:38ceb79fef03 44 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
kevman 0:38ceb79fef03 45 #if defined(MBEDTLS_PLATFORM_C)
kevman 0:38ceb79fef03 46 #include "mbedtls/platform.h"
kevman 0:38ceb79fef03 47 #else
kevman 0:38ceb79fef03 48 #include <stdio.h>
kevman 0:38ceb79fef03 49 #define mbedtls_printf printf
kevman 0:38ceb79fef03 50 #endif /* MBEDTLS_PLATFORM_C */
kevman 0:38ceb79fef03 51 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
kevman 0:38ceb79fef03 52
kevman 0:38ceb79fef03 53 #if !defined(MBEDTLS_CCM_ALT)
kevman 0:38ceb79fef03 54
kevman 0:38ceb79fef03 55 #define CCM_ENCRYPT 0
kevman 0:38ceb79fef03 56 #define CCM_DECRYPT 1
kevman 0:38ceb79fef03 57
kevman 0:38ceb79fef03 58 /*
kevman 0:38ceb79fef03 59 * Initialize context
kevman 0:38ceb79fef03 60 */
kevman 0:38ceb79fef03 61 void mbedtls_ccm_init( mbedtls_ccm_context *ctx )
kevman 0:38ceb79fef03 62 {
kevman 0:38ceb79fef03 63 memset( ctx, 0, sizeof( mbedtls_ccm_context ) );
kevman 0:38ceb79fef03 64 }
kevman 0:38ceb79fef03 65
kevman 0:38ceb79fef03 66 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
kevman 0:38ceb79fef03 67 mbedtls_cipher_id_t cipher,
kevman 0:38ceb79fef03 68 const unsigned char *key,
kevman 0:38ceb79fef03 69 unsigned int keybits )
kevman 0:38ceb79fef03 70 {
kevman 0:38ceb79fef03 71 int ret;
kevman 0:38ceb79fef03 72 const mbedtls_cipher_info_t *cipher_info;
kevman 0:38ceb79fef03 73
kevman 0:38ceb79fef03 74 cipher_info = mbedtls_cipher_info_from_values( cipher, keybits, MBEDTLS_MODE_ECB );
kevman 0:38ceb79fef03 75 if( cipher_info == NULL )
kevman 0:38ceb79fef03 76 return( MBEDTLS_ERR_CCM_BAD_INPUT );
kevman 0:38ceb79fef03 77
kevman 0:38ceb79fef03 78 if( cipher_info->block_size != 16 )
kevman 0:38ceb79fef03 79 return( MBEDTLS_ERR_CCM_BAD_INPUT );
kevman 0:38ceb79fef03 80
kevman 0:38ceb79fef03 81 mbedtls_cipher_free( &ctx->cipher_ctx );
kevman 0:38ceb79fef03 82
kevman 0:38ceb79fef03 83 if( ( ret = mbedtls_cipher_setup( &ctx->cipher_ctx, cipher_info ) ) != 0 )
kevman 0:38ceb79fef03 84 return( ret );
kevman 0:38ceb79fef03 85
kevman 0:38ceb79fef03 86 if( ( ret = mbedtls_cipher_setkey( &ctx->cipher_ctx, key, keybits,
kevman 0:38ceb79fef03 87 MBEDTLS_ENCRYPT ) ) != 0 )
kevman 0:38ceb79fef03 88 {
kevman 0:38ceb79fef03 89 return( ret );
kevman 0:38ceb79fef03 90 }
kevman 0:38ceb79fef03 91
kevman 0:38ceb79fef03 92 return( 0 );
kevman 0:38ceb79fef03 93 }
kevman 0:38ceb79fef03 94
kevman 0:38ceb79fef03 95 /*
kevman 0:38ceb79fef03 96 * Free context
kevman 0:38ceb79fef03 97 */
kevman 0:38ceb79fef03 98 void mbedtls_ccm_free( mbedtls_ccm_context *ctx )
kevman 0:38ceb79fef03 99 {
kevman 0:38ceb79fef03 100 mbedtls_cipher_free( &ctx->cipher_ctx );
kevman 0:38ceb79fef03 101 mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ccm_context ) );
kevman 0:38ceb79fef03 102 }
kevman 0:38ceb79fef03 103
kevman 0:38ceb79fef03 104 /*
kevman 0:38ceb79fef03 105 * Macros for common operations.
kevman 0:38ceb79fef03 106 * Results in smaller compiled code than static inline functions.
kevman 0:38ceb79fef03 107 */
kevman 0:38ceb79fef03 108
kevman 0:38ceb79fef03 109 /*
kevman 0:38ceb79fef03 110 * Update the CBC-MAC state in y using a block in b
kevman 0:38ceb79fef03 111 * (Always using b as the source helps the compiler optimise a bit better.)
kevman 0:38ceb79fef03 112 */
kevman 0:38ceb79fef03 113 #define UPDATE_CBC_MAC \
kevman 0:38ceb79fef03 114 for( i = 0; i < 16; i++ ) \
kevman 0:38ceb79fef03 115 y[i] ^= b[i]; \
kevman 0:38ceb79fef03 116 \
kevman 0:38ceb79fef03 117 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, y, 16, y, &olen ) ) != 0 ) \
kevman 0:38ceb79fef03 118 return( ret );
kevman 0:38ceb79fef03 119
kevman 0:38ceb79fef03 120 /*
kevman 0:38ceb79fef03 121 * Encrypt or decrypt a partial block with CTR
kevman 0:38ceb79fef03 122 * Warning: using b for temporary storage! src and dst must not be b!
kevman 0:38ceb79fef03 123 * This avoids allocating one more 16 bytes buffer while allowing src == dst.
kevman 0:38ceb79fef03 124 */
kevman 0:38ceb79fef03 125 #define CTR_CRYPT( dst, src, len ) \
kevman 0:38ceb79fef03 126 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, ctr, 16, b, &olen ) ) != 0 ) \
kevman 0:38ceb79fef03 127 return( ret ); \
kevman 0:38ceb79fef03 128 \
kevman 0:38ceb79fef03 129 for( i = 0; i < len; i++ ) \
kevman 0:38ceb79fef03 130 dst[i] = src[i] ^ b[i];
kevman 0:38ceb79fef03 131
kevman 0:38ceb79fef03 132 /*
kevman 0:38ceb79fef03 133 * Authenticated encryption or decryption
kevman 0:38ceb79fef03 134 */
kevman 0:38ceb79fef03 135 static int ccm_auth_crypt( mbedtls_ccm_context *ctx, int mode, size_t length,
kevman 0:38ceb79fef03 136 const unsigned char *iv, size_t iv_len,
kevman 0:38ceb79fef03 137 const unsigned char *add, size_t add_len,
kevman 0:38ceb79fef03 138 const unsigned char *input, unsigned char *output,
kevman 0:38ceb79fef03 139 unsigned char *tag, size_t tag_len )
kevman 0:38ceb79fef03 140 {
kevman 0:38ceb79fef03 141 int ret;
kevman 0:38ceb79fef03 142 unsigned char i;
kevman 0:38ceb79fef03 143 unsigned char q;
kevman 0:38ceb79fef03 144 size_t len_left, olen;
kevman 0:38ceb79fef03 145 unsigned char b[16];
kevman 0:38ceb79fef03 146 unsigned char y[16];
kevman 0:38ceb79fef03 147 unsigned char ctr[16];
kevman 0:38ceb79fef03 148 const unsigned char *src;
kevman 0:38ceb79fef03 149 unsigned char *dst;
kevman 0:38ceb79fef03 150
kevman 0:38ceb79fef03 151 /*
kevman 0:38ceb79fef03 152 * Check length requirements: SP800-38C A.1
kevman 0:38ceb79fef03 153 * Additional requirement: a < 2^16 - 2^8 to simplify the code.
kevman 0:38ceb79fef03 154 * 'length' checked later (when writing it to the first block)
kevman 0:38ceb79fef03 155 *
kevman 0:38ceb79fef03 156 * Also, loosen the requirements to enable support for CCM* (IEEE 802.15.4).
kevman 0:38ceb79fef03 157 */
kevman 0:38ceb79fef03 158 if( tag_len == 2 || tag_len > 16 || tag_len % 2 != 0 )
kevman 0:38ceb79fef03 159 return( MBEDTLS_ERR_CCM_BAD_INPUT );
kevman 0:38ceb79fef03 160
kevman 0:38ceb79fef03 161 /* Also implies q is within bounds */
kevman 0:38ceb79fef03 162 if( iv_len < 7 || iv_len > 13 )
kevman 0:38ceb79fef03 163 return( MBEDTLS_ERR_CCM_BAD_INPUT );
kevman 0:38ceb79fef03 164
kevman 0:38ceb79fef03 165 if( add_len > 0xFF00 )
kevman 0:38ceb79fef03 166 return( MBEDTLS_ERR_CCM_BAD_INPUT );
kevman 0:38ceb79fef03 167
kevman 0:38ceb79fef03 168 q = 16 - 1 - (unsigned char) iv_len;
kevman 0:38ceb79fef03 169
kevman 0:38ceb79fef03 170 /*
kevman 0:38ceb79fef03 171 * First block B_0:
kevman 0:38ceb79fef03 172 * 0 .. 0 flags
kevman 0:38ceb79fef03 173 * 1 .. iv_len nonce (aka iv)
kevman 0:38ceb79fef03 174 * iv_len+1 .. 15 length
kevman 0:38ceb79fef03 175 *
kevman 0:38ceb79fef03 176 * With flags as (bits):
kevman 0:38ceb79fef03 177 * 7 0
kevman 0:38ceb79fef03 178 * 6 add present?
kevman 0:38ceb79fef03 179 * 5 .. 3 (t - 2) / 2
kevman 0:38ceb79fef03 180 * 2 .. 0 q - 1
kevman 0:38ceb79fef03 181 */
kevman 0:38ceb79fef03 182 b[0] = 0;
kevman 0:38ceb79fef03 183 b[0] |= ( add_len > 0 ) << 6;
kevman 0:38ceb79fef03 184 b[0] |= ( ( tag_len - 2 ) / 2 ) << 3;
kevman 0:38ceb79fef03 185 b[0] |= q - 1;
kevman 0:38ceb79fef03 186
kevman 0:38ceb79fef03 187 memcpy( b + 1, iv, iv_len );
kevman 0:38ceb79fef03 188
kevman 0:38ceb79fef03 189 for( i = 0, len_left = length; i < q; i++, len_left >>= 8 )
kevman 0:38ceb79fef03 190 b[15-i] = (unsigned char)( len_left & 0xFF );
kevman 0:38ceb79fef03 191
kevman 0:38ceb79fef03 192 if( len_left > 0 )
kevman 0:38ceb79fef03 193 return( MBEDTLS_ERR_CCM_BAD_INPUT );
kevman 0:38ceb79fef03 194
kevman 0:38ceb79fef03 195
kevman 0:38ceb79fef03 196 /* Start CBC-MAC with first block */
kevman 0:38ceb79fef03 197 memset( y, 0, 16 );
kevman 0:38ceb79fef03 198 UPDATE_CBC_MAC;
kevman 0:38ceb79fef03 199
kevman 0:38ceb79fef03 200 /*
kevman 0:38ceb79fef03 201 * If there is additional data, update CBC-MAC with
kevman 0:38ceb79fef03 202 * add_len, add, 0 (padding to a block boundary)
kevman 0:38ceb79fef03 203 */
kevman 0:38ceb79fef03 204 if( add_len > 0 )
kevman 0:38ceb79fef03 205 {
kevman 0:38ceb79fef03 206 size_t use_len;
kevman 0:38ceb79fef03 207 len_left = add_len;
kevman 0:38ceb79fef03 208 src = add;
kevman 0:38ceb79fef03 209
kevman 0:38ceb79fef03 210 memset( b, 0, 16 );
kevman 0:38ceb79fef03 211 b[0] = (unsigned char)( ( add_len >> 8 ) & 0xFF );
kevman 0:38ceb79fef03 212 b[1] = (unsigned char)( ( add_len ) & 0xFF );
kevman 0:38ceb79fef03 213
kevman 0:38ceb79fef03 214 use_len = len_left < 16 - 2 ? len_left : 16 - 2;
kevman 0:38ceb79fef03 215 memcpy( b + 2, src, use_len );
kevman 0:38ceb79fef03 216 len_left -= use_len;
kevman 0:38ceb79fef03 217 src += use_len;
kevman 0:38ceb79fef03 218
kevman 0:38ceb79fef03 219 UPDATE_CBC_MAC;
kevman 0:38ceb79fef03 220
kevman 0:38ceb79fef03 221 while( len_left > 0 )
kevman 0:38ceb79fef03 222 {
kevman 0:38ceb79fef03 223 use_len = len_left > 16 ? 16 : len_left;
kevman 0:38ceb79fef03 224
kevman 0:38ceb79fef03 225 memset( b, 0, 16 );
kevman 0:38ceb79fef03 226 memcpy( b, src, use_len );
kevman 0:38ceb79fef03 227 UPDATE_CBC_MAC;
kevman 0:38ceb79fef03 228
kevman 0:38ceb79fef03 229 len_left -= use_len;
kevman 0:38ceb79fef03 230 src += use_len;
kevman 0:38ceb79fef03 231 }
kevman 0:38ceb79fef03 232 }
kevman 0:38ceb79fef03 233
kevman 0:38ceb79fef03 234 /*
kevman 0:38ceb79fef03 235 * Prepare counter block for encryption:
kevman 0:38ceb79fef03 236 * 0 .. 0 flags
kevman 0:38ceb79fef03 237 * 1 .. iv_len nonce (aka iv)
kevman 0:38ceb79fef03 238 * iv_len+1 .. 15 counter (initially 1)
kevman 0:38ceb79fef03 239 *
kevman 0:38ceb79fef03 240 * With flags as (bits):
kevman 0:38ceb79fef03 241 * 7 .. 3 0
kevman 0:38ceb79fef03 242 * 2 .. 0 q - 1
kevman 0:38ceb79fef03 243 */
kevman 0:38ceb79fef03 244 ctr[0] = q - 1;
kevman 0:38ceb79fef03 245 memcpy( ctr + 1, iv, iv_len );
kevman 0:38ceb79fef03 246 memset( ctr + 1 + iv_len, 0, q );
kevman 0:38ceb79fef03 247 ctr[15] = 1;
kevman 0:38ceb79fef03 248
kevman 0:38ceb79fef03 249 /*
kevman 0:38ceb79fef03 250 * Authenticate and {en,de}crypt the message.
kevman 0:38ceb79fef03 251 *
kevman 0:38ceb79fef03 252 * The only difference between encryption and decryption is
kevman 0:38ceb79fef03 253 * the respective order of authentication and {en,de}cryption.
kevman 0:38ceb79fef03 254 */
kevman 0:38ceb79fef03 255 len_left = length;
kevman 0:38ceb79fef03 256 src = input;
kevman 0:38ceb79fef03 257 dst = output;
kevman 0:38ceb79fef03 258
kevman 0:38ceb79fef03 259 while( len_left > 0 )
kevman 0:38ceb79fef03 260 {
kevman 0:38ceb79fef03 261 size_t use_len = len_left > 16 ? 16 : len_left;
kevman 0:38ceb79fef03 262
kevman 0:38ceb79fef03 263 if( mode == CCM_ENCRYPT )
kevman 0:38ceb79fef03 264 {
kevman 0:38ceb79fef03 265 memset( b, 0, 16 );
kevman 0:38ceb79fef03 266 memcpy( b, src, use_len );
kevman 0:38ceb79fef03 267 UPDATE_CBC_MAC;
kevman 0:38ceb79fef03 268 }
kevman 0:38ceb79fef03 269
kevman 0:38ceb79fef03 270 CTR_CRYPT( dst, src, use_len );
kevman 0:38ceb79fef03 271
kevman 0:38ceb79fef03 272 if( mode == CCM_DECRYPT )
kevman 0:38ceb79fef03 273 {
kevman 0:38ceb79fef03 274 memset( b, 0, 16 );
kevman 0:38ceb79fef03 275 memcpy( b, dst, use_len );
kevman 0:38ceb79fef03 276 UPDATE_CBC_MAC;
kevman 0:38ceb79fef03 277 }
kevman 0:38ceb79fef03 278
kevman 0:38ceb79fef03 279 dst += use_len;
kevman 0:38ceb79fef03 280 src += use_len;
kevman 0:38ceb79fef03 281 len_left -= use_len;
kevman 0:38ceb79fef03 282
kevman 0:38ceb79fef03 283 /*
kevman 0:38ceb79fef03 284 * Increment counter.
kevman 0:38ceb79fef03 285 * No need to check for overflow thanks to the length check above.
kevman 0:38ceb79fef03 286 */
kevman 0:38ceb79fef03 287 for( i = 0; i < q; i++ )
kevman 0:38ceb79fef03 288 if( ++ctr[15-i] != 0 )
kevman 0:38ceb79fef03 289 break;
kevman 0:38ceb79fef03 290 }
kevman 0:38ceb79fef03 291
kevman 0:38ceb79fef03 292 /*
kevman 0:38ceb79fef03 293 * Authentication: reset counter and crypt/mask internal tag
kevman 0:38ceb79fef03 294 */
kevman 0:38ceb79fef03 295 for( i = 0; i < q; i++ )
kevman 0:38ceb79fef03 296 ctr[15-i] = 0;
kevman 0:38ceb79fef03 297
kevman 0:38ceb79fef03 298 CTR_CRYPT( y, y, 16 );
kevman 0:38ceb79fef03 299 memcpy( tag, y, tag_len );
kevman 0:38ceb79fef03 300
kevman 0:38ceb79fef03 301 return( 0 );
kevman 0:38ceb79fef03 302 }
kevman 0:38ceb79fef03 303
kevman 0:38ceb79fef03 304 /*
kevman 0:38ceb79fef03 305 * Authenticated encryption
kevman 0:38ceb79fef03 306 */
kevman 0:38ceb79fef03 307 int mbedtls_ccm_star_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
kevman 0:38ceb79fef03 308 const unsigned char *iv, size_t iv_len,
kevman 0:38ceb79fef03 309 const unsigned char *add, size_t add_len,
kevman 0:38ceb79fef03 310 const unsigned char *input, unsigned char *output,
kevman 0:38ceb79fef03 311 unsigned char *tag, size_t tag_len )
kevman 0:38ceb79fef03 312 {
kevman 0:38ceb79fef03 313 return( ccm_auth_crypt( ctx, CCM_ENCRYPT, length, iv, iv_len,
kevman 0:38ceb79fef03 314 add, add_len, input, output, tag, tag_len ) );
kevman 0:38ceb79fef03 315 }
kevman 0:38ceb79fef03 316
kevman 0:38ceb79fef03 317 int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
kevman 0:38ceb79fef03 318 const unsigned char *iv, size_t iv_len,
kevman 0:38ceb79fef03 319 const unsigned char *add, size_t add_len,
kevman 0:38ceb79fef03 320 const unsigned char *input, unsigned char *output,
kevman 0:38ceb79fef03 321 unsigned char *tag, size_t tag_len )
kevman 0:38ceb79fef03 322 {
kevman 0:38ceb79fef03 323 if( tag_len == 0 )
kevman 0:38ceb79fef03 324 return( MBEDTLS_ERR_CCM_BAD_INPUT );
kevman 0:38ceb79fef03 325
kevman 0:38ceb79fef03 326 return( mbedtls_ccm_star_encrypt_and_tag( ctx, length, iv, iv_len, add,
kevman 0:38ceb79fef03 327 add_len, input, output, tag, tag_len ) );
kevman 0:38ceb79fef03 328 }
kevman 0:38ceb79fef03 329
kevman 0:38ceb79fef03 330 /*
kevman 0:38ceb79fef03 331 * Authenticated decryption
kevman 0:38ceb79fef03 332 */
kevman 0:38ceb79fef03 333 int mbedtls_ccm_star_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
kevman 0:38ceb79fef03 334 const unsigned char *iv, size_t iv_len,
kevman 0:38ceb79fef03 335 const unsigned char *add, size_t add_len,
kevman 0:38ceb79fef03 336 const unsigned char *input, unsigned char *output,
kevman 0:38ceb79fef03 337 const unsigned char *tag, size_t tag_len )
kevman 0:38ceb79fef03 338 {
kevman 0:38ceb79fef03 339 int ret;
kevman 0:38ceb79fef03 340 unsigned char check_tag[16];
kevman 0:38ceb79fef03 341 unsigned char i;
kevman 0:38ceb79fef03 342 int diff;
kevman 0:38ceb79fef03 343
kevman 0:38ceb79fef03 344 if( ( ret = ccm_auth_crypt( ctx, CCM_DECRYPT, length,
kevman 0:38ceb79fef03 345 iv, iv_len, add, add_len,
kevman 0:38ceb79fef03 346 input, output, check_tag, tag_len ) ) != 0 )
kevman 0:38ceb79fef03 347 {
kevman 0:38ceb79fef03 348 return( ret );
kevman 0:38ceb79fef03 349 }
kevman 0:38ceb79fef03 350
kevman 0:38ceb79fef03 351 /* Check tag in "constant-time" */
kevman 0:38ceb79fef03 352 for( diff = 0, i = 0; i < tag_len; i++ )
kevman 0:38ceb79fef03 353 diff |= tag[i] ^ check_tag[i];
kevman 0:38ceb79fef03 354
kevman 0:38ceb79fef03 355 if( diff != 0 )
kevman 0:38ceb79fef03 356 {
kevman 0:38ceb79fef03 357 mbedtls_platform_zeroize( output, length );
kevman 0:38ceb79fef03 358 return( MBEDTLS_ERR_CCM_AUTH_FAILED );
kevman 0:38ceb79fef03 359 }
kevman 0:38ceb79fef03 360
kevman 0:38ceb79fef03 361 return( 0 );
kevman 0:38ceb79fef03 362 }
kevman 0:38ceb79fef03 363
kevman 0:38ceb79fef03 364 int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
kevman 0:38ceb79fef03 365 const unsigned char *iv, size_t iv_len,
kevman 0:38ceb79fef03 366 const unsigned char *add, size_t add_len,
kevman 0:38ceb79fef03 367 const unsigned char *input, unsigned char *output,
kevman 0:38ceb79fef03 368 const unsigned char *tag, size_t tag_len )
kevman 0:38ceb79fef03 369 {
kevman 0:38ceb79fef03 370 if( tag_len == 0 )
kevman 0:38ceb79fef03 371 return( MBEDTLS_ERR_CCM_BAD_INPUT );
kevman 0:38ceb79fef03 372
kevman 0:38ceb79fef03 373 return( mbedtls_ccm_star_auth_decrypt( ctx, length, iv, iv_len, add,
kevman 0:38ceb79fef03 374 add_len, input, output, tag, tag_len ) );
kevman 0:38ceb79fef03 375 }
kevman 0:38ceb79fef03 376 #endif /* !MBEDTLS_CCM_ALT */
kevman 0:38ceb79fef03 377
kevman 0:38ceb79fef03 378 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
kevman 0:38ceb79fef03 379 /*
kevman 0:38ceb79fef03 380 * Examples 1 to 3 from SP800-38C Appendix C
kevman 0:38ceb79fef03 381 */
kevman 0:38ceb79fef03 382
kevman 0:38ceb79fef03 383 #define NB_TESTS 3
kevman 0:38ceb79fef03 384 #define CCM_SELFTEST_PT_MAX_LEN 24
kevman 0:38ceb79fef03 385 #define CCM_SELFTEST_CT_MAX_LEN 32
kevman 0:38ceb79fef03 386 /*
kevman 0:38ceb79fef03 387 * The data is the same for all tests, only the used length changes
kevman 0:38ceb79fef03 388 */
kevman 0:38ceb79fef03 389 static const unsigned char key[] = {
kevman 0:38ceb79fef03 390 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
kevman 0:38ceb79fef03 391 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
kevman 0:38ceb79fef03 392 };
kevman 0:38ceb79fef03 393
kevman 0:38ceb79fef03 394 static const unsigned char iv[] = {
kevman 0:38ceb79fef03 395 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
kevman 0:38ceb79fef03 396 0x18, 0x19, 0x1a, 0x1b
kevman 0:38ceb79fef03 397 };
kevman 0:38ceb79fef03 398
kevman 0:38ceb79fef03 399 static const unsigned char ad[] = {
kevman 0:38ceb79fef03 400 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
kevman 0:38ceb79fef03 401 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
kevman 0:38ceb79fef03 402 0x10, 0x11, 0x12, 0x13
kevman 0:38ceb79fef03 403 };
kevman 0:38ceb79fef03 404
kevman 0:38ceb79fef03 405 static const unsigned char msg[CCM_SELFTEST_PT_MAX_LEN] = {
kevman 0:38ceb79fef03 406 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
kevman 0:38ceb79fef03 407 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
kevman 0:38ceb79fef03 408 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
kevman 0:38ceb79fef03 409 };
kevman 0:38ceb79fef03 410
kevman 0:38ceb79fef03 411 static const size_t iv_len [NB_TESTS] = { 7, 8, 12 };
kevman 0:38ceb79fef03 412 static const size_t add_len[NB_TESTS] = { 8, 16, 20 };
kevman 0:38ceb79fef03 413 static const size_t msg_len[NB_TESTS] = { 4, 16, 24 };
kevman 0:38ceb79fef03 414 static const size_t tag_len[NB_TESTS] = { 4, 6, 8 };
kevman 0:38ceb79fef03 415
kevman 0:38ceb79fef03 416 static const unsigned char res[NB_TESTS][CCM_SELFTEST_CT_MAX_LEN] = {
kevman 0:38ceb79fef03 417 { 0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d },
kevman 0:38ceb79fef03 418 { 0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62,
kevman 0:38ceb79fef03 419 0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d,
kevman 0:38ceb79fef03 420 0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd },
kevman 0:38ceb79fef03 421 { 0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a,
kevman 0:38ceb79fef03 422 0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b,
kevman 0:38ceb79fef03 423 0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5,
kevman 0:38ceb79fef03 424 0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 }
kevman 0:38ceb79fef03 425 };
kevman 0:38ceb79fef03 426
kevman 0:38ceb79fef03 427 int mbedtls_ccm_self_test( int verbose )
kevman 0:38ceb79fef03 428 {
kevman 0:38ceb79fef03 429 mbedtls_ccm_context ctx;
kevman 0:38ceb79fef03 430 /*
kevman 0:38ceb79fef03 431 * Some hardware accelerators require the input and output buffers
kevman 0:38ceb79fef03 432 * would be in RAM, because the flash is not accessible.
kevman 0:38ceb79fef03 433 * Use buffers on the stack to hold the test vectors data.
kevman 0:38ceb79fef03 434 */
kevman 0:38ceb79fef03 435 unsigned char plaintext[CCM_SELFTEST_PT_MAX_LEN];
kevman 0:38ceb79fef03 436 unsigned char ciphertext[CCM_SELFTEST_CT_MAX_LEN];
kevman 0:38ceb79fef03 437 size_t i;
kevman 0:38ceb79fef03 438 int ret;
kevman 0:38ceb79fef03 439
kevman 0:38ceb79fef03 440 mbedtls_ccm_init( &ctx );
kevman 0:38ceb79fef03 441
kevman 0:38ceb79fef03 442 if( mbedtls_ccm_setkey( &ctx, MBEDTLS_CIPHER_ID_AES, key, 8 * sizeof key ) != 0 )
kevman 0:38ceb79fef03 443 {
kevman 0:38ceb79fef03 444 if( verbose != 0 )
kevman 0:38ceb79fef03 445 mbedtls_printf( " CCM: setup failed" );
kevman 0:38ceb79fef03 446
kevman 0:38ceb79fef03 447 return( 1 );
kevman 0:38ceb79fef03 448 }
kevman 0:38ceb79fef03 449
kevman 0:38ceb79fef03 450 for( i = 0; i < NB_TESTS; i++ )
kevman 0:38ceb79fef03 451 {
kevman 0:38ceb79fef03 452 if( verbose != 0 )
kevman 0:38ceb79fef03 453 mbedtls_printf( " CCM-AES #%u: ", (unsigned int) i + 1 );
kevman 0:38ceb79fef03 454
kevman 0:38ceb79fef03 455 memset( plaintext, 0, CCM_SELFTEST_PT_MAX_LEN );
kevman 0:38ceb79fef03 456 memset( ciphertext, 0, CCM_SELFTEST_CT_MAX_LEN );
kevman 0:38ceb79fef03 457 memcpy( plaintext, msg, msg_len[i] );
kevman 0:38ceb79fef03 458
kevman 0:38ceb79fef03 459 ret = mbedtls_ccm_encrypt_and_tag( &ctx, msg_len[i],
kevman 0:38ceb79fef03 460 iv, iv_len[i], ad, add_len[i],
kevman 0:38ceb79fef03 461 plaintext, ciphertext,
kevman 0:38ceb79fef03 462 ciphertext + msg_len[i], tag_len[i] );
kevman 0:38ceb79fef03 463
kevman 0:38ceb79fef03 464 if( ret != 0 ||
kevman 0:38ceb79fef03 465 memcmp( ciphertext, res[i], msg_len[i] + tag_len[i] ) != 0 )
kevman 0:38ceb79fef03 466 {
kevman 0:38ceb79fef03 467 if( verbose != 0 )
kevman 0:38ceb79fef03 468 mbedtls_printf( "failed\n" );
kevman 0:38ceb79fef03 469
kevman 0:38ceb79fef03 470 return( 1 );
kevman 0:38ceb79fef03 471 }
kevman 0:38ceb79fef03 472 memset( plaintext, 0, CCM_SELFTEST_PT_MAX_LEN );
kevman 0:38ceb79fef03 473
kevman 0:38ceb79fef03 474 ret = mbedtls_ccm_auth_decrypt( &ctx, msg_len[i],
kevman 0:38ceb79fef03 475 iv, iv_len[i], ad, add_len[i],
kevman 0:38ceb79fef03 476 ciphertext, plaintext,
kevman 0:38ceb79fef03 477 ciphertext + msg_len[i], tag_len[i] );
kevman 0:38ceb79fef03 478
kevman 0:38ceb79fef03 479 if( ret != 0 ||
kevman 0:38ceb79fef03 480 memcmp( plaintext, msg, msg_len[i] ) != 0 )
kevman 0:38ceb79fef03 481 {
kevman 0:38ceb79fef03 482 if( verbose != 0 )
kevman 0:38ceb79fef03 483 mbedtls_printf( "failed\n" );
kevman 0:38ceb79fef03 484
kevman 0:38ceb79fef03 485 return( 1 );
kevman 0:38ceb79fef03 486 }
kevman 0:38ceb79fef03 487
kevman 0:38ceb79fef03 488 if( verbose != 0 )
kevman 0:38ceb79fef03 489 mbedtls_printf( "passed\n" );
kevman 0:38ceb79fef03 490 }
kevman 0:38ceb79fef03 491
kevman 0:38ceb79fef03 492 mbedtls_ccm_free( &ctx );
kevman 0:38ceb79fef03 493
kevman 0:38ceb79fef03 494 if( verbose != 0 )
kevman 0:38ceb79fef03 495 mbedtls_printf( "\n" );
kevman 0:38ceb79fef03 496
kevman 0:38ceb79fef03 497 return( 0 );
kevman 0:38ceb79fef03 498 }
kevman 0:38ceb79fef03 499
kevman 0:38ceb79fef03 500 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
kevman 0:38ceb79fef03 501
kevman 0:38ceb79fef03 502 #endif /* MBEDTLS_CCM_C */