Maxim nexpaq / nexpaq_dev

Preliminary main mbed library for nexpaq development

features/mbedtls/src/ccm.c@1:d96dbedaebdb, 2016-11-04 (annotated)

Committer:
nexpaq
Date:
Fri Nov 04 20:54:50 2016 +0000
Revision:
1:d96dbedaebdb
Parent:
0:6c56fb4bc5f0 
Removed extra directories for other platforms

Who changed what in which revision?

UserRevisionLine numberNew contents of line
nexpaq 0:6c56fb4bc5f0 1 /*
nexpaq 0:6c56fb4bc5f0 2 * NIST SP800-38C compliant CCM implementation
nexpaq 0:6c56fb4bc5f0 3 *
nexpaq 0:6c56fb4bc5f0 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
nexpaq 0:6c56fb4bc5f0 5 * SPDX-License-Identifier: Apache-2.0
nexpaq 0:6c56fb4bc5f0 6 *
nexpaq 0:6c56fb4bc5f0 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
nexpaq 0:6c56fb4bc5f0 8 * not use this file except in compliance with the License.
nexpaq 0:6c56fb4bc5f0 9 * You may obtain a copy of the License at
nexpaq 0:6c56fb4bc5f0 10 *
nexpaq 0:6c56fb4bc5f0 11 * http://www.apache.org/licenses/LICENSE-2.0
nexpaq 0:6c56fb4bc5f0 12 *
nexpaq 0:6c56fb4bc5f0 13 * Unless required by applicable law or agreed to in writing, software
nexpaq 0:6c56fb4bc5f0 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
nexpaq 0:6c56fb4bc5f0 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
nexpaq 0:6c56fb4bc5f0 16 * See the License for the specific language governing permissions and
nexpaq 0:6c56fb4bc5f0 17 * limitations under the License.
nexpaq 0:6c56fb4bc5f0 18 *
nexpaq 0:6c56fb4bc5f0 19 * This file is part of mbed TLS (https://tls.mbed.org)
nexpaq 0:6c56fb4bc5f0 20 */
nexpaq 0:6c56fb4bc5f0 21
nexpaq 0:6c56fb4bc5f0 22 /*
nexpaq 0:6c56fb4bc5f0 23 * Definition of CCM:
nexpaq 0:6c56fb4bc5f0 24 * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
nexpaq 0:6c56fb4bc5f0 25 * RFC 3610 "Counter with CBC-MAC (CCM)"
nexpaq 0:6c56fb4bc5f0 26 *
nexpaq 0:6c56fb4bc5f0 27 * Related:
nexpaq 0:6c56fb4bc5f0 28 * RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
nexpaq 0:6c56fb4bc5f0 29 */
nexpaq 0:6c56fb4bc5f0 30
nexpaq 0:6c56fb4bc5f0 31 #if !defined(MBEDTLS_CONFIG_FILE)
nexpaq 0:6c56fb4bc5f0 32 #include "mbedtls/config.h"
nexpaq 0:6c56fb4bc5f0 33 #else
nexpaq 0:6c56fb4bc5f0 34 #include MBEDTLS_CONFIG_FILE
nexpaq 0:6c56fb4bc5f0 35 #endif
nexpaq 0:6c56fb4bc5f0 36
nexpaq 0:6c56fb4bc5f0 37 #if defined(MBEDTLS_CCM_C)
nexpaq 0:6c56fb4bc5f0 38
nexpaq 0:6c56fb4bc5f0 39 #include "mbedtls/ccm.h"
nexpaq 0:6c56fb4bc5f0 40
nexpaq 0:6c56fb4bc5f0 41 #include <string.h>
nexpaq 0:6c56fb4bc5f0 42
nexpaq 0:6c56fb4bc5f0 43 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
nexpaq 0:6c56fb4bc5f0 44 #if defined(MBEDTLS_PLATFORM_C)
nexpaq 0:6c56fb4bc5f0 45 #include "mbedtls/platform.h"
nexpaq 0:6c56fb4bc5f0 46 #else
nexpaq 0:6c56fb4bc5f0 47 #include <stdio.h>
nexpaq 0:6c56fb4bc5f0 48 #define mbedtls_printf printf
nexpaq 0:6c56fb4bc5f0 49 #endif /* MBEDTLS_PLATFORM_C */
nexpaq 0:6c56fb4bc5f0 50 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
nexpaq 0:6c56fb4bc5f0 51
nexpaq 0:6c56fb4bc5f0 52 /* Implementation that should never be optimized out by the compiler */
nexpaq 0:6c56fb4bc5f0 53 static void mbedtls_zeroize( void *v, size_t n ) {
nexpaq 0:6c56fb4bc5f0 54 volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
nexpaq 0:6c56fb4bc5f0 55 }
nexpaq 0:6c56fb4bc5f0 56
nexpaq 0:6c56fb4bc5f0 57 #define CCM_ENCRYPT 0
nexpaq 0:6c56fb4bc5f0 58 #define CCM_DECRYPT 1
nexpaq 0:6c56fb4bc5f0 59
nexpaq 0:6c56fb4bc5f0 60 /*
nexpaq 0:6c56fb4bc5f0 61 * Initialize context
nexpaq 0:6c56fb4bc5f0 62 */
nexpaq 0:6c56fb4bc5f0 63 void mbedtls_ccm_init( mbedtls_ccm_context *ctx )
nexpaq 0:6c56fb4bc5f0 64 {
nexpaq 0:6c56fb4bc5f0 65 memset( ctx, 0, sizeof( mbedtls_ccm_context ) );
nexpaq 0:6c56fb4bc5f0 66 }
nexpaq 0:6c56fb4bc5f0 67
nexpaq 0:6c56fb4bc5f0 68 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
nexpaq 0:6c56fb4bc5f0 69 mbedtls_cipher_id_t cipher,
nexpaq 0:6c56fb4bc5f0 70 const unsigned char *key,
nexpaq 0:6c56fb4bc5f0 71 unsigned int keybits )
nexpaq 0:6c56fb4bc5f0 72 {
nexpaq 0:6c56fb4bc5f0 73 int ret;
nexpaq 0:6c56fb4bc5f0 74 const mbedtls_cipher_info_t *cipher_info;
nexpaq 0:6c56fb4bc5f0 75
nexpaq 0:6c56fb4bc5f0 76 cipher_info = mbedtls_cipher_info_from_values( cipher, keybits, MBEDTLS_MODE_ECB );
nexpaq 0:6c56fb4bc5f0 77 if( cipher_info == NULL )
nexpaq 0:6c56fb4bc5f0 78 return( MBEDTLS_ERR_CCM_BAD_INPUT );
nexpaq 0:6c56fb4bc5f0 79
nexpaq 0:6c56fb4bc5f0 80 if( cipher_info->block_size != 16 )
nexpaq 0:6c56fb4bc5f0 81 return( MBEDTLS_ERR_CCM_BAD_INPUT );
nexpaq 0:6c56fb4bc5f0 82
nexpaq 0:6c56fb4bc5f0 83 mbedtls_cipher_free( &ctx->cipher_ctx );
nexpaq 0:6c56fb4bc5f0 84
nexpaq 0:6c56fb4bc5f0 85 if( ( ret = mbedtls_cipher_setup( &ctx->cipher_ctx, cipher_info ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 86 return( ret );
nexpaq 0:6c56fb4bc5f0 87
nexpaq 0:6c56fb4bc5f0 88 if( ( ret = mbedtls_cipher_setkey( &ctx->cipher_ctx, key, keybits,
nexpaq 0:6c56fb4bc5f0 89 MBEDTLS_ENCRYPT ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 90 {
nexpaq 0:6c56fb4bc5f0 91 return( ret );
nexpaq 0:6c56fb4bc5f0 92 }
nexpaq 0:6c56fb4bc5f0 93
nexpaq 0:6c56fb4bc5f0 94 return( 0 );
nexpaq 0:6c56fb4bc5f0 95 }
nexpaq 0:6c56fb4bc5f0 96
nexpaq 0:6c56fb4bc5f0 97 /*
nexpaq 0:6c56fb4bc5f0 98 * Free context
nexpaq 0:6c56fb4bc5f0 99 */
nexpaq 0:6c56fb4bc5f0 100 void mbedtls_ccm_free( mbedtls_ccm_context *ctx )
nexpaq 0:6c56fb4bc5f0 101 {
nexpaq 0:6c56fb4bc5f0 102 mbedtls_cipher_free( &ctx->cipher_ctx );
nexpaq 0:6c56fb4bc5f0 103 mbedtls_zeroize( ctx, sizeof( mbedtls_ccm_context ) );
nexpaq 0:6c56fb4bc5f0 104 }
nexpaq 0:6c56fb4bc5f0 105
nexpaq 0:6c56fb4bc5f0 106 /*
nexpaq 0:6c56fb4bc5f0 107 * Macros for common operations.
nexpaq 0:6c56fb4bc5f0 108 * Results in smaller compiled code than static inline functions.
nexpaq 0:6c56fb4bc5f0 109 */
nexpaq 0:6c56fb4bc5f0 110
nexpaq 0:6c56fb4bc5f0 111 /*
nexpaq 0:6c56fb4bc5f0 112 * Update the CBC-MAC state in y using a block in b
nexpaq 0:6c56fb4bc5f0 113 * (Always using b as the source helps the compiler optimise a bit better.)
nexpaq 0:6c56fb4bc5f0 114 */
nexpaq 0:6c56fb4bc5f0 115 #define UPDATE_CBC_MAC \
nexpaq 0:6c56fb4bc5f0 116 for( i = 0; i < 16; i++ ) \
nexpaq 0:6c56fb4bc5f0 117 y[i] ^= b[i]; \
nexpaq 0:6c56fb4bc5f0 118 \
nexpaq 0:6c56fb4bc5f0 119 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, y, 16, y, &olen ) ) != 0 ) \
nexpaq 0:6c56fb4bc5f0 120 return( ret );
nexpaq 0:6c56fb4bc5f0 121
nexpaq 0:6c56fb4bc5f0 122 /*
nexpaq 0:6c56fb4bc5f0 123 * Encrypt or decrypt a partial block with CTR
nexpaq 0:6c56fb4bc5f0 124 * Warning: using b for temporary storage! src and dst must not be b!
nexpaq 0:6c56fb4bc5f0 125 * This avoids allocating one more 16 bytes buffer while allowing src == dst.
nexpaq 0:6c56fb4bc5f0 126 */
nexpaq 0:6c56fb4bc5f0 127 #define CTR_CRYPT( dst, src, len ) \
nexpaq 0:6c56fb4bc5f0 128 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, ctr, 16, b, &olen ) ) != 0 ) \
nexpaq 0:6c56fb4bc5f0 129 return( ret ); \
nexpaq 0:6c56fb4bc5f0 130 \
nexpaq 0:6c56fb4bc5f0 131 for( i = 0; i < len; i++ ) \
nexpaq 0:6c56fb4bc5f0 132 dst[i] = src[i] ^ b[i];
nexpaq 0:6c56fb4bc5f0 133
nexpaq 0:6c56fb4bc5f0 134 /*
nexpaq 0:6c56fb4bc5f0 135 * Authenticated encryption or decryption
nexpaq 0:6c56fb4bc5f0 136 */
nexpaq 0:6c56fb4bc5f0 137 static int ccm_auth_crypt( mbedtls_ccm_context *ctx, int mode, size_t length,
nexpaq 0:6c56fb4bc5f0 138 const unsigned char *iv, size_t iv_len,
nexpaq 0:6c56fb4bc5f0 139 const unsigned char *add, size_t add_len,
nexpaq 0:6c56fb4bc5f0 140 const unsigned char *input, unsigned char *output,
nexpaq 0:6c56fb4bc5f0 141 unsigned char *tag, size_t tag_len )
nexpaq 0:6c56fb4bc5f0 142 {
nexpaq 0:6c56fb4bc5f0 143 int ret;
nexpaq 0:6c56fb4bc5f0 144 unsigned char i;
nexpaq 0:6c56fb4bc5f0 145 unsigned char q;
nexpaq 0:6c56fb4bc5f0 146 size_t len_left, olen;
nexpaq 0:6c56fb4bc5f0 147 unsigned char b[16];
nexpaq 0:6c56fb4bc5f0 148 unsigned char y[16];
nexpaq 0:6c56fb4bc5f0 149 unsigned char ctr[16];
nexpaq 0:6c56fb4bc5f0 150 const unsigned char *src;
nexpaq 0:6c56fb4bc5f0 151 unsigned char *dst;
nexpaq 0:6c56fb4bc5f0 152
nexpaq 0:6c56fb4bc5f0 153 /*
nexpaq 0:6c56fb4bc5f0 154 * Check length requirements: SP800-38C A.1
nexpaq 0:6c56fb4bc5f0 155 * Additional requirement: a < 2^16 - 2^8 to simplify the code.
nexpaq 0:6c56fb4bc5f0 156 * 'length' checked later (when writing it to the first block)
nexpaq 0:6c56fb4bc5f0 157 */
nexpaq 0:6c56fb4bc5f0 158 if( tag_len < 4 || tag_len > 16 || tag_len % 2 != 0 )
nexpaq 0:6c56fb4bc5f0 159 return( MBEDTLS_ERR_CCM_BAD_INPUT );
nexpaq 0:6c56fb4bc5f0 160
nexpaq 0:6c56fb4bc5f0 161 /* Also implies q is within bounds */
nexpaq 0:6c56fb4bc5f0 162 if( iv_len < 7 || iv_len > 13 )
nexpaq 0:6c56fb4bc5f0 163 return( MBEDTLS_ERR_CCM_BAD_INPUT );
nexpaq 0:6c56fb4bc5f0 164
nexpaq 0:6c56fb4bc5f0 165 if( add_len > 0xFF00 )
nexpaq 0:6c56fb4bc5f0 166 return( MBEDTLS_ERR_CCM_BAD_INPUT );
nexpaq 0:6c56fb4bc5f0 167
nexpaq 0:6c56fb4bc5f0 168 q = 16 - 1 - (unsigned char) iv_len;
nexpaq 0:6c56fb4bc5f0 169
nexpaq 0:6c56fb4bc5f0 170 /*
nexpaq 0:6c56fb4bc5f0 171 * First block B_0:
nexpaq 0:6c56fb4bc5f0 172 * 0 .. 0 flags
nexpaq 0:6c56fb4bc5f0 173 * 1 .. iv_len nonce (aka iv)
nexpaq 0:6c56fb4bc5f0 174 * iv_len+1 .. 15 length
nexpaq 0:6c56fb4bc5f0 175 *
nexpaq 0:6c56fb4bc5f0 176 * With flags as (bits):
nexpaq 0:6c56fb4bc5f0 177 * 7 0
nexpaq 0:6c56fb4bc5f0 178 * 6 add present?
nexpaq 0:6c56fb4bc5f0 179 * 5 .. 3 (t - 2) / 2
nexpaq 0:6c56fb4bc5f0 180 * 2 .. 0 q - 1
nexpaq 0:6c56fb4bc5f0 181 */
nexpaq 0:6c56fb4bc5f0 182 b[0] = 0;
nexpaq 0:6c56fb4bc5f0 183 b[0] |= ( add_len > 0 ) << 6;
nexpaq 0:6c56fb4bc5f0 184 b[0] |= ( ( tag_len - 2 ) / 2 ) << 3;
nexpaq 0:6c56fb4bc5f0 185 b[0] |= q - 1;
nexpaq 0:6c56fb4bc5f0 186
nexpaq 0:6c56fb4bc5f0 187 memcpy( b + 1, iv, iv_len );
nexpaq 0:6c56fb4bc5f0 188
nexpaq 0:6c56fb4bc5f0 189 for( i = 0, len_left = length; i < q; i++, len_left >>= 8 )
nexpaq 0:6c56fb4bc5f0 190 b[15-i] = (unsigned char)( len_left & 0xFF );
nexpaq 0:6c56fb4bc5f0 191
nexpaq 0:6c56fb4bc5f0 192 if( len_left > 0 )
nexpaq 0:6c56fb4bc5f0 193 return( MBEDTLS_ERR_CCM_BAD_INPUT );
nexpaq 0:6c56fb4bc5f0 194
nexpaq 0:6c56fb4bc5f0 195
nexpaq 0:6c56fb4bc5f0 196 /* Start CBC-MAC with first block */
nexpaq 0:6c56fb4bc5f0 197 memset( y, 0, 16 );
nexpaq 0:6c56fb4bc5f0 198 UPDATE_CBC_MAC;
nexpaq 0:6c56fb4bc5f0 199
nexpaq 0:6c56fb4bc5f0 200 /*
nexpaq 0:6c56fb4bc5f0 201 * If there is additional data, update CBC-MAC with
nexpaq 0:6c56fb4bc5f0 202 * add_len, add, 0 (padding to a block boundary)
nexpaq 0:6c56fb4bc5f0 203 */
nexpaq 0:6c56fb4bc5f0 204 if( add_len > 0 )
nexpaq 0:6c56fb4bc5f0 205 {
nexpaq 0:6c56fb4bc5f0 206 size_t use_len;
nexpaq 0:6c56fb4bc5f0 207 len_left = add_len;
nexpaq 0:6c56fb4bc5f0 208 src = add;
nexpaq 0:6c56fb4bc5f0 209
nexpaq 0:6c56fb4bc5f0 210 memset( b, 0, 16 );
nexpaq 0:6c56fb4bc5f0 211 b[0] = (unsigned char)( ( add_len >> 8 ) & 0xFF );
nexpaq 0:6c56fb4bc5f0 212 b[1] = (unsigned char)( ( add_len ) & 0xFF );
nexpaq 0:6c56fb4bc5f0 213
nexpaq 0:6c56fb4bc5f0 214 use_len = len_left < 16 - 2 ? len_left : 16 - 2;
nexpaq 0:6c56fb4bc5f0 215 memcpy( b + 2, src, use_len );
nexpaq 0:6c56fb4bc5f0 216 len_left -= use_len;
nexpaq 0:6c56fb4bc5f0 217 src += use_len;
nexpaq 0:6c56fb4bc5f0 218
nexpaq 0:6c56fb4bc5f0 219 UPDATE_CBC_MAC;
nexpaq 0:6c56fb4bc5f0 220
nexpaq 0:6c56fb4bc5f0 221 while( len_left > 0 )
nexpaq 0:6c56fb4bc5f0 222 {
nexpaq 0:6c56fb4bc5f0 223 use_len = len_left > 16 ? 16 : len_left;
nexpaq 0:6c56fb4bc5f0 224
nexpaq 0:6c56fb4bc5f0 225 memset( b, 0, 16 );
nexpaq 0:6c56fb4bc5f0 226 memcpy( b, src, use_len );
nexpaq 0:6c56fb4bc5f0 227 UPDATE_CBC_MAC;
nexpaq 0:6c56fb4bc5f0 228
nexpaq 0:6c56fb4bc5f0 229 len_left -= use_len;
nexpaq 0:6c56fb4bc5f0 230 src += use_len;
nexpaq 0:6c56fb4bc5f0 231 }
nexpaq 0:6c56fb4bc5f0 232 }
nexpaq 0:6c56fb4bc5f0 233
nexpaq 0:6c56fb4bc5f0 234 /*
nexpaq 0:6c56fb4bc5f0 235 * Prepare counter block for encryption:
nexpaq 0:6c56fb4bc5f0 236 * 0 .. 0 flags
nexpaq 0:6c56fb4bc5f0 237 * 1 .. iv_len nonce (aka iv)
nexpaq 0:6c56fb4bc5f0 238 * iv_len+1 .. 15 counter (initially 1)
nexpaq 0:6c56fb4bc5f0 239 *
nexpaq 0:6c56fb4bc5f0 240 * With flags as (bits):
nexpaq 0:6c56fb4bc5f0 241 * 7 .. 3 0
nexpaq 0:6c56fb4bc5f0 242 * 2 .. 0 q - 1
nexpaq 0:6c56fb4bc5f0 243 */
nexpaq 0:6c56fb4bc5f0 244 ctr[0] = q - 1;
nexpaq 0:6c56fb4bc5f0 245 memcpy( ctr + 1, iv, iv_len );
nexpaq 0:6c56fb4bc5f0 246 memset( ctr + 1 + iv_len, 0, q );
nexpaq 0:6c56fb4bc5f0 247 ctr[15] = 1;
nexpaq 0:6c56fb4bc5f0 248
nexpaq 0:6c56fb4bc5f0 249 /*
nexpaq 0:6c56fb4bc5f0 250 * Authenticate and {en,de}crypt the message.
nexpaq 0:6c56fb4bc5f0 251 *
nexpaq 0:6c56fb4bc5f0 252 * The only difference between encryption and decryption is
nexpaq 0:6c56fb4bc5f0 253 * the respective order of authentication and {en,de}cryption.
nexpaq 0:6c56fb4bc5f0 254 */
nexpaq 0:6c56fb4bc5f0 255 len_left = length;
nexpaq 0:6c56fb4bc5f0 256 src = input;
nexpaq 0:6c56fb4bc5f0 257 dst = output;
nexpaq 0:6c56fb4bc5f0 258
nexpaq 0:6c56fb4bc5f0 259 while( len_left > 0 )
nexpaq 0:6c56fb4bc5f0 260 {
nexpaq 0:6c56fb4bc5f0 261 size_t use_len = len_left > 16 ? 16 : len_left;
nexpaq 0:6c56fb4bc5f0 262
nexpaq 0:6c56fb4bc5f0 263 if( mode == CCM_ENCRYPT )
nexpaq 0:6c56fb4bc5f0 264 {
nexpaq 0:6c56fb4bc5f0 265 memset( b, 0, 16 );
nexpaq 0:6c56fb4bc5f0 266 memcpy( b, src, use_len );
nexpaq 0:6c56fb4bc5f0 267 UPDATE_CBC_MAC;
nexpaq 0:6c56fb4bc5f0 268 }
nexpaq 0:6c56fb4bc5f0 269
nexpaq 0:6c56fb4bc5f0 270 CTR_CRYPT( dst, src, use_len );
nexpaq 0:6c56fb4bc5f0 271
nexpaq 0:6c56fb4bc5f0 272 if( mode == CCM_DECRYPT )
nexpaq 0:6c56fb4bc5f0 273 {
nexpaq 0:6c56fb4bc5f0 274 memset( b, 0, 16 );
nexpaq 0:6c56fb4bc5f0 275 memcpy( b, dst, use_len );
nexpaq 0:6c56fb4bc5f0 276 UPDATE_CBC_MAC;
nexpaq 0:6c56fb4bc5f0 277 }
nexpaq 0:6c56fb4bc5f0 278
nexpaq 0:6c56fb4bc5f0 279 dst += use_len;
nexpaq 0:6c56fb4bc5f0 280 src += use_len;
nexpaq 0:6c56fb4bc5f0 281 len_left -= use_len;
nexpaq 0:6c56fb4bc5f0 282
nexpaq 0:6c56fb4bc5f0 283 /*
nexpaq 0:6c56fb4bc5f0 284 * Increment counter.
nexpaq 0:6c56fb4bc5f0 285 * No need to check for overflow thanks to the length check above.
nexpaq 0:6c56fb4bc5f0 286 */
nexpaq 0:6c56fb4bc5f0 287 for( i = 0; i < q; i++ )
nexpaq 0:6c56fb4bc5f0 288 if( ++ctr[15-i] != 0 )
nexpaq 0:6c56fb4bc5f0 289 break;
nexpaq 0:6c56fb4bc5f0 290 }
nexpaq 0:6c56fb4bc5f0 291
nexpaq 0:6c56fb4bc5f0 292 /*
nexpaq 0:6c56fb4bc5f0 293 * Authentication: reset counter and crypt/mask internal tag
nexpaq 0:6c56fb4bc5f0 294 */
nexpaq 0:6c56fb4bc5f0 295 for( i = 0; i < q; i++ )
nexpaq 0:6c56fb4bc5f0 296 ctr[15-i] = 0;
nexpaq 0:6c56fb4bc5f0 297
nexpaq 0:6c56fb4bc5f0 298 CTR_CRYPT( y, y, 16 );
nexpaq 0:6c56fb4bc5f0 299 memcpy( tag, y, tag_len );
nexpaq 0:6c56fb4bc5f0 300
nexpaq 0:6c56fb4bc5f0 301 return( 0 );
nexpaq 0:6c56fb4bc5f0 302 }
nexpaq 0:6c56fb4bc5f0 303
nexpaq 0:6c56fb4bc5f0 304 /*
nexpaq 0:6c56fb4bc5f0 305 * Authenticated encryption
nexpaq 0:6c56fb4bc5f0 306 */
nexpaq 0:6c56fb4bc5f0 307 int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
nexpaq 0:6c56fb4bc5f0 308 const unsigned char *iv, size_t iv_len,
nexpaq 0:6c56fb4bc5f0 309 const unsigned char *add, size_t add_len,
nexpaq 0:6c56fb4bc5f0 310 const unsigned char *input, unsigned char *output,
nexpaq 0:6c56fb4bc5f0 311 unsigned char *tag, size_t tag_len )
nexpaq 0:6c56fb4bc5f0 312 {
nexpaq 0:6c56fb4bc5f0 313 return( ccm_auth_crypt( ctx, CCM_ENCRYPT, length, iv, iv_len,
nexpaq 0:6c56fb4bc5f0 314 add, add_len, input, output, tag, tag_len ) );
nexpaq 0:6c56fb4bc5f0 315 }
nexpaq 0:6c56fb4bc5f0 316
nexpaq 0:6c56fb4bc5f0 317 /*
nexpaq 0:6c56fb4bc5f0 318 * Authenticated decryption
nexpaq 0:6c56fb4bc5f0 319 */
nexpaq 0:6c56fb4bc5f0 320 int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
nexpaq 0:6c56fb4bc5f0 321 const unsigned char *iv, size_t iv_len,
nexpaq 0:6c56fb4bc5f0 322 const unsigned char *add, size_t add_len,
nexpaq 0:6c56fb4bc5f0 323 const unsigned char *input, unsigned char *output,
nexpaq 0:6c56fb4bc5f0 324 const unsigned char *tag, size_t tag_len )
nexpaq 0:6c56fb4bc5f0 325 {
nexpaq 0:6c56fb4bc5f0 326 int ret;
nexpaq 0:6c56fb4bc5f0 327 unsigned char check_tag[16];
nexpaq 0:6c56fb4bc5f0 328 unsigned char i;
nexpaq 0:6c56fb4bc5f0 329 int diff;
nexpaq 0:6c56fb4bc5f0 330
nexpaq 0:6c56fb4bc5f0 331 if( ( ret = ccm_auth_crypt( ctx, CCM_DECRYPT, length,
nexpaq 0:6c56fb4bc5f0 332 iv, iv_len, add, add_len,
nexpaq 0:6c56fb4bc5f0 333 input, output, check_tag, tag_len ) ) != 0 )
nexpaq 0:6c56fb4bc5f0 334 {
nexpaq 0:6c56fb4bc5f0 335 return( ret );
nexpaq 0:6c56fb4bc5f0 336 }
nexpaq 0:6c56fb4bc5f0 337
nexpaq 0:6c56fb4bc5f0 338 /* Check tag in "constant-time" */
nexpaq 0:6c56fb4bc5f0 339 for( diff = 0, i = 0; i < tag_len; i++ )
nexpaq 0:6c56fb4bc5f0 340 diff |= tag[i] ^ check_tag[i];
nexpaq 0:6c56fb4bc5f0 341
nexpaq 0:6c56fb4bc5f0 342 if( diff != 0 )
nexpaq 0:6c56fb4bc5f0 343 {
nexpaq 0:6c56fb4bc5f0 344 mbedtls_zeroize( output, length );
nexpaq 0:6c56fb4bc5f0 345 return( MBEDTLS_ERR_CCM_AUTH_FAILED );
nexpaq 0:6c56fb4bc5f0 346 }
nexpaq 0:6c56fb4bc5f0 347
nexpaq 0:6c56fb4bc5f0 348 return( 0 );
nexpaq 0:6c56fb4bc5f0 349 }
nexpaq 0:6c56fb4bc5f0 350
nexpaq 0:6c56fb4bc5f0 351
nexpaq 0:6c56fb4bc5f0 352 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
nexpaq 0:6c56fb4bc5f0 353 /*
nexpaq 0:6c56fb4bc5f0 354 * Examples 1 to 3 from SP800-38C Appendix C
nexpaq 0:6c56fb4bc5f0 355 */
nexpaq 0:6c56fb4bc5f0 356
nexpaq 0:6c56fb4bc5f0 357 #define NB_TESTS 3
nexpaq 0:6c56fb4bc5f0 358
nexpaq 0:6c56fb4bc5f0 359 /*
nexpaq 0:6c56fb4bc5f0 360 * The data is the same for all tests, only the used length changes
nexpaq 0:6c56fb4bc5f0 361 */
nexpaq 0:6c56fb4bc5f0 362 static const unsigned char key[] = {
nexpaq 0:6c56fb4bc5f0 363 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
nexpaq 0:6c56fb4bc5f0 364 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
nexpaq 0:6c56fb4bc5f0 365 };
nexpaq 0:6c56fb4bc5f0 366
nexpaq 0:6c56fb4bc5f0 367 static const unsigned char iv[] = {
nexpaq 0:6c56fb4bc5f0 368 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
nexpaq 0:6c56fb4bc5f0 369 0x18, 0x19, 0x1a, 0x1b
nexpaq 0:6c56fb4bc5f0 370 };
nexpaq 0:6c56fb4bc5f0 371
nexpaq 0:6c56fb4bc5f0 372 static const unsigned char ad[] = {
nexpaq 0:6c56fb4bc5f0 373 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
nexpaq 0:6c56fb4bc5f0 374 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
nexpaq 0:6c56fb4bc5f0 375 0x10, 0x11, 0x12, 0x13
nexpaq 0:6c56fb4bc5f0 376 };
nexpaq 0:6c56fb4bc5f0 377
nexpaq 0:6c56fb4bc5f0 378 static const unsigned char msg[] = {
nexpaq 0:6c56fb4bc5f0 379 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
nexpaq 0:6c56fb4bc5f0 380 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
nexpaq 0:6c56fb4bc5f0 381 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
nexpaq 0:6c56fb4bc5f0 382 };
nexpaq 0:6c56fb4bc5f0 383
nexpaq 0:6c56fb4bc5f0 384 static const size_t iv_len [NB_TESTS] = { 7, 8, 12 };
nexpaq 0:6c56fb4bc5f0 385 static const size_t add_len[NB_TESTS] = { 8, 16, 20 };
nexpaq 0:6c56fb4bc5f0 386 static const size_t msg_len[NB_TESTS] = { 4, 16, 24 };
nexpaq 0:6c56fb4bc5f0 387 static const size_t tag_len[NB_TESTS] = { 4, 6, 8 };
nexpaq 0:6c56fb4bc5f0 388
nexpaq 0:6c56fb4bc5f0 389 static const unsigned char res[NB_TESTS][32] = {
nexpaq 0:6c56fb4bc5f0 390 { 0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d },
nexpaq 0:6c56fb4bc5f0 391 { 0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62,
nexpaq 0:6c56fb4bc5f0 392 0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d,
nexpaq 0:6c56fb4bc5f0 393 0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd },
nexpaq 0:6c56fb4bc5f0 394 { 0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a,
nexpaq 0:6c56fb4bc5f0 395 0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b,
nexpaq 0:6c56fb4bc5f0 396 0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5,
nexpaq 0:6c56fb4bc5f0 397 0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 }
nexpaq 0:6c56fb4bc5f0 398 };
nexpaq 0:6c56fb4bc5f0 399
nexpaq 0:6c56fb4bc5f0 400 int mbedtls_ccm_self_test( int verbose )
nexpaq 0:6c56fb4bc5f0 401 {
nexpaq 0:6c56fb4bc5f0 402 mbedtls_ccm_context ctx;
nexpaq 0:6c56fb4bc5f0 403 unsigned char out[32];
nexpaq 0:6c56fb4bc5f0 404 size_t i;
nexpaq 0:6c56fb4bc5f0 405 int ret;
nexpaq 0:6c56fb4bc5f0 406
nexpaq 0:6c56fb4bc5f0 407 mbedtls_ccm_init( &ctx );
nexpaq 0:6c56fb4bc5f0 408
nexpaq 0:6c56fb4bc5f0 409 if( mbedtls_ccm_setkey( &ctx, MBEDTLS_CIPHER_ID_AES, key, 8 * sizeof key ) != 0 )
nexpaq 0:6c56fb4bc5f0 410 {
nexpaq 0:6c56fb4bc5f0 411 if( verbose != 0 )
nexpaq 0:6c56fb4bc5f0 412 mbedtls_printf( " CCM: setup failed" );
nexpaq 0:6c56fb4bc5f0 413
nexpaq 0:6c56fb4bc5f0 414 return( 1 );
nexpaq 0:6c56fb4bc5f0 415 }
nexpaq 0:6c56fb4bc5f0 416
nexpaq 0:6c56fb4bc5f0 417 for( i = 0; i < NB_TESTS; i++ )
nexpaq 0:6c56fb4bc5f0 418 {
nexpaq 0:6c56fb4bc5f0 419 if( verbose != 0 )
nexpaq 0:6c56fb4bc5f0 420 mbedtls_printf( " CCM-AES #%u: ", (unsigned int) i + 1 );
nexpaq 0:6c56fb4bc5f0 421
nexpaq 0:6c56fb4bc5f0 422 ret = mbedtls_ccm_encrypt_and_tag( &ctx, msg_len[i],
nexpaq 0:6c56fb4bc5f0 423 iv, iv_len[i], ad, add_len[i],
nexpaq 0:6c56fb4bc5f0 424 msg, out,
nexpaq 0:6c56fb4bc5f0 425 out + msg_len[i], tag_len[i] );
nexpaq 0:6c56fb4bc5f0 426
nexpaq 0:6c56fb4bc5f0 427 if( ret != 0 ||
nexpaq 0:6c56fb4bc5f0 428 memcmp( out, res[i], msg_len[i] + tag_len[i] ) != 0 )
nexpaq 0:6c56fb4bc5f0 429 {
nexpaq 0:6c56fb4bc5f0 430 if( verbose != 0 )
nexpaq 0:6c56fb4bc5f0 431 mbedtls_printf( "failed\n" );
nexpaq 0:6c56fb4bc5f0 432
nexpaq 0:6c56fb4bc5f0 433 return( 1 );
nexpaq 0:6c56fb4bc5f0 434 }
nexpaq 0:6c56fb4bc5f0 435
nexpaq 0:6c56fb4bc5f0 436 ret = mbedtls_ccm_auth_decrypt( &ctx, msg_len[i],
nexpaq 0:6c56fb4bc5f0 437 iv, iv_len[i], ad, add_len[i],
nexpaq 0:6c56fb4bc5f0 438 res[i], out,
nexpaq 0:6c56fb4bc5f0 439 res[i] + msg_len[i], tag_len[i] );
nexpaq 0:6c56fb4bc5f0 440
nexpaq 0:6c56fb4bc5f0 441 if( ret != 0 ||
nexpaq 0:6c56fb4bc5f0 442 memcmp( out, msg, msg_len[i] ) != 0 )
nexpaq 0:6c56fb4bc5f0 443 {
nexpaq 0:6c56fb4bc5f0 444 if( verbose != 0 )
nexpaq 0:6c56fb4bc5f0 445 mbedtls_printf( "failed\n" );
nexpaq 0:6c56fb4bc5f0 446
nexpaq 0:6c56fb4bc5f0 447 return( 1 );
nexpaq 0:6c56fb4bc5f0 448 }
nexpaq 0:6c56fb4bc5f0 449
nexpaq 0:6c56fb4bc5f0 450 if( verbose != 0 )
nexpaq 0:6c56fb4bc5f0 451 mbedtls_printf( "passed\n" );
nexpaq 0:6c56fb4bc5f0 452 }
nexpaq 0:6c56fb4bc5f0 453
nexpaq 0:6c56fb4bc5f0 454 mbedtls_ccm_free( &ctx );
nexpaq 0:6c56fb4bc5f0 455
nexpaq 0:6c56fb4bc5f0 456 if( verbose != 0 )
nexpaq 0:6c56fb4bc5f0 457 mbedtls_printf( "\n" );
nexpaq 0:6c56fb4bc5f0 458
nexpaq 0:6c56fb4bc5f0 459 return( 0 );
nexpaq 0:6c56fb4bc5f0 460 }
nexpaq 0:6c56fb4bc5f0 461
nexpaq 0:6c56fb4bc5f0 462 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
nexpaq 0:6c56fb4bc5f0 463
nexpaq 0:6c56fb4bc5f0 464 #endif /* MBEDTLS_CCM_C */