Austin Blackstone / Mbed 2 deprecated client-lwip-lightswitch-demo-expanded

mbed client lightswitch demo

Dependencies:   mbed Socket lwip-eth lwip-sys lwip

Fork of mbed-client-classic-example-lwip by Austin Blackstone

mbedtls/source/ccm.c@11:cada08fc8a70, 2016-06-09 (annotated)

Committer:
mbedAustin
Date:
Thu Jun 09 17:08:36 2016 +0000
Revision:
11:cada08fc8a70
Commit for public Consumption

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbedAustin 11:cada08fc8a70 1 /*
mbedAustin 11:cada08fc8a70 2 * NIST SP800-38C compliant CCM implementation
mbedAustin 11:cada08fc8a70 3 *
mbedAustin 11:cada08fc8a70 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
mbedAustin 11:cada08fc8a70 5 * SPDX-License-Identifier: Apache-2.0
mbedAustin 11:cada08fc8a70 6 *
mbedAustin 11:cada08fc8a70 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
mbedAustin 11:cada08fc8a70 8 * not use this file except in compliance with the License.
mbedAustin 11:cada08fc8a70 9 * You may obtain a copy of the License at
mbedAustin 11:cada08fc8a70 10 *
mbedAustin 11:cada08fc8a70 11 * http://www.apache.org/licenses/LICENSE-2.0
mbedAustin 11:cada08fc8a70 12 *
mbedAustin 11:cada08fc8a70 13 * Unless required by applicable law or agreed to in writing, software
mbedAustin 11:cada08fc8a70 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
mbedAustin 11:cada08fc8a70 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbedAustin 11:cada08fc8a70 16 * See the License for the specific language governing permissions and
mbedAustin 11:cada08fc8a70 17 * limitations under the License.
mbedAustin 11:cada08fc8a70 18 *
mbedAustin 11:cada08fc8a70 19 * This file is part of mbed TLS (https://tls.mbed.org)
mbedAustin 11:cada08fc8a70 20 */
mbedAustin 11:cada08fc8a70 21
mbedAustin 11:cada08fc8a70 22 /*
mbedAustin 11:cada08fc8a70 23 * Definition of CCM:
mbedAustin 11:cada08fc8a70 24 * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
mbedAustin 11:cada08fc8a70 25 * RFC 3610 "Counter with CBC-MAC (CCM)"
mbedAustin 11:cada08fc8a70 26 *
mbedAustin 11:cada08fc8a70 27 * Related:
mbedAustin 11:cada08fc8a70 28 * RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
mbedAustin 11:cada08fc8a70 29 */
mbedAustin 11:cada08fc8a70 30
mbedAustin 11:cada08fc8a70 31 #if !defined(MBEDTLS_CONFIG_FILE)
mbedAustin 11:cada08fc8a70 32 #include "mbedtls/config.h"
mbedAustin 11:cada08fc8a70 33 #else
mbedAustin 11:cada08fc8a70 34 #include MBEDTLS_CONFIG_FILE
mbedAustin 11:cada08fc8a70 35 #endif
mbedAustin 11:cada08fc8a70 36
mbedAustin 11:cada08fc8a70 37 #if defined(MBEDTLS_CCM_C)
mbedAustin 11:cada08fc8a70 38
mbedAustin 11:cada08fc8a70 39 #include "mbedtls/ccm.h"
mbedAustin 11:cada08fc8a70 40
mbedAustin 11:cada08fc8a70 41 #include <string.h>
mbedAustin 11:cada08fc8a70 42
mbedAustin 11:cada08fc8a70 43 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
mbedAustin 11:cada08fc8a70 44 #if defined(MBEDTLS_PLATFORM_C)
mbedAustin 11:cada08fc8a70 45 #include "mbedtls/platform.h"
mbedAustin 11:cada08fc8a70 46 #else
mbedAustin 11:cada08fc8a70 47 #include <stdio.h>
mbedAustin 11:cada08fc8a70 48 #define mbedtls_printf printf
mbedAustin 11:cada08fc8a70 49 #endif /* MBEDTLS_PLATFORM_C */
mbedAustin 11:cada08fc8a70 50 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
mbedAustin 11:cada08fc8a70 51
mbedAustin 11:cada08fc8a70 52 /* Implementation that should never be optimized out by the compiler */
mbedAustin 11:cada08fc8a70 53 static void mbedtls_zeroize( void *v, size_t n ) {
mbedAustin 11:cada08fc8a70 54 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
mbedAustin 11:cada08fc8a70 55 }
mbedAustin 11:cada08fc8a70 56
mbedAustin 11:cada08fc8a70 57 #define CCM_ENCRYPT 0
mbedAustin 11:cada08fc8a70 58 #define CCM_DECRYPT 1
mbedAustin 11:cada08fc8a70 59
mbedAustin 11:cada08fc8a70 60 /*
mbedAustin 11:cada08fc8a70 61 * Initialize context
mbedAustin 11:cada08fc8a70 62 */
mbedAustin 11:cada08fc8a70 63 void mbedtls_ccm_init( mbedtls_ccm_context *ctx )
mbedAustin 11:cada08fc8a70 64 {
mbedAustin 11:cada08fc8a70 65 memset( ctx, 0, sizeof( mbedtls_ccm_context ) );
mbedAustin 11:cada08fc8a70 66 }
mbedAustin 11:cada08fc8a70 67
mbedAustin 11:cada08fc8a70 68 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
mbedAustin 11:cada08fc8a70 69 mbedtls_cipher_id_t cipher,
mbedAustin 11:cada08fc8a70 70 const unsigned char *key,
mbedAustin 11:cada08fc8a70 71 unsigned int keybits )
mbedAustin 11:cada08fc8a70 72 {
mbedAustin 11:cada08fc8a70 73 int ret;
mbedAustin 11:cada08fc8a70 74 const mbedtls_cipher_info_t *cipher_info;
mbedAustin 11:cada08fc8a70 75
mbedAustin 11:cada08fc8a70 76 cipher_info = mbedtls_cipher_info_from_values( cipher, keybits, MBEDTLS_MODE_ECB );
mbedAustin 11:cada08fc8a70 77 if( cipher_info == NULL )
mbedAustin 11:cada08fc8a70 78 return( MBEDTLS_ERR_CCM_BAD_INPUT );
mbedAustin 11:cada08fc8a70 79
mbedAustin 11:cada08fc8a70 80 if( cipher_info->block_size != 16 )
mbedAustin 11:cada08fc8a70 81 return( MBEDTLS_ERR_CCM_BAD_INPUT );
mbedAustin 11:cada08fc8a70 82
mbedAustin 11:cada08fc8a70 83 mbedtls_cipher_free( &ctx->cipher_ctx );
mbedAustin 11:cada08fc8a70 84
mbedAustin 11:cada08fc8a70 85 if( ( ret = mbedtls_cipher_setup( &ctx->cipher_ctx, cipher_info ) ) != 0 )
mbedAustin 11:cada08fc8a70 86 return( ret );
mbedAustin 11:cada08fc8a70 87
mbedAustin 11:cada08fc8a70 88 if( ( ret = mbedtls_cipher_setkey( &ctx->cipher_ctx, key, keybits,
mbedAustin 11:cada08fc8a70 89 MBEDTLS_ENCRYPT ) ) != 0 )
mbedAustin 11:cada08fc8a70 90 {
mbedAustin 11:cada08fc8a70 91 return( ret );
mbedAustin 11:cada08fc8a70 92 }
mbedAustin 11:cada08fc8a70 93
mbedAustin 11:cada08fc8a70 94 return( 0 );
mbedAustin 11:cada08fc8a70 95 }
mbedAustin 11:cada08fc8a70 96
mbedAustin 11:cada08fc8a70 97 /*
mbedAustin 11:cada08fc8a70 98 * Free context
mbedAustin 11:cada08fc8a70 99 */
mbedAustin 11:cada08fc8a70 100 void mbedtls_ccm_free( mbedtls_ccm_context *ctx )
mbedAustin 11:cada08fc8a70 101 {
mbedAustin 11:cada08fc8a70 102 mbedtls_cipher_free( &ctx->cipher_ctx );
mbedAustin 11:cada08fc8a70 103 mbedtls_zeroize( ctx, sizeof( mbedtls_ccm_context ) );
mbedAustin 11:cada08fc8a70 104 }
mbedAustin 11:cada08fc8a70 105
mbedAustin 11:cada08fc8a70 106 /*
mbedAustin 11:cada08fc8a70 107 * Macros for common operations.
mbedAustin 11:cada08fc8a70 108 * Results in smaller compiled code than static inline functions.
mbedAustin 11:cada08fc8a70 109 */
mbedAustin 11:cada08fc8a70 110
mbedAustin 11:cada08fc8a70 111 /*
mbedAustin 11:cada08fc8a70 112 * Update the CBC-MAC state in y using a block in b
mbedAustin 11:cada08fc8a70 113 * (Always using b as the source helps the compiler optimise a bit better.)
mbedAustin 11:cada08fc8a70 114 */
mbedAustin 11:cada08fc8a70 115 #define UPDATE_CBC_MAC \
mbedAustin 11:cada08fc8a70 116 for( i = 0; i < 16; i++ ) \
mbedAustin 11:cada08fc8a70 117 y[i] ^= b[i]; \
mbedAustin 11:cada08fc8a70 118 \
mbedAustin 11:cada08fc8a70 119 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, y, 16, y, &olen ) ) != 0 ) \
mbedAustin 11:cada08fc8a70 120 return( ret );
mbedAustin 11:cada08fc8a70 121
mbedAustin 11:cada08fc8a70 122 /*
mbedAustin 11:cada08fc8a70 123 * Encrypt or decrypt a partial block with CTR
mbedAustin 11:cada08fc8a70 124 * Warning: using b for temporary storage! src and dst must not be b!
mbedAustin 11:cada08fc8a70 125 * This avoids allocating one more 16 bytes buffer while allowing src == dst.
mbedAustin 11:cada08fc8a70 126 */
mbedAustin 11:cada08fc8a70 127 #define CTR_CRYPT( dst, src, len ) \
mbedAustin 11:cada08fc8a70 128 if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, ctr, 16, b, &olen ) ) != 0 ) \
mbedAustin 11:cada08fc8a70 129 return( ret ); \
mbedAustin 11:cada08fc8a70 130 \
mbedAustin 11:cada08fc8a70 131 for( i = 0; i < len; i++ ) \
mbedAustin 11:cada08fc8a70 132 dst[i] = src[i] ^ b[i];
mbedAustin 11:cada08fc8a70 133
mbedAustin 11:cada08fc8a70 134 /*
mbedAustin 11:cada08fc8a70 135 * Authenticated encryption or decryption
mbedAustin 11:cada08fc8a70 136 */
mbedAustin 11:cada08fc8a70 137 static int ccm_auth_crypt( mbedtls_ccm_context *ctx, int mode, size_t length,
mbedAustin 11:cada08fc8a70 138 const unsigned char *iv, size_t iv_len,
mbedAustin 11:cada08fc8a70 139 const unsigned char *add, size_t add_len,
mbedAustin 11:cada08fc8a70 140 const unsigned char *input, unsigned char *output,
mbedAustin 11:cada08fc8a70 141 unsigned char *tag, size_t tag_len )
mbedAustin 11:cada08fc8a70 142 {
mbedAustin 11:cada08fc8a70 143 int ret;
mbedAustin 11:cada08fc8a70 144 unsigned char i;
mbedAustin 11:cada08fc8a70 145 unsigned char q;
mbedAustin 11:cada08fc8a70 146 size_t len_left, olen;
mbedAustin 11:cada08fc8a70 147 unsigned char b[16];
mbedAustin 11:cada08fc8a70 148 unsigned char y[16];
mbedAustin 11:cada08fc8a70 149 unsigned char ctr[16];
mbedAustin 11:cada08fc8a70 150 const unsigned char *src;
mbedAustin 11:cada08fc8a70 151 unsigned char *dst;
mbedAustin 11:cada08fc8a70 152
mbedAustin 11:cada08fc8a70 153 /*
mbedAustin 11:cada08fc8a70 154 * Check length requirements: SP800-38C A.1
mbedAustin 11:cada08fc8a70 155 * Additional requirement: a < 2^16 - 2^8 to simplify the code.
mbedAustin 11:cada08fc8a70 156 * 'length' checked later (when writing it to the first block)
mbedAustin 11:cada08fc8a70 157 */
mbedAustin 11:cada08fc8a70 158 if( tag_len < 4 || tag_len > 16 || tag_len % 2 != 0 )
mbedAustin 11:cada08fc8a70 159 return( MBEDTLS_ERR_CCM_BAD_INPUT );
mbedAustin 11:cada08fc8a70 160
mbedAustin 11:cada08fc8a70 161 /* Also implies q is within bounds */
mbedAustin 11:cada08fc8a70 162 if( iv_len < 7 || iv_len > 13 )
mbedAustin 11:cada08fc8a70 163 return( MBEDTLS_ERR_CCM_BAD_INPUT );
mbedAustin 11:cada08fc8a70 164
mbedAustin 11:cada08fc8a70 165 if( add_len > 0xFF00 )
mbedAustin 11:cada08fc8a70 166 return( MBEDTLS_ERR_CCM_BAD_INPUT );
mbedAustin 11:cada08fc8a70 167
mbedAustin 11:cada08fc8a70 168 q = 16 - 1 - (unsigned char) iv_len;
mbedAustin 11:cada08fc8a70 169
mbedAustin 11:cada08fc8a70 170 /*
mbedAustin 11:cada08fc8a70 171 * First block B_0:
mbedAustin 11:cada08fc8a70 172 * 0 .. 0 flags
mbedAustin 11:cada08fc8a70 173 * 1 .. iv_len nonce (aka iv)
mbedAustin 11:cada08fc8a70 174 * iv_len+1 .. 15 length
mbedAustin 11:cada08fc8a70 175 *
mbedAustin 11:cada08fc8a70 176 * With flags as (bits):
mbedAustin 11:cada08fc8a70 177 * 7 0
mbedAustin 11:cada08fc8a70 178 * 6 add present?
mbedAustin 11:cada08fc8a70 179 * 5 .. 3 (t - 2) / 2
mbedAustin 11:cada08fc8a70 180 * 2 .. 0 q - 1
mbedAustin 11:cada08fc8a70 181 */
mbedAustin 11:cada08fc8a70 182 b[0] = 0;
mbedAustin 11:cada08fc8a70 183 b[0] |= ( add_len > 0 ) << 6;
mbedAustin 11:cada08fc8a70 184 b[0] |= ( ( tag_len - 2 ) / 2 ) << 3;
mbedAustin 11:cada08fc8a70 185 b[0] |= q - 1;
mbedAustin 11:cada08fc8a70 186
mbedAustin 11:cada08fc8a70 187 memcpy( b + 1, iv, iv_len );
mbedAustin 11:cada08fc8a70 188
mbedAustin 11:cada08fc8a70 189 for( i = 0, len_left = length; i < q; i++, len_left >>= 8 )
mbedAustin 11:cada08fc8a70 190 b[15-i] = (unsigned char)( len_left & 0xFF );
mbedAustin 11:cada08fc8a70 191
mbedAustin 11:cada08fc8a70 192 if( len_left > 0 )
mbedAustin 11:cada08fc8a70 193 return( MBEDTLS_ERR_CCM_BAD_INPUT );
mbedAustin 11:cada08fc8a70 194
mbedAustin 11:cada08fc8a70 195
mbedAustin 11:cada08fc8a70 196 /* Start CBC-MAC with first block */
mbedAustin 11:cada08fc8a70 197 memset( y, 0, 16 );
mbedAustin 11:cada08fc8a70 198 UPDATE_CBC_MAC;
mbedAustin 11:cada08fc8a70 199
mbedAustin 11:cada08fc8a70 200 /*
mbedAustin 11:cada08fc8a70 201 * If there is additional data, update CBC-MAC with
mbedAustin 11:cada08fc8a70 202 * add_len, add, 0 (padding to a block boundary)
mbedAustin 11:cada08fc8a70 203 */
mbedAustin 11:cada08fc8a70 204 if( add_len > 0 )
mbedAustin 11:cada08fc8a70 205 {
mbedAustin 11:cada08fc8a70 206 size_t use_len;
mbedAustin 11:cada08fc8a70 207 len_left = add_len;
mbedAustin 11:cada08fc8a70 208 src = add;
mbedAustin 11:cada08fc8a70 209
mbedAustin 11:cada08fc8a70 210 memset( b, 0, 16 );
mbedAustin 11:cada08fc8a70 211 b[0] = (unsigned char)( ( add_len >> 8 ) & 0xFF );
mbedAustin 11:cada08fc8a70 212 b[1] = (unsigned char)( ( add_len ) & 0xFF );
mbedAustin 11:cada08fc8a70 213
mbedAustin 11:cada08fc8a70 214 use_len = len_left < 16 - 2 ? len_left : 16 - 2;
mbedAustin 11:cada08fc8a70 215 memcpy( b + 2, src, use_len );
mbedAustin 11:cada08fc8a70 216 len_left -= use_len;
mbedAustin 11:cada08fc8a70 217 src += use_len;
mbedAustin 11:cada08fc8a70 218
mbedAustin 11:cada08fc8a70 219 UPDATE_CBC_MAC;
mbedAustin 11:cada08fc8a70 220
mbedAustin 11:cada08fc8a70 221 while( len_left > 0 )
mbedAustin 11:cada08fc8a70 222 {
mbedAustin 11:cada08fc8a70 223 use_len = len_left > 16 ? 16 : len_left;
mbedAustin 11:cada08fc8a70 224
mbedAustin 11:cada08fc8a70 225 memset( b, 0, 16 );
mbedAustin 11:cada08fc8a70 226 memcpy( b, src, use_len );
mbedAustin 11:cada08fc8a70 227 UPDATE_CBC_MAC;
mbedAustin 11:cada08fc8a70 228
mbedAustin 11:cada08fc8a70 229 len_left -= use_len;
mbedAustin 11:cada08fc8a70 230 src += use_len;
mbedAustin 11:cada08fc8a70 231 }
mbedAustin 11:cada08fc8a70 232 }
mbedAustin 11:cada08fc8a70 233
mbedAustin 11:cada08fc8a70 234 /*
mbedAustin 11:cada08fc8a70 235 * Prepare counter block for encryption:
mbedAustin 11:cada08fc8a70 236 * 0 .. 0 flags
mbedAustin 11:cada08fc8a70 237 * 1 .. iv_len nonce (aka iv)
mbedAustin 11:cada08fc8a70 238 * iv_len+1 .. 15 counter (initially 1)
mbedAustin 11:cada08fc8a70 239 *
mbedAustin 11:cada08fc8a70 240 * With flags as (bits):
mbedAustin 11:cada08fc8a70 241 * 7 .. 3 0
mbedAustin 11:cada08fc8a70 242 * 2 .. 0 q - 1
mbedAustin 11:cada08fc8a70 243 */
mbedAustin 11:cada08fc8a70 244 ctr[0] = q - 1;
mbedAustin 11:cada08fc8a70 245 memcpy( ctr + 1, iv, iv_len );
mbedAustin 11:cada08fc8a70 246 memset( ctr + 1 + iv_len, 0, q );
mbedAustin 11:cada08fc8a70 247 ctr[15] = 1;
mbedAustin 11:cada08fc8a70 248
mbedAustin 11:cada08fc8a70 249 /*
mbedAustin 11:cada08fc8a70 250 * Authenticate and {en,de}crypt the message.
mbedAustin 11:cada08fc8a70 251 *
mbedAustin 11:cada08fc8a70 252 * The only difference between encryption and decryption is
mbedAustin 11:cada08fc8a70 253 * the respective order of authentication and {en,de}cryption.
mbedAustin 11:cada08fc8a70 254 */
mbedAustin 11:cada08fc8a70 255 len_left = length;
mbedAustin 11:cada08fc8a70 256 src = input;
mbedAustin 11:cada08fc8a70 257 dst = output;
mbedAustin 11:cada08fc8a70 258
mbedAustin 11:cada08fc8a70 259 while( len_left > 0 )
mbedAustin 11:cada08fc8a70 260 {
mbedAustin 11:cada08fc8a70 261 size_t use_len = len_left > 16 ? 16 : len_left;
mbedAustin 11:cada08fc8a70 262
mbedAustin 11:cada08fc8a70 263 if( mode == CCM_ENCRYPT )
mbedAustin 11:cada08fc8a70 264 {
mbedAustin 11:cada08fc8a70 265 memset( b, 0, 16 );
mbedAustin 11:cada08fc8a70 266 memcpy( b, src, use_len );
mbedAustin 11:cada08fc8a70 267 UPDATE_CBC_MAC;
mbedAustin 11:cada08fc8a70 268 }
mbedAustin 11:cada08fc8a70 269
mbedAustin 11:cada08fc8a70 270 CTR_CRYPT( dst, src, use_len );
mbedAustin 11:cada08fc8a70 271
mbedAustin 11:cada08fc8a70 272 if( mode == CCM_DECRYPT )
mbedAustin 11:cada08fc8a70 273 {
mbedAustin 11:cada08fc8a70 274 memset( b, 0, 16 );
mbedAustin 11:cada08fc8a70 275 memcpy( b, dst, use_len );
mbedAustin 11:cada08fc8a70 276 UPDATE_CBC_MAC;
mbedAustin 11:cada08fc8a70 277 }
mbedAustin 11:cada08fc8a70 278
mbedAustin 11:cada08fc8a70 279 dst += use_len;
mbedAustin 11:cada08fc8a70 280 src += use_len;
mbedAustin 11:cada08fc8a70 281 len_left -= use_len;
mbedAustin 11:cada08fc8a70 282
mbedAustin 11:cada08fc8a70 283 /*
mbedAustin 11:cada08fc8a70 284 * Increment counter.
mbedAustin 11:cada08fc8a70 285 * No need to check for overflow thanks to the length check above.
mbedAustin 11:cada08fc8a70 286 */
mbedAustin 11:cada08fc8a70 287 for( i = 0; i < q; i++ )
mbedAustin 11:cada08fc8a70 288 if( ++ctr[15-i] != 0 )
mbedAustin 11:cada08fc8a70 289 break;
mbedAustin 11:cada08fc8a70 290 }
mbedAustin 11:cada08fc8a70 291
mbedAustin 11:cada08fc8a70 292 /*
mbedAustin 11:cada08fc8a70 293 * Authentication: reset counter and crypt/mask internal tag
mbedAustin 11:cada08fc8a70 294 */
mbedAustin 11:cada08fc8a70 295 for( i = 0; i < q; i++ )
mbedAustin 11:cada08fc8a70 296 ctr[15-i] = 0;
mbedAustin 11:cada08fc8a70 297
mbedAustin 11:cada08fc8a70 298 CTR_CRYPT( y, y, 16 );
mbedAustin 11:cada08fc8a70 299 memcpy( tag, y, tag_len );
mbedAustin 11:cada08fc8a70 300
mbedAustin 11:cada08fc8a70 301 return( 0 );
mbedAustin 11:cada08fc8a70 302 }
mbedAustin 11:cada08fc8a70 303
mbedAustin 11:cada08fc8a70 304 /*
mbedAustin 11:cada08fc8a70 305 * Authenticated encryption
mbedAustin 11:cada08fc8a70 306 */
mbedAustin 11:cada08fc8a70 307 int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
mbedAustin 11:cada08fc8a70 308 const unsigned char *iv, size_t iv_len,
mbedAustin 11:cada08fc8a70 309 const unsigned char *add, size_t add_len,
mbedAustin 11:cada08fc8a70 310 const unsigned char *input, unsigned char *output,
mbedAustin 11:cada08fc8a70 311 unsigned char *tag, size_t tag_len )
mbedAustin 11:cada08fc8a70 312 {
mbedAustin 11:cada08fc8a70 313 return( ccm_auth_crypt( ctx, CCM_ENCRYPT, length, iv, iv_len,
mbedAustin 11:cada08fc8a70 314 add, add_len, input, output, tag, tag_len ) );
mbedAustin 11:cada08fc8a70 315 }
mbedAustin 11:cada08fc8a70 316
mbedAustin 11:cada08fc8a70 317 /*
mbedAustin 11:cada08fc8a70 318 * Authenticated decryption
mbedAustin 11:cada08fc8a70 319 */
mbedAustin 11:cada08fc8a70 320 int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
mbedAustin 11:cada08fc8a70 321 const unsigned char *iv, size_t iv_len,
mbedAustin 11:cada08fc8a70 322 const unsigned char *add, size_t add_len,
mbedAustin 11:cada08fc8a70 323 const unsigned char *input, unsigned char *output,
mbedAustin 11:cada08fc8a70 324 const unsigned char *tag, size_t tag_len )
mbedAustin 11:cada08fc8a70 325 {
mbedAustin 11:cada08fc8a70 326 int ret;
mbedAustin 11:cada08fc8a70 327 unsigned char check_tag[16];
mbedAustin 11:cada08fc8a70 328 unsigned char i;
mbedAustin 11:cada08fc8a70 329 int diff;
mbedAustin 11:cada08fc8a70 330
mbedAustin 11:cada08fc8a70 331 if( ( ret = ccm_auth_crypt( ctx, CCM_DECRYPT, length,
mbedAustin 11:cada08fc8a70 332 iv, iv_len, add, add_len,
mbedAustin 11:cada08fc8a70 333 input, output, check_tag, tag_len ) ) != 0 )
mbedAustin 11:cada08fc8a70 334 {
mbedAustin 11:cada08fc8a70 335 return( ret );
mbedAustin 11:cada08fc8a70 336 }
mbedAustin 11:cada08fc8a70 337
mbedAustin 11:cada08fc8a70 338 /* Check tag in "constant-time" */
mbedAustin 11:cada08fc8a70 339 for( diff = 0, i = 0; i < tag_len; i++ )
mbedAustin 11:cada08fc8a70 340 diff |= tag[i] ^ check_tag[i];
mbedAustin 11:cada08fc8a70 341
mbedAustin 11:cada08fc8a70 342 if( diff != 0 )
mbedAustin 11:cada08fc8a70 343 {
mbedAustin 11:cada08fc8a70 344 mbedtls_zeroize( output, length );
mbedAustin 11:cada08fc8a70 345 return( MBEDTLS_ERR_CCM_AUTH_FAILED );
mbedAustin 11:cada08fc8a70 346 }
mbedAustin 11:cada08fc8a70 347
mbedAustin 11:cada08fc8a70 348 return( 0 );
mbedAustin 11:cada08fc8a70 349 }
mbedAustin 11:cada08fc8a70 350
mbedAustin 11:cada08fc8a70 351
mbedAustin 11:cada08fc8a70 352 #if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
mbedAustin 11:cada08fc8a70 353 /*
mbedAustin 11:cada08fc8a70 354 * Examples 1 to 3 from SP800-38C Appendix C
mbedAustin 11:cada08fc8a70 355 */
mbedAustin 11:cada08fc8a70 356
mbedAustin 11:cada08fc8a70 357 #define NB_TESTS 3
mbedAustin 11:cada08fc8a70 358
mbedAustin 11:cada08fc8a70 359 /*
mbedAustin 11:cada08fc8a70 360 * The data is the same for all tests, only the used length changes
mbedAustin 11:cada08fc8a70 361 */
mbedAustin 11:cada08fc8a70 362 static const unsigned char key[] = {
mbedAustin 11:cada08fc8a70 363 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
mbedAustin 11:cada08fc8a70 364 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
mbedAustin 11:cada08fc8a70 365 };
mbedAustin 11:cada08fc8a70 366
mbedAustin 11:cada08fc8a70 367 static const unsigned char iv[] = {
mbedAustin 11:cada08fc8a70 368 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
mbedAustin 11:cada08fc8a70 369 0x18, 0x19, 0x1a, 0x1b
mbedAustin 11:cada08fc8a70 370 };
mbedAustin 11:cada08fc8a70 371
mbedAustin 11:cada08fc8a70 372 static const unsigned char ad[] = {
mbedAustin 11:cada08fc8a70 373 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
mbedAustin 11:cada08fc8a70 374 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
mbedAustin 11:cada08fc8a70 375 0x10, 0x11, 0x12, 0x13
mbedAustin 11:cada08fc8a70 376 };
mbedAustin 11:cada08fc8a70 377
mbedAustin 11:cada08fc8a70 378 static const unsigned char msg[] = {
mbedAustin 11:cada08fc8a70 379 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
mbedAustin 11:cada08fc8a70 380 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
mbedAustin 11:cada08fc8a70 381 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
mbedAustin 11:cada08fc8a70 382 };
mbedAustin 11:cada08fc8a70 383
mbedAustin 11:cada08fc8a70 384 static const size_t iv_len [NB_TESTS] = { 7, 8, 12 };
mbedAustin 11:cada08fc8a70 385 static const size_t add_len[NB_TESTS] = { 8, 16, 20 };
mbedAustin 11:cada08fc8a70 386 static const size_t msg_len[NB_TESTS] = { 4, 16, 24 };
mbedAustin 11:cada08fc8a70 387 static const size_t tag_len[NB_TESTS] = { 4, 6, 8 };
mbedAustin 11:cada08fc8a70 388
mbedAustin 11:cada08fc8a70 389 static const unsigned char res[NB_TESTS][32] = {
mbedAustin 11:cada08fc8a70 390 { 0x71, 0x62, 0x01, 0x5b, 0x4d, 0xac, 0x25, 0x5d },
mbedAustin 11:cada08fc8a70 391 { 0xd2, 0xa1, 0xf0, 0xe0, 0x51, 0xea, 0x5f, 0x62,
mbedAustin 11:cada08fc8a70 392 0x08, 0x1a, 0x77, 0x92, 0x07, 0x3d, 0x59, 0x3d,
mbedAustin 11:cada08fc8a70 393 0x1f, 0xc6, 0x4f, 0xbf, 0xac, 0xcd },
mbedAustin 11:cada08fc8a70 394 { 0xe3, 0xb2, 0x01, 0xa9, 0xf5, 0xb7, 0x1a, 0x7a,
mbedAustin 11:cada08fc8a70 395 0x9b, 0x1c, 0xea, 0xec, 0xcd, 0x97, 0xe7, 0x0b,
mbedAustin 11:cada08fc8a70 396 0x61, 0x76, 0xaa, 0xd9, 0xa4, 0x42, 0x8a, 0xa5,
mbedAustin 11:cada08fc8a70 397 0x48, 0x43, 0x92, 0xfb, 0xc1, 0xb0, 0x99, 0x51 }
mbedAustin 11:cada08fc8a70 398 };
mbedAustin 11:cada08fc8a70 399
mbedAustin 11:cada08fc8a70 400 int mbedtls_ccm_self_test( int verbose )
mbedAustin 11:cada08fc8a70 401 {
mbedAustin 11:cada08fc8a70 402 mbedtls_ccm_context ctx;
mbedAustin 11:cada08fc8a70 403 unsigned char out[32];
mbedAustin 11:cada08fc8a70 404 size_t i;
mbedAustin 11:cada08fc8a70 405 int ret;
mbedAustin 11:cada08fc8a70 406
mbedAustin 11:cada08fc8a70 407 mbedtls_ccm_init( &ctx );
mbedAustin 11:cada08fc8a70 408
mbedAustin 11:cada08fc8a70 409 if( mbedtls_ccm_setkey( &ctx, MBEDTLS_CIPHER_ID_AES, key, 8 * sizeof key ) != 0 )
mbedAustin 11:cada08fc8a70 410 {
mbedAustin 11:cada08fc8a70 411 if( verbose != 0 )
mbedAustin 11:cada08fc8a70 412 mbedtls_printf( " CCM: setup failed" );
mbedAustin 11:cada08fc8a70 413
mbedAustin 11:cada08fc8a70 414 return( 1 );
mbedAustin 11:cada08fc8a70 415 }
mbedAustin 11:cada08fc8a70 416
mbedAustin 11:cada08fc8a70 417 for( i = 0; i < NB_TESTS; i++ )
mbedAustin 11:cada08fc8a70 418 {
mbedAustin 11:cada08fc8a70 419 if( verbose != 0 )
mbedAustin 11:cada08fc8a70 420 mbedtls_printf( " CCM-AES #%u: ", (unsigned int) i + 1 );
mbedAustin 11:cada08fc8a70 421
mbedAustin 11:cada08fc8a70 422 ret = mbedtls_ccm_encrypt_and_tag( &ctx, msg_len[i],
mbedAustin 11:cada08fc8a70 423 iv, iv_len[i], ad, add_len[i],
mbedAustin 11:cada08fc8a70 424 msg, out,
mbedAustin 11:cada08fc8a70 425 out + msg_len[i], tag_len[i] );
mbedAustin 11:cada08fc8a70 426
mbedAustin 11:cada08fc8a70 427 if( ret != 0 ||
mbedAustin 11:cada08fc8a70 428 memcmp( out, res[i], msg_len[i] + tag_len[i] ) != 0 )
mbedAustin 11:cada08fc8a70 429 {
mbedAustin 11:cada08fc8a70 430 if( verbose != 0 )
mbedAustin 11:cada08fc8a70 431 mbedtls_printf( "failed\n" );
mbedAustin 11:cada08fc8a70 432
mbedAustin 11:cada08fc8a70 433 return( 1 );
mbedAustin 11:cada08fc8a70 434 }
mbedAustin 11:cada08fc8a70 435
mbedAustin 11:cada08fc8a70 436 ret = mbedtls_ccm_auth_decrypt( &ctx, msg_len[i],
mbedAustin 11:cada08fc8a70 437 iv, iv_len[i], ad, add_len[i],
mbedAustin 11:cada08fc8a70 438 res[i], out,
mbedAustin 11:cada08fc8a70 439 res[i] + msg_len[i], tag_len[i] );
mbedAustin 11:cada08fc8a70 440
mbedAustin 11:cada08fc8a70 441 if( ret != 0 ||
mbedAustin 11:cada08fc8a70 442 memcmp( out, msg, msg_len[i] ) != 0 )
mbedAustin 11:cada08fc8a70 443 {
mbedAustin 11:cada08fc8a70 444 if( verbose != 0 )
mbedAustin 11:cada08fc8a70 445 mbedtls_printf( "failed\n" );
mbedAustin 11:cada08fc8a70 446
mbedAustin 11:cada08fc8a70 447 return( 1 );
mbedAustin 11:cada08fc8a70 448 }
mbedAustin 11:cada08fc8a70 449
mbedAustin 11:cada08fc8a70 450 if( verbose != 0 )
mbedAustin 11:cada08fc8a70 451 mbedtls_printf( "passed\n" );
mbedAustin 11:cada08fc8a70 452 }
mbedAustin 11:cada08fc8a70 453
mbedAustin 11:cada08fc8a70 454 mbedtls_ccm_free( &ctx );
mbedAustin 11:cada08fc8a70 455
mbedAustin 11:cada08fc8a70 456 if( verbose != 0 )
mbedAustin 11:cada08fc8a70 457 mbedtls_printf( "\n" );
mbedAustin 11:cada08fc8a70 458
mbedAustin 11:cada08fc8a70 459 return( 0 );
mbedAustin 11:cada08fc8a70 460 }
mbedAustin 11:cada08fc8a70 461
mbedAustin 11:cada08fc8a70 462 #endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
mbedAustin 11:cada08fc8a70 463
mbedAustin 11:cada08fc8a70 464 #endif /* MBEDTLS_CCM_C */