mbedtls/library/cmac.c
2016-10-05 14:19:17 +01:00

857 lines
25 KiB
C

/*
* NIST SP800-38B compliant CMAC implementation
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
* Definition of CMAC:
* http://csrc.nist.gov/publications/nistpubs/800-38B/SP_800-38B.pdf
* RFC 4493 "The AES-CMAC Algorithm"
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_CMAC_C)
#include "mbedtls/cmac.h"
#include <string.h>
#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdio.h>
#define mbedtls_printf printf
#endif /* MBEDTLS_PLATFORM_C */
#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) {
volatile unsigned char *p = v; while( n-- ) *p++ = 0;
}
/*
* Initialize context
*/
void mbedtls_cmac_init( mbedtls_cmac_context *ctx )
{
memset( ctx, 0, sizeof( mbedtls_cmac_context ) );
}
/*
* Multiplication by u in the Galois field of GF(2^n)
*
* As explained in the paper, this can be computed:
* If MSB(p) = 0, then p = (p << 1)
* If MSB(p) = 1, then p = (p << 1) ^ R_n
* with R_64 = 0x1B and R_128 = 0x87
*
* Input and output MUST not point to the same buffer
* Block size must be 8 byes or 16 bytes.
*/
static int cmac_multiply_by_u( unsigned char *output,
const unsigned char *input,
size_t blocksize )
{
const unsigned char R_128 = 0x87;
const unsigned char R_64 = 0x1B;
unsigned char R_n, mask;
unsigned char overflow = 0x00;
int i, starting_index;
starting_index = blocksize -1;
if( blocksize == 16 )
{
R_n = R_128;
} else if( blocksize == 8 )
{
R_n = R_64;
} else
{
return( MBEDTLS_ERR_CMAC_BAD_INPUT );
}
for( i = starting_index; i >= 0; i-- )
{
output[i] = input[i] << 1 | overflow;
overflow = input[i] >> 7;
}
/* mask = ( input[0] >> 7 ) ? 0xff : 0x00
* using bit operations to avoid branches */
/* MSVC has a warning about unary minus on unsigned, but this is
* well-defined and precisely what we want to do here */
#if defined(_MSC_VER)
#pragma warning( push )
#pragma warning( disable : 4146 )
#endif
mask = - ( input[0] >> 7 );
#if defined(_MSC_VER)
#pragma warning( pop )
#endif
output[starting_index] ^= R_n & mask;
return( 0 );
}
/*
* Generate subkeys
*/
static int cmac_generate_subkeys( mbedtls_cmac_context *ctx )
{
int ret;
unsigned char *L;
size_t olen, block_size;
block_size = ctx->cipher_ctx.cipher_info->block_size;
L = mbedtls_calloc( block_size, sizeof( unsigned char ) );
if( L == NULL )
{
ret = MBEDTLS_ERR_CMAC_ALLOC_FAILED;
goto exit;
}
/* Calculate Ek(0) */
if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx,
L, block_size, L, &olen ) ) != 0 )
{
goto exit;
}
/*
* Generate K1 and K2
*/
if( ( ret = cmac_multiply_by_u( ctx->K1, L , block_size ) ) != 0 )
goto exit;
if( ( ret = cmac_multiply_by_u( ctx->K2, ctx->K1 , block_size ) ) != 0 )
goto exit;
exit:
if( L != NULL )
mbedtls_zeroize( L, sizeof( L ) );
mbedtls_free( L );
return( ret );
}
/*
* Set key and prepare context for use
*/
int mbedtls_cmac_setkey( mbedtls_cmac_context *ctx,
mbedtls_cipher_id_t cipher,
const unsigned char *key,
unsigned int keybits )
{
int ret;
const mbedtls_cipher_info_t *cipher_info;
cipher_info = mbedtls_cipher_info_from_values( cipher, keybits,
MBEDTLS_MODE_ECB );
if( cipher_info == NULL )
return( MBEDTLS_ERR_CMAC_BAD_INPUT );
mbedtls_cipher_free( &ctx->cipher_ctx );
if( ( ret = mbedtls_cipher_setup( &ctx->cipher_ctx, cipher_info ) ) != 0 )
return( ret );
if( ( ret = mbedtls_cipher_setkey( &ctx->cipher_ctx, key, keybits,
MBEDTLS_ENCRYPT ) ) != 0 )
{
return( ret );
}
ctx->K1 = mbedtls_calloc( cipher_info->block_size, sizeof( unsigned char ) );
ctx->K2 = mbedtls_calloc( cipher_info->block_size, sizeof( unsigned char ) );
if( ctx->K1 == NULL || ctx->K2 == NULL )
{
mbedtls_free(ctx->K1);
mbedtls_free(ctx->K2);
return( MBEDTLS_ERR_CMAC_ALLOC_FAILED );
}
return( cmac_generate_subkeys( ctx ) );
}
/*
* Free context
*/
void mbedtls_cmac_free( mbedtls_cmac_context *ctx )
{
int block_size;
block_size = ctx->cipher_ctx.cipher_info->block_size;
mbedtls_cipher_free( &ctx->cipher_ctx );
if( ctx->K1 != NULL )
mbedtls_zeroize( ctx->K1, block_size * sizeof( unsigned char ) );
if( ctx->K2 != NULL )
mbedtls_zeroize( ctx->K2, block_size * sizeof( unsigned char ) );
mbedtls_free( ctx->K1 );
mbedtls_free( ctx->K2 );
}
/*
* Create padded last block from (partial) last block.
*
* We can't use the padding option from the cipher layer, as it only works for
* CBC and we use ECB mode, and anyway we need to XOR K1 or K2 in addition.
*/
static void cmac_pad( unsigned char padded_block[16],
size_t padded_block_len,
const unsigned char *last_block,
size_t last_block_len )
{
size_t j;
for( j = 0; j < padded_block_len; j++ )
{
if( j < last_block_len )
padded_block[j] = last_block[j];
else if( j == last_block_len )
padded_block[j] = 0x80;
else
padded_block[j] = 0x00;
}
}
/*
* XOR Block
* Here, macro results in smaller compiled code than static inline function
*/
#define XOR_BLOCK( o, i1, i2 ) \
for( i = 0; i < block_size; i++ ) \
( o )[i] = ( i1 )[i] ^ ( i2 )[i];
/*
* Update the CMAC state using an input block
*/
#define UPDATE_CMAC( x ) \
do { \
XOR_BLOCK( state, ( x ), state ); \
if( ( ret = mbedtls_cipher_update( &ctx->cipher_ctx, \
state, block_size, \
state, &olen ) ) != 0 ) \
{ \
goto exit; \
} \
} while( 0 )
/*
* Generate tag on complete message
*/
int mbedtls_cmac_generate( mbedtls_cmac_context *ctx,
const unsigned char *input, size_t in_len,
unsigned char *tag, size_t tag_len )
{
unsigned char *state;
unsigned char *M_last;
int n, j, ret, needs_padding;
size_t olen, block_size, i;
ret = 0;
block_size = ctx->cipher_ctx.cipher_info->block_size;
state = mbedtls_calloc( block_size, sizeof( unsigned char ) );
M_last = mbedtls_calloc( block_size, sizeof( unsigned char ) );
if( state == NULL || M_last == NULL )
{
ret = MBEDTLS_ERR_CMAC_ALLOC_FAILED;
goto exit;
}
if( tag_len < 2 || tag_len > block_size || tag_len % 2 != 0 )
{
ret = MBEDTLS_ERR_CMAC_BAD_INPUT;
goto exit;
}
if( in_len == 0 )
needs_padding = 1;
else
needs_padding = in_len % block_size != 0;
n = in_len / block_size + needs_padding;
/* Calculate last block */
if( needs_padding )
{
cmac_pad( M_last, block_size, input + block_size * ( n - 1 ), in_len % block_size );
XOR_BLOCK( M_last, M_last, ctx->K2 );
}
else
{
/* Last block is complete block */
XOR_BLOCK( M_last, input + block_size * ( n - 1 ), ctx->K1 );
}
for( j = 0; j < n - 1; j++ )
UPDATE_CMAC( input + block_size * j );
UPDATE_CMAC( M_last );
memcpy( tag, state, tag_len );
exit:
mbedtls_free( state );
mbedtls_free( M_last );
return( ret );
}
#undef XOR_BLOCK
#undef UPDATE_CMAC
/*
* Verify tag on complete message
*/
int mbedtls_cmac_verify( mbedtls_cmac_context *ctx,
const unsigned char *input, size_t in_len,
const unsigned char *tag, size_t tag_len )
{
int ret;
unsigned char *check_tag;
unsigned char i;
int diff;
check_tag = mbedtls_calloc( ctx->cipher_ctx.cipher_info->block_size,
sizeof( unsigned char ) );
if( check_tag == NULL )
{
ret = MBEDTLS_ERR_CMAC_ALLOC_FAILED;
goto exit;
}
if( ( ret = mbedtls_cmac_generate( ctx, input, in_len,
check_tag, tag_len ) ) != 0 )
{
goto exit;
}
/* Check tag in "constant-time" */
for( diff = 0, i = 0; i < tag_len; i++ )
diff |= tag[i] ^ check_tag[i];
if( diff != 0 )
ret = MBEDTLS_ERR_CMAC_VERIFY_FAILED;
goto exit;
exit:
mbedtls_free( check_tag );
return( ret );
}
#ifdef MBEDTLS_AES_C
/*
* PRF based on CMAC with AES-128
* See RFC 4615
*/
int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_length,
const unsigned char *input, size_t in_len,
unsigned char tag[16] )
{
int ret;
mbedtls_cmac_context ctx;
unsigned char zero_key[16];
unsigned char int_key[16];
mbedtls_cmac_init(&ctx );
if( key_length == 16 )
{
/* Use key as is */
memcpy( int_key, key, 16 );
}
else
{
mbedtls_cmac_context zero_ctx;
/* Key is AES_CMAC( 0, key ) */
mbedtls_cmac_init( &zero_ctx );
memset( zero_key, 0, 16 );
ret = mbedtls_cmac_setkey( &zero_ctx, MBEDTLS_CIPHER_ID_AES,
zero_key, 8 * sizeof( zero_key ) );
if( ret != 0 )
goto exit;
ret = mbedtls_cmac_generate( &zero_ctx, key, key_length, int_key, 16 );
if( ret != 0 )
goto exit;
}
ret = mbedtls_cmac_setkey( &ctx, MBEDTLS_CIPHER_ID_AES,
int_key, 8 * sizeof( int_key ) );
if( ret != 0 )
goto exit;
ret = mbedtls_cmac_generate( &ctx, input, in_len, tag, 16 );
exit:
mbedtls_zeroize( int_key, sizeof( int_key ) );
mbedtls_cmac_free( &ctx );
return( ret );
}
#endif /* MBEDTLS_AES_C */
#ifdef MBEDTLS_SELF_TEST
/*
* CMAC test data from SP800-38B Appendix D.1 (corrected)
* http://csrc.nist.gov/publications/nistpubs/800-38B/Updated_CMAC_Examples.pdf
*
* AES-CMAC-PRF-128 test data from RFC 4615
* https://tools.ietf.org/html/rfc4615#page-4
*/
#define NB_CMAC_TESTS_PER_KEY 4
#define NB_PRF_TESTS 3
#define AES_BLOCK_SIZE 16
#define DES3_BLOCK_SIZE 8
#if defined(MBEDTLS_AES_C) || defined(MBEDTLS_DES_C)
/* All CMAC test inputs are truncated from the same 64 byte buffer. */
static const unsigned char test_message[] = {
0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96,
0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c,
0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11,
0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17,
0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10
};
#endif /* defined(MBEDTLS_AES_C) || defined(MBEDTLS_DES_C) */
#ifdef MBEDTLS_AES_C
/* Truncation point of message for AES CMAC tests */
static const unsigned int aes_message_lengths[NB_CMAC_TESTS_PER_KEY] = {
0,
16,
40,
64
};
/* AES 128 CMAC Test Data */
static const unsigned char aes_128_key[16] = {
0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6,
0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c
};
static const unsigned char aes_128_subkeys[2][AES_BLOCK_SIZE] = {
{
0xfb, 0xee, 0xd6, 0x18, 0x35, 0x71, 0x33, 0x66,
0x7c, 0x85, 0xe0, 0x8f, 0x72, 0x36, 0xa8, 0xde
},
{
0xf7, 0xdd, 0xac, 0x30, 0x6a, 0xe2, 0x66, 0xcc,
0xf9, 0x0b, 0xc1, 0x1e, 0xe4, 0x6d, 0x51, 0x3b
}
};
static const unsigned char aes_128_expected_result[NB_CMAC_TESTS_PER_KEY][AES_BLOCK_SIZE] = {
{
0xbb, 0x1d, 0x69, 0x29, 0xe9, 0x59, 0x37, 0x28,
0x7f, 0xa3, 0x7d, 0x12, 0x9b, 0x75, 0x67, 0x46
},
{
0x07, 0x0a, 0x16, 0xb4, 0x6b, 0x4d, 0x41, 0x44,
0xf7, 0x9b, 0xdd, 0x9d, 0xd0, 0x4a, 0x28, 0x7c
},
{
0xdf, 0xa6, 0x67, 0x47, 0xde, 0x9a, 0xe6, 0x30,
0x30, 0xca, 0x32, 0x61, 0x14, 0x97, 0xc8, 0x27
},
{
0x51, 0xf0, 0xbe, 0xbf, 0x7e, 0x3b, 0x9d, 0x92,
0xfc, 0x49, 0x74, 0x17, 0x79, 0x36, 0x3c, 0xfe
}
};
/* AES 192 CMAC Test Data */
static const unsigned char aes_192_key[24] = {
0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52,
0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5,
0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b
};
static const unsigned char aes_192_subkeys[2][AES_BLOCK_SIZE] = {
{
0x44, 0x8a, 0x5b, 0x1c, 0x93, 0x51, 0x4b, 0x27,
0x3e, 0xe6, 0x43, 0x9d, 0xd4, 0xda, 0xa2, 0x96
},
{
0x89, 0x14, 0xb6, 0x39, 0x26, 0xa2, 0x96, 0x4e,
0x7d, 0xcc, 0x87, 0x3b, 0xa9, 0xb5, 0x45, 0x2c
}
};
static const unsigned char aes_192_expected_result[NB_CMAC_TESTS_PER_KEY][AES_BLOCK_SIZE] = {
{
0xd1, 0x7d, 0xdf, 0x46, 0xad, 0xaa, 0xcd, 0xe5,
0x31, 0xca, 0xc4, 0x83, 0xde, 0x7a, 0x93, 0x67
},
{
0x9e, 0x99, 0xa7, 0xbf, 0x31, 0xe7, 0x10, 0x90,
0x06, 0x62, 0xf6, 0x5e, 0x61, 0x7c, 0x51, 0x84
},
{
0x8a, 0x1d, 0xe5, 0xbe, 0x2e, 0xb3, 0x1a, 0xad,
0x08, 0x9a, 0x82, 0xe6, 0xee, 0x90, 0x8b, 0x0e
},
{
0xa1, 0xd5, 0xdf, 0x0e, 0xed, 0x79, 0x0f, 0x79,
0x4d, 0x77, 0x58, 0x96, 0x59, 0xf3, 0x9a, 0x11
}
};
/* AES 256 CMAC Test Data */
static const unsigned char aes_256_key[32] = {
0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe,
0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7,
0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4
};
static const unsigned char aes_256_subkeys[2][AES_BLOCK_SIZE] = {
{
0xca, 0xd1, 0xed, 0x03, 0x29, 0x9e, 0xed, 0xac,
0x2e, 0x9a, 0x99, 0x80, 0x86, 0x21, 0x50, 0x2f
},
{
0x95, 0xa3, 0xda, 0x06, 0x53, 0x3d, 0xdb, 0x58,
0x5d, 0x35, 0x33, 0x01, 0x0c, 0x42, 0xa0, 0xd9
}
};
static const unsigned char aes_256_expected_result[NB_CMAC_TESTS_PER_KEY][AES_BLOCK_SIZE] = {
{
0x02, 0x89, 0x62, 0xf6, 0x1b, 0x7b, 0xf8, 0x9e,
0xfc, 0x6b, 0x55, 0x1f, 0x46, 0x67, 0xd9, 0x83
},
{
0x28, 0xa7, 0x02, 0x3f, 0x45, 0x2e, 0x8f, 0x82,
0xbd, 0x4b, 0xf2, 0x8d, 0x8c, 0x37, 0xc3, 0x5c
},
{
0xaa, 0xf3, 0xd8, 0xf1, 0xde, 0x56, 0x40, 0xc2,
0x32, 0xf5, 0xb1, 0x69, 0xb9, 0xc9, 0x11, 0xe6
},
{
0xe1, 0x99, 0x21, 0x90, 0x54, 0x9f, 0x6e, 0xd5,
0x69, 0x6a, 0x2c, 0x05, 0x6c, 0x31, 0x54, 0x10
}
};
#endif /* MBEDTLS_AES_C */
#ifdef MBEDTLS_DES_C
/* Truncation point of message for 3DES CMAC tests */
static const unsigned int des3_message_lengths[NB_CMAC_TESTS_PER_KEY] = {
0,
8,
20,
32
};
/* 3DES 2 Key CMAC Test Data */
static const unsigned char des3_2key_key[24] = {
0x4c, 0xf1, 0x51, 0x34, 0xa2, 0x85, 0x0d, 0xd5,
0x8a, 0x3d, 0x10, 0xba, 0x80, 0x57, 0x0d, 0x38,
0x4c, 0xf1, 0x51, 0x34, 0xa2, 0x85, 0x0d, 0xd5
};
static const unsigned char des3_2key_subkeys[2][8] = {
{
0x8e, 0xcf, 0x37, 0x3e, 0xd7, 0x1a, 0xfa, 0xef
},
{
0x1d, 0x9e, 0x6e, 0x7d, 0xae, 0x35, 0xf5, 0xc5
}
};
static const unsigned char des3_2key_expected_result[NB_CMAC_TESTS_PER_KEY][DES3_BLOCK_SIZE] = {
{
0xbd, 0x2e, 0xbf, 0x9a, 0x3b, 0xa0, 0x03, 0x61
},
{
0x4f, 0xf2, 0xab, 0x81, 0x3c, 0x53, 0xce, 0x83
},
{
0x62, 0xdd, 0x1b, 0x47, 0x19, 0x02, 0xbd, 0x4e
},
{
0x31, 0xb1, 0xe4, 0x31, 0xda, 0xbc, 0x4e, 0xb8
}
};
/* 3DES 3 Key CMAC Test Data */
static const unsigned char des3_3key_key[24] = {
0x8a, 0xa8, 0x3b, 0xf8, 0xcb, 0xda, 0x10, 0x62,
0x0b, 0xc1, 0xbf, 0x19, 0xfb, 0xb6, 0xcd, 0x58,
0xbc, 0x31, 0x3d, 0x4a, 0x37, 0x1c, 0xa8, 0xb5
};
static const unsigned char des3_3key_subkeys[2][8] = {
{
0x91, 0x98, 0xe9, 0xd3, 0x14, 0xe6, 0x53, 0x5f
},
{
0x23, 0x31, 0xd3, 0xa6, 0x29, 0xcc, 0xa6, 0xa5
}
};
static const unsigned char des3_3key_expected_result[NB_CMAC_TESTS_PER_KEY][DES3_BLOCK_SIZE] = {
{
0xb7, 0xa6, 0x88, 0xe1, 0x22, 0xff, 0xaf, 0x95
},
{
0x8e, 0x8f, 0x29, 0x31, 0x36, 0x28, 0x37, 0x97
},
{
0x74, 0x3d, 0xdb, 0xe0, 0xce, 0x2d, 0xc2, 0xed
},
{
0x33, 0xe6, 0xb1, 0x09, 0x24, 0x00, 0xea, 0xe5
}
};
#endif /* MBEDTLS_DES_C */
#ifdef MBEDTLS_AES_C
/* AES AES-CMAC-PRF-128 Test Data */
static const unsigned char PRFK[] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0xed, 0xcb
};
/* Sizes in bytes */
static const size_t PRFKlen[NB_PRF_TESTS] = {
18,
16,
10
};
/* PRF M */
static const unsigned char PRFM[] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0x10, 0x11, 0x12, 0x13
};
static const unsigned char PRFT[NB_PRF_TESTS][16] = {
{
0x84, 0xa3, 0x48, 0xa4, 0xa4, 0x5d, 0x23, 0x5b,
0xab, 0xff, 0xfc, 0x0d, 0x2b, 0x4d, 0xa0, 0x9a
},
{
0x98, 0x0a, 0xe8, 0x7b, 0x5f, 0x4c, 0x9c, 0x52,
0x14, 0xf5, 0xb6, 0xa8, 0x45, 0x5e, 0x4c, 0x2d
},
{
0x29, 0x0d, 0x9e, 0x11, 0x2e, 0xdb, 0x09, 0xee,
0x14, 0x1f, 0xcf, 0x64, 0xc0, 0xb7, 0x2f, 0x3d
}
};
#endif /* MBEDTLS_AES_C */
int test_cmac_with_cipher( int verbose,
char* testname,
const unsigned char* key,
int keybits,
const unsigned char* messages,
const unsigned int message_lengths[4],
const unsigned char* subkeys,
const unsigned char* expected_result,
mbedtls_cipher_id_t cipher_id,
int block_size )
{
const int num_tests = 4;
mbedtls_cmac_context ctx;
int i, ret;
unsigned char* tag;
tag = mbedtls_calloc( block_size, sizeof( unsigned char ) );
if( tag == NULL )
{
ret = MBEDTLS_ERR_CMAC_ALLOC_FAILED;
goto exit;
}
mbedtls_cmac_init( &ctx );
if( ( ret = mbedtls_cmac_setkey( &ctx, cipher_id, key, keybits ) ) != 0 )
{
if( verbose != 0 )
mbedtls_printf( " CMAC: setup failed\n" );
goto exit;
}
if( ( ret = memcmp( ctx.K1, subkeys, block_size ) != 0 ) ||
( ret = memcmp( ctx.K2, &subkeys[block_size], block_size ) != 0 ) )
{
if( verbose != 0 )
mbedtls_printf( " CMAC: subkey generation failed\n" );
goto exit;
}
for( i = 0; i < num_tests; i++ )
{
if( verbose != 0 )
mbedtls_printf( " %s CMAC #%u: ", testname, i +1 );
if( ( ret = mbedtls_cmac_generate( &ctx, messages, message_lengths[i], tag, block_size ) ) != 0 )
{
if( verbose != 0 )
mbedtls_printf( "failed\n" );
goto exit;
}
if( ( ret = memcmp( tag, &expected_result[i * block_size], block_size ) ) != 0 )
{
if( verbose != 0 )
mbedtls_printf( "failed\n" );
goto exit;
}
if( ( ret = mbedtls_cmac_verify( &ctx, messages, message_lengths[i], &expected_result[i * block_size], block_size ) != 0 ) )
{
if( verbose != 0 )
mbedtls_printf( "failed\n" );
goto exit;
}
mbedtls_printf( "passed\n" );
}
exit:
mbedtls_free( tag );
mbedtls_cmac_free( &ctx );
return( ret );
}
#ifdef MBEDTLS_AES_C
int test_aes128_cmac_prf( int verbose )
{
int i;
int ret;
unsigned char tag[16];
for( i = 0; i < NB_PRF_TESTS; i++ )
{
mbedtls_printf( " AES CMAC 128 PRF #%u: ", i );
ret = mbedtls_aes_cmac_prf_128( PRFK, PRFKlen[i], PRFM, 20, tag );
if( ret != 0 ||
memcmp( tag, PRFT[i], 16 ) != 0 )
{
if( verbose != 0 )
mbedtls_printf( "failed\n" );
return( ret );
} else if( verbose != 0 )
{
mbedtls_printf( "passed\n" );
}
}
return( ret );
}
#endif /* MBEDTLS_AES_C */
int mbedtls_cmac_self_test( int verbose )
{
int ret;
#ifdef MBEDTLS_AES_C
if( ( ret = test_cmac_with_cipher( verbose,
"AES 128",
aes_128_key,
128,
test_message,
aes_message_lengths,
(const unsigned char*) aes_128_subkeys,
(const unsigned char*) aes_128_expected_result,
MBEDTLS_CIPHER_ID_AES,
AES_BLOCK_SIZE ) !=0 ) )
{
return( ret );
}
if( ( ret = test_cmac_with_cipher( verbose,
"AES 192",
aes_192_key,
192,
test_message,
aes_message_lengths,
(const unsigned char*) aes_192_subkeys,
(const unsigned char*) aes_192_expected_result,
MBEDTLS_CIPHER_ID_AES,
AES_BLOCK_SIZE ) !=0 ) )
{
return( ret );
}
if( ( ret = test_cmac_with_cipher ( verbose,
"AES 256",
aes_256_key,
256,
test_message,
aes_message_lengths,
(const unsigned char*) aes_256_subkeys,
(const unsigned char*) aes_256_expected_result,
MBEDTLS_CIPHER_ID_AES,
AES_BLOCK_SIZE ) !=0 ) )
{
return( ret );
}
#endif /* MBEDTLS_AES_C */
#ifdef MBEDTLS_DES_C
if( ( ret = test_cmac_with_cipher( verbose,
"3DES 2 key",
des3_2key_key,
192,
test_message,
des3_message_lengths,
(const unsigned char*) des3_2key_subkeys,
(const unsigned char*) des3_2key_expected_result,
MBEDTLS_CIPHER_ID_3DES,
DES3_BLOCK_SIZE ) !=0 ) )
{
return( ret );
}
if( ( ret = test_cmac_with_cipher( verbose,
"3DES 3 key",
des3_3key_key,
192,
test_message,
des3_message_lengths,
(const unsigned char*) des3_3key_subkeys,
(const unsigned char*) des3_3key_expected_result,
MBEDTLS_CIPHER_ID_3DES,
DES3_BLOCK_SIZE ) !=0 ) )
{
return( ret );
}
#endif /* MBEDTLS_DES_C */
#ifdef MBEDTLS_AES_C
if( ( ret = test_aes128_cmac_prf( verbose ) != 0 ) )
return( ret );
#endif /* MBEDTLS_AES_C */
if( verbose != 0 )
mbedtls_printf( "\n" );
return( 0 );
}
#endif /* MBEDTLS_SELF_TEST */
#endif /* MBEDTLS_CMAC_C */