Commit b439d455 authored by Brian Murray's avatar Brian Murray Committed by Simon Butcher

Only compile AES CMAC PRF support if MBEDTLS_AES_C is defined and other cleanups

parent 0f6af735
......@@ -33,12 +33,12 @@ extern "C" {
#endif
/**
* \brief CCM context structure
* \brief CMAC context structure
*/
typedef struct {
mbedtls_cipher_context_t cipher_ctx; /*!< cipher context used */
unsigned char* K1;
unsigned char* K2;
unsigned char* K1; /*!< CMAC Subkey 1 */
unsigned char* K2; /*!< CMAC Subkey 2 */
}
mbedtls_cmac_context;
......@@ -52,12 +52,12 @@ mbedtls_cmac_context;
void mbedtls_cmac_init( mbedtls_cmac_context *ctx );
/**
* \brief CMAC initialization
* \brief Initialize the CMAC context
*
* \param ctx CMAC context to be initialized
* \param cipher cipher to use (a 128-bit block cipher)
* \param cipher cipher to use
* \param key encryption key
* \param keybits key size in bits (must be acceptable by the cipher)
* \param keybits encryption key size in bits (must be acceptable by the cipher)
*
* \return 0 if successful, or a cipher specific error code
*/
......@@ -68,20 +68,22 @@ int mbedtls_cmac_setkey( mbedtls_cmac_context *ctx,
/**
* \brief Free a CMAC context and underlying cipher sub-context
* Securely wipes sub keys and other sensitive data.
*
* \param ctx CMAC context to free
*/
void mbedtls_cmac_free( mbedtls_cmac_context *ctx );
/**
* \brief CMAC generate
* \brief Generate a CMAC tag.
*
* \param ctx CMAC context
* \param input buffer holding the input data
* \param in_len length of the input data in bytes
* \param tag buffer for holding the generated tag
* \param tag_len length of the tag to generate in bytes
* must be between 4, 6, 8, 10, 14 or 16
* Must be 4, 6, 8 if cipher block size is 64
* Must be 4, 6, 8 0, 14 or 16 if cipher block size is 128
*
* \return 0 if successful
*/
......@@ -90,47 +92,48 @@ int mbedtls_cmac_generate( mbedtls_cmac_context *ctx,
unsigned char *tag, size_t tag_len );
/**
* \brief CMAC verify
* \brief Verify a CMAC tag.
*
* \param ctx CMAC context
* \param input buffer holding the input data
* \param in_len length of the input data in bytes
* \param tag buffer holding the tag to verify
* \param tag_len length of the tag to verify in bytes
* must be 4, 6, 8, 10, 14 or 16
*
* \return 0 if successful and authenticated,
* Must be 4, 6, 8 if cipher block size is 64
* Must be 4, 6, 8 0, 14 or 16 if cipher block size is 128
* \return 0 if successful and authenticated
* MBEDTLS_ERR_CMAC_VERIFY_FAILED if tag does not match
*/
int mbedtls_cmac_verify( mbedtls_cmac_context *ctx,
const unsigned char *input, size_t in_len,
const unsigned char *tag, size_t tag_len );
#ifdef MBEDTLS_AES_C
/**
* \brief AES-CMAC-128-PRF
* See RFC
* See RFC 4615 for details
*
* \param key PRF key
* \param key_len PRF key length
* \param input buffer holding the input data
* \param in_len length of the input data in bytes
* \param tag buffer holding the tag to verify (16 bytes)
* TODO: update description of tag
*
* \return 0 if successful
*/
int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_len,
const unsigned char *input, size_t in_len,
unsigned char *tag );
unsigned char tag[16] );
#endif /* MBEDTLS_AES_C */
#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
#if defined(MBEDTLS_SELF_TEST) && ( defined(MBEDTLS_AES_C) || defined(MBEDTLS_DES_C) )
/**
* \brief Checkup routine
*
* \return 0 if successful, or 1 if the test failed
*/
int mbedtls_cmac_self_test( int verbose );
#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
#endif /* MBEDTLS_SELF_TEST && ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
#ifdef __cplusplus
}
......
......@@ -73,7 +73,7 @@ void mbedtls_cmac_init( mbedtls_cmac_context *ctx )
*/
static int cmac_multiply_by_u( unsigned char *output,
const unsigned char *input,
size_t blocksize)
size_t blocksize )
{
const unsigned char R_128 = 0x87;
......@@ -84,12 +84,12 @@ static int cmac_multiply_by_u( unsigned char *output,
starting_index = blocksize -1;
if(blocksize == 16){
if( blocksize == 16 ){
R_n = R_128;
} else if(blocksize == 8) {
} else if( blocksize == 8 ) {
R_n = R_64;
} else {
return MBEDTLS_ERR_CMAC_BAD_INPUT;
return( MBEDTLS_ERR_CMAC_BAD_INPUT );
}
......@@ -113,7 +113,7 @@ static int cmac_multiply_by_u( unsigned char *output,
#endif
output[starting_index] ^= R_n & mask;
return 0;
return( 0 );
}
/*
......@@ -128,7 +128,7 @@ static int cmac_generate_subkeys( mbedtls_cmac_context *ctx )
ret = 0;
block_size = ctx->cipher_ctx.cipher_info->block_size;
L = mbedtls_calloc(block_size, sizeof(unsigned char));
L = mbedtls_calloc( block_size, sizeof( unsigned char ) );
/* Calculate Ek(0) */
memset( L, 0, block_size );
......@@ -141,15 +141,15 @@ static int cmac_generate_subkeys( mbedtls_cmac_context *ctx )
/*
* Generate K1 and K2
*/
if( ( ret = cmac_multiply_by_u( ctx->K1, L , block_size) ) != 0 )
if( ( ret = cmac_multiply_by_u( ctx->K1, L , block_size ) ) != 0 )
goto exit;
if( ( cmac_multiply_by_u( ctx->K2, ctx->K1 , block_size) ) != 0 )
if( ( cmac_multiply_by_u( ctx->K2, ctx->K1 , block_size ) ) != 0 )
goto exit;
exit:
mbedtls_zeroize( L, sizeof( L ) );
free(L);
return ret;
free( L );
return( ret );
}
/*
......@@ -195,8 +195,8 @@ void mbedtls_cmac_free( mbedtls_cmac_context *ctx )
mbedtls_cipher_free( &ctx->cipher_ctx );
mbedtls_zeroize(ctx->K1, block_size * sizeof( unsigned char ) );
mbedtls_zeroize(ctx->K2, block_size * sizeof( unsigned char ) );
mbedtls_zeroize( ctx->K1, block_size * sizeof( unsigned char ) );
mbedtls_zeroize( ctx->K2, block_size * sizeof( unsigned char ) );
mbedtls_free( ctx->K1 );
mbedtls_free( ctx->K2 );
}
......@@ -263,8 +263,8 @@ int mbedtls_cmac_generate( mbedtls_cmac_context *ctx,
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) );
state = mbedtls_calloc( block_size, sizeof( unsigned char ) );
M_last = mbedtls_calloc( block_size, sizeof( unsigned char ) );
/*
* Check in_len requirements: SP800-38B A
......@@ -302,8 +302,8 @@ int mbedtls_cmac_generate( mbedtls_cmac_context *ctx,
memcpy( tag, state, tag_len );
exit:
free(state);
free(M_last);
free( state );
free( M_last );
return( ret );
}
......@@ -322,8 +322,8 @@ int mbedtls_cmac_verify( mbedtls_cmac_context *ctx,
unsigned char i;
int diff;
check_tag = mbedtls_calloc(ctx->cipher_ctx.cipher_info->block_size,
sizeof(unsigned char) );
check_tag = mbedtls_calloc( ctx->cipher_ctx.cipher_info->block_size,
sizeof( unsigned char ) );
if( ( ret = mbedtls_cmac_generate( ctx, input, in_len,
check_tag, tag_len ) ) != 0 )
......@@ -340,24 +340,25 @@ int mbedtls_cmac_verify( mbedtls_cmac_context *ctx,
goto exit;
exit:
free(check_tag);
return ret;
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 )
unsigned char tag[16] )
{
int ret;
mbedtls_cmac_context ctx;
unsigned char zero_key[16];
unsigned char int_key[16];
mbedtls_cmac_init(&ctx);
mbedtls_cmac_init(&ctx );
if( key_length == 16 )
{
......@@ -368,7 +369,7 @@ int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_length,
{
mbedtls_cmac_context zero_ctx;
/* Key is AES_CMAC(0, key) */
/* 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,
......@@ -391,11 +392,10 @@ int mbedtls_aes_cmac_prf_128( const unsigned char *key, size_t key_length,
ret = mbedtls_cmac_generate( &ctx, input, in_len, tag, 16 );
exit:
mbedtls_cmac_free(&ctx);
mbedtls_cmac_free( &ctx );
return( ret );
}
#endif /* MBEDTLS_AES_C */
#ifdef MBEDTLS_SELF_TEST
/*
......@@ -647,7 +647,7 @@ static const unsigned char PRFT[NB_PRF_TESTS][16] = {
};
#endif /* MBEDTLS_AES_C */
int test_cmac_with_cipher(int verbose,
int test_cmac_with_cipher( int verbose,
const unsigned char* testname,
const unsigned char* key,
int keybits,
......@@ -656,7 +656,7 @@ int test_cmac_with_cipher(int verbose,
const unsigned char* subkeys,
const unsigned char* expected_result,
mbedtls_cipher_id_t cipher_id,
int block_size)
int block_size )
{
const int num_tests = 4;
mbedtls_cmac_context ctx;
......@@ -743,7 +743,7 @@ int mbedtls_cmac_self_test( int verbose )
int ret;
#ifdef MBEDTLS_AES_C
test_cmac_with_cipher(verbose,
test_cmac_with_cipher( verbose,
"AES 128",
aes_128_key,
128,
......@@ -754,7 +754,7 @@ int mbedtls_cmac_self_test( int verbose )
MBEDTLS_CIPHER_ID_AES,
AES_BLOCK_SIZE );
test_cmac_with_cipher(verbose,
test_cmac_with_cipher( verbose,
"AES 192",
aes_192_key,
192,
......@@ -765,7 +765,7 @@ int mbedtls_cmac_self_test( int verbose )
MBEDTLS_CIPHER_ID_AES,
AES_BLOCK_SIZE );
test_cmac_with_cipher(verbose,
test_cmac_with_cipher ( verbose,
"AES 256",
aes_256_key,
256,
......@@ -778,7 +778,7 @@ int mbedtls_cmac_self_test( int verbose )
#endif /* MBEDTLS_AES_C */
#ifdef MBEDTLS_DES_C
test_cmac_with_cipher(verbose,
test_cmac_with_cipher( verbose,
"3DES 2 key",
des3_2key_key,
192,
......@@ -789,7 +789,7 @@ int mbedtls_cmac_self_test( int verbose )
MBEDTLS_CIPHER_ID_3DES,
DES3_BLOCK_SIZE );
test_cmac_with_cipher(verbose,
test_cmac_with_cipher( verbose,
"3DES 3 key",
des3_3key_key,
192,
......
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