Only compile AES CMAC PRF support if MBEDTLS_AES_C is defined and other cleanups
diff --git a/include/mbedtls/cmac.h b/include/mbedtls/cmac.h
index 3e02f91..fed337d 100644
--- a/include/mbedtls/cmac.h
+++ b/include/mbedtls/cmac.h
@@ -33,12 +33,12 @@
#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 @@
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 @@
/**
* \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 @@
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
}
diff --git a/library/cmac.c b/library/cmac.c
index 0de85bc..3d22319 100644
--- a/library/cmac.c
+++ b/library/cmac.c
@@ -73,7 +73,7 @@
*/
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 @@
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 @@
#endif
output[starting_index] ^= R_n & mask;
- return 0;
+ return( 0 );
}
/*
@@ -128,7 +128,7 @@
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 @@
/*
* 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 @@
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 @@
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 @@
memcpy( tag, state, tag_len );
exit:
- free(state);
- free(M_last);
+ free( state );
+ free( M_last );
return( ret );
}
@@ -322,8 +322,8 @@
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 @@
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 @@
{
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 @@
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 @@
};
#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 @@
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 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 @@
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 @@
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 @@
#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 @@
MBEDTLS_CIPHER_ID_3DES,
DES3_BLOCK_SIZE );
- test_cmac_with_cipher(verbose,
+ test_cmac_with_cipher( verbose,
"3DES 3 key",
des3_3key_key,
192,