cmac.h File Reference

Cipher-based Message Authentication Code (CMAC) Mode for Authentication. More...

#include "mbedtls/cipher.h"

Include dependency graph for cmac.h:

Go to the source code of this file.

Classes
struct	mbedtls_cmac_context_t

Macros
#define	MBEDTLS_AES_BLOCK_SIZE   16
#define	MBEDTLS_DES3_BLOCK_SIZE   8
#define	MBEDTLS_CIPHER_BLKSIZE_MAX   8 /* longest used by CMAC is 3DES */

Functions
int	mbedtls_cipher_cmac_starts (mbedtls_cipher_context_t *ctx, const unsigned char *key, size_t keybits)
	Set the CMAC key and prepare to authenticate the input data. Should be called with an initialized cipher context. More...
int	mbedtls_cipher_cmac_update (mbedtls_cipher_context_t *ctx, const unsigned char *input, size_t ilen)
	Generic CMAC process buffer. Called between mbedtls_cipher_cmac_starts() or mbedtls_cipher_cmac_reset() and mbedtls_cipher_cmac_finish(). May be called repeatedly. More...
int	mbedtls_cipher_cmac_finish (mbedtls_cipher_context_t *ctx, unsigned char *output)
	Output CMAC. Called after mbedtls_cipher_cmac_update(). Usually followed by mbedtls_cipher_cmac_reset(), then mbedtls_cipher_cmac_starts(), or mbedtls_cipher_free(). More...
int	mbedtls_cipher_cmac_reset (mbedtls_cipher_context_t *ctx)
	Prepare to authenticate a new message with the same key. Called after mbedtls_cipher_cmac_finish() and before mbedtls_cipher_cmac_update(). More...
int	mbedtls_cipher_cmac (const mbedtls_cipher_info_t *cipher_info, const unsigned char *key, size_t keylen, const unsigned char *input, size_t ilen, unsigned char *output)
	Output = Generic_CMAC( cmac key, input buffer ) More...

Detailed Description

Cipher-based Message Authentication Code (CMAC) Mode for Authentication.

Copyright (C) 2015-2016, 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)

Macro Definition Documentation

MBEDTLS_AES_BLOCK_SIZE

#define MBEDTLS_AES_BLOCK_SIZE   16

MBEDTLS_CIPHER_BLKSIZE_MAX

#define MBEDTLS_CIPHER_BLKSIZE_MAX   8 /* longest used by CMAC is 3DES */

MBEDTLS_DES3_BLOCK_SIZE

#define MBEDTLS_DES3_BLOCK_SIZE   8

Function Documentation

mbedtls_cipher_cmac()

int mbedtls_cipher_cmac	(	const mbedtls_cipher_info_t *	cipher_info,
		const unsigned char *	key,
		size_t	keylen,
		const unsigned char *	input,
		size_t	ilen,
		unsigned char *	output
	)

Output = Generic_CMAC( cmac key, input buffer )

Parameters

cipher_info	message digest info
key	CMAC key
keylen	length of the CMAC key in bits
input	buffer holding the data
ilen	length of the input data
output	Generic CMAC-result

Returns

0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

mbedtls_cipher_cmac_finish()

int mbedtls_cipher_cmac_finish	(	mbedtls_cipher_context_t *	ctx,
		unsigned char *	output
	)

Output CMAC. Called after mbedtls_cipher_cmac_update(). Usually followed by mbedtls_cipher_cmac_reset(), then mbedtls_cipher_cmac_starts(), or mbedtls_cipher_free().

Parameters

ctx	CMAC context
output	Generic CMAC checksum result

Returns

0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

mbedtls_cipher_cmac_reset()

int mbedtls_cipher_cmac_reset

(

mbedtls_cipher_context_t *

ctx

)

Prepare to authenticate a new message with the same key. Called after mbedtls_cipher_cmac_finish() and before mbedtls_cipher_cmac_update().

Parameters

ctx	CMAC context to be reset

Returns

0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

mbedtls_cipher_cmac_starts()

int mbedtls_cipher_cmac_starts	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	key,
		size_t	keybits
	)

Set the CMAC key and prepare to authenticate the input data. Should be called with an initialized cipher context.

Parameters

ctx	Cipher context. This should be a cipher context, initialized to be one of the following types: MBEDTLS_CIPHER_AES_128_ECB, MBEDTLS_CIPHER_AES_192_ECB, MBEDTLS_CIPHER_AES_256_ECB or MBEDTLS_CIPHER_DES_EDE3_ECB.
key	CMAC key
keybits	length of the CMAC key in bits (must be acceptable by the cipher)

Returns

0 if successful, or a cipher specific error code

mbedtls_cipher_cmac_update()

int mbedtls_cipher_cmac_update	(	mbedtls_cipher_context_t *	ctx,
		const unsigned char *	input,
		size_t	ilen
	)

Generic CMAC process buffer. Called between mbedtls_cipher_cmac_starts() or mbedtls_cipher_cmac_reset() and mbedtls_cipher_cmac_finish(). May be called repeatedly.

Parameters

ctx	CMAC context
input	buffer holding the data
ilen	length of the input data

Returns

0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.