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cmac.c File Reference

cmac.c File Reference

NIST SP800-38B compliant CMAC implementation for AES and 3DES. More...

Go to the source code of this file.

Functions

int mbedtls_cipher_cmac_starts (mbedtls_cipher_context_t *ctx, const unsigned char *key, size_t keybits)
 This function sets the CMAC key, and prepares to authenticate the input data.
int mbedtls_cipher_cmac_update (mbedtls_cipher_context_t *ctx, const unsigned char *input, size_t ilen)
 This function feeds an input buffer into an ongoing CMAC computation.
int mbedtls_cipher_cmac_finish (mbedtls_cipher_context_t *ctx, unsigned char *output)
 This function finishes the CMAC operation, and writes the result to the output buffer.
int mbedtls_cipher_cmac_reset (mbedtls_cipher_context_t *ctx)
 This function prepares the authentication of another message with the same key as the previous CMAC operation.
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)
 This function calculates the full generic CMAC on the input buffer with the provided key.
int mbedtls_cmac_self_test (int verbose)
 The CMAC checkup routine.

Detailed Description

NIST SP800-38B compliant CMAC implementation for AES and 3DES.

Copyright (C) 2006-2016, 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)

Definition in file cmac.c.


Function Documentation

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 
)

This function calculates the full generic CMAC on the input buffer with the provided key.

The function allocates the context, performs the calculation, and frees the context.

The CMAC result is calculated as output = generic CMAC(cmac key, input buffer).

Parameters:
cipher_infoThe cipher information.
keyThe CMAC key.
keylenThe length of the CMAC key in bits.
inputThe buffer holding the input data.
ilenThe length of the input data.
outputThe buffer for the generic CMAC result.
Returns:
0 on success.
MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 390 of file cmac.c.

int mbedtls_cipher_cmac_finish ( mbedtls_cipher_context_t ctx,
unsigned char *  output 
)

This function finishes the CMAC operation, and writes the result to the output buffer.

It is called after mbedtls_cipher_cmac_update(). It can be followed by mbedtls_cipher_cmac_reset() and mbedtls_cipher_cmac_update(), or mbedtls_cipher_free().

Parameters:
ctxThe cipher context used for the CMAC operation.
outputThe output buffer for the CMAC checksum result.
Returns:
0 on success.
MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 310 of file cmac.c.

int mbedtls_cipher_cmac_reset ( mbedtls_cipher_context_t ctx )

This function prepares the authentication of another message with the same key as the previous CMAC operation.

It is called after mbedtls_cipher_cmac_finish() and before mbedtls_cipher_cmac_update().

Parameters:
ctxThe cipher context used for the CMAC operation.
Returns:
0 on success.
MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 371 of file cmac.c.

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

This function sets the CMAC key, and prepares to authenticate the input data.

Must be called with an initialized cipher context.

Parameters:
ctxThe cipher context used for the CMAC operation, initialized as 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.
keyThe CMAC key.
keybitsThe length of the CMAC key in bits. Must be supported by the cipher.
Returns:
0 on success.
A cipher-specific error code on failure.

Definition at line 202 of file cmac.c.

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

This function feeds an input buffer into an ongoing CMAC computation.

It is called between mbedtls_cipher_cmac_starts() or mbedtls_cipher_cmac_reset(), and mbedtls_cipher_cmac_finish(). Can be called repeatedly.

Parameters:
ctxThe cipher context used for the CMAC operation.
inputThe buffer holding the input data.
ilenThe length of the input data.
Returns:
0 on success.
MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter verification fails.

Definition at line 242 of file cmac.c.

int mbedtls_cmac_self_test ( int  verbose )

The CMAC checkup routine.

Returns:
0 on success.
1 on failure.

Definition at line 920 of file cmac.c.