ccm.h File Reference

Detailed Description

Counter with CBC-MAC (CCM) for 128-bit block ciphers.

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 in file ccm.h.

#include "cipher.h"

Include dependency graph for ccm.h:

Go to the source code of this file.

Data Structures
struct	mbedtls_ccm_context
	CCM context structure. More...

Macros
#define	MBEDTLS_ERR_CCM_BAD_INPUT   -0x000D
	Bad input parameters to function. More...
#define	MBEDTLS_ERR_CCM_AUTH_FAILED   -0x000F
	Authenticated decryption failed. More...

Functions
void	mbedtls_ccm_init (mbedtls_ccm_context *ctx)
	Initialize CCM context (just makes references valid) Makes the context ready for mbedtls_ccm_setkey() or mbedtls_ccm_free(). More...
int	mbedtls_ccm_setkey (mbedtls_ccm_context *ctx, mbedtls_cipher_id_t cipher, const unsigned char *key, unsigned int keybits)
	CCM initialization (encryption and decryption) More...
void	mbedtls_ccm_free (mbedtls_ccm_context *ctx)
	Free a CCM context and underlying cipher sub-context. More...
int	mbedtls_ccm_encrypt_and_tag (mbedtls_ccm_context *ctx, size_t length, const unsigned char *iv, size_t iv_len, const unsigned char *add, size_t add_len, const unsigned char *input, unsigned char *output, unsigned char *tag, size_t tag_len)
	CCM buffer encryption. More...
int	mbedtls_ccm_auth_decrypt (mbedtls_ccm_context *ctx, size_t length, const unsigned char *iv, size_t iv_len, const unsigned char *add, size_t add_len, const unsigned char *input, unsigned char *output, const unsigned char *tag, size_t tag_len)
	CCM buffer authenticated decryption. More...

Macro Definition Documentation

#define MBEDTLS_ERR_CCM_AUTH_FAILED   -0x000F

Authenticated decryption failed.

Definition at line 29 of file ccm.h.

#define MBEDTLS_ERR_CCM_BAD_INPUT   -0x000D

Bad input parameters to function.

Definition at line 28 of file ccm.h.

Function Documentation

int mbedtls_ccm_auth_decrypt	(	mbedtls_ccm_context *	ctx,
		size_t	length,
		const unsigned char *	iv,
		size_t	iv_len,
		const unsigned char *	add,
		size_t	add_len,
		const unsigned char *	input,
		unsigned char *	output,
		const unsigned char *	tag,
		size_t	tag_len
	)

CCM buffer authenticated decryption.

Parameters

ctx	CCM context
length	length of the input data
iv	initialization vector
iv_len	length of IV
add	additional data
add_len	length of additional data
input	buffer holding the input data
output	buffer for holding the output data
tag	buffer holding the tag
tag_len	length of the tag

Returns

0 if successful and authenticated, MBEDTLS_ERR_CCM_AUTH_FAILED if tag does not match

int mbedtls_ccm_encrypt_and_tag	(	mbedtls_ccm_context *	ctx,
		size_t	length,
		const unsigned char *	iv,
		size_t	iv_len,
		const unsigned char *	add,
		size_t	add_len,
		const unsigned char *	input,
		unsigned char *	output,
		unsigned char *	tag,
		size_t	tag_len
	)

CCM buffer encryption.

Parameters

ctx	CCM context
length	length of the input data in bytes
iv	nonce (initialization vector)
iv_len	length of IV in bytes must be 2, 3, 4, 5, 6, 7 or 8
add	additional data
add_len	length of additional data in bytes must be less than 2^16 - 2^8
input	buffer holding the input data
output	buffer for holding the output data must be at least 'length' bytes wide
tag	buffer for holding the tag
tag_len	length of the tag to generate in bytes must be 4, 6, 8, 10, 14 or 16

Note

The tag is written to a separate buffer. To get the tag concatenated with the output as in the CCM spec, use tag = output + length and make sure the output buffer is at least length + tag_len wide.

Returns

0 if successful

void mbedtls_ccm_free

(

mbedtls_ccm_context *

ctx

)

Free a CCM context and underlying cipher sub-context.

Parameters

ctx	CCM context to free

void mbedtls_ccm_init

(

mbedtls_ccm_context *

ctx

)

Initialize CCM context (just makes references valid) Makes the context ready for mbedtls_ccm_setkey() or mbedtls_ccm_free().

Parameters

ctx	CCM context to initialize

int mbedtls_ccm_setkey	(	mbedtls_ccm_context *	ctx,
		mbedtls_cipher_id_t	cipher,
		const unsigned char *	key,
		unsigned int	keybits
	)

CCM initialization (encryption and decryption)

Parameters

ctx	CCM context to be initialized
cipher	cipher to use (a 128-bit block cipher)
key	encryption key
keybits	key size in bits (must be acceptable by the cipher)

Returns

0 if successful, or a cipher specific error code