mbedtls/include/polarssl/ccm.h
2014-05-14 14:10:35 +02:00

135 lines
4.6 KiB
C

/**
* \file ccm.h
*
* \brief Counter with CBC-MAC (CCM) for 128-bit block ciphers
*
* Copyright (C) 2014, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef POLARSSL_CCM_H
#define POLARSSL_CCM_H
#include "cipher.h"
#define POLARSSL_ERR_CCM_BAD_INPUT -0x000D /**< Bad input parameters to function. */
#define POLARSSL_ERR_CCM_AUTH_FAILED -0x000F /**< Authenticated decryption failed. */
#ifdef __cplusplus
extern "C" {
#endif
/**
* \brief CCM context structure
*/
typedef struct {
cipher_context_t cipher_ctx; /*!< cipher context used */
}
ccm_context;
/**
* \brief CCM initialization (encryption and decryption)
*
* \param ctx CCM context to be initialized
* \param cipher cipher to use (a 128-bit block cipher)
* \param key encryption key
* \param keysize key size in bits (must be acceptable by the cipher)
*
* \return 0 if successful, or a cipher specific error code
*/
int ccm_init( ccm_context *ctx, cipher_id_t cipher,
const unsigned char *key, unsigned int keysize );
/**
* \brief Free a CCM context and underlying cipher sub-context
*
* \param ctx CCM context to free
*/
void ccm_free( ccm_context *ctx );
/**
* \brief CCM buffer encryption
*
* \param ctx CCM context
* \param length length of the input data in bytes
* \param iv nonce (initialization vector)
* \param iv_len length of IV in bytes
* must be 2, 3, 4, 5, 6, 7 or 8
* \param add additional data
* \param add_len length of additional data in bytes
* must be less than 2^16 - 2^8
* \param input buffer holding the input data
* \param output buffer for holding the output data
* must be at least 'length' bytes wide
* \param tag buffer for holding the tag
* \param 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.
*
* \return 0 if successful
*/
int ccm_encrypt_and_tag( 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 );
/**
* \brief CCM buffer authenticated decryption
*
* \param ctx CCM context
* \param length length of the input data
* \param iv initialization vector
* \param iv_len length of IV
* \param add additional data
* \param add_len length of additional data
* \param input buffer holding the input data
* \param output buffer for holding the output data
* \param tag buffer holding the tag
* \param tag_len length of the tag
*
* \return 0 if successful and authenticated,
* POLARSSL_ERR_CCM_AUTH_FAILED if tag does not match
*/
int ccm_auth_decrypt( 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 );
#if defined(POLARSSL_SELF_TEST) && defined(POLARSSL_AES_C)
/**
* \brief Checkup routine
*
* \return 0 if successful, or 1 if the test failed
*/
int ccm_self_test( int verbose );
#endif /* POLARSSL_SELF_TEST && POLARSSL_AES_C */
#ifdef __cplusplus
}
#endif
#endif /* POLARSSL_CGM_H */