ccm.h

00001 /**
00002  * \file ccm.h
00003  *
00004  * \brief Counter with CBC-MAC (CCM) for 128-bit block ciphers
00005  *
00006  *  Copyright (C) 2014, ARM Limited, All Rights Reserved
00007  *
00008  *  This file is part of mbed TLS (https://tls.mbed.org)
00009  *
00010  *  This program is free software; you can redistribute it and/or modify
00011  *  it under the terms of the GNU General Public License as published by
00012  *  the Free Software Foundation; either version 2 of the License, or
00013  *  (at your option) any later version.
00014  *
00015  *  This program is distributed in the hope that it will be useful,
00016  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00017  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00018  *  GNU General Public License for more details.
00019  *
00020  *  You should have received a copy of the GNU General Public License along
00021  *  with this program; if not, write to the Free Software Foundation, Inc.,
00022  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
00023  */
00024 #ifndef POLARSSL_CCM_H
00025 #define POLARSSL_CCM_H
00026 
00027 #include "cipher.h"
00028 
00029 #define POLARSSL_ERR_CCM_BAD_INPUT      -0x000D /**< Bad input parameters to function. */
00030 #define POLARSSL_ERR_CCM_AUTH_FAILED    -0x000F /**< Authenticated decryption failed. */
00031 
00032 #ifdef __cplusplus
00033 extern "C" {
00034 #endif
00035 
00036 /**
00037  * \brief          CCM context structure
00038  */
00039 typedef struct {
00040     cipher_context_t cipher_ctx ;    /*!< cipher context used */
00041 }
00042 ccm_context;
00043 
00044 /**
00045  * \brief           CCM initialization (encryption and decryption)
00046  *
00047  * \param ctx       CCM context to be initialized
00048  * \param cipher    cipher to use (a 128-bit block cipher)
00049  * \param key       encryption key
00050  * \param keysize   key size in bits (must be acceptable by the cipher)
00051  *
00052  * \return          0 if successful, or a cipher specific error code
00053  */
00054 int ccm_init( ccm_context *ctx, cipher_id_t cipher,
00055               const unsigned char *key, unsigned int keysize );
00056 
00057 /**
00058  * \brief           Free a CCM context and underlying cipher sub-context
00059  *
00060  * \param ctx       CCM context to free
00061  */
00062 void ccm_free( ccm_context *ctx );
00063 
00064 /**
00065  * \brief           CCM buffer encryption
00066  *
00067  * \param ctx       CCM context
00068  * \param length    length of the input data in bytes
00069  * \param iv        nonce (initialization vector)
00070  * \param iv_len    length of IV in bytes
00071  *                  must be 2, 3, 4, 5, 6, 7 or 8
00072  * \param add       additional data
00073  * \param add_len   length of additional data in bytes
00074  *                  must be less than 2^16 - 2^8
00075  * \param input     buffer holding the input data
00076  * \param output    buffer for holding the output data
00077  *                  must be at least 'length' bytes wide
00078  * \param tag       buffer for holding the tag
00079  * \param tag_len   length of the tag to generate in bytes
00080  *                  must be 4, 6, 8, 10, 14 or 16
00081  *
00082  * \note            The tag is written to a separate buffer. To get the tag
00083  *                  concatenated with the output as in the CCM spec, use
00084  *                  tag = output + length and make sure the output buffer is
00085  *                  at least length + tag_len wide.
00086  *
00087  * \return          0 if successful
00088  */
00089 int ccm_encrypt_and_tag( ccm_context *ctx, size_t length,
00090                          const unsigned char *iv, size_t iv_len,
00091                          const unsigned char *add, size_t add_len,
00092                          const unsigned char *input, unsigned char *output,
00093                          unsigned char *tag, size_t tag_len );
00094 
00095 /**
00096  * \brief           CCM buffer authenticated decryption
00097  *
00098  * \param ctx       CCM context
00099  * \param length    length of the input data
00100  * \param iv        initialization vector
00101  * \param iv_len    length of IV
00102  * \param add       additional data
00103  * \param add_len   length of additional data
00104  * \param input     buffer holding the input data
00105  * \param output    buffer for holding the output data
00106  * \param tag       buffer holding the tag
00107  * \param tag_len   length of the tag
00108  *
00109  * \return         0 if successful and authenticated,
00110  *                 POLARSSL_ERR_CCM_AUTH_FAILED if tag does not match
00111  */
00112 int ccm_auth_decrypt( ccm_context *ctx, size_t length,
00113                       const unsigned char *iv, size_t iv_len,
00114                       const unsigned char *add, size_t add_len,
00115                       const unsigned char *input, unsigned char *output,
00116                       const unsigned char *tag, size_t tag_len );
00117 
00118 #if defined(POLARSSL_SELF_TEST) && defined(POLARSSL_AES_C)
00119 /**
00120  * \brief          Checkup routine
00121  *
00122  * \return         0 if successful, or 1 if the test failed
00123  */
00124 int ccm_self_test( int verbose );
00125 #endif /* POLARSSL_SELF_TEST && POLARSSL_AES_C */
00126 
00127 #ifdef __cplusplus
00128 }
00129 #endif
00130 
00131 #endif /* POLARSSL_CGM_H */
00132