src/libstrongswan/crypto/mac.h

   1 /*
   2  * Copyright (C) 2012 Tobias Brunner
   3  * Copyright (C) 2005-2008 Martin Willi
   4  * Copyright (C) 2005 Jan Hutter
   5  * HSR Hochschule fuer Technik Rapperswil
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or (at your
  10  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * for more details.
  16  */
  17
  18 /**
  19  * @defgroup mac mac
  20  * @{ @ingroup crypto
  21  */
  22
  23 #ifndef MAC_H_
  24 #define MAC_H_
  25
  26 typedef struct mac_t mac_t;
  27
  28 #include <library.h>
  29
  30 /**
  31  * Generic interface for message authentication codes.
  32  *
  33  * Classes implementing this interface can use the PRF and signer wrappers.
  34  */
  35 struct mac_t {
  36
  37         /**
  38          * Generate message authentication code.
  39          *
  40          * If out is NULL, no result is given back.  A next call will
  41          * append the data to already supplied data.  If out is not NULL,
  42          * the mac of all apended data is calculated, written to out and the
  43          * internal state is reset.
  44          *
  45          * @param data          chunk of data to authenticate
  46          * @param out           pointer where the generated bytes will be written
  47          * @return                      TRUE if mac generated successfully
  48          */
  49         bool (*get_mac)(mac_t *this, chunk_t data,
  50                                         uint8_t *out) __attribute__((warn_unused_result));
  51
  52         /**
  53          * Get the size of the resulting MAC.
  54          *
  55          * @return                      block size in bytes
  56          */
  57         size_t (*get_mac_size)(mac_t *this);
  58
  59         /**
  60          * Set the key to be used for the MAC.
  61          *
  62          * Any key length must be accepted.
  63          *
  64          * @param key           key to set
  65          * @return                      TRUE if key set successfully
  66          */
  67         bool (*set_key)(mac_t *this,
  68                                         chunk_t key) __attribute__((warn_unused_result));
  69
  70         /**
  71          * Destroys a mac_t object.
  72          */
  73         void (*destroy) (mac_t *this);
  74 };
  75
  76 #endif /** MAC_H_ @}*/