libavutil/des.h

   1 /*
   2  * DES encryption/decryption
   3  * Copyright (c) 2007 Reimar Doeffinger
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef AVUTIL_DES_H
  23 #define AVUTIL_DES_H
  24
  25 #include <stdint.h>
  26
  27 /**
  28  * @defgroup lavu_des DES
  29  * @ingroup lavu_crypto
  30  * @{
  31  */
  32
  33 typedef struct AVDES {
  34     uint64_t round_keys[3][16];
  35     int triple_des;
  36 } AVDES;
  37
  38 /**
  39  * Allocate an AVDES context.
  40  */
  41 AVDES *av_des_alloc(void);
  42
  43 /**
  44  * @brief Initializes an AVDES context.
  45  *
  46  * @param d pointer to a AVDES structure to initialize
  47  * @param key pointer to the key to use
  48  * @param key_bits must be 64 or 192
  49  * @param decrypt 0 for encryption/CBC-MAC, 1 for decryption
  50  * @return zero on success, negative value otherwise
  51  */
  52 int av_des_init(struct AVDES *d, const uint8_t *key, int key_bits, int decrypt);
  53
  54 /**
  55  * @brief Encrypts / decrypts using the DES algorithm.
  56  *
  57  * @param d pointer to the AVDES structure
  58  * @param dst destination array, can be equal to src, must be 8-byte aligned
  59  * @param src source array, can be equal to dst, must be 8-byte aligned, may be NULL
  60  * @param count number of 8 byte blocks
  61  * @param iv initialization vector for CBC mode, if NULL then ECB will be used,
  62  *           must be 8-byte aligned
  63  * @param decrypt 0 for encryption, 1 for decryption
  64  */
  65 void av_des_crypt(struct AVDES *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt);
  66
  67 /**
  68  * @brief Calculates CBC-MAC using the DES algorithm.
  69  *
  70  * @param d pointer to the AVDES structure
  71  * @param dst destination array, can be equal to src, must be 8-byte aligned
  72  * @param src source array, can be equal to dst, must be 8-byte aligned, may be NULL
  73  * @param count number of 8 byte blocks
  74  */
  75 void av_des_mac(struct AVDES *d, uint8_t *dst, const uint8_t *src, int count);
  76
  77 /**
  78  * @}
  79  */
  80
  81 #endif /* AVUTIL_DES_H */