gl/des.h

   1 /* des.h --- DES cipher implementation.
   2  * Copyright (C) 2005 Free Software Foundation, Inc.
   3  *
   4  * This file is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published
   6  * by the Free Software Foundation; either version 2, or (at your
   7  * option) any later version.
   8  *
   9  * This file is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this file; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA.
  18  *
  19  */
  20
  21 /* Adapted for gnulib by Simon Josefsson, based on Libgcrypt. */
  22
  23 #ifndef DES_H
  24 # define DES_H
  25
  26 #include <stddef.h>
  27 #include <stdint.h>
  28 #include <stdbool.h>
  29
  30 /*
  31  * Encryption/Decryption context of DES
  32  */
  33 typedef struct
  34 {
  35   uint32_t encrypt_subkeys[32];
  36   uint32_t decrypt_subkeys[32];
  37 } des_ctx;
  38
  39 /*
  40  * Encryption/Decryption context of Triple-DES
  41  */
  42 typedef struct
  43 {
  44   uint32_t encrypt_subkeys[96];
  45   uint32_t decrypt_subkeys[96];
  46 } tripledes_ctx;
  47
  48 /* Check whether the 8 byte key is weak.  Does not check the parity
  49  * bits of the key but simple ignore them. */
  50 extern bool
  51 des_is_weak_key (const char * key);
  52
  53 /*
  54  * DES
  55  * ---
  56  */
  57
  58 /* Fill a DES context CTX with subkeys calculated from 64bit KEY.
  59  * Does not check parity bits, but simply ignore them.  Does not check
  60  * for weak keys. */
  61 extern void
  62 des_setkey (des_ctx *ctx, const char * key);
  63
  64 /* Fill a DES context CTX with subkeys calculated from 64bit KEY, with
  65  * weak key checking.  Does not check parity bits, but simply ignore
  66  * them. */
  67 extern bool
  68 des_makekey (des_ctx *ctx, const char * key, size_t keylen);
  69
  70 /* Electronic Codebook Mode DES encryption/decryption of data
  71  * according to 'mode'. */
  72 extern void
  73 des_ecb_crypt (des_ctx *ctx, const char * from,  char * to, int mode);
  74
  75 #define des_ecb_encrypt(ctx, from, to)        des_ecb_crypt(ctx, from, to, 0)
  76 #define des_ecb_decrypt(ctx, from, to)        des_ecb_crypt(ctx, from, to, 1)
  77
  78 /* Triple-DES
  79  * ----------
  80  */
  81
  82 /* Fill a Triple-DES context CTX with subkeys calculated from two
  83  * 64bit keys in KEY1 and KEY2.  Does not check the parity bits of the
  84  * keys, but simply ignore them.  Does not check for weak keys. */
  85 extern void
  86 tripledes_set2keys (tripledes_ctx *ctx, const char * key1, const char * key2);
  87
  88 /*
  89  * Fill a Triple-DES context CTX with subkeys calculated from three
  90  * 64bit keys in KEY1, KEY2 and KEY3.  Does not check the parity bits
  91  * of the keys, but simply ignore them.  Does not check for weak
  92  * keys. */
  93 extern void
  94 tripledes_set3keys (tripledes_ctx *ctx, const char * key1,
  95                     const char * key2, const char * key3);
  96
  97 /* Fill a Triple-DES context CTX with subkeys calculated from three
  98  * concatenated 64bit keys in KEY, with weak key checking.  Does not
  99  * check the parity bits of the keys, but simply ignore them. */
 100 extern bool
 101 tripledes_makekey (tripledes_ctx *ctx, const char * key, size_t keylen);
 102
 103 /* Electronic Codebook Mode Triple-DES encryption/decryption of data
 104  * according to 'mode'.  Sometimes this mode is named 'EDE' mode
 105  * (Encryption-Decryption-Encryption). */
 106 extern void
 107 tripledes_ecb_crypt (tripledes_ctx *ctx,
 108                      const char * from,
 109                      char * to, int mode);
 110
 111 #define tripledes_ecb_encrypt(ctx, from, to) tripledes_ecb_crypt(ctx,from,to,0)
 112 #define tripledes_ecb_decrypt(ctx, from, to) tripledes_ecb_crypt(ctx,from,to,1)
 113
 114 #endif /* DES_H */