lib/des.h

   1 /* des.h --- DES cipher implementation.
   2  * Copyright (C) 2005, 2007, 2009-2024 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 Lesser General Public License as
   6  * published by the Free Software Foundation; either version 2.1 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This file is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public License
  15  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  16  *
  17  */
  18
  19 /* Adapted for gnulib by Simon Josefsson, based on Libgcrypt. */
  20
  21 #ifndef DES_H
  22 #define DES_H
  23
  24 #include <stddef.h>
  25 #include <stdint.h>
  26
  27 #ifdef __cplusplus
  28 extern "C" {
  29 #endif
  30
  31
  32 /*
  33  * Encryption/Decryption context of DES
  34  */
  35 typedef struct
  36 {
  37   uint32_t encrypt_subkeys[32];
  38   uint32_t decrypt_subkeys[32];
  39 } gl_des_ctx;
  40
  41 /*
  42  * Encryption/Decryption context of Triple-DES
  43  */
  44 typedef struct
  45 {
  46   uint32_t encrypt_subkeys[96];
  47   uint32_t decrypt_subkeys[96];
  48 } gl_3des_ctx;
  49
  50 /* Check whether the 8 byte key is weak.  Does not check the parity
  51  * bits of the key but simple ignore them. */
  52 extern bool
  53 gl_des_is_weak_key (const char * key);
  54
  55 /*
  56  * DES
  57  * ---
  58  */
  59
  60 /* Fill a DES context CTX with subkeys calculated from 64bit KEY.
  61  * Does not check parity bits, but simply ignore them.  Does not check
  62  * for weak keys. */
  63 extern void
  64 gl_des_setkey (gl_des_ctx *ctx, const char * key);
  65
  66 /* Fill a DES context CTX with subkeys calculated from 64bit KEY, with
  67  * weak key checking.  Does not check parity bits, but simply ignore
  68  * them. */
  69 extern bool
  70 gl_des_makekey (gl_des_ctx *ctx, const char * key, size_t keylen);
  71
  72 /* Electronic Codebook Mode DES encryption/decryption of data
  73  * according to 'mode'. */
  74 extern void
  75 gl_des_ecb_crypt (gl_des_ctx *ctx, const char * from,  char * to, int mode);
  76
  77 #define gl_des_ecb_encrypt(ctx, from, to)  gl_des_ecb_crypt(ctx, from, to, 0)
  78 #define gl_des_ecb_decrypt(ctx, from, to)  gl_des_ecb_crypt(ctx, from, to, 1)
  79
  80 /* Triple-DES
  81  * ----------
  82  */
  83
  84 /* Fill a Triple-DES context CTX with subkeys calculated from two
  85  * 64bit keys in KEY1 and KEY2.  Does not check the parity bits of the
  86  * keys, but simply ignore them.  Does not check for weak keys. */
  87 extern void
  88 gl_3des_set2keys (gl_3des_ctx *ctx,
  89                   const char * key1,
  90                   const char * key2);
  91
  92 /*
  93  * Fill a Triple-DES context CTX with subkeys calculated from three
  94  * 64bit keys in KEY1, KEY2 and KEY3.  Does not check the parity bits
  95  * of the keys, but simply ignore them.  Does not check for weak
  96  * keys. */
  97 extern void
  98 gl_3des_set3keys (gl_3des_ctx *ctx,
  99                   const char * key1,
 100                   const char * key2,
 101                   const char * key3);
 102
 103 /* Fill a Triple-DES context CTX with subkeys calculated from three
 104  * concatenated 64bit keys in KEY, with weak key checking.  Does not
 105  * check the parity bits of the keys, but simply ignore them. */
 106 extern bool
 107 gl_3des_makekey (gl_3des_ctx *ctx,
 108                  const char * key,
 109                  size_t keylen);
 110
 111 /* Electronic Codebook Mode Triple-DES encryption/decryption of data
 112  * according to 'mode'.  Sometimes this mode is named 'EDE' mode
 113  * (Encryption-Decryption-Encryption). */
 114 extern void
 115 gl_3des_ecb_crypt (gl_3des_ctx *ctx,
 116                    const char * from,
 117                    char * to,
 118                    int mode);
 119
 120 #define gl_3des_ecb_encrypt(ctx, from, to) gl_3des_ecb_crypt(ctx,from,to,0)
 121 #define gl_3des_ecb_decrypt(ctx, from, to) gl_3des_ecb_crypt(ctx,from,to,1)
 122
 123
 124 #ifdef __cplusplus
 125 }
 126 #endif
 127
 128 #endif /* DES_H */