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 /*
  28  * Encryption/Decryption context of DES
  29  */
  30 typedef struct
  31 {
  32   uint32_t encrypt_subkeys[32];
  33   uint32_t decrypt_subkeys[32];
  34 } gl_des_ctx;
  35
  36 /*
  37  * Encryption/Decryption context of Triple-DES
  38  */
  39 typedef struct
  40 {
  41   uint32_t encrypt_subkeys[96];
  42   uint32_t decrypt_subkeys[96];
  43 } gl_3des_ctx;
  44
  45 /* Check whether the 8 byte key is weak.  Does not check the parity
  46  * bits of the key but simple ignore them. */
  47 extern bool
  48 gl_des_is_weak_key (const char * key);
  49
  50 /*
  51  * DES
  52  * ---
  53  */
  54
  55 /* Fill a DES context CTX with subkeys calculated from 64bit KEY.
  56  * Does not check parity bits, but simply ignore them.  Does not check
  57  * for weak keys. */
  58 extern void
  59 gl_des_setkey (gl_des_ctx *ctx, const char * key);
  60
  61 /* Fill a DES context CTX with subkeys calculated from 64bit KEY, with
  62  * weak key checking.  Does not check parity bits, but simply ignore
  63  * them. */
  64 extern bool
  65 gl_des_makekey (gl_des_ctx *ctx, const char * key, size_t keylen);
  66
  67 /* Electronic Codebook Mode DES encryption/decryption of data
  68  * according to 'mode'. */
  69 extern void
  70 gl_des_ecb_crypt (gl_des_ctx *ctx, const char * from,  char * to, int mode);
  71
  72 #define gl_des_ecb_encrypt(ctx, from, to)  gl_des_ecb_crypt(ctx, from, to, 0)
  73 #define gl_des_ecb_decrypt(ctx, from, to)  gl_des_ecb_crypt(ctx, from, to, 1)
  74
  75 /* Triple-DES
  76  * ----------
  77  */
  78
  79 /* Fill a Triple-DES context CTX with subkeys calculated from two
  80  * 64bit keys in KEY1 and KEY2.  Does not check the parity bits of the
  81  * keys, but simply ignore them.  Does not check for weak keys. */
  82 extern void
  83 gl_3des_set2keys (gl_3des_ctx *ctx,
  84                   const char * key1,
  85                   const char * key2);
  86
  87 /*
  88  * Fill a Triple-DES context CTX with subkeys calculated from three
  89  * 64bit keys in KEY1, KEY2 and KEY3.  Does not check the parity bits
  90  * of the keys, but simply ignore them.  Does not check for weak
  91  * keys. */
  92 extern void
  93 gl_3des_set3keys (gl_3des_ctx *ctx,
  94                   const char * key1,
  95                   const char * key2,
  96                   const char * key3);
  97
  98 /* Fill a Triple-DES context CTX with subkeys calculated from three
  99  * concatenated 64bit keys in KEY, with weak key checking.  Does not
 100  * check the parity bits of the keys, but simply ignore them. */
 101 extern bool
 102 gl_3des_makekey (gl_3des_ctx *ctx,
 103                  const char * key,
 104                  size_t keylen);
 105
 106 /* Electronic Codebook Mode Triple-DES encryption/decryption of data
 107  * according to 'mode'.  Sometimes this mode is named 'EDE' mode
 108  * (Encryption-Decryption-Encryption). */
 109 extern void
 110 gl_3des_ecb_crypt (gl_3des_ctx *ctx,
 111                    const char * from,
 112                    char * to,
 113                    int mode);
 114
 115 #define gl_3des_ecb_encrypt(ctx, from, to) gl_3des_ecb_crypt(ctx,from,to,0)
 116 #define gl_3des_ecb_decrypt(ctx, from, to) gl_3des_ecb_crypt(ctx,from,to,1)
 117
 118 #endif /* DES_H */