lib/des.h

   1 /* des.h --- DES cipher implementation.
   2  * Copyright (C) 2005, 2007, 2009-2019 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, 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 #include <stdbool.h>
  27
  28 /*
  29  * Encryption/Decryption context of DES
  30  */
  31 typedef struct
  32 {
  33   uint32_t encrypt_subkeys[32];
  34   uint32_t decrypt_subkeys[32];
  35 } gl_des_ctx;
  36
  37 /*
  38  * Encryption/Decryption context of Triple-DES
  39  */
  40 typedef struct
  41 {
  42   uint32_t encrypt_subkeys[96];
  43   uint32_t decrypt_subkeys[96];
  44 } gl_3des_ctx;
  45
  46 /* Check whether the 8 byte key is weak.  Does not check the parity
  47  * bits of the key but simple ignore them. */
  48 extern bool
  49 gl_des_is_weak_key (const char * key);
  50
  51 /*
  52  * DES
  53  * ---
  54  */
  55
  56 /* Fill a DES context CTX with subkeys calculated from 64bit KEY.
  57  * Does not check parity bits, but simply ignore them.  Does not check
  58  * for weak keys. */
  59 extern void
  60 gl_des_setkey (gl_des_ctx *ctx, const char * key);
  61
  62 /* Fill a DES context CTX with subkeys calculated from 64bit KEY, with
  63  * weak key checking.  Does not check parity bits, but simply ignore
  64  * them. */
  65 extern bool
  66 gl_des_makekey (gl_des_ctx *ctx, const char * key, size_t keylen);
  67
  68 /* Electronic Codebook Mode DES encryption/decryption of data
  69  * according to 'mode'. */
  70 extern void
  71 gl_des_ecb_crypt (gl_des_ctx *ctx, const char * from,  char * to, int mode);
  72
  73 #define gl_des_ecb_encrypt(ctx, from, to)  gl_des_ecb_crypt(ctx, from, to, 0)
  74 #define gl_des_ecb_decrypt(ctx, from, to)  gl_des_ecb_crypt(ctx, from, to, 1)
  75
  76 /* Triple-DES
  77  * ----------
  78  */
  79
  80 /* Fill a Triple-DES context CTX with subkeys calculated from two
  81  * 64bit keys in KEY1 and KEY2.  Does not check the parity bits of the
  82  * keys, but simply ignore them.  Does not check for weak keys. */
  83 extern void
  84 gl_3des_set2keys (gl_3des_ctx *ctx,
  85                   const char * key1,
  86                   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 gl_3des_set3keys (gl_3des_ctx *ctx,
  95                   const char * key1,
  96                   const char * key2,
  97                   const char * key3);
  98
  99 /* Fill a Triple-DES context CTX with subkeys calculated from three
 100  * concatenated 64bit keys in KEY, with weak key checking.  Does not
 101  * check the parity bits of the keys, but simply ignore them. */
 102 extern bool
 103 gl_3des_makekey (gl_3des_ctx *ctx,
 104                  const char * key,
 105                  size_t keylen);
 106
 107 /* Electronic Codebook Mode Triple-DES encryption/decryption of data
 108  * according to 'mode'.  Sometimes this mode is named 'EDE' mode
 109  * (Encryption-Decryption-Encryption). */
 110 extern void
 111 gl_3des_ecb_crypt (gl_3des_ctx *ctx,
 112                    const char * from,
 113                    char * to,
 114                    int mode);
 115
 116 #define gl_3des_ecb_encrypt(ctx, from, to) gl_3des_ecb_crypt(ctx,from,to,0)
 117 #define gl_3des_ecb_decrypt(ctx, from, to) gl_3des_ecb_crypt(ctx,from,to,1)
 118
 119 #endif /* DES_H */