lgl/arctwo.h

   1 /* arctwo.h --- The arctwo block cipher
   2  * Copyright (C) 2000, 2001, 2002, 2003, 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 Lesser General Public License as published
   6  * by the Free Software Foundation; either version 2.1, 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 Lesser 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 /* Code from Libgcrypt adapted for gnulib by Simon Josefsson. */
  22
  23 #ifndef ARCTWO_H
  24 # define ARCTWO_H
  25
  26 # include <stddef.h>
  27 # include <stdint.h>
  28
  29 typedef struct
  30 {
  31   uint16_t S[64];
  32 } arctwo_context;
  33
  34 #define ARCTWO_BLOCK_SIZE 8
  35
  36 /* Initialize CONTEXT using KEY of KEYLEN length.  If
  37    EFFECTIVE_KEYLEN, truncate the key (using a special algorithm) to
  38    only be of EFFECTIVE_KEYLEN bits.  Normally, you use
  39    EFFECTIVE_KEYLEN of 0, but see RFC 2268 for more information. */
  40 void
  41 arctwo_setkey_ekb (arctwo_context *context,
  42                    size_t keylen, const char *key, size_t effective_keylen);
  43
  44 #define arctwo_setkey(context,keylen,key) \
  45   arctwo_setkey_ekb (context, keylen, key, 8 * (keylen))
  46
  47 /* Encrypt INBUF of size LENGTH into OUTBUF.  LENGTH must be a
  48    multiple of ARCTWO_BLOCK_SIZE.  CONTEXT hold the encryption key,
  49    and must have been initialized with arctwo_setkey or
  50    arctwo_setkey_ekb. */
  51 extern void
  52 arctwo_encrypt (arctwo_context *context, const char *inbuf,
  53                 char *outbuf, size_t length);
  54
  55 /* Decrypt INBUF of size LENGTH into OUTBUF.  LENGTH must be a
  56    multiple of ARCTWO_BLOCK_SIZE.  CONTEXT hold the decryption key,
  57    and must have been initialized with arctwo_setkey or
  58    arctwo_setkey_ekb. */
  59 extern void
  60 arctwo_decrypt (arctwo_context *context, const char *inbuf,
  61                 char *outbuf, size_t length);
  62
  63 #endif /* ARCTWO_H */