crypto/dist/ssh/cipher-bf1.c

   1 /*      $NetBSD$        */
   2 /* $OpenBSD: cipher-bf1.c,v 1.5 2006/08/03 03:34:42 deraadt Exp $ */
   3 /*
   4  * Copyright (c) 2003 Markus Friedl.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include "includes.h"
  28 __RCSID("$NetBSD$");
  29
  30 #include <sys/types.h>
  31
  32 #include <openssl/evp.h>
  33
  34 #include <string.h>
  35
  36 #include "xmalloc.h"
  37 #include "log.h"
  38 /*
  39  * SSH1 uses a variation on Blowfish, all bytes must be swapped before
  40  * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
  41  */
  42
  43 const EVP_CIPHER * evp_ssh1_bf(void);
  44
  45 static void
  46 swap_bytes(const u_char *src, u_char *dst, int n)
  47 {
  48         u_char c[4];
  49
  50         /* Process 4 bytes every lap. */
  51         for (n = n / 4; n > 0; n--) {
  52                 c[3] = *src++;
  53                 c[2] = *src++;
  54                 c[1] = *src++;
  55                 c[0] = *src++;
  56
  57                 *dst++ = c[0];
  58                 *dst++ = c[1];
  59                 *dst++ = c[2];
  60                 *dst++ = c[3];
  61         }
  62 }
  63
  64 static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL;
  65
  66 static int
  67 bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len)
  68 {
  69         int ret;
  70
  71         swap_bytes(in, out, len);
  72         ret = (*orig_bf)(ctx, out, out, len);
  73         swap_bytes(out, out, len);
  74         return (ret);
  75 }
  76
  77 const EVP_CIPHER *
  78 evp_ssh1_bf(void)
  79 {
  80         static EVP_CIPHER ssh1_bf;
  81
  82         memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
  83         orig_bf = ssh1_bf.do_cipher;
  84         ssh1_bf.nid = NID_undef;
  85         ssh1_bf.do_cipher = bf_ssh1_cipher;
  86         ssh1_bf.key_len = 32;
  87         return (&ssh1_bf);
  88 }