crypto/external/bsd/openssh/dist/cipher-bf1.c

   1 /*      $NetBSD: cipher-bf1.c,v 1.2 2009/06/07 22:38:46 christos Exp $  */
   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: cipher-bf1.c,v 1.2 2009/06/07 22:38:46 christos Exp $");
  29 #include <sys/types.h>
  30
  31 #include <openssl/evp.h>
  32
  33 #include <string.h>
  34
  35 #include "xmalloc.h"
  36 #include "log.h"
  37 /*
  38  * SSH1 uses a variation on Blowfish, all bytes must be swapped before
  39  * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
  40  */
  41
  42 const EVP_CIPHER * evp_ssh1_bf(void);
  43
  44 static void
  45 swap_bytes(const u_char *src, u_char *dst, int n)
  46 {
  47         u_char c[4];
  48
  49         /* Process 4 bytes every lap. */
  50         for (n = n / 4; n > 0; n--) {
  51                 c[3] = *src++;
  52                 c[2] = *src++;
  53                 c[1] = *src++;
  54                 c[0] = *src++;
  55
  56                 *dst++ = c[0];
  57                 *dst++ = c[1];
  58                 *dst++ = c[2];
  59                 *dst++ = c[3];
  60         }
  61 }
  62
  63 static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, size_t) = NULL;
  64
  65 static int
  66 bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, size_t len)
  67 {
  68         int ret;
  69
  70         swap_bytes(in, out, len);
  71         ret = (*orig_bf)(ctx, out, out, len);
  72         swap_bytes(out, out, len);
  73         return (ret);
  74 }
  75
  76 const EVP_CIPHER *
  77 evp_ssh1_bf(void)
  78 {
  79         static EVP_CIPHER ssh1_bf;
  80
  81         memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
  82         orig_bf = ssh1_bf.do_cipher;
  83         ssh1_bf.nid = NID_undef;
  84         ssh1_bf.do_cipher = bf_ssh1_cipher;
  85         ssh1_bf.key_len = 32;
  86         return (&ssh1_bf);
  87 }