crypto/openssh/cipher-bf1.c

   1 /* $OpenBSD: cipher-bf1.c,v 1.7 2015/01/14 10:24:42 markus Exp $ */
   2 /*
   3  * Copyright (c) 2003 Markus Friedl.  All rights reserved.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  10  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  11  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  12  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  13  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  14  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  15  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  16  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  17  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  18  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  19  */
  20
  21 #include "includes.h"
  22
  23 #if defined(WITH_OPENSSL) && !defined(OPENSSL_NO_BF)
  24
  25 #include <sys/types.h>
  26
  27 #include <stdarg.h>
  28 #include <string.h>
  29
  30 #include <openssl/evp.h>
  31
  32 #include "openbsd-compat/openssl-compat.h"
  33
  34 /*
  35  * SSH1 uses a variation on Blowfish, all bytes must be swapped before
  36  * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
  37  */
  38
  39 const EVP_CIPHER * evp_ssh1_bf(void);
  40
  41 static void
  42 swap_bytes(const u_char *src, u_char *dst, int n)
  43 {
  44         u_char c[4];
  45
  46         /* Process 4 bytes every lap. */
  47         for (n = n / 4; n > 0; n--) {
  48                 c[3] = *src++;
  49                 c[2] = *src++;
  50                 c[1] = *src++;
  51                 c[0] = *src++;
  52
  53                 *dst++ = c[0];
  54                 *dst++ = c[1];
  55                 *dst++ = c[2];
  56                 *dst++ = c[3];
  57         }
  58 }
  59
  60 #ifdef SSH_OLD_EVP
  61 static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
  62                           const unsigned char *iv, int enc)
  63 {
  64         if (iv != NULL)
  65                 memcpy (&(ctx->oiv[0]), iv, 8);
  66         memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
  67         if (key != NULL)
  68                 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
  69                             key);
  70 }
  71 #endif
  72
  73 static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *,
  74     const u_char *, LIBCRYPTO_EVP_INL_TYPE) = NULL;
  75
  76 static int
  77 bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in,
  78     LIBCRYPTO_EVP_INL_TYPE len)
  79 {
  80         int ret;
  81
  82         swap_bytes(in, out, len);
  83         ret = (*orig_bf)(ctx, out, out, len);
  84         swap_bytes(out, out, len);
  85         return (ret);
  86 }
  87
  88 const EVP_CIPHER *
  89 evp_ssh1_bf(void)
  90 {
  91         static EVP_CIPHER ssh1_bf;
  92
  93         memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
  94         orig_bf = ssh1_bf.do_cipher;
  95         ssh1_bf.nid = NID_undef;
  96 #ifdef SSH_OLD_EVP
  97         ssh1_bf.init = bf_ssh1_init;
  98 #endif
  99         ssh1_bf.do_cipher = bf_ssh1_cipher;
 100         ssh1_bf.key_len = 32;
 101         return (&ssh1_bf);
 102 }
 103 #endif /* defined(WITH_OPENSSL) && !defined(OPENSSL_NO_BF) */