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       1                 :            : /* $OpenBSD: cipher-bf1.c,v 1.6 2010/10/01 23:05:32 djm Exp $ */
       2                 :            : /*
       3                 :            :  * Copyright (c) 2003 Markus Friedl.  All rights reserved.
       4                 :            :  *
       5                 :            :  * Redistribution and use in source and binary forms, with or without
       6                 :            :  * modification, are permitted provided that the following conditions
       7                 :            :  * are met:
       8                 :            :  * 1. Redistributions of source code must retain the above copyright
       9                 :            :  *    notice, this list of conditions and the following disclaimer.
      10                 :            :  * 2. Redistributions in binary form must reproduce the above copyright
      11                 :            :  *    notice, this list of conditions and the following disclaimer in the
      12                 :            :  *    documentation and/or other materials provided with the distribution.
      13                 :            :  *
      14                 :            :  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
      15                 :            :  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
      16                 :            :  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
      17                 :            :  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
      18                 :            :  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
      19                 :            :  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      20                 :            :  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      21                 :            :  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      22                 :            :  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
      23                 :            :  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      24                 :            :  */
      25                 :            : 
      26                 :            : #include "includes.h"
      27                 :            : 
      28                 :            : #include <sys/types.h>
      29                 :            : 
      30                 :            : #include <openssl/evp.h>
      31                 :            : 
      32                 :            : #include <stdarg.h>
      33                 :            : #include <string.h>
      34                 :            : 
      35                 :            : #include "xmalloc.h"
      36                 :            : #include "log.h"
      37                 :            : 
      38                 :            : #include "openbsd-compat/openssl-compat.h"
      39                 :            : 
      40                 :            : /*
      41                 :            :  * SSH1 uses a variation on Blowfish, all bytes must be swapped before
      42                 :            :  * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
      43                 :            :  */
      44                 :            : 
      45                 :            : const EVP_CIPHER * evp_ssh1_bf(void);
      46                 :            : 
      47                 :            : static void
      48                 :            : swap_bytes(const u_char *src, u_char *dst, int n)
      49                 :            : {
      50                 :            :         u_char c[4];
      51                 :            : 
      52                 :            :         /* Process 4 bytes every lap. */
      53 [ +  + ][ +  + ]:        680 :         for (n = n / 4; n > 0; n--) {
      54                 :        660 :                 c[3] = *src++;
      55                 :        660 :                 c[2] = *src++;
      56                 :        660 :                 c[1] = *src++;
      57                 :        660 :                 c[0] = *src++;
      58                 :            : 
      59                 :        660 :                 *dst++ = c[0];
      60                 :        660 :                 *dst++ = c[1];
      61                 :        660 :                 *dst++ = c[2];
      62                 :        660 :                 *dst++ = c[3];
      63                 :            :         }
      64                 :            : }
      65                 :            : 
      66                 :            : #ifdef SSH_OLD_EVP
      67                 :            : static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
      68                 :            :                           const unsigned char *iv, int enc)
      69                 :            : {
      70                 :            :         if (iv != NULL)
      71                 :            :                 memcpy (&(ctx->oiv[0]), iv, 8);
      72                 :            :         memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
      73                 :            :         if (key != NULL)
      74                 :            :                 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
      75                 :            :                             key);
      76                 :            : }
      77                 :            : #endif
      78                 :            : 
      79                 :            : static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *,
      80                 :            :     const u_char *, LIBCRYPTO_EVP_INL_TYPE) = NULL;
      81                 :            : 
      82                 :            : static int
      83                 :         20 : bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in,
      84                 :            :     LIBCRYPTO_EVP_INL_TYPE len)
      85                 :            : {
      86                 :            :         int ret;
      87                 :            : 
      88                 :         20 :         swap_bytes(in, out, len);
      89                 :         20 :         ret = (*orig_bf)(ctx, out, out, len);
      90                 :         20 :         swap_bytes(out, out, len);
      91                 :         20 :         return (ret);
      92                 :            : }
      93                 :            : 
      94                 :            : const EVP_CIPHER *
      95                 :          6 : evp_ssh1_bf(void)
      96                 :            : {
      97                 :            :         static EVP_CIPHER ssh1_bf;
      98                 :            : 
      99                 :          6 :         memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
     100                 :          6 :         orig_bf = ssh1_bf.do_cipher;
     101                 :          6 :         ssh1_bf.nid = NID_undef;
     102                 :            : #ifdef SSH_OLD_EVP
     103                 :            :         ssh1_bf.init = bf_ssh1_init;
     104                 :            : #endif
     105                 :          6 :         ssh1_bf.do_cipher = bf_ssh1_cipher;
     106                 :          6 :         ssh1_bf.key_len = 32;
     107                 :          6 :         return (&ssh1_bf);
     108                 :            : }