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/*
* Copyright (c) 2003 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
RCSID("$OpenBSD: cipher-bf1.c,v 1.1 2003/05/15 03:08:29 markus Exp $");
#include <openssl/evp.h>
#include "xmalloc.h"
#include "log.h"
#if OPENSSL_VERSION_NUMBER < 0x00906000L
#define SSH_OLD_EVP
#endif
/*
* SSH1 uses a variation on Blowfish, all bytes must be swapped before
* and after encryption/decryption. Thus the swap_bytes stuff (yuk).
*/
const EVP_CIPHER * evp_ssh1_bf(void);
static void
swap_bytes(const u_char *src, u_char *dst, int n)
{
u_char c[4];
/* Process 4 bytes every lap. */
for (n = n / 4; n > 0; n--) {
c[3] = *src++;
c[2] = *src++;
c[1] = *src++;
c[0] = *src++;
*dst++ = c[0];
*dst++ = c[1];
*dst++ = c[2];
*dst++ = c[3];
}
}
#ifdef SSH_OLD_EVP
static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
const unsigned char *iv, int enc)
{
if (iv != NULL)
memcpy (&(ctx->oiv[0]), iv, 8);
memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
if (key != NULL)
BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
key);
}
#endif
static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL;
static int
bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len)
{
int ret;
swap_bytes(in, out, len);
ret = (*orig_bf)(ctx, out, out, len);
swap_bytes(out, out, len);
return (ret);
}
const EVP_CIPHER *
evp_ssh1_bf(void)
{
static EVP_CIPHER ssh1_bf;
memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
orig_bf = ssh1_bf.do_cipher;
ssh1_bf.nid = NID_undef;
#ifdef SSH_OLD_EVP
ssh1_bf.init = bf_ssh1_init;
#endif
ssh1_bf.do_cipher = bf_ssh1_cipher;
ssh1_bf.key_len = 32;
return (&ssh1_bf);
}
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