[openssh.git] / cipher-bf1.c

/* $OpenBSD: cipher-bf1.c,v 1.5 2006/08/03 03:34:42 deraadt Exp $ */
/*
 * 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"

#include <sys/types.h>

#include <openssl/evp.h>

#include <string.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);
}
Commit	Line	Data
31652869	1	/* $OpenBSD: cipher-bf1.c,v 1.5 2006/08/03 03:34:42 deraadt Exp $ */
3b6e3da9	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"
3b6e3da9	27
31652869	28	#include <sys/types.h>
31652869	29
3b6e3da9	30	#include <openssl/evp.h>
00146caa	31
	32	#include <string.h>
	33
3b6e3da9	34	#include "xmalloc.h"
3b6e3da9	35	#include "log.h"
0a23d79f	36
	37	#if OPENSSL_VERSION_NUMBER < 0x00906000L
	38	#define SSH_OLD_EVP
	39	#endif
	40
3b6e3da9	41	/*
	42	* SSH1 uses a variation on Blowfish, all bytes must be swapped before
	43	* and after encryption/decryption. Thus the swap_bytes stuff (yuk).
	44	*/
	45
	46	const EVP_CIPHER * evp_ssh1_bf(void);
	47
	48	static void
	49	swap_bytes(const u_char src, u_char dst, int n)
	50	{
	51	u_char c[4];
	52
	53	/* Process 4 bytes every lap. */
	54	for (n = n / 4; n > 0; n--) {
	55	c[3] = *src++;
	56	c[2] = *src++;
	57	c[1] = *src++;
	58	c[0] = *src++;
	59
	60	*dst++ = c[0];
	61	*dst++ = c[1];
	62	*dst++ = c[2];
	63	*dst++ = c[3];
	64	}
	65	}
	66
	67	#ifdef SSH_OLD_EVP
	68	static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
	69	const unsigned char *iv, int enc)
	70	{
	71	if (iv != NULL)
	72	memcpy (&(ctx->oiv[0]), iv, 8);
	73	memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
	74	if (key != NULL)
	75	BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
	76	key);
	77	}
	78	#endif
	79
	80	static int (orig_bf)(EVP_CIPHER_CTX , u_char , const u_char , u_int) = NULL;
	81
	82	static int
	83	bf_ssh1_cipher(EVP_CIPHER_CTX ctx, u_char out, const u_char *in, u_int len)
	84	{
	85	int ret;
	86
	87	swap_bytes(in, out, len);
	88	ret = (*orig_bf)(ctx, out, out, len);
	89	swap_bytes(out, out, len);
	90	return (ret);
	91	}
	92
	93	const EVP_CIPHER *
	94	evp_ssh1_bf(void)
	95	{
	96	static EVP_CIPHER ssh1_bf;
	97
	98	memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
	99	orig_bf = ssh1_bf.do_cipher;
	100	ssh1_bf.nid = NID_undef;
	101	#ifdef SSH_OLD_EVP
	102	ssh1_bf.init = bf_ssh1_init;
	103	#endif
	104	ssh1_bf.do_cipher = bf_ssh1_cipher;
105	ssh1_bf.key_len = 32;
106	return (&ssh1_bf);
107	}