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#ifdef __APPLE_CRYPTO__
31#include "ossl-evp.h"
32#else
33#include <openssl/evp.h>
34#endif
35
36#include <stdarg.h>
37#include <string.h>
38
39#include "xmalloc.h"
40#include "log.h"
41
42#include "openbsd-compat/openssl-compat.h"
43
44/*
45 * SSH1 uses a variation on Blowfish, all bytes must be swapped before
46 * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
47 */
48
49const EVP_CIPHER * evp_ssh1_bf(void);
50
51static void
52swap_bytes(const u_char *src, u_char *dst, int n)
53{
54	u_char c[4];
55
56	/* Process 4 bytes every lap. */
57	for (n = n / 4; n > 0; n--) {
58		c[3] = *src++;
59		c[2] = *src++;
60		c[1] = *src++;
61		c[0] = *src++;
62
63		*dst++ = c[0];
64		*dst++ = c[1];
65		*dst++ = c[2];
66		*dst++ = c[3];
67	}
68}
69
70#ifdef SSH_OLD_EVP
71static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
72			  const unsigned char *iv, int enc)
73{
74	if (iv != NULL)
75		memcpy (&(ctx->oiv[0]), iv, 8);
76	memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
77	if (key != NULL)
78		BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
79			    key);
80}
81#endif
82
83static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *,
84    const u_char *, LIBCRYPTO_EVP_INL_TYPE) = NULL;
85
86static int
87bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in,
88    LIBCRYPTO_EVP_INL_TYPE len)
89{
90	int ret;
91
92	swap_bytes(in, out, len);
93	ret = (*orig_bf)(ctx, out, out, len);
94	swap_bytes(out, out, len);
95	return (ret);
96}
97
98const EVP_CIPHER *
99evp_ssh1_bf(void)
100{
101	static EVP_CIPHER ssh1_bf;
102
103	memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
104	orig_bf = ssh1_bf.do_cipher;
105	ssh1_bf.nid = NID_undef;
106#ifdef SSH_OLD_EVP
107	ssh1_bf.init = bf_ssh1_init;
108#endif
109	ssh1_bf.do_cipher = bf_ssh1_cipher;
110	ssh1_bf.key_len = 32;
111	return (&ssh1_bf);
112}
113