cipher-bf1.c revision 323129 
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
39const EVP_CIPHER * evp_ssh1_bf(void);
40
41static void
42swap_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
61static 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
73static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *,
74    const u_char *, LIBCRYPTO_EVP_INL_TYPE) = NULL;
75
76static int
77bf_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
88const EVP_CIPHER *
89evp_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) */
104