blob: b6aa0152a78ae0219c778725ad4c443dabbcda08 [file] [log] [blame]
Damien Miller57c30112006-03-26 14:24:48 +11001/* $OpenBSD: cipher-bf1.c,v 1.3 2006/03/25 13:17:01 djm Exp $ */
Damien Miller3a3261f2003-05-15 13:37:19 +10002/*
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"
Damien Miller3a3261f2003-05-15 13:37:19 +100027
28#include <openssl/evp.h>
29#include "xmalloc.h"
30#include "log.h"
Damien Miller5c3a5582003-09-23 22:12:38 +100031
32#if OPENSSL_VERSION_NUMBER < 0x00906000L
33#define SSH_OLD_EVP
34#endif
35
Damien Miller3a3261f2003-05-15 13:37:19 +100036/*
37 * SSH1 uses a variation on Blowfish, all bytes must be swapped before
38 * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
39 */
40
41const EVP_CIPHER * evp_ssh1_bf(void);
42
43static void
44swap_bytes(const u_char *src, u_char *dst, int n)
45{
46 u_char c[4];
47
48 /* Process 4 bytes every lap. */
49 for (n = n / 4; n > 0; n--) {
50 c[3] = *src++;
51 c[2] = *src++;
52 c[1] = *src++;
53 c[0] = *src++;
54
55 *dst++ = c[0];
56 *dst++ = c[1];
57 *dst++ = c[2];
58 *dst++ = c[3];
59 }
60}
61
62#ifdef SSH_OLD_EVP
63static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
64 const unsigned char *iv, int enc)
65{
66 if (iv != NULL)
67 memcpy (&(ctx->oiv[0]), iv, 8);
68 memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
69 if (key != NULL)
70 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
71 key);
72}
73#endif
74
75static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL;
76
77static int
78bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int 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}