blob: 95b4e5e93dd487fa73f2466bae2e4a8880a9b188 [file] [log] [blame]
Damien Millere3476ed2006-07-24 14:13:33 +10001/* $OpenBSD: cipher-bf1.c,v 1.4 2006/07/22 20:48:22 stevesk 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>
Damien Millere3476ed2006-07-24 14:13:33 +100029
30#include <string.h>
31
Damien Miller3a3261f2003-05-15 13:37:19 +100032#include "xmalloc.h"
33#include "log.h"
Damien Miller5c3a5582003-09-23 22:12:38 +100034
35#if OPENSSL_VERSION_NUMBER < 0x00906000L
36#define SSH_OLD_EVP
37#endif
38
Damien Miller3a3261f2003-05-15 13:37:19 +100039/*
40 * SSH1 uses a variation on Blowfish, all bytes must be swapped before
41 * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
42 */
43
44const EVP_CIPHER * evp_ssh1_bf(void);
45
46static void
47swap_bytes(const u_char *src, u_char *dst, int n)
48{
49 u_char c[4];
50
51 /* Process 4 bytes every lap. */
52 for (n = n / 4; n > 0; n--) {
53 c[3] = *src++;
54 c[2] = *src++;
55 c[1] = *src++;
56 c[0] = *src++;
57
58 *dst++ = c[0];
59 *dst++ = c[1];
60 *dst++ = c[2];
61 *dst++ = c[3];
62 }
63}
64
65#ifdef SSH_OLD_EVP
66static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
67 const unsigned char *iv, int enc)
68{
69 if (iv != NULL)
70 memcpy (&(ctx->oiv[0]), iv, 8);
71 memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
72 if (key != NULL)
73 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
74 key);
75}
76#endif
77
78static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL;
79
80static int
81bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len)
82{
83 int ret;
84
85 swap_bytes(in, out, len);
86 ret = (*orig_bf)(ctx, out, out, len);
87 swap_bytes(out, out, len);
88 return (ret);
89}
90
91const EVP_CIPHER *
92evp_ssh1_bf(void)
93{
94 static EVP_CIPHER ssh1_bf;
95
96 memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
97 orig_bf = ssh1_bf.do_cipher;
98 ssh1_bf.nid = NID_undef;
99#ifdef SSH_OLD_EVP
100 ssh1_bf.init = bf_ssh1_init;
101#endif
102 ssh1_bf.do_cipher = bf_ssh1_cipher;
103 ssh1_bf.key_len = 32;
104 return (&ssh1_bf);
105}