blob: 292488c5c61778bb4a1fd15577e40ae5a2c80266 [file] [log] [blame]
Damien Millerd7834352006-08-05 12:39:39 +10001/* $OpenBSD: cipher-bf1.c,v 1.5 2006/08/03 03:34:42 deraadt 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
Damien Millerd7834352006-08-05 12:39:39 +100028#include <sys/types.h>
29
Damien Miller3a3261f2003-05-15 13:37:19 +100030#include <openssl/evp.h>
Damien Millere3476ed2006-07-24 14:13:33 +100031
Damien Millerded319c2006-09-01 15:38:36 +100032#include <stdarg.h>
Damien Millere3476ed2006-07-24 14:13:33 +100033#include <string.h>
34
Damien Miller3a3261f2003-05-15 13:37:19 +100035#include "xmalloc.h"
36#include "log.h"
Damien Miller5c3a5582003-09-23 22:12:38 +100037
38#if OPENSSL_VERSION_NUMBER < 0x00906000L
39#define SSH_OLD_EVP
40#endif
41
Damien Miller3a3261f2003-05-15 13:37:19 +100042/*
43 * SSH1 uses a variation on Blowfish, all bytes must be swapped before
44 * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
45 */
46
47const EVP_CIPHER * evp_ssh1_bf(void);
48
49static void
50swap_bytes(const u_char *src, u_char *dst, int n)
51{
52 u_char c[4];
53
54 /* Process 4 bytes every lap. */
55 for (n = n / 4; n > 0; n--) {
56 c[3] = *src++;
57 c[2] = *src++;
58 c[1] = *src++;
59 c[0] = *src++;
60
61 *dst++ = c[0];
62 *dst++ = c[1];
63 *dst++ = c[2];
64 *dst++ = c[3];
65 }
66}
67
68#ifdef SSH_OLD_EVP
69static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
70 const unsigned char *iv, int enc)
71{
72 if (iv != NULL)
73 memcpy (&(ctx->oiv[0]), iv, 8);
74 memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
75 if (key != NULL)
76 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
77 key);
78}
79#endif
80
81static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL;
82
83static int
84bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len)
85{
86 int ret;
87
88 swap_bytes(in, out, len);
89 ret = (*orig_bf)(ctx, out, out, len);
90 swap_bytes(out, out, len);
91 return (ret);
92}
93
94const EVP_CIPHER *
95evp_ssh1_bf(void)
96{
97 static EVP_CIPHER ssh1_bf;
98
99 memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
100 orig_bf = ssh1_bf.do_cipher;
101 ssh1_bf.nid = NID_undef;
102#ifdef SSH_OLD_EVP
103 ssh1_bf.init = bf_ssh1_init;
104#endif
105 ssh1_bf.do_cipher = bf_ssh1_cipher;
106 ssh1_bf.key_len = 32;
107 return (&ssh1_bf);
108}