blob: e7246650ba4af0d7877b0ae08db299ce3463d13d [file] [log] [blame]
Damien Miller3a3261f2003-05-15 13:37:19 +10001/*
2 * Copyright (c) 2003 Markus Friedl. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include "includes.h"
Damien Miller3a3261f2003-05-15 13:37:19 +100026
27#include <openssl/evp.h>
28#include "xmalloc.h"
29#include "log.h"
Damien Miller5c3a5582003-09-23 22:12:38 +100030
31#if OPENSSL_VERSION_NUMBER < 0x00906000L
32#define SSH_OLD_EVP
33#endif
34
Damien Miller3a3261f2003-05-15 13:37:19 +100035/*
36 * SSH1 uses a variation on Blowfish, all bytes must be swapped before
37 * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
38 */
39
40const EVP_CIPHER * evp_ssh1_bf(void);
41
42static void
43swap_bytes(const u_char *src, u_char *dst, int n)
44{
45 u_char c[4];
46
47 /* Process 4 bytes every lap. */
48 for (n = n / 4; n > 0; n--) {
49 c[3] = *src++;
50 c[2] = *src++;
51 c[1] = *src++;
52 c[0] = *src++;
53
54 *dst++ = c[0];
55 *dst++ = c[1];
56 *dst++ = c[2];
57 *dst++ = c[3];
58 }
59}
60
61#ifdef SSH_OLD_EVP
62static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
63 const unsigned char *iv, int enc)
64{
65 if (iv != NULL)
66 memcpy (&(ctx->oiv[0]), iv, 8);
67 memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
68 if (key != NULL)
69 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
70 key);
71}
72#endif
73
74static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL;
75
76static int
77bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len)
78{
79 int ret;
80
81 swap_bytes(in, out, len);
82 ret = (*orig_bf)(ctx, out, out, len);
83 swap_bytes(out, out, len);
84 return (ret);
85}
86
87const EVP_CIPHER *
88evp_ssh1_bf(void)
89{
90 static EVP_CIPHER ssh1_bf;
91
92 memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
93 orig_bf = ssh1_bf.do_cipher;
94 ssh1_bf.nid = NID_undef;
95#ifdef SSH_OLD_EVP
96 ssh1_bf.init = bf_ssh1_init;
97#endif
98 ssh1_bf.do_cipher = bf_ssh1_cipher;
99 ssh1_bf.key_len = 32;
100 return (&ssh1_bf);
101}