1 /* $OpenBSD: cipher-bf1.c,v 1.6 2010/10/01 23:05:32 djm Exp $ */
2 /*
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"
27
28 #include <sys/types.h>
29
30 #include <openssl/evp.h>
31
32 #include <stdarg.h>
33 #include <string.h>
34
35 #include "xmalloc.h"
36 #include "log.h"
37
38 #include "openbsd-compat/openssl-compat.h"
39
40 /*
41 * SSH1 uses a variation on Blowfish, all bytes must be swapped before
42 * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
43 */
44
45 const EVP_CIPHER * evp_ssh1_bf(void);
46
47 static void
swap_bytes(const u_char * src,u_char * dst,int n)48 swap_bytes(const u_char *src, u_char *dst, int n)
49 {
50 u_char c[4];
51
52 /* Process 4 bytes every lap. */
53 for (n = n / 4; n > 0; n--) {
54 c[3] = *src++;
55 c[2] = *src++;
56 c[1] = *src++;
57 c[0] = *src++;
58
59 *dst++ = c[0];
60 *dst++ = c[1];
61 *dst++ = c[2];
62 *dst++ = c[3];
63 }
64 }
65
66 #ifdef SSH_OLD_EVP
bf_ssh1_init(EVP_CIPHER_CTX * ctx,const unsigned char * key,const unsigned char * iv,int enc)67 static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
68 const unsigned char *iv, int enc)
69 {
70 if (iv != NULL)
71 memcpy (&(ctx->oiv[0]), iv, 8);
72 memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
73 if (key != NULL)
74 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
75 key);
76 }
77 #endif
78
79 static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *,
80 const u_char *, LIBCRYPTO_EVP_INL_TYPE) = NULL;
81
82 static int
bf_ssh1_cipher(EVP_CIPHER_CTX * ctx,u_char * out,const u_char * in,LIBCRYPTO_EVP_INL_TYPE len)83 bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in,
84 LIBCRYPTO_EVP_INL_TYPE 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
94 const EVP_CIPHER *
evp_ssh1_bf(void)95 evp_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 }
109