1 /* $OpenBSD: cipher-bf1.c,v 1.7 2015/01/14 10:24:42 markus Exp $ */
2 /*
3 * Copyright (c) 2003 Markus Friedl. All rights reserved.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
10 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
11 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
12 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
13 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
14 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
15 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
16 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
17 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
18 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
19 */
20
21 #include "includes.h"
22
23 #ifdef WITH_SSH1
24 #if defined(WITH_OPENSSL) && !defined(OPENSSL_NO_BF)
25
26 #include <sys/types.h>
27
28 #include <stdarg.h>
29 #include <string.h>
30
31 #include <openssl/evp.h>
32
33 #include "openbsd-compat/openssl-compat.h"
34
35 /*
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
40 const EVP_CIPHER * evp_ssh1_bf(void);
41
42 static void
swap_bytes(const u_char * src,u_char * dst,int n)43 swap_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
bf_ssh1_init(EVP_CIPHER_CTX * ctx,const unsigned char * key,const unsigned char * iv,int enc)62 static 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
74 static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *,
75 const u_char *, LIBCRYPTO_EVP_INL_TYPE) = NULL;
76
77 static int
bf_ssh1_cipher(EVP_CIPHER_CTX * ctx,u_char * out,const u_char * in,LIBCRYPTO_EVP_INL_TYPE len)78 bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in,
79 LIBCRYPTO_EVP_INL_TYPE len)
80 {
81 int ret;
82
83 swap_bytes(in, out, len);
84 ret = (*orig_bf)(ctx, out, out, len);
85 swap_bytes(out, out, len);
86 return (ret);
87 }
88
89 const EVP_CIPHER *
evp_ssh1_bf(void)90 evp_ssh1_bf(void)
91 {
92 static EVP_CIPHER ssh1_bf;
93
94 memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
95 orig_bf = ssh1_bf.do_cipher;
96 ssh1_bf.nid = NID_undef;
97 #ifdef SSH_OLD_EVP
98 ssh1_bf.init = bf_ssh1_init;
99 #endif
100 ssh1_bf.do_cipher = bf_ssh1_cipher;
101 ssh1_bf.key_len = 32;
102 return (&ssh1_bf);
103 }
104 #endif /* defined(WITH_OPENSSL) && !defined(OPENSSL_NO_BF) */
105
106 #endif /* WITH_SSH1 */
107