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_OPENSSL
24
25 #include <sys/types.h>
26
27 #include <stdarg.h>
28 #include <string.h>
29
30 #include <openssl/evp.h>
31
32 #include "openbsd-compat/openssl-compat.h"
33
34 /*
35 * SSH1 uses a variation on Blowfish, all bytes must be swapped before
36 * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
37 */
38
39 const EVP_CIPHER * evp_ssh1_bf(void);
40
41 static void
swap_bytes(const u_char * src,u_char * dst,int n)42 swap_bytes(const u_char *src, u_char *dst, int n)
43 {
44 u_char c[4];
45
46 /* Process 4 bytes every lap. */
47 for (n = n / 4; n > 0; n--) {
48 c[3] = *src++;
49 c[2] = *src++;
50 c[1] = *src++;
51 c[0] = *src++;
52
53 *dst++ = c[0];
54 *dst++ = c[1];
55 *dst++ = c[2];
56 *dst++ = c[3];
57 }
58 }
59
60 #ifdef SSH_OLD_EVP
bf_ssh1_init(EVP_CIPHER_CTX * ctx,const unsigned char * key,const unsigned char * iv,int enc)61 static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key,
62 const unsigned char *iv, int enc)
63 {
64 if (iv != NULL)
65 memcpy (&(ctx->oiv[0]), iv, 8);
66 memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8);
67 if (key != NULL)
68 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx),
69 key);
70 }
71 #endif
72
73 static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *,
74 const u_char *, LIBCRYPTO_EVP_INL_TYPE) = NULL;
75
76 static int
bf_ssh1_cipher(EVP_CIPHER_CTX * ctx,u_char * out,const u_char * in,LIBCRYPTO_EVP_INL_TYPE len)77 bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in,
78 LIBCRYPTO_EVP_INL_TYPE len)
79 {
80 int ret;
81
82 swap_bytes(in, out, len);
83 ret = (*orig_bf)(ctx, out, out, len);
84 swap_bytes(out, out, len);
85 return (ret);
86 }
87
88 const EVP_CIPHER *
evp_ssh1_bf(void)89 evp_ssh1_bf(void)
90 {
91 static EVP_CIPHER ssh1_bf;
92
93 memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER));
94 orig_bf = ssh1_bf.do_cipher;
95 ssh1_bf.nid = NID_undef;
96 #ifdef SSH_OLD_EVP
97 ssh1_bf.init = bf_ssh1_init;
98 #endif
99 ssh1_bf.do_cipher = bf_ssh1_cipher;
100 ssh1_bf.key_len = 32;
101 return (&ssh1_bf);
102 }
103 #endif /* WITH_OPENSSL */
104