1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/*
* Copyright (c) 2003 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <string.h>
#include <openssl/evp.h>
#include <config.h>
#include "log.h"
#include "xmalloc.h"
#if OPENSSL_VERSION_NUMBER < 0x00906000L
#define SSH_OLD_EVP
#endif
/*
* This is used by SSH1:
*
* What kind of triple DES are these 2 routines?
*
* Why is there a redundant initialization vector?
*
* If only iv3 was used, then, this would till effect have been
* outer-cbc. However, there is also a private iv1 == iv2 which
* perhaps makes differential analysis easier. On the other hand, the
* private iv1 probably makes the CRC-32 attack ineffective. This is a
* result of that there is no longer any known iv1 to use when
* choosing the X block.
*/
struct ssh1_3des_ctx
{
EVP_CIPHER_CTX k1, k2, k3;
};
const EVP_CIPHER * evp_ssh1_3des(void);
void ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int);
static int
ssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
int enc)
{
struct ssh1_3des_ctx *c;
u_char *k1, *k2, *k3;
if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
c = xmalloc(sizeof(*c));
EVP_CIPHER_CTX_set_app_data(ctx, c);
}
if (key == NULL)
return (1);
if (enc == -1)
enc = ctx->encrypt;
k1 = k2 = k3 = (u_char *) key;
k2 += 8;
if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) {
if (enc)
k3 += 16;
else
k1 += 16;
}
EVP_CIPHER_CTX_init(&c->k1);
EVP_CIPHER_CTX_init(&c->k2);
EVP_CIPHER_CTX_init(&c->k3);
#ifdef SSH_OLD_EVP
EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc);
EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc);
EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc);
#else
if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 ||
EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 ||
EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) {
memset(c, 0, sizeof(*c));
xfree(c);
EVP_CIPHER_CTX_set_app_data(ctx, NULL);
return (0);
}
#endif
return (1);
}
static int
ssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, u_int len)
{
struct ssh1_3des_ctx *c;
if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
error("ssh1_3des_cbc: no context");
return (0);
}
#ifdef SSH_OLD_EVP
EVP_Cipher(&c->k1, dest, (u_char *)src, len);
EVP_Cipher(&c->k2, dest, dest, len);
EVP_Cipher(&c->k3, dest, dest, len);
#else
if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 ||
EVP_Cipher(&c->k2, dest, dest, len) == 0 ||
EVP_Cipher(&c->k3, dest, dest, len) == 0)
return (0);
#endif
return (1);
}
static int
ssh1_3des_cleanup(EVP_CIPHER_CTX *ctx)
{
struct ssh1_3des_ctx *c;
if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
memset(c, 0, sizeof(*c));
xfree(c);
EVP_CIPHER_CTX_set_app_data(ctx, NULL);
}
return (1);
}
void
ssh1_3des_iv(EVP_CIPHER_CTX *evp, int doset, u_char *iv, int len)
{
struct ssh1_3des_ctx *c;
if (len != 24)
fatal("%s: bad 3des iv length: %d", __func__, len);
if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
fatal("%s: no 3des context", __func__);
if (doset) {
debug3("%s: Installed 3DES IV", __func__);
memcpy(c->k1.iv, iv, 8);
memcpy(c->k2.iv, iv + 8, 8);
memcpy(c->k3.iv, iv + 16, 8);
} else {
debug3("%s: Copying 3DES IV", __func__);
memcpy(iv, c->k1.iv, 8);
memcpy(iv + 8, c->k2.iv, 8);
memcpy(iv + 16, c->k3.iv, 8);
}
}
const EVP_CIPHER *
evp_ssh1_3des(void)
{
static EVP_CIPHER ssh1_3des;
memset(&ssh1_3des, 0, sizeof(EVP_CIPHER));
ssh1_3des.nid = NID_undef;
ssh1_3des.block_size = 8;
ssh1_3des.iv_len = 0;
ssh1_3des.key_len = 16;
ssh1_3des.init = ssh1_3des_init;
ssh1_3des.cleanup = ssh1_3des_cleanup;
ssh1_3des.do_cipher = ssh1_3des_cbc;
#ifndef SSH_OLD_EVP
ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH;
#endif
return (&ssh1_3des);
}
|
