1 /* $OpenBSD: compat.c,v 1.78 2008/09/11 14:22:37 markus Exp $ */
2 /*
3 * Copyright (c) 1999, 2000, 2001, 2002 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 <stdlib.h>
31 #include <string.h>
32 #include <stdarg.h>
33
34 #include "xmalloc.h"
35 #include "buffer.h"
36 #include "packet.h"
37 #include "compat.h"
38 #include "log.h"
39 #include "match.h"
40
41 int compat13 = 0;
42 int compat20 = 0;
43 int datafellows = 0;
44
45 void
enable_compat20(void)46 enable_compat20(void)
47 {
48 debug("Enabling compatibility mode for protocol 2.0");
49 compat20 = 1;
50 }
51 void
enable_compat13(void)52 enable_compat13(void)
53 {
54 debug("Enabling compatibility mode for protocol 1.3");
55 compat13 = 1;
56 }
57 /* datafellows bug compatibility */
58 void
compat_datafellows(const char * version)59 compat_datafellows(const char *version)
60 {
61 int i;
62 static struct {
63 char *pat;
64 int bugs;
65 } check[] = {
66 { "OpenSSH-2.0*,"
67 "OpenSSH-2.1*,"
68 "OpenSSH_2.1*,"
69 "OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER|
70 SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
71 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
72 { "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
73 SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
74 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
75 { "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
76 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
77 SSH_OLD_FORWARD_ADDR},
78 { "OpenSSH_2.5.0p1*,"
79 "OpenSSH_2.5.1p1*",
80 SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
81 SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
82 SSH_OLD_FORWARD_ADDR},
83 { "OpenSSH_2.5.0*,"
84 "OpenSSH_2.5.1*,"
85 "OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
86 SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
87 { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
88 SSH_OLD_FORWARD_ADDR},
89 { "OpenSSH_2.*,"
90 "OpenSSH_3.0*,"
91 "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
92 { "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR },
93 { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
94 { "OpenSSH_4*", 0 },
95 { "OpenSSH*", SSH_NEW_OPENSSH },
96 { "*MindTerm*", 0 },
97 { "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
98 SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
99 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
100 SSH_BUG_FIRSTKEX },
101 { "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
102 SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
103 SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
104 SSH_BUG_FIRSTKEX },
105 { "2.0.13*,"
106 "2.0.14*,"
107 "2.0.15*,"
108 "2.0.16*,"
109 "2.0.17*,"
110 "2.0.18*,"
111 "2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
112 SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
113 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
114 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
115 SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
116 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
117 { "2.0.11*,"
118 "2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
119 SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
120 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
121 SSH_BUG_PKAUTH|SSH_BUG_PKOK|
122 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
123 SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
124 { "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
125 SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
126 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
127 SSH_BUG_PKAUTH|SSH_BUG_PKOK|
128 SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
129 SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
130 SSH_BUG_FIRSTKEX },
131 { "2.2.0*,"
132 "2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG|
133 SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
134 { "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
135 SSH_BUG_FIRSTKEX },
136 { "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */
137 { "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX|
138 SSH_BUG_RFWD_ADDR },
139 { "3.0.*", SSH_BUG_DEBUG },
140 { "3.0 SecureCRT*", SSH_OLD_SESSIONID },
141 { "1.7 SecureFX*", SSH_OLD_SESSIONID },
142 { "1.2.18*,"
143 "1.2.19*,"
144 "1.2.20*,"
145 "1.2.21*,"
146 "1.2.22*", SSH_BUG_IGNOREMSG },
147 { "1.3.2*", /* F-Secure */
148 SSH_BUG_IGNOREMSG },
149 { "*SSH Compatible Server*", /* Netscreen */
150 SSH_BUG_PASSWORDPAD },
151 { "*OSU_0*,"
152 "OSU_1.0*,"
153 "OSU_1.1*,"
154 "OSU_1.2*,"
155 "OSU_1.3*,"
156 "OSU_1.4*,"
157 "OSU_1.5alpha1*,"
158 "OSU_1.5alpha2*,"
159 "OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD },
160 { "*SSH_Version_Mapper*",
161 SSH_BUG_SCANNER },
162 { "Probe-*",
163 SSH_BUG_PROBE },
164 { NULL, 0 }
165 };
166
167 /* process table, return first match */
168 for (i = 0; check[i].pat; i++) {
169 if (match_pattern_list(version, check[i].pat,
170 strlen(check[i].pat), 0) == 1) {
171 debug("match: %s pat %s", version, check[i].pat);
172 datafellows = check[i].bugs;
173 return;
174 }
175 }
176 debug("no match: %s", version);
177 }
178
179 #define SEP ","
180 int
proto_spec(const char * spec)181 proto_spec(const char *spec)
182 {
183 char *s, *p, *q;
184 int ret = SSH_PROTO_UNKNOWN;
185
186 if (spec == NULL)
187 return ret;
188 q = s = xstrdup(spec);
189 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
190 switch (atoi(p)) {
191 case 1:
192 if (ret == SSH_PROTO_UNKNOWN)
193 ret |= SSH_PROTO_1_PREFERRED;
194 ret |= SSH_PROTO_1;
195 break;
196 case 2:
197 ret |= SSH_PROTO_2;
198 break;
199 default:
200 logit("ignoring bad proto spec: '%s'.", p);
201 break;
202 }
203 }
204 xfree(s);
205 return ret;
206 }
207
208 char *
compat_cipher_proposal(char * cipher_prop)209 compat_cipher_proposal(char *cipher_prop)
210 {
211 Buffer b;
212 char *orig_prop, *fix_ciphers;
213 char *cp, *tmp;
214
215 if (!(datafellows & SSH_BUG_BIGENDIANAES))
216 return(cipher_prop);
217
218 buffer_init(&b);
219 tmp = orig_prop = xstrdup(cipher_prop);
220 while ((cp = strsep(&tmp, ",")) != NULL) {
221 if (strncmp(cp, "aes", 3) != 0) {
222 if (buffer_len(&b) > 0)
223 buffer_append(&b, ",", 1);
224 buffer_append(&b, cp, strlen(cp));
225 }
226 }
227 buffer_append(&b, "\0", 1);
228 fix_ciphers = xstrdup(buffer_ptr(&b));
229 buffer_free(&b);
230 xfree(orig_prop);
231 debug2("Original cipher proposal: %s", cipher_prop);
232 debug2("Compat cipher proposal: %s", fix_ciphers);
233 if (!*fix_ciphers)
234 fatal("No available ciphers found.");
235
236 return(fix_ciphers);
237 }
238