xref: /netbsd-src/crypto/external/bsd/openssh/dist/compat.c (revision a4ddc2c8fb9af816efe3b1c375a5530aef0e89e9)
1 /*	$NetBSD: compat.c,v 1.4 2012/05/02 02:41:08 christos Exp $	*/
2 /* $OpenBSD: compat.c,v 1.79 2011/09/23 07:45:05 markus Exp $ */
3 /*
4  * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "includes.h"
28 __RCSID("$NetBSD: compat.c,v 1.4 2012/05/02 02:41:08 christos Exp $");
29 #include <sys/types.h>
30 
31 #include <stdlib.h>
32 #include <string.h>
33 #include <stdarg.h>
34 
35 #include "xmalloc.h"
36 #include "buffer.h"
37 #include "packet.h"
38 #include "compat.h"
39 #include "log.h"
40 #include "match.h"
41 
42 int compat13 = 0;
43 int compat20 = 0;
44 int datafellows = 0;
45 
46 void
47 enable_compat20(void)
48 {
49 	debug("Enabling compatibility mode for protocol 2.0");
50 	compat20 = 1;
51 }
52 void
53 enable_compat13(void)
54 {
55 	debug("Enabling compatibility mode for protocol 1.3");
56 	compat13 = 1;
57 }
58 /* datafellows bug compatibility */
59 void
60 compat_datafellows(const char *version)
61 {
62 	int i;
63 	static struct {
64 		const char	*pat;
65 		int	bugs;
66 	} check[] = {
67 		{ "OpenSSH-2.0*,"
68 		  "OpenSSH-2.1*,"
69 		  "OpenSSH_2.1*,"
70 		  "OpenSSH_2.2*",	SSH_OLD_SESSIONID|SSH_BUG_BANNER|
71 					SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
72 					SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
73 		{ "OpenSSH_2.3.0*",	SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
74 					SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
75 					SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
76 		{ "OpenSSH_2.3.*",	SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
77 					SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
78 					SSH_OLD_FORWARD_ADDR},
79 		{ "OpenSSH_2.5.0p1*,"
80 		  "OpenSSH_2.5.1p1*",
81 					SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
82 					SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
83 					SSH_OLD_FORWARD_ADDR},
84 		{ "OpenSSH_2.5.0*,"
85 		  "OpenSSH_2.5.1*,"
86 		  "OpenSSH_2.5.2*",	SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
87 					SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
88 		{ "OpenSSH_2.5.3*",	SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
89 					SSH_OLD_FORWARD_ADDR},
90 		{ "OpenSSH_2.*,"
91 		  "OpenSSH_3.0*,"
92 		  "OpenSSH_3.1*",	SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
93 		{ "OpenSSH_3.*",	SSH_OLD_FORWARD_ADDR },
94 		{ "Sun_SSH_1.0*",	SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
95 		{ "OpenSSH_4*",		0 },
96 		{ "OpenSSH_5*",		SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT},
97 		{ "OpenSSH*",		SSH_NEW_OPENSSH },
98 		{ "*MindTerm*",		0 },
99 		{ "2.1.0*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
100 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
101 					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
102 					SSH_BUG_FIRSTKEX },
103 		{ "2.1 *",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
104 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
105 					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
106 					SSH_BUG_FIRSTKEX },
107 		{ "2.0.13*,"
108 		  "2.0.14*,"
109 		  "2.0.15*,"
110 		  "2.0.16*,"
111 		  "2.0.17*,"
112 		  "2.0.18*,"
113 		  "2.0.19*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
114 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
115 					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
116 					SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
117 					SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
118 					SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
119 		{ "2.0.11*,"
120 		  "2.0.12*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
121 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
122 					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
123 					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
124 					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
125 					SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
126 		{ "2.0.*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
127 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
128 					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
129 					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
130 					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
131 					SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
132 					SSH_BUG_FIRSTKEX },
133 		{ "2.2.0*,"
134 		  "2.3.0*",		SSH_BUG_HMAC|SSH_BUG_DEBUG|
135 					SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
136 		{ "2.3.*",		SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
137 					SSH_BUG_FIRSTKEX },
138 		{ "2.4",		SSH_OLD_SESSIONID },	/* Van Dyke */
139 		{ "2.*",		SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX|
140 					SSH_BUG_RFWD_ADDR },
141 		{ "3.0.*",		SSH_BUG_DEBUG },
142 		{ "3.0 SecureCRT*",	SSH_OLD_SESSIONID },
143 		{ "1.7 SecureFX*",	SSH_OLD_SESSIONID },
144 		{ "1.2.18*,"
145 		  "1.2.19*,"
146 		  "1.2.20*,"
147 		  "1.2.21*,"
148 		  "1.2.22*",		SSH_BUG_IGNOREMSG|SSH_BUG_K5USER },
149 		{ "1.3.2*",		/* F-Secure */
150 					SSH_BUG_IGNOREMSG|SSH_BUG_K5USER },
151 		{ "1.2.1*,"
152 		  "1.2.2*,"
153 		  "1.2.3*",		SSH_BUG_K5USER },
154 		{ "*SSH Compatible Server*",			/* Netscreen */
155 					SSH_BUG_PASSWORDPAD },
156 		{ "*OSU_0*,"
157 		  "OSU_1.0*,"
158 		  "OSU_1.1*,"
159 		  "OSU_1.2*,"
160 		  "OSU_1.3*,"
161 		  "OSU_1.4*,"
162 		  "OSU_1.5alpha1*,"
163 		  "OSU_1.5alpha2*,"
164 		  "OSU_1.5alpha3*",	SSH_BUG_PASSWORDPAD },
165 		{ "*SSH_Version_Mapper*",
166 					SSH_BUG_SCANNER },
167 		{ "Probe-*",
168 					SSH_BUG_PROBE },
169 		{ NULL,			0 }
170 	};
171 
172 	/* process table, return first match */
173 	for (i = 0; check[i].pat; i++) {
174 		if (match_pattern_list(version, check[i].pat,
175 		    strlen(check[i].pat), 0) == 1) {
176 			debug("match: %s pat %s", version, check[i].pat);
177 			datafellows = check[i].bugs;
178 			/* Check to see if the remote side is OpenSSH and not HPN */
179 			if(strstr(version,"OpenSSH") != NULL)
180 			{
181 				if (strstr(version,"hpn") == NULL)
182 				{
183 					datafellows |= SSH_BUG_LARGEWINDOW;
184 					debug("Remote is NON-HPN aware");
185 				}
186 			}
187 			return;
188 		}
189 	}
190 	debug("no match: %s", version);
191 }
192 
193 #define	SEP	","
194 int
195 proto_spec(const char *spec)
196 {
197 	char *s, *p, *q;
198 	int ret = SSH_PROTO_UNKNOWN;
199 
200 	if (spec == NULL)
201 		return ret;
202 	q = s = xstrdup(spec);
203 	for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
204 		switch (atoi(p)) {
205 		case 1:
206 			if (ret == SSH_PROTO_UNKNOWN)
207 				ret |= SSH_PROTO_1_PREFERRED;
208 			ret |= SSH_PROTO_1;
209 			break;
210 		case 2:
211 			ret |= SSH_PROTO_2;
212 			break;
213 		default:
214 			logit("ignoring bad proto spec: '%s'.", p);
215 			break;
216 		}
217 	}
218 	xfree(s);
219 	return ret;
220 }
221 
222 const char *
223 compat_cipher_proposal(const char *cipher_prop)
224 {
225 	Buffer b;
226 	char *orig_prop, *fix_ciphers;
227 	char *cp, *tmp;
228 
229 	if (!(datafellows & SSH_BUG_BIGENDIANAES))
230 		return(cipher_prop);
231 
232 	buffer_init(&b);
233 	tmp = orig_prop = xstrdup(cipher_prop);
234 	while ((cp = strsep(&tmp, ",")) != NULL) {
235 		if (strncmp(cp, "aes", 3) != 0) {
236 			if (buffer_len(&b) > 0)
237 				buffer_append(&b, ",", 1);
238 			buffer_append(&b, cp, strlen(cp));
239 		}
240 	}
241 	buffer_append(&b, "\0", 1);
242 	fix_ciphers = xstrdup(buffer_ptr(&b));
243 	buffer_free(&b);
244 	xfree(orig_prop);
245 	debug2("Original cipher proposal: %s", cipher_prop);
246 	debug2("Compat cipher proposal: %s", fix_ciphers);
247 	if (!*fix_ciphers)
248 		fatal("No available ciphers found.");
249 
250 	return(fix_ciphers);
251 }
252