compat.c revision 124211 
1/*
2 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include "includes.h"
26RCSID("$OpenBSD: compat.c,v 1.69 2003/08/29 10:03:15 markus Exp $");
27RCSID("$FreeBSD: head/crypto/openssh/compat.c 124211 2004-01-07 11:16:27Z des $");
28
29#include "buffer.h"
30#include "packet.h"
31#include "xmalloc.h"
32#include "compat.h"
33#include "log.h"
34#include "match.h"
35
36int compat13 = 0;
37int compat20 = 0;
38int datafellows = 0;
39
40void
41enable_compat20(void)
42{
43	debug("Enabling compatibility mode for protocol 2.0");
44	compat20 = 1;
45}
46void
47enable_compat13(void)
48{
49	debug("Enabling compatibility mode for protocol 1.3");
50	compat13 = 1;
51}
52/* datafellows bug compatibility */
53void
54compat_datafellows(const char *version)
55{
56	int i;
57	static struct {
58		char	*pat;
59		int	bugs;
60	} check[] = {
61		{ "OpenSSH-2.0*,"
62		  "OpenSSH-2.1*,"
63		  "OpenSSH_2.1*,"
64		  "OpenSSH_2.2*",	SSH_OLD_SESSIONID|SSH_BUG_BANNER|
65					SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
66					SSH_BUG_EXTEOF},
67		{ "OpenSSH_2.3.0*",	SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
68					SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
69					SSH_BUG_EXTEOF},
70		{ "OpenSSH_2.3.*",	SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
71					SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
72		{ "OpenSSH_2.5.0p1*,"
73		  "OpenSSH_2.5.1p1*",
74					SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
75					SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
76		{ "OpenSSH_2.5.0*,"
77		  "OpenSSH_2.5.1*,"
78		  "OpenSSH_2.5.2*",	SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
79					SSH_BUG_EXTEOF},
80		{ "OpenSSH_2.5.3*",	SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
81		{ "OpenSSH_2.*,"
82		  "OpenSSH_3.0*,"
83		  "OpenSSH_3.1*",	SSH_BUG_EXTEOF|SSH_BUG_GSSAPI_BER},
84		{ "OpenSSH_3.2*,"
85		  "OpenSSH_3.3*,"
86		  "OpenSSH_3.4*,"
87		  "OpenSSH_3.5*",	SSH_BUG_GSSAPI_BER},
88		{ "Sun_SSH_1.0*",	SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
89		{ "OpenSSH*",		0 },
90		{ "*MindTerm*",		0 },
91		{ "2.1.0*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
92					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
93					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
94					SSH_BUG_FIRSTKEX },
95		{ "2.1 *",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
96					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
97					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
98					SSH_BUG_FIRSTKEX },
99		{ "2.0.13*,"
100		  "2.0.14*,"
101		  "2.0.15*,"
102		  "2.0.16*,"
103		  "2.0.17*,"
104		  "2.0.18*,"
105		  "2.0.19*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
106					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
107					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
108					SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
109					SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
110					SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
111		{ "2.0.11*,"
112		  "2.0.12*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
113					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
114					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
115					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
116					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
117					SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
118		{ "2.0.*",		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_DERIVEKEY|SSH_BUG_DUMMYCHAN|
124					SSH_BUG_FIRSTKEX },
125		{ "2.2.0*,"
126		  "2.3.0*",		SSH_BUG_HMAC|SSH_BUG_DEBUG|
127					SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
128		{ "2.3.*",		SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
129					SSH_BUG_FIRSTKEX },
130		{ "2.4",		SSH_OLD_SESSIONID },	/* Van Dyke */
131		{ "2.*",		SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX },
132		{ "3.0.*",		SSH_BUG_DEBUG },
133		{ "3.0 SecureCRT*",	SSH_OLD_SESSIONID },
134		{ "1.7 SecureFX*",	SSH_OLD_SESSIONID },
135		{ "1.2.18*,"
136		  "1.2.19*,"
137		  "1.2.20*,"
138		  "1.2.21*,"
139		  "1.2.22*",		SSH_BUG_IGNOREMSG },
140		{ "1.3.2*",		/* F-Secure */
141					SSH_BUG_IGNOREMSG },
142		{ "*SSH Compatible Server*",			/* Netscreen */
143					SSH_BUG_PASSWORDPAD },
144		{ "*OSU_0*,"
145		  "OSU_1.0*,"
146		  "OSU_1.1*,"
147		  "OSU_1.2*,"
148		  "OSU_1.3*,"
149		  "OSU_1.4*,"
150		  "OSU_1.5alpha1*,"
151		  "OSU_1.5alpha2*,"
152		  "OSU_1.5alpha3*",	SSH_BUG_PASSWORDPAD },
153		{ "*SSH_Version_Mapper*",
154					SSH_BUG_SCANNER },
155		{ "Probe-*",
156					SSH_BUG_PROBE },
157		{ NULL,			0 }
158	};
159
160	/* process table, return first match */
161	for (i = 0; check[i].pat; i++) {
162		if (match_pattern_list(version, check[i].pat,
163		    strlen(check[i].pat), 0) == 1) {
164			debug("match: %s pat %s", version, check[i].pat);
165			datafellows = check[i].bugs;
166			return;
167		}
168	}
169	debug("no match: %s", version);
170}
171
172#define	SEP	","
173int
174proto_spec(const char *spec)
175{
176	char *s, *p, *q;
177	int ret = SSH_PROTO_UNKNOWN;
178
179	if (spec == NULL)
180		return ret;
181	q = s = xstrdup(spec);
182	for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
183		switch (atoi(p)) {
184		case 1:
185			if (ret == SSH_PROTO_UNKNOWN)
186				ret |= SSH_PROTO_1_PREFERRED;
187			ret |= SSH_PROTO_1;
188			break;
189		case 2:
190			ret |= SSH_PROTO_2;
191			break;
192		default:
193			logit("ignoring bad proto spec: '%s'.", p);
194			break;
195		}
196	}
197	xfree(s);
198	return ret;
199}
200
201char *
202compat_cipher_proposal(char *cipher_prop)
203{
204	Buffer b;
205	char *orig_prop, *fix_ciphers;
206	char *cp, *tmp;
207
208	if (!(datafellows & SSH_BUG_BIGENDIANAES))
209		return(cipher_prop);
210
211	buffer_init(&b);
212	tmp = orig_prop = xstrdup(cipher_prop);
213	while ((cp = strsep(&tmp, ",")) != NULL) {
214		if (strncmp(cp, "aes", 3) != 0) {
215			if (buffer_len(&b) > 0)
216				buffer_append(&b, ",", 1);
217			buffer_append(&b, cp, strlen(cp));
218		}
219	}
220	buffer_append(&b, "\0", 1);
221	fix_ciphers = xstrdup(buffer_ptr(&b));
222	buffer_free(&b);
223	xfree(orig_prop);
224	debug2("Original cipher proposal: %s", cipher_prop);
225	debug2("Compat cipher proposal: %s", fix_ciphers);
226	if (!*fix_ciphers)
227		fatal("No available ciphers found.");
228
229	return(fix_ciphers);
230}
231