compat.c revision 126277 
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 1.70 2003/11/02 11:01:03 markus Exp $");
27RCSID("$FreeBSD: head/crypto/openssh/compat.c 126277 2004-02-26 10:52:33Z 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},
84		{ "Sun_SSH_1.0*",	SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
85		{ "OpenSSH*",		0 },
86		{ "*MindTerm*",		0 },
87		{ "2.1.0*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
88					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
89					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
90					SSH_BUG_FIRSTKEX },
91		{ "2.1 *",		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		{ "2.0.13*,"
96		  "2.0.14*,"
97		  "2.0.15*,"
98		  "2.0.16*,"
99		  "2.0.17*,"
100		  "2.0.18*,"
101		  "2.0.19*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
102					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
103					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
104					SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
105					SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
106					SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
107		{ "2.0.11*,"
108		  "2.0.12*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
109					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
110					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
111					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
112					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
113					SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
114		{ "2.0.*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
115					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
116					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
117					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
118					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
119					SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
120					SSH_BUG_FIRSTKEX },
121		{ "2.2.0*,"
122		  "2.3.0*",		SSH_BUG_HMAC|SSH_BUG_DEBUG|
123					SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
124		{ "2.3.*",		SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
125					SSH_BUG_FIRSTKEX },
126		{ "2.4",		SSH_OLD_SESSIONID },	/* Van Dyke */
127		{ "2.*",		SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX },
128		{ "3.0.*",		SSH_BUG_DEBUG },
129		{ "3.0 SecureCRT*",	SSH_OLD_SESSIONID },
130		{ "1.7 SecureFX*",	SSH_OLD_SESSIONID },
131		{ "1.2.18*,"
132		  "1.2.19*,"
133		  "1.2.20*,"
134		  "1.2.21*,"
135		  "1.2.22*",		SSH_BUG_IGNOREMSG },
136		{ "1.3.2*",		/* F-Secure */
137					SSH_BUG_IGNOREMSG },
138		{ "*SSH Compatible Server*",			/* Netscreen */
139					SSH_BUG_PASSWORDPAD },
140		{ "*OSU_0*,"
141		  "OSU_1.0*,"
142		  "OSU_1.1*,"
143		  "OSU_1.2*,"
144		  "OSU_1.3*,"
145		  "OSU_1.4*,"
146		  "OSU_1.5alpha1*,"
147		  "OSU_1.5alpha2*,"
148		  "OSU_1.5alpha3*",	SSH_BUG_PASSWORDPAD },
149		{ "*SSH_Version_Mapper*",
150					SSH_BUG_SCANNER },
151		{ "Probe-*",
152					SSH_BUG_PROBE },
153		{ NULL,			0 }
154	};
155
156	/* process table, return first match */
157	for (i = 0; check[i].pat; i++) {
158		if (match_pattern_list(version, check[i].pat,
159		    strlen(check[i].pat), 0) == 1) {
160			debug("match: %s pat %s", version, check[i].pat);
161			datafellows = check[i].bugs;
162			return;
163		}
164	}
165	debug("no match: %s", version);
166}
167
168#define	SEP	","
169int
170proto_spec(const char *spec)
171{
172	char *s, *p, *q;
173	int ret = SSH_PROTO_UNKNOWN;
174
175	if (spec == NULL)
176		return ret;
177	q = s = xstrdup(spec);
178	for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
179		switch (atoi(p)) {
180		case 1:
181			if (ret == SSH_PROTO_UNKNOWN)
182				ret |= SSH_PROTO_1_PREFERRED;
183			ret |= SSH_PROTO_1;
184			break;
185		case 2:
186			ret |= SSH_PROTO_2;
187			break;
188		default:
189			logit("ignoring bad proto spec: '%s'.", p);
190			break;
191		}
192	}
193	xfree(s);
194	return ret;
195}
196
197char *
198compat_cipher_proposal(char *cipher_prop)
199{
200	Buffer b;
201	char *orig_prop, *fix_ciphers;
202	char *cp, *tmp;
203
204	if (!(datafellows & SSH_BUG_BIGENDIANAES))
205		return(cipher_prop);
206
207	buffer_init(&b);
208	tmp = orig_prop = xstrdup(cipher_prop);
209	while ((cp = strsep(&tmp, ",")) != NULL) {
210		if (strncmp(cp, "aes", 3) != 0) {
211			if (buffer_len(&b) > 0)
212				buffer_append(&b, ",", 1);
213			buffer_append(&b, cp, strlen(cp));
214		}
215	}
216	buffer_append(&b, "\0", 1);
217	fix_ciphers = xstrdup(buffer_ptr(&b));
218	buffer_free(&b);
219	xfree(orig_prop);
220	debug2("Original cipher proposal: %s", cipher_prop);
221	debug2("Compat cipher proposal: %s", fix_ciphers);
222	if (!*fix_ciphers)
223		fatal("No available ciphers found.");
224
225	return(fix_ciphers);
226}
227