compat.c revision 92559 
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 1.61 2002/03/06 00:24:39 markus Exp $");
27RCSID("$FreeBSD: head/crypto/openssh/compat.c 92559 2002-03-18 10:09:43Z 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	verbose("Enabling compatibility mode for protocol 2.0");
44	compat20 = 1;
45}
46void
47enable_compat13(void)
48{
49	verbose("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		{ "OpenSSH_2.3.0*",	SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
67					SSH_OLD_DHGEX|SSH_BUG_NOREKEY},
68		{ "OpenSSH_2.3.*",	SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
69					SSH_BUG_NOREKEY},
70		{ "OpenSSH_2.5.0p1*,"
71		  "OpenSSH_2.5.1p1*",
72					SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
73					SSH_BUG_NOREKEY },
74		{ "OpenSSH_2.5.0*,"
75		  "OpenSSH_2.5.1*,"
76		  "OpenSSH_2.5.2*",	SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
77		{ "OpenSSH_2.5.3*",	SSH_BUG_NOREKEY },
78		{ "Sun_SSH_1.0*",	SSH_BUG_NOREKEY },
79		{ "OpenSSH*",		0 },
80		{ "*MindTerm*",		0 },
81		{ "2.1.0*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
82					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
83					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
84		{ "2.1 *",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
85					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
86					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
87		{ "2.0.13*,"
88		  "2.0.14*,"
89		  "2.0.15*,"
90		  "2.0.16*,"
91		  "2.0.17*,"
92		  "2.0.18*,"
93		  "2.0.19*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
94					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
95					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
96					SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
97					SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
98					SSH_BUG_DUMMYCHAN },
99		{ "2.0.11*,"
100		  "2.0.12*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
101					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
102					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
103					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
104					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
105					SSH_BUG_DUMMYCHAN },
106		{ "2.0.*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
107					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
108					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
109					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
110					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
111					SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN },
112		{ "2.2.0*,"
113		  "2.3.0*",		SSH_BUG_HMAC|SSH_BUG_DEBUG|
114					SSH_BUG_RSASIGMD5 },
115		{ "2.3.*",		SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5 },
116		{ "2.4",		SSH_OLD_SESSIONID },	/* Van Dyke */
117		{ "2.*",		SSH_BUG_DEBUG },
118		{ "3.0.*",		SSH_BUG_DEBUG },
119		{ "3.0 SecureCRT*",	SSH_OLD_SESSIONID },
120		{ "1.7 SecureFX*",	SSH_OLD_SESSIONID },
121		{ "1.2.18*,"
122		  "1.2.19*,"
123		  "1.2.20*,"
124		  "1.2.21*,"
125		  "1.2.22*",		SSH_BUG_IGNOREMSG },
126		{ "1.3.2*",		SSH_BUG_IGNOREMSG },	/* f-secure */
127		{ "*SSH Compatible Server*",			/* Netscreen */
128					SSH_BUG_PASSWORDPAD },
129		{ "*OSU_0*,"
130		  "OSU_1.0*,"
131		  "OSU_1.1*,"
132		  "OSU_1.2*,"
133		  "OSU_1.3*,"
134		  "OSU_1.4*,"
135		  "OSU_1.5alpha1*,"
136		  "OSU_1.5alpha2*,"
137		  "OSU_1.5alpha3*",	SSH_BUG_PASSWORDPAD },
138		{ "*SSH_Version_Mapper*",
139					SSH_BUG_SCANNER },
140		{ NULL,			0 }
141	};
142
143	/* process table, return first match */
144	for (i = 0; check[i].pat; i++) {
145		if (match_pattern_list(version, check[i].pat,
146		    strlen(check[i].pat), 0) == 1) {
147			debug("match: %s pat %s", version, check[i].pat);
148			datafellows = check[i].bugs;
149			return;
150		}
151	}
152	debug("no match: %s", version);
153}
154
155#define	SEP	","
156int
157proto_spec(const char *spec)
158{
159	char *s, *p, *q;
160	int ret = SSH_PROTO_UNKNOWN;
161
162	if (spec == NULL)
163		return ret;
164	q = s = xstrdup(spec);
165	for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
166		switch (atoi(p)) {
167		case 1:
168			if (ret == SSH_PROTO_UNKNOWN)
169				ret |= SSH_PROTO_1_PREFERRED;
170			ret |= SSH_PROTO_1;
171			break;
172		case 2:
173			ret |= SSH_PROTO_2;
174			break;
175		default:
176			log("ignoring bad proto spec: '%s'.", p);
177			break;
178		}
179	}
180	xfree(s);
181	return ret;
182}
183
184char *
185compat_cipher_proposal(char *cipher_prop)
186{
187	Buffer b;
188	char *orig_prop, *fix_ciphers;
189	char *cp, *tmp;
190
191	if (!(datafellows & SSH_BUG_BIGENDIANAES))
192		return(cipher_prop);
193
194	buffer_init(&b);
195	tmp = orig_prop = xstrdup(cipher_prop);
196	while ((cp = strsep(&tmp, ",")) != NULL) {
197		if (strncmp(cp, "aes", 3) != 0) {
198			if (buffer_len(&b) > 0)
199				buffer_append(&b, ",", 1);
200			buffer_append(&b, cp, strlen(cp));
201		}
202	}
203	buffer_append(&b, "\0", 1);
204	fix_ciphers = xstrdup(buffer_ptr(&b));
205	buffer_free(&b);
206	xfree(orig_prop);
207	debug2("Original cipher proposal: %s", cipher_prop);
208	debug2("Compat cipher proposal: %s", fix_ciphers);
209	if (!*fix_ciphers)
210		fatal("No available ciphers found.");
211
212	return(fix_ciphers);
213}
214