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Damien Miller5428f641999-11-25 11:54:57 +11001/*
Damien Millere4340be2000-09-16 13:29:08 +11002 * Copyright (c) 1999,2000 Markus Friedl. All rights reserved.
Damien Miller5428f641999-11-25 11:54:57 +11003 *
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.
Damien Miller5428f641999-11-25 11:54:57 +110012 *
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
Damien Millerd4a8b7e1999-10-27 13:42:43 +100025#include "includes.h"
Ben Lindstroma8baf362001-04-05 23:28:36 +000026RCSID("$OpenBSD: compat.c,v 1.45 2001/04/05 11:09:16 markus Exp $");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100027
Ben Lindstromb5628642000-10-18 00:02:25 +000028#ifdef HAVE_LIBPCRE
29# include <pcreposix.h>
Ben Lindstromca1c2a02000-10-14 21:33:19 +000030#else /* Use native regex libraries */
Ben Lindstrom401d58f2001-01-19 17:11:43 +000031# ifdef HAVE_REGEX_H
32# include <regex.h>
33# else
Tim Riceb399be42001-03-17 18:43:16 -080034# include "openbsd-compat/fake-regex.h"
Ben Lindstrom401d58f2001-01-19 17:11:43 +000035# endif
Kevin Steves48d0d252000-12-15 23:05:57 +000036#endif /* HAVE_LIBPCRE */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100037
Ben Lindstrom226cfa02001-01-22 05:34:40 +000038#include "packet.h"
39#include "xmalloc.h"
40#include "compat.h"
41#include "log.h"
42
Damien Miller95def091999-11-25 00:26:21 +110043int compat13 = 0;
Damien Miller33b13562000-04-04 14:38:59 +100044int compat20 = 0;
45int datafellows = 0;
Damien Miller95def091999-11-25 00:26:21 +110046
Damien Miller4af51302000-04-16 11:18:38 +100047void
Damien Miller33b13562000-04-04 14:38:59 +100048enable_compat20(void)
49{
Damien Miller1383bd82000-04-06 12:32:37 +100050 verbose("Enabling compatibility mode for protocol 2.0");
51 compat20 = 1;
Damien Miller33b13562000-04-04 14:38:59 +100052}
Damien Miller4af51302000-04-16 11:18:38 +100053void
Damien Miller95def091999-11-25 00:26:21 +110054enable_compat13(void)
55{
56 verbose("Enabling compatibility mode for protocol 1.3");
57 compat13 = 1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100058}
Damien Miller33b13562000-04-04 14:38:59 +100059/* datafellows bug compatibility */
60void
61compat_datafellows(const char *version)
62{
Damien Miller874d77b2000-10-14 16:23:11 +110063 int i, ret;
64 char ebuf[1024];
65 regex_t reg;
66 static struct {
67 char *pat;
Damien Miller30c3d422000-05-09 11:02:59 +100068 int bugs;
69 } check[] = {
Ben Lindstrom48bd7c12001-01-09 00:35:42 +000070 { "^OpenSSH[-_]2\\.[012]",
Ben Lindstromdf221392001-03-29 00:36:16 +000071 SSH_OLD_SESSIONID|SSH_BUG_BANNER|
Ben Lindstroma8baf362001-04-05 23:28:36 +000072 SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
Ben Lindstromdf221392001-03-29 00:36:16 +000073 { "^OpenSSH_2\\.3\\.0", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
Ben Lindstroma8baf362001-04-05 23:28:36 +000074 SSH_OLD_DHGEX|SSH_BUG_NOREKEY},
75 { "^OpenSSH_2\\.3\\.", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
76 SSH_BUG_NOREKEY},
Ben Lindstromc8530c72001-03-24 00:35:19 +000077 { "^OpenSSH_2\\.5\\.[01]p1",
Ben Lindstroma8baf362001-04-05 23:28:36 +000078 SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
79 SSH_BUG_NOREKEY },
Ben Lindstromdf221392001-03-29 00:36:16 +000080 { "^OpenSSH_2\\.5\\.[012]",
Ben Lindstroma8baf362001-04-05 23:28:36 +000081 SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
82 { "^OpenSSH_2\\.5\\.3",
83 SSH_BUG_NOREKEY },
Ben Lindstrom48bd7c12001-01-09 00:35:42 +000084 { "^OpenSSH", 0 },
Damien Miller50a41ed2000-10-16 12:14:42 +110085 { "MindTerm", 0 },
Ben Lindstromd121f612000-12-03 17:00:47 +000086 { "^2\\.1\\.0", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
Ben Lindstrom60a43812001-03-29 00:32:56 +000087 SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
88 SSH_BUG_RSASIGMD5 },
Ben Lindstrom5de86cc2001-03-05 06:08:19 +000089 { "^2\\.1 ", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
Ben Lindstrom60a43812001-03-29 00:32:56 +000090 SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
91 SSH_BUG_RSASIGMD5 },
Ben Lindstromd121f612000-12-03 17:00:47 +000092 { "^2\\.0\\.1[3-9]", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
Ben Lindstroma14ee472000-12-07 01:24:58 +000093 SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
Ben Lindstrom266dfdf2001-03-09 00:12:22 +000094 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
Ben Lindstrom60a43812001-03-29 00:32:56 +000095 SSH_BUG_PKOK|SSH_BUG_RSASIGMD5 },
Ben Lindstromd121f612000-12-03 17:00:47 +000096 { "^2\\.0\\.", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
Ben Lindstroma14ee472000-12-07 01:24:58 +000097 SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
98 SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
Ben Lindstrom60a43812001-03-29 00:32:56 +000099 SSH_BUG_PKAUTH|SSH_BUG_PKOK|
100 SSH_BUG_RSASIGMD5 },
101 { "^2\\.[23]\\.0", SSH_BUG_HMAC|SSH_BUG_RSASIGMD5 },
102 { "^2\\.3\\.", SSH_BUG_RSASIGMD5 },
Damien Miller50a41ed2000-10-16 12:14:42 +1100103 { "^2\\.[2-9]\\.", 0 },
Ben Lindstromd20d0f32001-03-10 17:22:20 +0000104 { "^2\\.4$", SSH_OLD_SESSIONID }, /* Van Dyke */
105 { "^3\\.0 SecureCRT", SSH_OLD_SESSIONID },
106 { "^1\\.7 SecureFX", SSH_OLD_SESSIONID },
107 { "^1\\.2\\.1[89]", SSH_BUG_IGNOREMSG },
108 { "^1\\.2\\.2[012]", SSH_BUG_IGNOREMSG },
Ben Lindstrom78c261a2001-04-04 23:43:26 +0000109 { "^1\\.3\\.2", SSH_BUG_IGNOREMSG }, /* f-secure */
Ben Lindstromd20d0f32001-03-10 17:22:20 +0000110 { "^SSH Compatible Server", /* Netscreen */
111 SSH_BUG_PASSWORDPAD },
112 { "^OSU_0", SSH_BUG_PASSWORDPAD },
113 { "^OSU_1\\.[0-4]", SSH_BUG_PASSWORDPAD },
114 { "^OSU_1\\.5alpha[1-3]",
115 SSH_BUG_PASSWORDPAD },
Damien Miller27dbe6f2001-03-19 22:36:20 +1100116 { "^SSH_Version_Mapper",
117 SSH_BUG_SCANNER },
Damien Miller50a41ed2000-10-16 12:14:42 +1100118 { NULL, 0 }
Damien Miller33b13562000-04-04 14:38:59 +1000119 };
Damien Millercaf6dd62000-08-29 11:33:50 +1100120 /* process table, return first match */
Damien Miller874d77b2000-10-14 16:23:11 +1100121 for (i = 0; check[i].pat; i++) {
122 ret = regcomp(&reg, check[i].pat, REG_EXTENDED|REG_NOSUB);
123 if (ret != 0) {
124 regerror(ret, &reg, ebuf, sizeof(ebuf));
125 ebuf[sizeof(ebuf)-1] = '\0';
126 error("regerror: %s", ebuf);
127 continue;
128 }
129 ret = regexec(&reg, version, 0, NULL, 0);
130 regfree(&reg);
131 if (ret == 0) {
Ben Lindstrom971c9732000-12-10 02:01:50 +0000132 debug("match: %s pat %s", version, check[i].pat);
Damien Miller30c3d422000-05-09 11:02:59 +1000133 datafellows = check[i].bugs;
Damien Miller33b13562000-04-04 14:38:59 +1000134 return;
135 }
136 }
Damien Miller874d77b2000-10-14 16:23:11 +1100137 debug("no match: %s", version);
Damien Miller33b13562000-04-04 14:38:59 +1000138}
Damien Miller78928792000-04-12 20:17:38 +1000139
140#define SEP ","
141int
142proto_spec(const char *spec)
143{
Damien Miller37023962000-07-11 17:31:38 +1000144 char *s, *p, *q;
Damien Miller78928792000-04-12 20:17:38 +1000145 int ret = SSH_PROTO_UNKNOWN;
146
Damien Millerb1715dc2000-05-30 13:44:51 +1000147 if (spec == NULL)
148 return ret;
Damien Miller37023962000-07-11 17:31:38 +1000149 q = s = xstrdup(spec);
150 for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
Damien Miller78928792000-04-12 20:17:38 +1000151 switch(atoi(p)) {
152 case 1:
153 if (ret == SSH_PROTO_UNKNOWN)
154 ret |= SSH_PROTO_1_PREFERRED;
155 ret |= SSH_PROTO_1;
156 break;
157 case 2:
158 ret |= SSH_PROTO_2;
159 break;
160 default:
161 log("ignoring bad proto spec: '%s'.", p);
162 break;
163 }
164 }
165 xfree(s);
166 return ret;
167}
Ben Lindstromc8530c72001-03-24 00:35:19 +0000168
169char *
170compat_cipher_proposal(char *cipher_prop)
171{
172 char *orig_prop, *fix_ciphers;
173 char *cp, *tmp;
174 size_t len;
175
176 if (!(datafellows & SSH_BUG_BIGENDIANAES))
177 return(cipher_prop);
178
179 len = strlen(cipher_prop) + 1;
180 fix_ciphers = xmalloc(len);
181 *fix_ciphers = '\0';
182 tmp = orig_prop = xstrdup(cipher_prop);
183 while((cp = strsep(&tmp, ",")) != NULL) {
184 if (strncmp(cp, "aes", 3) && strncmp(cp, "rijndael", 8)) {
185 if (*fix_ciphers)
186 strlcat(fix_ciphers, ",", len);
187 strlcat(fix_ciphers, cp, len);
188 }
189 }
190 xfree(orig_prop);
191 debug2("Original cipher proposal: %s", cipher_prop);
192 debug2("Compat cipher proposal: %s", fix_ciphers);
193 if (!*fix_ciphers)
194 fatal("No available ciphers found.");
195
196 return(fix_ciphers);
197}