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      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  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
     26  * Use is subject to license terms.
     27  */
     28 
     29 #include "includes.h"
     30 RCSID("$OpenBSD: compat.c,v 1.65 2002/09/27 10:42:09 mickey Exp $");
     31 
     32 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     33 
     34 #include "buffer.h"
     35 #include "packet.h"
     36 #include "xmalloc.h"
     37 #include "compat.h"
     38 #include "log.h"
     39 #include "match.h"
     40 
     41 int compat13 = 0;
     42 int compat20 = 0;
     43 int datafellows = 0;
     44 
     45 void
     46 enable_compat20(void)
     47 {
     48 	debug("Enabling compatibility mode for protocol 2.0");
     49 	compat20 = 1;
     50 }
     51 void
     52 enable_compat13(void)
     53 {
     54 	debug("Enabling compatibility mode for protocol 1.3");
     55 	compat13 = 1;
     56 }
     57 /* datafellows bug compatibility */
     58 void
     59 compat_datafellows(const char *version)
     60 {
     61 	int i;
     62 	static struct {
     63 		char	*pat;
     64 		int	bugs;
     65 	} check[] = {
     66 		{ "OpenSSH-2.0*,"
     67 		  "OpenSSH-2.1*,"
     68 		  "OpenSSH_2.1*,"
     69 		  "OpenSSH_2.2*",	SSH_OLD_SESSIONID|SSH_BUG_BANNER|
     70 					SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
     71 					SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
     72 		{ "OpenSSH_2.3.0*",	SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
     73 					SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
     74 					SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
     75 		{ "OpenSSH_2.3.*",	SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
     76 					SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
     77 					SSH_OLD_FORWARD_ADDR},
     78 		{ "OpenSSH_2.5.0p1*,"
     79 		  "OpenSSH_2.5.1p1*",
     80 					SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
     81 					SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
     82 					SSH_OLD_GSSAPI|SSH_OLD_FORWARD_ADDR},
     83 		{ "OpenSSH_2.5.0*,"
     84 		  "OpenSSH_2.5.1*,"
     85 		  "OpenSSH_2.5.2*",	SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
     86 					SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
     87 		{ "OpenSSH_2.5.3*",	SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
     88 					SSH_OLD_FORWARD_ADDR},
     89 		{ "OpenSSH_2.9p*",      SSH_BUG_EXTEOF|SSH_OLD_GSSAPI|
     90 					SSH_BUG_GSSKEX_HOSTKEY|SSH_OLD_FORWARD_ADDR},
     91 		{ "OpenSSH_2.*,"
     92 		  "OpenSSH_3.0*,"
     93 		  "OpenSSH_3.1*",       SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR|
     94 		  			SSH_OLD_GSSAPI|SSH_BUG_GSSAPI_BER|
     95 					SSH_BUG_GSSKEX_HOSTKEY},
     96 		{ "OpenSSH_3.2*,"
     97 		  "OpenSSH_3.3*,"
     98 		  "OpenSSH_3.4*,"
     99 		  "OpenSSH_3.5*",       SSH_BUG_GSSAPI_BER|SSH_OLD_GSSAPI|
    100 					SSH_BUG_GSSKEX_HOSTKEY|SSH_OLD_FORWARD_ADDR},
    101 		{ "OpenSSH_3.6*,"
    102 		  "OpenSSH_3.7*,"
    103 		  "OpenSSH_3.8*",	SSH_BUG_GSSKEX_HOSTKEY|SSH_OLD_FORWARD_ADDR},
    104 		{ "OpenSSH_3.*",	SSH_OLD_FORWARD_ADDR},
    105 		{ "OpenSSH*",		0 },
    106 		{ "Sun_SSH_1.0.*",	SSH_BUG_NOREKEY|
    107 					SSH_BUG_LOCALES_NOT_LANGTAGS|SSH_OLD_FORWARD_ADDR},
    108 		{ "Sun_SSH_1.0*",	SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
    109 					SSH_BUG_LOCALES_NOT_LANGTAGS|SSH_OLD_FORWARD_ADDR},
    110 		{ "Sun_SSH_1.1*",	SSH_OLD_FORWARD_ADDR},
    111 		{ "Sun_SSH_1.2*",	0 },
    112 		{ "*MindTerm*",		0 },
    113 		{ "2.1.0*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
    114 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
    115 					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
    116 					SSH_BUG_FIRSTKEX },
    117 		{ "2.1 *",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
    118 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
    119 					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
    120 					SSH_BUG_FIRSTKEX },
    121 		{ "2.0.13*,"
    122 		  "2.0.14*,"
    123 		  "2.0.15*,"
    124 		  "2.0.16*,"
    125 		  "2.0.17*,"
    126 		  "2.0.18*,"
    127 		  "2.0.19*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
    128 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
    129 					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
    130 					SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
    131 					SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
    132 					SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
    133 		{ "2.0.11*,"
    134 		  "2.0.12*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
    135 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
    136 					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
    137 					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
    138 					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
    139 					SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
    140 		{ "2.0.*",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
    141 					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
    142 					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
    143 					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
    144 					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
    145 					SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
    146 					SSH_BUG_FIRSTKEX },
    147 		{ "2.2.0*,"
    148 		  "2.3.0*",		SSH_BUG_HMAC|SSH_BUG_DEBUG|
    149 					SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
    150 		{ "2.3.*",		SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
    151 					SSH_BUG_FIRSTKEX },
    152 		{ "2.4",		SSH_OLD_SESSIONID },	/* Van Dyke */
    153 		{ "2.*",		SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX|
    154 					SSH_BUG_RFWD_ADDR},
    155 		{ "3.0.*",		SSH_BUG_DEBUG },
    156 		{ "3.0 SecureCRT*",	SSH_OLD_SESSIONID },
    157 		{ "1.7 SecureFX*",	SSH_OLD_SESSIONID },
    158 		{ "1.2.18*,"
    159 		  "1.2.19*,"
    160 		  "1.2.20*,"
    161 		  "1.2.21*,"
    162 		  "1.2.22*",		SSH_BUG_IGNOREMSG|SSH_BUG_K5USER },
    163 		{ "1.3.2*",		/* F-Secure */
    164 					SSH_BUG_IGNOREMSG|SSH_BUG_K5USER },
    165 		{ "1.2.1*,"
    166 		  "1.2.2*,"
    167 		  "1.2.3*",		SSH_BUG_K5USER },
    168 		{ "*SSH Compatible Server*",			/* Netscreen */
    169 					SSH_BUG_PASSWORDPAD },
    170 		{ "*OSU_0*,"
    171 		  "OSU_1.0*,"
    172 		  "OSU_1.1*,"
    173 		  "OSU_1.2*,"
    174 		  "OSU_1.3*,"
    175 		  "OSU_1.4*,"
    176 		  "OSU_1.5alpha1*,"
    177 		  "OSU_1.5alpha2*,"
    178 		  "OSU_1.5alpha3*",	SSH_BUG_PASSWORDPAD },
    179 		{ "*SSH_Version_Mapper*",
    180 					SSH_BUG_SCANNER },
    181 		{ "Probe-*",
    182 					SSH_BUG_PROBE },
    183 		{ NULL,			0 }
    184 	};
    185 
    186 	/* process table, return first match */
    187 	for (i = 0; check[i].pat; i++) {
    188 		if (match_pattern_list(version, check[i].pat,
    189 		    strlen(check[i].pat), 0) == 1) {
    190 			debug("match: %s pat %s", version, check[i].pat);
    191 			datafellows = check[i].bugs;
    192 			return;
    193 		}
    194 	}
    195 	debug("no match: %s", version);
    196 }
    197 
    198 #define	SEP	","
    199 int
    200 proto_spec(const char *spec)
    201 {
    202 	char *s, *p, *q;
    203 	int ret = SSH_PROTO_UNKNOWN;
    204 
    205 	if (spec == NULL)
    206 		return ret;
    207 	q = s = xstrdup(spec);
    208 	for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
    209 		switch (atoi(p)) {
    210 		case 1:
    211 			if (ret == SSH_PROTO_UNKNOWN)
    212 				ret |= SSH_PROTO_1_PREFERRED;
    213 			ret |= SSH_PROTO_1;
    214 			break;
    215 		case 2:
    216 			ret |= SSH_PROTO_2;
    217 			break;
    218 		default:
    219 			log("ignoring bad proto spec: '%s'.", p);
    220 			break;
    221 		}
    222 	}
    223 	xfree(s);
    224 	return ret;
    225 }
    226 
    227 char *
    228 compat_cipher_proposal(char *cipher_prop)
    229 {
    230 	Buffer b;
    231 	char *orig_prop, *fix_ciphers;
    232 	char *cp, *tmp;
    233 
    234 	if (!(datafellows & SSH_BUG_BIGENDIANAES))
    235 		return(cipher_prop);
    236 
    237 	buffer_init(&b);
    238 	tmp = orig_prop = xstrdup(cipher_prop);
    239 	while ((cp = strsep(&tmp, ",")) != NULL) {
    240 		if (strncmp(cp, "aes", 3) != 0) {
    241 			if (buffer_len(&b) > 0)
    242 				buffer_append(&b, ",", 1);
    243 			buffer_append(&b, cp, strlen(cp));
    244 		}
    245 	}
    246 	buffer_append(&b, "\0", 1);
    247 	fix_ciphers = xstrdup(buffer_ptr(&b));
    248 	buffer_free(&b);
    249 	xfree(orig_prop);
    250 	debug2("Original cipher proposal: %s", cipher_prop);
    251 	debug2("Compat cipher proposal: %s", fix_ciphers);
    252 	if (!*fix_ciphers)
    253 		fatal("No available ciphers found.");
    254 
    255 	return(fix_ciphers);
    256 }
    257