[openssh.git] / compat.c

/*
 * Copyright (c) 1999, 2000, 2001 Markus Friedl.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"
RCSID("$OpenBSD: compat.c,v 1.52 2001/09/17 21:09:47 markus Exp $");

#ifdef HAVE_LIBPCRE
#  include <pcreposix.h>
#else /* Use native regex libraries */
#  ifdef HAVE_REGEX_H
#    include <regex.h>
#  else
#    include "openbsd-compat/fake-regex.h"
#  endif
#endif /* HAVE_LIBPCRE */

#include "packet.h"
#include "xmalloc.h"
#include "compat.h"
#include "log.h"

int compat13 = 0;
int compat20 = 0;
int datafellows = 0;

void
enable_compat20(void)
{
	verbose("Enabling compatibility mode for protocol 2.0");
	compat20 = 1;
}
void
enable_compat13(void)
{
	verbose("Enabling compatibility mode for protocol 1.3");
	compat13 = 1;
}
/* datafellows bug compatibility */
void
compat_datafellows(const char *version)
{
	int i, ret;
	char ebuf[1024];
	regex_t reg;
	static struct {
		char	*pat;
		int	bugs;
	} check[] = {
		{ "^OpenSSH[-_]2\\.[012]",
					SSH_OLD_SESSIONID|SSH_BUG_BANNER|
					SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
		{ "^OpenSSH_2\\.3\\.0", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
					SSH_OLD_DHGEX|SSH_BUG_NOREKEY},
		{ "^OpenSSH_2\\.3\\.",  SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
					SSH_BUG_NOREKEY},
		{ "^OpenSSH_2\\.5\\.[01]p1",
					SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
					SSH_BUG_NOREKEY },
		{ "^OpenSSH_2\\.5\\.[012]",
					SSH_OLD_DHGEX|SSH_BUG_NOREKEY },
		{ "^OpenSSH_2\\.5\\.3",
					SSH_BUG_NOREKEY },
		{ "^OpenSSH",		0 },
		{ "MindTerm",		0 },
		{ "^2\\.1\\.0",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
		{ "^2\\.1 ",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
					SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE },
		{ "^2\\.0\\.1[3-9]",	SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
					SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
					SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE },
		{ "^2\\.0\\.1[1-2]",	SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE },
		{ "^2\\.0\\.",		SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
					SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
					SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
					SSH_BUG_PKAUTH|SSH_BUG_PKOK|
					SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
					SSH_BUG_DERIVEKEY },
		{ "^2\\.[23]\\.0",	SSH_BUG_HMAC|SSH_BUG_DEBUG|
					SSH_BUG_RSASIGMD5 },
		{ "^2\\.3\\.",		SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5 },
		{ "^2\\.[2-9]\\.",	SSH_BUG_DEBUG },
		{ "^3\\.0\\.",		SSH_BUG_DEBUG },
		{ "^2\\.4$",		SSH_OLD_SESSIONID },	/* Van Dyke */
		{ "^3\\.0 SecureCRT",	SSH_OLD_SESSIONID },
		{ "^1\\.7 SecureFX",	SSH_OLD_SESSIONID },
		{ "^1\\.2\\.1[89]",	SSH_BUG_IGNOREMSG },
		{ "^1\\.2\\.2[012]",	SSH_BUG_IGNOREMSG },
		{ "^1\\.3\\.2",		SSH_BUG_IGNOREMSG },	/* f-secure */
		{ "^SSH Compatible Server",			/* Netscreen */
					SSH_BUG_PASSWORDPAD },
		{ "^OSU_0",		SSH_BUG_PASSWORDPAD },
		{ "^OSU_1\\.[0-4]",	SSH_BUG_PASSWORDPAD },
		{ "^OSU_1\\.5alpha[1-3]",
					SSH_BUG_PASSWORDPAD },
		{ "^SSH_Version_Mapper",
					SSH_BUG_SCANNER },
		{ NULL,			0 }
	};
	/* process table, return first match */
	for (i = 0; check[i].pat; i++) {
		ret = regcomp(&reg, check[i].pat, REG_EXTENDED|REG_NOSUB);
		if (ret != 0) {
			regerror(ret, &reg, ebuf, sizeof(ebuf));
			ebuf[sizeof(ebuf)-1] = '\0';
			error("regerror: %s", ebuf);
			continue;
		}
		ret = regexec(&reg, version, 0, NULL, 0);
		regfree(&reg);
		if (ret == 0) {
			debug("match: %s pat %s", version, check[i].pat);
			datafellows = check[i].bugs;
			return;
		}
	}
	debug("no match: %s", version);
}

#define	SEP	","
int
proto_spec(const char *spec)
{
	char *s, *p, *q;
	int ret = SSH_PROTO_UNKNOWN;

	if (spec == NULL)
		return ret;
	q = s = xstrdup(spec);
	for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
		switch(atoi(p)) {
		case 1:
			if (ret == SSH_PROTO_UNKNOWN)
				ret |= SSH_PROTO_1_PREFERRED;
			ret |= SSH_PROTO_1;
			break;
		case 2:
			ret |= SSH_PROTO_2;
			break;
		default:
			log("ignoring bad proto spec: '%s'.", p);
			break;
		}
	}
	xfree(s);
	return ret;
}

char *
compat_cipher_proposal(char *cipher_prop)
{
	char *orig_prop, *fix_ciphers;
	char *cp, *tmp;
	size_t len;

	if (!(datafellows & SSH_BUG_BIGENDIANAES))
		return(cipher_prop);

	len = strlen(cipher_prop) + 1;
	fix_ciphers = xmalloc(len);
	*fix_ciphers = '\0';
	tmp = orig_prop = xstrdup(cipher_prop);
	while((cp = strsep(&tmp, ",")) != NULL) {
		if (strncmp(cp, "aes", 3) && strncmp(cp, "rijndael", 8)) {
			if (*fix_ciphers)
				strlcat(fix_ciphers, ",", len);
			strlcat(fix_ciphers, cp, len);
		}
	}
	xfree(orig_prop);
	debug2("Original cipher proposal: %s", cipher_prop);
	debug2("Compat cipher proposal: %s", fix_ciphers);
	if (!*fix_ciphers)
		fatal("No available ciphers found.");

	return(fix_ciphers);
}
Commit	Line	Data
aa3378df	1	/*
a96070d4	2	* Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
aa3378df	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.
aa3378df	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
8efc0c15	25	#include "includes.h"
b6761a3e	26	RCSID("$OpenBSD: compat.c,v 1.52 2001/09/17 21:09:47 markus Exp $");
8efc0c15	27
66d6c27e	28	#ifdef HAVE_LIBPCRE
66d6c27e	29	# include <pcreposix.h>
d8f1edd5	30	#else /* Use native regex libraries */
47af6577	31	# ifdef HAVE_REGEX_H
	32	# include <regex.h>
	33	# else
7411201c	34	# include "openbsd-compat/fake-regex.h"
47af6577	35	# endif
bc6bf501	36	#endif /* HAVE_LIBPCRE */
8efc0c15	37
42f11eb2	38	#include "packet.h"
	39	#include "xmalloc.h"
	40	#include "compat.h"
	41	#include "log.h"
	42
5260325f	43	int compat13 = 0;
7e7327a1	44	int compat20 = 0;
7e7327a1	45	int datafellows = 0;
5260325f	46
6ae2364d	47	void
7e7327a1	48	enable_compat20(void)
7e7327a1	49	{
8ce64345	50	verbose("Enabling compatibility mode for protocol 2.0");
8ce64345	51	compat20 = 1;
7e7327a1	52	}
6ae2364d	53	void
5260325f	54	enable_compat13(void)
	55	{
	56	verbose("Enabling compatibility mode for protocol 1.3");
	57	compat13 = 1;
8efc0c15	58	}
7e7327a1	59	/* datafellows bug compatibility */
	60	void
	61	compat_datafellows(const char *version)
	62	{
94ec8c6b	63	int i, ret;
	64	char ebuf[1024];
	65	regex_t reg;
	66	static struct {
	67	char *pat;
d0c832f3	68	int bugs;
d0c832f3	69	} check[] = {
eea39c02	70	{ "^OpenSSH[-_]2\\.[012]",
db1cd2f3	71	SSH_OLD_SESSIONID\|SSH_BUG_BANNER\|
255cfda1	72	SSH_OLD_DHGEX\|SSH_BUG_NOREKEY },
db1cd2f3	73	{ "^OpenSSH_2\\.3\\.0", SSH_BUG_BANNER\|SSH_BUG_BIGENDIANAES\|
255cfda1	74	SSH_OLD_DHGEX\|SSH_BUG_NOREKEY},
	75	{ "^OpenSSH_2\\.3\\.", SSH_BUG_BIGENDIANAES\|SSH_OLD_DHGEX\|
	76	SSH_BUG_NOREKEY},
80cd07ae	77	{ "^OpenSSH_2\\.5\\.[01]p1",
255cfda1	78	SSH_BUG_BIGENDIANAES\|SSH_OLD_DHGEX\|
255cfda1	79	SSH_BUG_NOREKEY },
db1cd2f3	80	{ "^OpenSSH_2\\.5\\.[012]",
255cfda1	81	SSH_OLD_DHGEX\|SSH_BUG_NOREKEY },
	82	{ "^OpenSSH_2\\.5\\.3",
	83	SSH_BUG_NOREKEY },
eea39c02	84	{ "^OpenSSH", 0 },
33de75a3	85	{ "MindTerm", 0 },
cbc5abf9	86	{ "^2\\.1\\.0", SSH_BUG_SIGBLOB\|SSH_BUG_HMAC\|
a4da628b	87	SSH_OLD_SESSIONID\|SSH_BUG_DEBUG\|
8002af61	88	SSH_BUG_RSASIGMD5\|SSH_BUG_HBSERVICE },
1b5dfeb2	89	{ "^2\\.1 ", SSH_BUG_SIGBLOB\|SSH_BUG_HMAC\|
a4da628b	90	SSH_OLD_SESSIONID\|SSH_BUG_DEBUG\|
8002af61	91	SSH_BUG_RSASIGMD5\|SSH_BUG_HBSERVICE },
cbc5abf9	92	{ "^2\\.0\\.1[3-9]", SSH_BUG_SIGBLOB\|SSH_BUG_HMAC\|
f72fc97f	93	SSH_OLD_SESSIONID\|SSH_BUG_DEBUG\|
fee56204	94	SSH_BUG_PKSERVICE\|SSH_BUG_X11FWD\|
8dddf799	95	SSH_BUG_PKOK\|SSH_BUG_RSASIGMD5\|
fbe90f7b	96	SSH_BUG_HBSERVICE\|SSH_BUG_OPENFAILURE },
ec430473	97	{ "^2\\.0\\.1[1-2]", SSH_BUG_SIGBLOB\|SSH_BUG_HMAC\|
f72fc97f	98	SSH_OLD_SESSIONID\|SSH_BUG_DEBUG\|
f72fc97f	99	SSH_BUG_PKSERVICE\|SSH_BUG_X11FWD\|
a4da628b	100	SSH_BUG_PKAUTH\|SSH_BUG_PKOK\|
fbe90f7b	101	SSH_BUG_RSASIGMD5\|SSH_BUG_OPENFAILURE },
eef7adcb	102	{ "^2\\.0\\.", SSH_BUG_SIGBLOB\|SSH_BUG_HMAC\|
	103	SSH_OLD_SESSIONID\|SSH_BUG_DEBUG\|
	104	SSH_BUG_PKSERVICE\|SSH_BUG_X11FWD\|
	105	SSH_BUG_PKAUTH\|SSH_BUG_PKOK\|
	106	SSH_BUG_RSASIGMD5\|SSH_BUG_OPENFAILURE\|
	107	SSH_BUG_DERIVEKEY },
b6761a3e	108	{ "^2\\.[23]\\.0", SSH_BUG_HMAC\|SSH_BUG_DEBUG\|
	109	SSH_BUG_RSASIGMD5 },
	110	{ "^2\\.3\\.", SSH_BUG_DEBUG\|SSH_BUG_RSASIGMD5 },
	111	{ "^2\\.[2-9]\\.", SSH_BUG_DEBUG },
	112	{ "^3\\.0\\.", SSH_BUG_DEBUG },
99c415db	113	{ "^2\\.4$", SSH_OLD_SESSIONID }, /* Van Dyke */
	114	{ "^3\\.0 SecureCRT", SSH_OLD_SESSIONID },
	115	{ "^1\\.7 SecureFX", SSH_OLD_SESSIONID },
	116	{ "^1\\.2\\.1[89]", SSH_BUG_IGNOREMSG },
	117	{ "^1\\.2\\.2[012]", SSH_BUG_IGNOREMSG },
5adb303f	118	{ "^1\\.3\\.2", SSH_BUG_IGNOREMSG }, /* f-secure */
99c415db	119	{ "^SSH Compatible Server", /* Netscreen */
	120	SSH_BUG_PASSWORDPAD },
	121	{ "^OSU_0", SSH_BUG_PASSWORDPAD },
	122	{ "^OSU_1\\.[0-4]", SSH_BUG_PASSWORDPAD },
	123	{ "^OSU_1\\.5alpha[1-3]",
	124	SSH_BUG_PASSWORDPAD },
3a1c54d4	125	{ "^SSH_Version_Mapper",
3a1c54d4	126	SSH_BUG_SCANNER },
33de75a3	127	{ NULL, 0 }
7e7327a1	128	};
14a9a859	129	/* process table, return first match */
94ec8c6b	130	for (i = 0; check[i].pat; i++) {
	131	ret = regcomp(&reg, check[i].pat, REG_EXTENDED\|REG_NOSUB);
	132	if (ret != 0) {
	133	regerror(ret, &reg, ebuf, sizeof(ebuf));
	134	ebuf[sizeof(ebuf)-1] = '\0';
	135	error("regerror: %s", ebuf);
	136	continue;
	137	}
	138	ret = regexec(&reg, version, 0, NULL, 0);
	139	regfree(&reg);
	140	if (ret == 0) {
13af0aa2	141	debug("match: %s pat %s", version, check[i].pat);
d0c832f3	142	datafellows = check[i].bugs;
7e7327a1	143	return;
	144	}
	145	}
94ec8c6b	146	debug("no match: %s", version);
7e7327a1	147	}
a8be9f80	148
	149	#define SEP ","
	150	int
	151	proto_spec(const char *spec)
	152	{
089fbbd2	153	char s, p, *q;
a8be9f80	154	int ret = SSH_PROTO_UNKNOWN;
a8be9f80	155
71276795	156	if (spec == NULL)
71276795	157	return ret;
089fbbd2	158	q = s = xstrdup(spec);
089fbbd2	159	for ((p = strsep(&q, SEP)); p && *p != '\0'; (p = strsep(&q, SEP))) {
a8be9f80	160	switch(atoi(p)) {
	161	case 1:
	162	if (ret == SSH_PROTO_UNKNOWN)
	163	ret \|= SSH_PROTO_1_PREFERRED;
	164	ret \|= SSH_PROTO_1;
	165	break;
	166	case 2:
	167	ret \|= SSH_PROTO_2;
	168	break;
	169	default:
	170	log("ignoring bad proto spec: '%s'.", p);
	171	break;
	172	}
	173	}
	174	xfree(s);
	175	return ret;
	176	}
80cd07ae	177
	178	char *
	179	compat_cipher_proposal(char *cipher_prop)
	180	{
	181	char orig_prop, fix_ciphers;
	182	char cp, tmp;
	183	size_t len;
	184
	185	if (!(datafellows & SSH_BUG_BIGENDIANAES))
	186	return(cipher_prop);
	187
	188	len = strlen(cipher_prop) + 1;
	189	fix_ciphers = xmalloc(len);
	190	*fix_ciphers = '\0';
	191	tmp = orig_prop = xstrdup(cipher_prop);
	192	while((cp = strsep(&tmp, ",")) != NULL) {
	193	if (strncmp(cp, "aes", 3) && strncmp(cp, "rijndael", 8)) {
	194	if (*fix_ciphers)
	195	strlcat(fix_ciphers, ",", len);
	196	strlcat(fix_ciphers, cp, len);
	197	}
	198	}
	199	xfree(orig_prop);
	200	debug2("Original cipher proposal: %s", cipher_prop);
	201	debug2("Compat cipher proposal: %s", fix_ciphers);
	202	if (!*fix_ciphers)
	203	fatal("No available ciphers found.");
	204
	205	return(fix_ciphers);
	206	}