[openssh.git] / match.c

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * Simple pattern matching, with '*' and '?' as wildcards.
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */
/*
 * Copyright (c) 2000 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"

#include <ctype.h>

#include "match.h"
#include "xmalloc.h"

/*
 * Returns true if the given string matches the pattern (which may contain ?
 * and * as wildcards), and zero if it does not match.
 */

int
match_pattern(const char *s, const char *pattern)
{
	for (;;) {
		/* If at end of pattern, accept if also at end of string. */
		if (!*pattern)
			return !*s;

		if (*pattern == '*') {
			/* Skip the asterisk. */
			pattern++;

			/* If at end of pattern, accept immediately. */
			if (!*pattern)
				return 1;

			/* If next character in pattern is known, optimize. */
			if (*pattern != '?' && *pattern != '*') {
				/*
				 * Look instances of the next character in
				 * pattern, and try to match starting from
				 * those.
				 */
				for (; *s; s++)
					if (*s == *pattern &&
					    match_pattern(s + 1, pattern + 1))
						return 1;
				/* Failed. */
				return 0;
			}
			/*
			 * Move ahead one character at a time and try to
			 * match at each position.
			 */
			for (; *s; s++)
				if (match_pattern(s, pattern))
					return 1;
			/* Failed. */
			return 0;
		}
		/*
		 * There must be at least one more character in the string.
		 * If we are at the end, fail.
		 */
		if (!*s)
			return 0;

		/* Check if the next character of the string is acceptable. */
		if (*pattern != '?' && *pattern != *s)
			return 0;

		/* Move to the next character, both in string and in pattern. */
		s++;
		pattern++;
	}
	/* NOTREACHED */
}

/*
 * Tries to match the string against the
 * comma-separated sequence of subpatterns (each possibly preceded by ! to
 * indicate negation).  Returns -1 if negation matches, 1 if there is
 * a positive match, 0 if there is no match at all.
 */

int
match_pattern_list(const char *string, const char *pattern, u_int len,
    int dolower)
{
	char sub[1024];
	int negated;
	int got_positive;
	u_int i, subi;

	got_positive = 0;
	for (i = 0; i < len;) {
		/* Check if the subpattern is negated. */
		if (pattern[i] == '!') {
			negated = 1;
			i++;
		} else
			negated = 0;

		/*
		 * Extract the subpattern up to a comma or end.  Convert the
		 * subpattern to lowercase.
		 */
		for (subi = 0;
		    i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
		    subi++, i++)
			sub[subi] = dolower && isupper(pattern[i]) ?
			    tolower(pattern[i]) : pattern[i];
		/* If subpattern too long, return failure (no match). */
		if (subi >= sizeof(sub) - 1)
			return 0;

		/* If the subpattern was terminated by a comma, skip the comma. */
		if (i < len && pattern[i] == ',')
			i++;

		/* Null-terminate the subpattern. */
		sub[subi] = '\0';

		/* Try to match the subpattern against the string. */
		if (match_pattern(string, sub)) {
			if (negated)
				return -1;		/* Negative */
			else
				got_positive = 1;	/* Positive */
		}
	}

	/*
	 * Return success if got a positive match.  If there was a negative
	 * match, we have already returned -1 and never get here.
	 */
	return got_positive;
}

/*
 * Tries to match the host name (which must be in all lowercase) against the
 * comma-separated sequence of subpatterns (each possibly preceded by ! to
 * indicate negation).  Returns -1 if negation matches, 1 if there is
 * a positive match, 0 if there is no match at all.
 */
int
match_hostname(const char *host, const char *pattern, u_int len)
{
	return match_pattern_list(host, pattern, len, 1);
}

/*
 * returns 0 if we get a negative match for the hostname or the ip
 * or if we get no match at all.  returns 1 otherwise.
 */
int
match_host_and_ip(const char *host, const char *ipaddr,
    const char *patterns)
{
	int mhost, mip;

	/* negative ipaddr match */
	if ((mip = match_hostname(ipaddr, patterns, strlen(patterns))) == -1)
		return 0;
	/* negative hostname match */
	if ((mhost = match_hostname(host, patterns, strlen(patterns))) == -1)
		return 0;
	/* no match at all */
	if (mhost == 0 && mip == 0)
		return 0;
	return 1;
}

/*
 * match user, user@host_or_ip, user@host_or_ip_list against pattern
 */
int
match_user(const char *user, const char *host, const char *ipaddr,
    const char *pattern)
{
	char *p, *pat;
	int ret;

	if ((p = strchr(pattern,'@')) == NULL)
		return match_pattern(user, pattern);

	pat = xstrdup(pattern);
	p = strchr(pat, '@');
	*p++ = '\0';

	if ((ret = match_pattern(user, pat)) == 1)
		ret = match_host_and_ip(host, ipaddr, p);
	xfree(pat);

	return ret;
}

/*
 * Returns first item from client-list that is also supported by server-list,
 * caller must xfree() returned string.
 */
#define	MAX_PROP	40
#define	SEP	","
char *
match_list(const char *client, const char *server, u_int *next)
{
	char *sproposals[MAX_PROP];
	char *c, *s, *p, *ret, *cp, *sp;
	int i, j, nproposals;

	c = cp = xstrdup(client);
	s = sp = xstrdup(server);

	for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0';
	    (p = strsep(&sp, SEP)), i++) {
		if (i < MAX_PROP)
			sproposals[i] = p;
		else
			break;
	}
	nproposals = i;

	for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0';
	    (p = strsep(&cp, SEP)), i++) {
		for (j = 0; j < nproposals; j++) {
			if (strcmp(p, sproposals[j]) == 0) {
				ret = xstrdup(p);
				if (next != NULL)
					*next = (cp == NULL) ?
					    strlen(c) : (u_int)(cp - c);
				xfree(c);
				xfree(s);
				return ret;
			}
		}
	}
	if (next != NULL)
		*next = strlen(c);
	xfree(c);
	xfree(s);
	return NULL;
}
Commit	Line	Data
8efc0c15	1	/*
5260325f	2	* Author: Tatu Ylonen <ylo@cs.hut.fi>
5260325f	3	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5260325f	4	* All rights reserved
5260325f	5	* Simple pattern matching, with '*' and '?' as wildcards.
6ae2364d	6	*
bcbf86ec	7	* As far as I am concerned, the code I have written for this software
	8	* can be used freely for any purpose. Any derived versions of this
	9	* software must be clearly marked as such, and if the derived work is
	10	* incompatible with the protocol description in the RFC file, it must be
	11	* called by a name other than "ssh" or "Secure Shell".
5260325f	12	*/
cab80f75	13	/*
	14	* Copyright (c) 2000 Markus Friedl. All rights reserved.
	15	*
	16	* Redistribution and use in source and binary forms, with or without
	17	* modification, are permitted provided that the following conditions
	18	* are met:
	19	* 1. Redistributions of source code must retain the above copyright
	20	* notice, this list of conditions and the following disclaimer.
	21	* 2. Redistributions in binary form must reproduce the above copyright
	22	* notice, this list of conditions and the following disclaimer in the
	23	* documentation and/or other materials provided with the distribution.
	24	*
	25	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	26	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	27	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	28	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	29	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	30	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	31	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	32	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	33	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	34	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	35	*/
8efc0c15	36
8efc0c15	37	#include "includes.h"
b6438382	38
b6438382	39	#include <ctype.h>
8efc0c15	40
42f11eb2	41	#include "match.h"
cab80f75	42	#include "xmalloc.h"
8efc0c15	43
aa3378df	44	/*
	45	* Returns true if the given string matches the pattern (which may contain ?
	46	* and * as wildcards), and zero if it does not match.
	47	*/
8efc0c15	48
6ae2364d	49	int
5260325f	50	match_pattern(const char s, const char pattern)
	51	{
	52	for (;;) {
	53	/* If at end of pattern, accept if also at end of string. */
	54	if (!*pattern)
	55	return !*s;
8efc0c15	56
5260325f	57	if (pattern == '') {
	58	/* Skip the asterisk. */
	59	pattern++;
8efc0c15	60
5260325f	61	/* If at end of pattern, accept immediately. */
	62	if (!*pattern)
	63	return 1;
8efc0c15	64
5260325f	65	/* If next character in pattern is known, optimize. */
5260325f	66	if (pattern != '?' && pattern != '*') {
aa3378df	67	/*
	68	* Look instances of the next character in
	69	* pattern, and try to match starting from
	70	* those.
	71	*/
5260325f	72	for (; *s; s++)
	73	if (s == pattern &&
	74	match_pattern(s + 1, pattern + 1))
	75	return 1;
	76	/* Failed. */
	77	return 0;
	78	}
aa3378df	79	/*
	80	* Move ahead one character at a time and try to
	81	* match at each position.
	82	*/
5260325f	83	for (; *s; s++)
	84	if (match_pattern(s, pattern))
	85	return 1;
	86	/* Failed. */
	87	return 0;
	88	}
aa3378df	89	/*
	90	* There must be at least one more character in the string.
	91	* If we are at the end, fail.
	92	*/
5260325f	93	if (!*s)
5260325f	94	return 0;
8efc0c15	95
aa3378df	96	/* Check if the next character of the string is acceptable. */
5260325f	97	if (pattern != '?' && pattern != *s)
5260325f	98	return 0;
8efc0c15	99
aa3378df	100	/* Move to the next character, both in string and in pattern. */
5260325f	101	s++;
	102	pattern++;
	103	}
	104	/* NOTREACHED */
8efc0c15	105	}
4fe2af09	106
4fe2af09	107	/*
6a92533a	108	* Tries to match the string against the
4fe2af09	109	* comma-separated sequence of subpatterns (each possibly preceded by ! to
fa649821	110	* indicate negation). Returns -1 if negation matches, 1 if there is
fa649821	111	* a positive match, 0 if there is no match at all.
4fe2af09	112	*/
	113
	114	int
6a92533a	115	match_pattern_list(const char string, const char pattern, u_int len,
6a92533a	116	int dolower)
4fe2af09	117	{
	118	char sub[1024];
	119	int negated;
	120	int got_positive;
1e3b8b07	121	u_int i, subi;
4fe2af09	122
	123	got_positive = 0;
	124	for (i = 0; i < len;) {
	125	/* Check if the subpattern is negated. */
	126	if (pattern[i] == '!') {
	127	negated = 1;
	128	i++;
	129	} else
	130	negated = 0;
	131
	132	/*
	133	* Extract the subpattern up to a comma or end. Convert the
	134	* subpattern to lowercase.
	135	*/
	136	for (subi = 0;
184eed6a	137	i < len && subi < sizeof(sub) - 1 && pattern[i] != ',';
184eed6a	138	subi++, i++)
6a92533a	139	sub[subi] = dolower && isupper(pattern[i]) ?
184eed6a	140	tolower(pattern[i]) : pattern[i];
4fe2af09	141	/* If subpattern too long, return failure (no match). */
	142	if (subi >= sizeof(sub) - 1)
	143	return 0;
	144
	145	/* If the subpattern was terminated by a comma, skip the comma. */
	146	if (i < len && pattern[i] == ',')
	147	i++;
	148
	149	/* Null-terminate the subpattern. */
	150	sub[subi] = '\0';
	151
6a92533a	152	/* Try to match the subpattern against the string. */
6a92533a	153	if (match_pattern(string, sub)) {
4fe2af09	154	if (negated)
fa649821	155	return -1; /* Negative */
4fe2af09	156	else
fa649821	157	got_positive = 1; /* Positive */
4fe2af09	158	}
	159	}
	160
	161	/*
	162	* Return success if got a positive match. If there was a negative
fa649821	163	* match, we have already returned -1 and never get here.
4fe2af09	164	*/
	165	return got_positive;
	166	}
cab80f75	167
6a92533a	168	/*
	169	* Tries to match the host name (which must be in all lowercase) against the
	170	* comma-separated sequence of subpatterns (each possibly preceded by ! to
	171	* indicate negation). Returns -1 if negation matches, 1 if there is
	172	* a positive match, 0 if there is no match at all.
	173	*/
	174	int
	175	match_hostname(const char host, const char pattern, u_int len)
	176	{
	177	return match_pattern_list(host, pattern, len, 1);
	178	}
	179
2cee8a25	180	/*
	181	* returns 0 if we get a negative match for the hostname or the ip
	182	* or if we get no match at all. returns 1 otherwise.
	183	*/
	184	int
	185	match_host_and_ip(const char host, const char ipaddr,
	186	const char *patterns)
	187	{
	188	int mhost, mip;
	189
	190	/* negative ipaddr match */
	191	if ((mip = match_hostname(ipaddr, patterns, strlen(patterns))) == -1)
	192	return 0;
	193	/* negative hostname match */
	194	if ((mhost = match_hostname(host, patterns, strlen(patterns))) == -1)
	195	return 0;
	196	/* no match at all */
	197	if (mhost == 0 && mip == 0)
	198	return 0;
	199	return 1;
	200	}
cab80f75	201
80f8f24f	202	/*
	203	* match user, user@host_or_ip, user@host_or_ip_list against pattern
	204	*/
	205	int
6805fc56	206	match_user(const char user, const char host, const char *ipaddr,
80f8f24f	207	const char *pattern)
	208	{
	209	char p, pat;
	210	int ret;
	211
	212	if ((p = strchr(pattern,'@')) == NULL)
	213	return match_pattern(user, pattern);
	214
	215	pat = xstrdup(pattern);
	216	p = strchr(pat, '@');
	217	*p++ = '\0';
	218
	219	if ((ret = match_pattern(user, pat)) == 1)
6805fc56	220	ret = match_host_and_ip(host, ipaddr, p);
80f8f24f	221	xfree(pat);
	222
	223	return ret;
	224	}
	225
2cee8a25	226	/*
	227	* Returns first item from client-list that is also supported by server-list,
	228	* caller must xfree() returned string.
	229	*/
fa869228	230	#define MAX_PROP 40
cab80f75	231	#define SEP ","
	232	char *
	233	match_list(const char client, const char server, u_int *next)
	234	{
	235	char *sproposals[MAX_PROP];
	236	char c, s, p, ret, cp, sp;
	237	int i, j, nproposals;
	238
	239	c = cp = xstrdup(client);
	240	s = sp = xstrdup(server);
	241
	242	for ((p = strsep(&sp, SEP)), i=0; p && *p != '\0';
184eed6a	243	(p = strsep(&sp, SEP)), i++) {
cab80f75	244	if (i < MAX_PROP)
	245	sproposals[i] = p;
	246	else
	247	break;
	248	}
	249	nproposals = i;
	250
	251	for ((p = strsep(&cp, SEP)), i=0; p && *p != '\0';
184eed6a	252	(p = strsep(&cp, SEP)), i++) {
cab80f75	253	for (j = 0; j < nproposals; j++) {
	254	if (strcmp(p, sproposals[j]) == 0) {
	255	ret = xstrdup(p);
	256	if (next != NULL)
	257	*next = (cp == NULL) ?
2ceb8101	258	strlen(c) : (u_int)(cp - c);
cab80f75	259	xfree(c);
	260	xfree(s);
	261	return ret;
	262	}
	263	}
	264	}
	265	if (next != NULL)
	266	*next = strlen(c);
	267	xfree(c);
	268	xfree(s);
	269	return NULL;
	270	}