Adding upstream version 1:8.4p1.upstream/1%8.4p1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 364 insertions, 0 deletions

diff --git a/match.c b/match.c
new file mode 100644
index 0000000..927565c
--- /dev/null
+++ b/match.c
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+/* $OpenBSD: match.c,v 1.42 2020/07/05 23:59:45 djm Exp $ */
+/*
+ * 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 <sys/types.h>
+
+#include <ctype.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "xmalloc.h"
+#include "match.h"
+#include "misc.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, int dolower)
+{
+	char sub[1024];
+	int negated;
+	int got_positive;
+	u_int i, subi, len = strlen(pattern);
+
+	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((u_char)pattern[i]) ?
+			    tolower((u_char)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, then skip it. */
+		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;
+}
+
+/* Match a list representing users or groups. */
+int
+match_usergroup_pattern_list(const char *string, const char *pattern)
+{
+#ifdef HAVE_CYGWIN
+	/* Windows usernames may be Unicode and are not case sensitive */
+	return cygwin_ug_match_pattern_list(string, pattern);
+#else
+	/* Case sensitive match */
+	return match_pattern_list(string, pattern, 0);
+#endif
+}
+
+/*
+ * 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)
+{
+	char *hostcopy = xstrdup(host);
+	int r;
+
+	lowercase(hostcopy);
+	r = match_pattern_list(hostcopy, pattern, 1);
+	free(hostcopy);
+	return r;
+}
+
+/*
+ * returns 0 if we get a negative match for the hostname or the ip
+ * or if we get no match at all.  returns -1 on error, or 1 on
+ * successful match.
+ */
+int
+match_host_and_ip(const char *host, const char *ipaddr,
+    const char *patterns)
+{
+	int mhost, mip;
+
+	if ((mip = addr_match_list(ipaddr, patterns)) == -2)
+		return -1; /* error in ipaddr match */
+	else if (host == NULL || ipaddr == NULL || mip == -1)
+		return 0; /* negative ip address match, or testing pattern */
+
+	/* negative hostname match */
+	if ((mhost = match_hostname(host, 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.
+ * If user, host and ipaddr are all NULL then validate pattern/
+ * Returns -1 on invalid pattern, 0 on no match, 1 on match.
+ */
+int
+match_user(const char *user, const char *host, const char *ipaddr,
+    const char *pattern)
+{
+	char *p, *pat;
+	int ret;
+
+	/* test mode */
+	if (user == NULL && host == NULL && ipaddr == NULL) {
+		if ((p = strchr(pattern, '@')) != NULL &&
+		    match_host_and_ip(NULL, NULL, p + 1) < 0)
+			return -1;
+		return 0;
+	}
+
+	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);
+	free(pat);
+
+	return ret;
+}
+
+/*
+ * Returns first item from client-list that is also supported by server-list,
+ * caller must free the 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);
+				free(c);
+				free(s);
+				return ret;
+			}
+		}
+	}
+	if (next != NULL)
+		*next = strlen(c);
+	free(c);
+	free(s);
+	return NULL;
+}
+
+/*
+ * Filter proposal using pattern-list filter.
+ * "denylist" determines sense of filter:
+ * non-zero indicates that items matching filter should be excluded.
+ * zero indicates that only items matching filter should be included.
+ * returns NULL on allocation error, otherwise caller must free result.
+ */
+static char *
+filter_list(const char *proposal, const char *filter, int denylist)
+{
+	size_t len = strlen(proposal) + 1;
+	char *fix_prop = malloc(len);
+	char *orig_prop = strdup(proposal);
+	char *cp, *tmp;
+	int r;
+
+	if (fix_prop == NULL || orig_prop == NULL) {
+		free(orig_prop);
+		free(fix_prop);
+		return NULL;
+	}
+
+	tmp = orig_prop;
+	*fix_prop = '\0';
+	while ((cp = strsep(&tmp, ",")) != NULL) {
+		r = match_pattern_list(cp, filter, 0);
+		if ((denylist && r != 1) || (!denylist && r == 1)) {
+			if (*fix_prop != '\0')
+				strlcat(fix_prop, ",", len);
+			strlcat(fix_prop, cp, len);
+		}
+	}
+	free(orig_prop);
+	return fix_prop;
+}
+
+/*
+ * Filters a comma-separated list of strings, excluding any entry matching
+ * the 'filter' pattern list. Caller must free returned string.
+ */
+char *
+match_filter_denylist(const char *proposal, const char *filter)
+{
+	return filter_list(proposal, filter, 1);
+}
+
+/*
+ * Filters a comma-separated list of strings, including only entries matching
+ * the 'filter' pattern list. Caller must free returned string.
+ */
+char *
+match_filter_allowlist(const char *proposal, const char *filter)
+{
+	return filter_list(proposal, filter, 0);
+}