1 files changed, 134 insertions, 0 deletions
diff --git a/groupaccess.c b/groupaccess.c
new file mode 100644
index 0000000..80d3019
--- /dev/null
+++ b/groupaccess.c
@@ -0,0 +1,134 @@
+/* $OpenBSD: groupaccess.c,v 1.17 2019/03/06 22:14:23 dtucker Exp $ */
+/*
+ * Copyright (c) 2001 Kevin Steves.  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 <grp.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+#include "xmalloc.h"
+#include "groupaccess.h"
+#include "match.h"
+#include "log.h"
+
+static int ngroups;
+static char **groups_byname;
+
+/*
+ * Initialize group access list for user with primary (base) and
+ * supplementary groups.  Return the number of groups in the list.
+ */
+int
+ga_init(const char *user, gid_t base)
+{
+	gid_t *groups_bygid;
+	int i, j, retry = 0;
+	struct group *gr;
+
+	if (ngroups > 0)
+		ga_free();
+
+	ngroups = NGROUPS_MAX;
+#if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
+	ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX));
+#endif
+
+	groups_bygid = xcalloc(ngroups, sizeof(*groups_bygid));
+	while (getgrouplist(user, base, groups_bygid, &ngroups) == -1) {
+		if (retry++ > 0)
+			fatal("getgrouplist: groups list too small");
+		groups_bygid = xreallocarray(groups_bygid, ngroups,
+		    sizeof(*groups_bygid));
+	}
+	groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
+
+	for (i = 0, j = 0; i < ngroups; i++)
+		if ((gr = getgrgid(groups_bygid[i])) != NULL)
+			groups_byname[j++] = xstrdup(gr->gr_name);
+	free(groups_bygid);
+	return (ngroups = j);
+}
+
+/*
+ * Return 1 if one of user's groups is contained in groups.
+ * Return 0 otherwise.  Use match_pattern() for string comparison.
+ */
+int
+ga_match(char * const *groups, int n)
+{
+	int i, j;
+
+	for (i = 0; i < ngroups; i++)
+		for (j = 0; j < n; j++)
+			if (match_pattern(groups_byname[i], groups[j]))
+				return 1;
+	return 0;
+}
+
+/*
+ * Return 1 if one of user's groups matches group_pattern list.
+ * Return 0 on negated or no match.
+ */
+int
+ga_match_pattern_list(const char *group_pattern)
+{
+	int i, found = 0;
+
+	for (i = 0; i < ngroups; i++) {
+		switch (match_usergroup_pattern_list(groups_byname[i],
+		    group_pattern)) {
+		case -1:
+			return 0;	/* Negated match wins */
+		case 0:
+			continue;
+		case 1:
+			found = 1;
+		}
+	}
+	return found;
+}
+
+/*
+ * Free memory allocated for group access list.
+ */
+void
+ga_free(void)
+{
+	int i;
+
+	if (ngroups > 0) {
+		for (i = 0; i < ngroups; i++)
+			free(groups_byname[i]);
+		ngroups = 0;
+		free(groups_byname);
+		groups_byname = NULL;
+	}
+}