1 files changed, 130 insertions, 0 deletions
diff --git a/libpam/pam_modutil_ingroup.c b/libpam/pam_modutil_ingroup.c
new file mode 100644
index 0000000..356302e
--- /dev/null
+++ b/libpam/pam_modutil_ingroup.c
@@ -0,0 +1,130 @@
+/*
+ * $Id$
+ *
+ * This function provides common methods for checking if a user is in a
+ * specified group.
+ */
+
+#include "pam_modutil_private.h"
+
+#include <stdlib.h>
+#include <pwd.h>
+#include <grp.h>
+
+#ifdef HAVE_GETGROUPLIST
+
+#define NGROUPS_MIN 100
+#define NGROUPS_MAX 65536
+
+static int checkgrouplist(const char *user, gid_t primary, gid_t target)
+{
+	int ngroups, pgroups, i;
+
+	ngroups = NGROUPS_MIN;
+	do {
+		gid_t *grouplist;
+
+		pgroups = ngroups;
+		grouplist = malloc(sizeof(gid_t) * ngroups);
+		if (grouplist == NULL) {
+			return 0;
+		}
+		i = getgrouplist(user, primary, grouplist, &ngroups);
+		if (i >= 0) {
+			for (i = 0; i < ngroups; i++) {
+				if (grouplist[i] == target) {
+					free(grouplist);
+					return 1;
+				}
+			}
+		}
+		free(grouplist);
+	} while (i < 0 && ngroups > 0 && ngroups != pgroups && ngroups <= NGROUPS_MAX);
+	return 0;
+}
+#endif
+
+static int
+pam_modutil_user_in_group_common(pam_handle_t *pamh UNUSED,
+				 struct passwd *pwd,
+				 struct group *grp)
+{
+	int i;
+
+	if (pwd == NULL) {
+		return 0;
+	}
+	if (grp == NULL) {
+		return 0;
+	}
+
+	if (pwd->pw_gid == grp->gr_gid) {
+		return 1;
+	}
+
+	for (i = 0; (grp->gr_mem != NULL) && (grp->gr_mem[i] != NULL); i++) {
+		if (strcmp(pwd->pw_name, grp->gr_mem[i]) == 0) {
+			return 1;
+		}
+	}
+
+#ifdef HAVE_GETGROUPLIST
+	if (checkgrouplist(pwd->pw_name, pwd->pw_gid, grp->gr_gid)) {
+		return 1;
+	}
+#endif
+
+	return 0;
+}
+
+int
+pam_modutil_user_in_group_nam_nam(pam_handle_t *pamh,
+				 const char *user, const char *group)
+{
+	struct passwd *pwd;
+	struct group *grp;
+
+	pwd = pam_modutil_getpwnam(pamh, user);
+	grp = pam_modutil_getgrnam(pamh, group);
+
+	return pam_modutil_user_in_group_common(pamh, pwd, grp);
+}
+
+int
+pam_modutil_user_in_group_nam_gid(pam_handle_t *pamh,
+				  const char *user, gid_t group)
+{
+	struct passwd *pwd;
+	struct group *grp;
+
+	pwd = pam_modutil_getpwnam(pamh, user);
+	grp = pam_modutil_getgrgid(pamh, group);
+
+	return pam_modutil_user_in_group_common(pamh, pwd, grp);
+}
+
+int
+pam_modutil_user_in_group_uid_nam(pam_handle_t *pamh,
+				  uid_t user, const char *group)
+{
+	struct passwd *pwd;
+	struct group *grp;
+
+	pwd = pam_modutil_getpwuid(pamh, user);
+	grp = pam_modutil_getgrnam(pamh, group);
+
+	return pam_modutil_user_in_group_common(pamh, pwd, grp);
+}
+
+int
+pam_modutil_user_in_group_uid_gid(pam_handle_t *pamh,
+				  uid_t user, gid_t group)
+{
+	struct passwd *pwd;
+	struct group *grp;
+
+	pwd = pam_modutil_getpwuid(pamh, user);
+	grp = pam_modutil_getgrgid(pamh, group);
+
+	return pam_modutil_user_in_group_common(pamh, pwd, grp);
+}