1 files changed, 125 insertions, 0 deletions
diff --git a/lib/setugid.c b/lib/setugid.c
new file mode 100644
index 0000000..6dbe38e
--- /dev/null
+++ b/lib/setugid.c
@@ -0,0 +1,125 @@
+/*
+ * SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 1998, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2003 - 2005, Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2008 - 2010, Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*
+ * Separated from setup.c.  --marekm
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <stdio.h>
+#include <grp.h>
+#include <errno.h>
+#include "prototypes.h"
+#include "defines.h"
+#include <pwd.h>
+#include "getdef.h"
+
+/*
+ * setup_groups - set the group credentials
+ *	set the group ID to the value from the password file entry
+ *	set the supplementary group IDs
+ *
+ * In case of PAM enabled configurations, this shall be called before
+ * pam_setcred.
+ *
+ * Returns 0 on success, or -1 on failure.
+ */
+int setup_groups (const struct passwd *info)
+{
+	/*
+	 * Set the real group ID to the primary group ID in the password
+	 * file.
+	 */
+	if (setgid (info->pw_gid) == -1) {
+		int err = errno;
+		perror ("setgid");
+		SYSLOG ((LOG_ERR, "bad group ID `%d' for user `%s': %s\n",
+		         info->pw_gid, info->pw_name, strerror (err)));
+		closelog ();
+		return -1;
+	}
+#ifdef HAVE_INITGROUPS
+	/*
+	 * For systems which support multiple concurrent groups, go get
+	 * the group set from the /etc/group file.
+	 */
+	if (initgroups (info->pw_name, info->pw_gid) == -1) {
+		int err = errno;
+		perror ("initgroups");
+		SYSLOG ((LOG_ERR, "initgroups failed for user `%s': %s\n",
+		         info->pw_name, strerror (err)));
+		closelog ();
+		return -1;
+	}
+#endif
+	return 0;
+}
+
+/*
+ * change_uid - Set the real UID
+ *
+ * Returns 0 on success, or -1 on failure.
+ */
+int change_uid (const struct passwd *info)
+{
+	/*
+	 * Set the real UID to the UID value in the password file.
+	 */
+	if (setuid (info->pw_uid) != 0) {
+		int err = errno;
+		perror ("setuid");
+		SYSLOG ((LOG_ERR, "bad user ID `%d' for user `%s': %s\n",
+		         (int) info->pw_uid, info->pw_name, strerror (err)));
+		closelog ();
+		return -1;
+	}
+	return 0;
+}
+
+/*
+ *	setup_uid_gid() performs the following steps -
+ *
+ *	set the group ID to the value from the password file entry
+ *	set the supplementary group IDs
+ *	optionally call specified function which may add more groups
+ *	set the user ID to the value from the password file entry
+ *
+ *	Returns 0 on success, or -1 on failure.
+ */
+
+#if defined (HAVE_INITGROUPS) && ! (defined USE_PAM)
+int setup_uid_gid (const struct passwd *info, bool is_console)
+#else
+int setup_uid_gid (const struct passwd *info)
+#endif
+{
+	if (setup_groups (info) < 0) {
+		return -1;
+	}
+
+#if defined (HAVE_INITGROUPS) && ! defined (USE_PAM)
+	if (is_console) {
+		const char *cp = getdef_str ("CONSOLE_GROUPS");
+
+		if ((NULL != cp) && (add_groups (cp) != 0)) {
+			perror ("Warning: add_groups");
+		}
+	}
+#endif				/* HAVE_INITGROUPS && !USE_PAM*/
+
+	if (change_uid (info) < 0) {
+		return -1;
+	}
+
+	return 0;
+}
+