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-rw-r--r--lib/setugid.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/lib/setugid.c b/lib/setugid.c
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+++ b/lib/setugid.c
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+/*
+ * 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;
+}
+