util_sec.c from 2.0.6

(This used to be commit 955d187139365d16f3fca1abd3853ca4e49f244c)

1 files changed, 326 insertions, 0 deletions

diff --git a/source3/lib/util_sec.c b/source3/lib/util_sec.c
new file mode 100644
index 0000000000..4a2ac2565e
--- /dev/null
+++ b/source3/lib/util_sec.c
@@ -0,0 +1,326 @@
+/*
+   Unix SMB/Netbios implementation.
+   Version 2.0
+   Copyright (C) Jeremy Allison 1998.
+   rewritten for version 2.0.6 by Tridge
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifndef AUTOCONF_TEST
+#include "includes.h"
+extern int DEBUGLEVEL;
+#else
+/* we are running this code in autoconf test mode to see which type of setuid
+   function works */
+#if defined(HAVE_UNISTD_H)
+#include <unistd.h>
+#endif
+#include <stdlib.h>
+#include <stdio.h>
+
+#ifdef HAVE_SYS_PRIV_H
+#include <sys/priv.h>
+#endif
+#ifdef HAVE_SYS_ID_H
+#include <sys/id.h>
+#endif
+
+#define DEBUG(x, y) printf y
+#define smb_panic(x) exit(1)
+#endif
+
+/****************************************************************************
+abort if we haven't set the uid correctly
+****************************************************************************/
+static void assert_uid(uid_t ruid, uid_t euid)
+{
+	if ((euid != (uid_t)-1 && geteuid() != euid) ||
+	    (ruid != (uid_t)-1 && getuid() != ruid)) {
+		DEBUG(0,("Failed to set uid privileges to (%d,%d) now set to (%d,%d)\n",
+			 (int)ruid, (int)euid,
+			 (int)getuid(), (int)geteuid()));
+		smb_panic("failed to set uid\n");
+		exit(1);
+	}
+}
+
+/****************************************************************************
+abort if we haven't set the gid correctly
+****************************************************************************/
+static void assert_gid(gid_t rgid, gid_t egid)
+{
+	if ((egid != (gid_t)-1 && getegid() != egid) ||
+	    (rgid != (gid_t)-1 && getgid() != rgid)) {
+		DEBUG(0,("Failed to set gid privileges to (%d,%d) now set to (%d,%d) uid=(%d,%d)\n",
+			 (int)rgid, (int)egid,
+			 (int)getgid(), (int)getegid(),
+			 (int)getuid(), (int)geteuid()));
+		smb_panic("failed to set gid\n");
+		exit(1);
+	}
+}
+
+/****************************************************************************
+ Gain root privilege before doing something. 
+ We want to end up with ruid==euid==0
+****************************************************************************/
+void gain_root_privilege(void)
+{	
+#if USE_SETRESUID
+	setresuid(0,0,0);
+#endif
+    
+#if USE_SETEUID
+	seteuid(0);
+#endif
+
+#if USE_SETREUID
+	setreuid(0, 0);
+#endif
+
+#if USE_SETUIDX
+	setuidx(ID_EFFECTIVE, 0);
+	setuidx(ID_REAL, 0);
+#endif
+
+	/* this is needed on some systems */
+	setuid(0);
+
+	assert_uid(0, 0);
+}
+
+
+/****************************************************************************
+ Ensure our real and effective groups are zero.
+ we want to end up with rgid==egid==0
+****************************************************************************/
+void gain_root_group_privilege(void)
+{
+#if USE_SETRESUID
+	setresgid(0,0,0);
+#endif
+
+#if USE_SETREUID
+	setregid(0,0);
+#endif
+
+#if USE_SETEUID
+	setegid(0);
+#endif
+
+#if USE_SETUIDX
+	setgidx(ID_EFFECTIVE, 0);
+	setgidx(ID_REAL, 0);
+#endif
+
+	setgid(0);
+
+	assert_gid(0, 0);
+}
+
+
+/****************************************************************************
+ Set *only* the effective uid.
+ we want to end up with ruid==0 and euid==uid
+****************************************************************************/
+void set_effective_uid(uid_t uid)
+{
+#if USE_SETRESUID
+	setresuid(-1,uid,-1);
+#endif
+
+#if USE_SETREUID
+	setreuid(-1,uid);
+#endif
+
+#if USE_SETEUID
+	seteuid(uid);
+#endif
+
+#if USE_SETUIDX
+	setuidx(ID_EFFECTIVE, uid);
+#endif
+
+	assert_uid(-1, uid);
+}
+
+/****************************************************************************
+ Set *only* the effective gid.
+ we want to end up with rgid==0 and egid==gid
+****************************************************************************/
+void set_effective_gid(gid_t gid)
+{
+#if USE_SETRESUID
+	setresgid(-1,gid,-1);
+#endif
+
+#if USE_SETREUID
+	setregid(-1,gid);
+#endif
+
+#if USE_SETEUID
+	setegid(gid);
+#endif
+
+#if USE_SETUIDX
+	setgidx(ID_EFFECTIVE, gid);
+#endif
+
+	assert_gid(-1, gid);
+}
+
+static uid_t saved_euid, saved_ruid;
+
+/****************************************************************************
+ save the real and effective uid for later restoration. Used by the quotas
+ code
+****************************************************************************/
+void save_re_uid(void)
+{
+	saved_ruid = getuid();
+	saved_euid = geteuid();
+}
+
+
+/****************************************************************************
+ and restore them!
+****************************************************************************/
+void restore_re_uid(void)
+{
+	set_effective_uid(0);
+	set_effective_uid(saved_euid);
+	if (getuid() != saved_ruid) setuid(saved_ruid);
+	set_effective_uid(saved_euid);
+
+	assert_uid(saved_ruid, saved_euid);
+}
+
+/****************************************************************************
+ set the real AND effective uid to the current effective uid in a way that
+ allows root to be regained.
+ This is only possible on some platforms.
+****************************************************************************/
+int set_re_uid(void)
+{
+	uid_t uid = geteuid();
+
+#if USE_SETRESUID
+	setresuid(geteuid(), -1, -1);
+#endif
+
+#if USE_SETREUID
+	setreuid(0, 0);
+	setreuid(uid, -1);
+	setreuid(-1, uid);
+#endif
+
+#if USE_SETEUID
+	/* can't be done */
+	return -1;
+#endif
+
+#if USE_SETUIDX
+	/* can't be done */
+	return -1;
+#endif
+
+	assert_uid(uid, uid);
+	return 0;
+}
+
+
+/****************************************************************************
+ Become the specified uid and gid - permanently !
+ there should be no way back if possible
+****************************************************************************/
+void become_user_permanently(uid_t uid, gid_t gid)
+{
+	/*
+	 * First - gain root privilege. We do this to ensure
+	 * we can lose it again.
+	 */
+
+	gain_root_privilege();
+	gain_root_group_privilege();
+
+#if USE_SETRESUID
+	setresgid(gid,gid,gid);
+	setgid(gid);
+	setresuid(uid,uid,uid);
+	setuid(uid);
+#endif
+
+#if USE_SETREUID
+	setregid(gid,gid);
+	setgid(gid);
+	setreuid(uid,uid);
+	setuid(uid);
+#endif
+
+#if USE_SETEUID
+	setegid(gid);
+	setgid(gid);
+	setuid(uid);
+	seteuid(uid);
+	setuid(uid);
+#endif
+
+#if USE_SETUIDX
+	setgidx(ID_REAL, gid);
+	setgidx(ID_EFFECTIVE, gid);
+	setgid(gid);
+	setuidx(ID_REAL, uid);
+	setuidx(ID_EFFECTIVE, uid);
+	setuid(uid);
+#endif
+	
+	assert_uid(uid, uid);
+	assert_gid(gid, gid);
+}
+
+#ifdef AUTOCONF_TEST
+main()
+{
+        if (getuid() != 0) {
+#if (defined(AIX) && defined(USE_SETREUID))
+		/* setreuid is badly broken on AIX 4.1, we avoid it completely */
+                fprintf(stderr,"avoiding possibly broken setreuid\n");
+		exit(1);
+#endif
+
+		/* assume that if we have the functions then they work */
+                fprintf(stderr,"not running as root: assuming OK\n");
+		exit(0);
+	}
+
+	gain_root_privilege();
+	gain_root_group_privilege();
+	set_effective_gid(1);
+	set_effective_uid(1);
+	gain_root_privilege();
+	gain_root_group_privilege();
+	become_user_permanently(1, 1);
+	setuid(0);
+	if (getuid() == 0) {
+		fprintf(stderr,"uid not set permanently\n");
+		exit(1);
+	}
+
+	printf("OK\n");
+
+	exit(0);
+}
+#endif