SELinux bases access to files on the domain of the requesting process,

the operation being performed, and the context applied to the file.

In many cases, applications needn't be SELinux aware to work properly,

because SELinux can apply a default label to a file based on the label

of the directory in which it's created.

In the case of files such as /etc/krb5.keytab, however, this isn't

sufficient, as /etc/krb5.keytab will almost always need to be given a

label which differs from that of /etc/issue or /etc/resolv.conf.  The

the kdb stash file needs a different label than the database for which

it's holding a master key, even though both typically live in the same

directory.

To give the file the correct label, we can either force a "restorecon"

call to fix a file's label after it's created, or create the file with

the right label, as we attempt to do here.  We lean on THREEPARAMOPEN

and define a similar macro named WRITABLEFOPEN with which we replace

several uses of fopen().

The file creation context that we're manipulating here is a process-wide

attribute.  While for the most part, applications which need to label

files when they're created have tended to be single-threaded, there's

not much we can do to avoid interfering with an application that

manipulates the creation context directly.  Right now we're mediating

access using a library-local mutex, but that can only work for consumers

that are part of this package -- an unsuspecting application will still

stomp all over us.

The selabel APIs for looking up the context should be thread-safe (per

Red Hat #273081), so switching to using them instead of matchpathcon(),

which we used earlier, is some improvement.

--- krb5/src/aclocal.m4

+++ krb5/src/aclocal.m4

@@ -103,6 +103,7 @@ AC_SUBST_FILE(libnodeps_frag)

 dnl

 KRB5_AC_PRAGMA_WEAK_REF

 WITH_LDAP

+KRB5_WITH_SELINUX

 KRB5_LIB_PARAMS

 KRB5_AC_INITFINI

 KRB5_AC_ENABLE_THREADS

@@ -1791,3 +1792,51 @@ AC_SUBST(manlocalstatedir)

 AC_SUBST(PAM_MAN)

 AC_SUBST(NON_PAM_MAN)

 ])dnl

+dnl

+dnl Use libselinux to set file contexts on newly-created files.

+dnl 

+AC_DEFUN(KRB5_WITH_SELINUX,[

+AC_ARG_WITH(selinux,[AC_HELP_STRING(--with-selinux,[compile with SELinux labeling support])],

+           withselinux="$withval",withselinux=auto)

+old_LIBS="$LIBS"

+if test "$withselinux" != no ; then

+       AC_MSG_RESULT([checking for libselinux...])

+       SELINUX_LIBS=

+       AC_CHECK_HEADERS(selinux/selinux.h selinux/label.h)

+       if test "x$ac_cv_header_selinux_selinux_h" != xyes ; then

+               if test "$withselinux" = auto ; then

+                       AC_MSG_RESULT([Unable to locate selinux/selinux.h.])

+                       withselinux=no

+               else

+                       AC_MSG_ERROR([Unable to locate selinux/selinux.h.])

+               fi

+       fi

+

+       LIBS=

+       unset ac_cv_func_setfscreatecon

+       AC_CHECK_FUNCS(setfscreatecon selabel_open)

+       if test "x$ac_cv_func_setfscreatecon" = xno ; then

+               AC_CHECK_LIB(selinux,setfscreatecon)

+               unset ac_cv_func_setfscreatecon

+               AC_CHECK_FUNCS(setfscreatecon selabel_open)

+               if test "x$ac_cv_func_setfscreatecon" = xyes ; then

+                       SELINUX_LIBS="$LIBS"

+               else

+                       if test "$withselinux" = auto ; then

+                               AC_MSG_RESULT([Unable to locate libselinux.])

+                               withselinux=no

+                       else

+                               AC_MSG_ERROR([Unable to locate libselinux.])

+                       fi

+               fi

+       fi

+       if test "$withselinux" != no ; then

+               AC_MSG_NOTICE([building with SELinux labeling support])

+               AC_DEFINE(USE_SELINUX,1,[Define if Kerberos-aware tools should set SELinux file contexts when creating files.])

+               SELINUX_LIBS="$LIBS"

+		EXTRA_SUPPORT_SYMS="$EXTRA_SUPPORT_SYMS krb5int_labeled_open krb5int_labeled_fopen krb5int_push_fscreatecon_for krb5int_pop_fscreatecon"

+       fi

+fi

+LIBS="$old_LIBS"

+AC_SUBST(SELINUX_LIBS)

+])dnl

--- krb5/src/config/pre.in

+++ krb5/src/config/pre.in

@@ -180,6 +180,7 @@ LD_UNRESOLVED_PREFIX = @LD_UNRESOLVED_PREFIX@

 LD_SHLIBDIR_PREFIX = @LD_SHLIBDIR_PREFIX@

 LDARGS = @LDARGS@

 LIBS = @LIBS@

+SELINUX_LIBS=@SELINUX_LIBS@

 INSTALL=@INSTALL@

 INSTALL_STRIP=

@@ -379,7 +380,7 @@ SUPPORT_LIB			= -l$(SUPPORT_LIBNAME)

 # HESIOD_LIBS is -lhesiod...

 HESIOD_LIBS	= @HESIOD_LIBS@

-KRB5_BASE_LIBS	= $(KRB5_LIB) $(K5CRYPTO_LIB) $(COM_ERR_LIB) $(SUPPORT_LIB) $(GEN_LIB) $(LIBS) $(DL_LIB)

+KRB5_BASE_LIBS	= $(KRB5_LIB) $(K5CRYPTO_LIB) $(COM_ERR_LIB) $(SUPPORT_LIB) $(GEN_LIB) $(LIBS) $(SELINUX_LIBS) $(DL_LIB)

 KDB5_LIBS	= $(KDB5_LIB) $(GSSRPC_LIBS)

 GSS_LIBS	= $(GSS_KRB5_LIB)

 # needs fixing if ever used on Mac OS X!

--- krb5/src/configure.in

+++ krb5/src/configure.in

@@ -1053,6 +1053,8 @@ fi

 KRB5_WITH_PAM

+KRB5_WITH_SELINUX

+

 # Make localedir work in autoconf 2.5x.

 if test "${localedir+set}" != set; then

     localedir='$(datadir)/locale'

--- krb5/src/include/k5-int.h

+++ krb5/src/include/k5-int.h

@@ -133,6 +133,7 @@ typedef unsigned char   u_char;

 typedef UINT64_TYPE krb5_ui_8;

 typedef INT64_TYPE krb5_int64;

+#include "k5-label.h"

 #define DEFAULT_PWD_STRING1 "Enter password"

 #define DEFAULT_PWD_STRING2 "Re-enter password for verification"

--- krb5/src/include/k5-label.h

+++ krb5/src/include/k5-label.h

@@ -0,0 +1,32 @@

+#ifndef _KRB5_LABEL_H

+#define _KRB5_LABEL_H

+

+#ifdef THREEPARAMOPEN

+#undef THREEPARAMOPEN

+#endif

+#ifdef WRITABLEFOPEN

+#undef WRITABLEFOPEN

+#endif

+

+/* Wrapper functions which help us create files and directories with the right

+ * context labels. */

+#ifdef USE_SELINUX

+#include <sys/types.h>

+#include <sys/stat.h>

+#include <fcntl.h>

+#include <stdio.h>

+#include <unistd.h>

+FILE *krb5int_labeled_fopen(const char *path, const char *mode);

+int krb5int_labeled_creat(const char *path, mode_t mode);

+int krb5int_labeled_open(const char *path, int flags, ...);

+int krb5int_labeled_mkdir(const char *path, mode_t mode);

+int krb5int_labeled_mknod(const char *path, mode_t mode, dev_t device);

+#define THREEPARAMOPEN(x,y,z) krb5int_labeled_open(x,y,z)

+#define WRITABLEFOPEN(x,y) krb5int_labeled_fopen(x,y)

+void *krb5int_push_fscreatecon_for(const char *pathname);

+void krb5int_pop_fscreatecon(void *previous);

+#else

+#define WRITABLEFOPEN(x,y) fopen(x,y)

+#define THREEPARAMOPEN(x,y,z) open(x,y,z)

+#endif

+#endif

--- krb5/src/include/krb5/krb5.hin

+++ krb5/src/include/krb5/krb5.hin

@@ -87,6 +87,12 @@

 #define THREEPARAMOPEN(x,y,z) open(x,y,z)

 #endif

+#if KRB5_PRIVATE

+#ifndef WRITABLEFOPEN

+#define WRITABLEFOPEN(x,y) fopen(x,y)

+#endif

+#endif

+

 #define KRB5_OLD_CRYPTO

 #include <stdlib.h>

--- krb5/src/kadmin/dbutil/dump.c

+++ krb5/src/kadmin/dbutil/dump.c

@@ -376,12 +376,21 @@ create_ofile(char *ofile, char **tmpname

 {

     int fd = -1;

     FILE *f;

+#ifdef USE_SELINUX

+    void *selabel;

+#endif

     *tmpname = NULL;

     if (asprintf(tmpname, "%s-XXXXXX", ofile) < 0)

         goto error;

+#ifdef USE_SELINUX

+    selabel = krb5int_push_fscreatecon_for(ofile);

+#endif

     fd = mkstemp(*tmpname);

+#ifdef USE_SELINUX

+    krb5int_pop_fscreatecon(selabel);

+#endif

     if (fd == -1)

         goto error;

@@ -514,7 +514,7 @@ prep_ok_file(krb5_context context, char

         return 0;

     }

-    *fd = open(file_ok, O_WRONLY | O_CREAT | O_TRUNC, 0600);

+    *fd = THREEPARAMOPEN(file_ok, O_WRONLY | O_CREAT | O_TRUNC, 0600);

     if (*fd == -1) {

         com_err(progname, errno, _("while creating 'ok' file, '%s'"), file_ok);

         exit_status++;

--- krb5/src/krb5-config.in

+++ krb5/src/krb5-config.in

@@ -38,6 +38,7 @@ RPATH_FLAG='@RPATH_FLAG@'

 DEFCCNAME='@DEFCCNAME@'

 DEFKTNAME='@DEFKTNAME@'

 DEFCKTNAME='@DEFCKTNAME@'

+SELINUX_LIBS='@SELINUX_LIBS@'

 LIBS='@LIBS@'

 GEN_LIB=@GEN_LIB@

@@ -218,7 +219,7 @@

     fi

     # If we ever support a flag to generate output suitable for static

-    # linking, we would output "-lkrb5support $GEN_LIB $LIBS $DL_LIB"

+    # linking, we would output "-lkrb5support $GEN_LIB $LIBS $SELINUX_LIBS $DL_LIB"

     # here.

     echo $lib_flags

--- krb5/src/lib/kadm5/logger.c

+++ krb5/src/lib/kadm5/logger.c

@@ -425,7 +425,7 @@ krb5_klog_init(krb5_context kcontext, ch

                      * Check for append/overwrite, then open the file.

                      */

                     if (cp[4] == ':' || cp[4] == '=') {

-                        f = fopen(&cp[5], (cp[4] == ':') ? "a" : "w");

+                        f = WRITABLEFOPEN(&cp[5], (cp[4] == ':') ? "a" : "w");

                         if (f) {

                             set_cloexec_file(f);

                             log_control.log_entries[i].lfu_filep = f;

@@ -961,7 +961,7 @@ krb5_klog_reopen(krb5_context kcontext)

              * In case the old logfile did not get moved out of the

              * way, open for append to prevent squashing the old logs.

              */

-            f = fopen(log_control.log_entries[lindex].lfu_fname, "a+");

+            f = WRITABLEFOPEN(log_control.log_entries[lindex].lfu_fname, "a+");

             if (f) {

                 set_cloexec_file(f);

                 log_control.log_entries[lindex].lfu_filep = f;

--- krb5/src/lib/krb5/keytab/kt_file.c

+++ krb5/src/lib/krb5/keytab/kt_file.c

@@ -1050,7 +1050,7 @@ krb5_ktfileint_open(krb5_context context

     KTCHECKLOCK(id);

     errno = 0;

-    KTFILEP(id) = fopen(KTFILENAME(id),

+    KTFILEP(id) = WRITABLEFOPEN(KTFILENAME(id),

                         (mode == KRB5_LOCKMODE_EXCLUSIVE) ?

                         fopen_mode_rbplus : fopen_mode_rb);

     if (!KTFILEP(id)) {

@@ -1058,7 +1058,7 @@ krb5_ktfileint_open(krb5_context context

             /* try making it first time around */

             krb5_create_secure_file(context, KTFILENAME(id));

             errno = 0;

-            KTFILEP(id) = fopen(KTFILENAME(id), fopen_mode_rbplus);

+            KTFILEP(id) = WRITABLEFOPEN(KTFILENAME(id), fopen_mode_rbplus);

             if (!KTFILEP(id))

                 goto report_errno;

             writevno = 1;

--- krb5/src/plugins/kdb/db2/adb_openclose.c

+++ krb5/src/plugins/kdb/db2/adb_openclose.c

@@ -201,7 +201,7 @@ osa_adb_init_db(osa_adb_db_t *dbp, char 

          * POSIX systems

          */

         lockp->lockinfo.filename = strdup(lockfilename);

-        if ((lockp->lockinfo.lockfile = fopen(lockfilename, "r+")) == NULL) {

+        if ((lockp->lockinfo.lockfile = WRITABLEFOPEN(lockfilename, "r+")) == NULL) {

             /*

              * maybe someone took away write permission so we could only

              * get shared locks?

--- krb5/src/plugins/kdb/db2/libdb2/btree/bt_open.c

+++ krb5/src/plugins/kdb/db2/libdb2/btree/bt_open.c

@@ -60,6 +60,7 @@ static char sccsid[] = "@(#)bt_open.c	8.

 #include "k5-platform.h"	/* mkstemp? */

+#include "k5-int.h"

 #include "db-int.h"

 #include "btree.h"

@@ -203,7 +204,7 @@ __bt_open(fname, flags, mode, openinfo, 

 			goto einval;

 		}

-		if ((t->bt_fd = open(fname, flags | O_BINARY, mode)) < 0)

+		if ((t->bt_fd = THREEPARAMOPEN(fname, flags | O_BINARY, mode)) < 0)

 			goto err;

 	} else {

--- krb5/src/plugins/kdb/db2/libdb2/hash/hash.c

+++ krb5/src/plugins/kdb/db2/libdb2/hash/hash.c

@@ -51,6 +51,7 @@ static char sccsid[] = "@(#)hash.c	8.12 

 #include <assert.h>

 #endif

+#include "k5-int.h"

 #include "db-int.h"

 #include "hash.h"

 #include "page.h"

@@ -140,7 +141,7 @@ __kdb2_hash_open(file, flags, mode, info

 		new_table = 1;

 	}

 	if (file) {

-		if ((hashp->fp = open(file, flags|O_BINARY, mode)) == -1)

+		if ((hashp->fp = THREEPARAMOPEN(file, flags|O_BINARY, mode)) == -1)

 			RETURN_ERROR(errno, error0);

 		(void)fcntl(hashp->fp, F_SETFD, 1);

 	}

--- krb5/src/plugins/kdb/db2/libdb2/test/Makefile.in

+++ krb5/src/plugins/kdb/db2/libdb2/test/Makefile.in

@@ -12,7 +12,8 @@ PROG_RPATH=$(KRB5_LIBDIR)

 KRB5_RUN_ENV= @KRB5_RUN_ENV@

-DB_LIB		= -ldb

+DB_LIB		= -ldb $(SUPPORT_DEPLIB)

+

 DB_DEPLIB	= ../libdb$(DEPLIBEXT)

 all::

--- krb5/src/plugins/kdb/ldap/ldap_util/kdb5_ldap_services.c

+++ krb5/src/plugins/kdb/ldap/ldap_util/kdb5_ldap_services.c

@@ -179,7 +179,7 @@ done:

     /* set password in the file */

     old_mode = umask(0177);

-    pfile = fopen(file_name, "a+");

+    pfile = WRITABLEFOPEN(file_name, "a+");

     if (pfile == NULL) {

         com_err(me, errno, _("Failed to open file %s: %s"), file_name,

                 strerror (errno));

@@ -220,6 +220,9 @@ done:

          * Delete the existing entry and add the new entry

          */

         FILE *newfile;

+#ifdef USE_SELINUX

+        void *selabel;

+#endif

         mode_t omask;

@@ -231,7 +234,13 @@ done:

         }

         omask = umask(077);

+#ifdef USE_SELINUX

+        selabel = krb5int_push_fscreatecon_for(file_name);

+#endif

         newfile = fopen(tmp_file, "w");

+#ifdef USE_SELINUX

+        krb5int_pop_fscreatecon(selabel);

+#endif

         umask (omask);

         if (newfile == NULL) {

             com_err(me, errno, _("Error creating file %s"), tmp_file);

--- krb5/src/slave/kpropd.c

+++ krb5/src/slave/kpropd.c

@@ -437,6 +437,9 @@ void doit(fd)

     krb5_enctype etype;

     int database_fd;

     char host[INET6_ADDRSTRLEN+1];

+#ifdef USE_SELINUX

+    void *selabel;

+#endif

     signal_wrapper(SIGALRM, alarm_handler);

     alarm(params.iprop_resync_timeout);

@@ -515,9 +518,15 @@ void doit(fd)

         free(name);

         exit(1);

     }

+#ifdef USE_SELINUX

+    selabel = krb5int_push_fscreatecon_for(file);

+#endif

     omask = umask(077);

     lock_fd = open(temp_file_name, O_RDWR|O_CREAT, 0600);

     (void) umask(omask);

+#ifdef USE_SELINUX

+    krb5int_pop_fscreatecon(selabel);

+#endif

     retval = krb5_lock_file(kpropd_context, lock_fd,

                             KRB5_LOCKMODE_EXCLUSIVE|KRB5_LOCKMODE_DONTBLOCK);

     if (retval) {

--- krb5/src/util/profile/prof_file.c

+++ krb5/src/util/profile/prof_file.c

@@ -30,6 +30,7 @@

 #endif

 #include "k5-platform.h"

+#include "k5-label.h"

 struct global_shared_profile_data {

     /* This is the head of the global list of shared trees */

@@ -418,7 +419,7 @@ static errcode_t write_data_to_file(prf_

     errno = 0;

-    f = fopen(new_file, "w");

+    f = WRITABLEFOPEN(new_file, "w");

     if (!f) {

         retval = errno;

         if (retval == 0)

--- krb5/src/util/support/Makefile.in

+++ krb5/src/util/support/Makefile.in

@@ -54,6 +54,7 @@ IPC_SYMS= \

 STLIBOBJS= \

 	threads.o \

+	selinux.o \

 	init-addrinfo.o \

 	plugins.o \

 	errors.o \

@@ -108,7 +109,7 @@ SRCS=\

 SHLIB_EXPDEPS =

 # Add -lm if dumping thread stats, for sqrt.

-SHLIB_EXPLIBS= $(LIBS) $(DL_LIB)

+SHLIB_EXPLIBS= $(LIBS) $(SELINUX_LIBS) $(DL_LIB)

 SHLIB_DIRS=

 SHLIB_RDIRS=$(KRB5_LIBDIR)

--- krb5/src/util/support/selinux.c

+++ krb5/src/util/support/selinux.c

@@ -0,0 +1,405 @@

+/*

+ * Copyright 2007,2008,2009,2011,2012 Red Hat, Inc.  All Rights Reserved.

+ *

+ * Redistribution and use in source and binary forms, with or without

+ * modification, are permitted provided that the following conditions are met:

+ *

+ *  Redistributions of source code must retain the above copyright notice, this

+ *  list of conditions and the following disclaimer.

+ *

+ *  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.

+ *

+ *  Neither the name of Red Hat, Inc. nor the names of its contributors may be

+ *  used to endorse or promote products derived from this software without

+ *  specific prior written permission.

+ *

+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.

+ * 

+ * File-opening wrappers for creating correctly-labeled files.  So far, we can

+ * assume that this is Linux-specific, so we make many simplifying assumptions.

+ */

+

+#include "../../include/autoconf.h"

+

+#ifdef USE_SELINUX

+

+#include <k5-label.h>

+#include <k5-platform.h>

+#include <sys/types.h>

+#include <sys/stat.h>

+#include <errno.h>

+#include <fcntl.h>

+#include <limits.h>

+#include <pthread.h>

+#include <stdarg.h>

+#include <stdio.h>

+#include <stdlib.h>

+#include <string.h>

+#include <unistd.h>

+#include <selinux/selinux.h>

+#include <selinux/context.h>

+#ifdef HAVE_SELINUX_LABEL_H

+#include <selinux/label.h>

+#endif

+

+/* #define DEBUG 1 */

+

+/* Mutex used to serialize use of the process-global file creation context. */

+k5_mutex_t labeled_mutex = K5_MUTEX_PARTIAL_INITIALIZER;

+

+/* Make sure we finish initializing that mutex before attempting to use it. */

+k5_once_t labeled_once = K5_ONCE_INIT;

+static void

+label_mutex_init(void)

+{

+	k5_mutex_finish_init(&labeled_mutex);

+}

+

+#ifdef HAVE_SELINUX_LABEL_H

+static struct selabel_handle *selabel_ctx;

+static time_t selabel_last_changed;

+

+MAKE_FINI_FUNCTION(cleanup_fscreatecon);

+

+static void

+cleanup_fscreatecon(void)

+{

+	if (selabel_ctx != NULL) {

+		selabel_close(selabel_ctx);

+		selabel_ctx = NULL;

+	}

+}

+#endif

+

+static security_context_t

+push_fscreatecon(const char *pathname, mode_t mode)

+{

+	security_context_t previous, configuredsc, currentsc, derivedsc;

+	context_t current, derived;

+	const char *fullpath, *currentuser;

+

+	previous = NULL;

+	if (is_selinux_enabled()) {

+		if (getfscreatecon(&previous) == 0) {

+			char *genpath;

+			genpath = NULL;

+			if (pathname[0] != '/') {

+				char *wd;

+				size_t len;

+				len = 0;

+				wd = getcwd(NULL, len);

+				if (wd == NULL) {

+					if (previous != NULL) {

+						freecon(previous);

+					}

+					return NULL;

+				}

+				len = strlen(wd) + 1 + strlen(pathname) + 1;

+				genpath = malloc(len);

+				if (genpath == NULL) {

+					free(wd);

+					if (previous != NULL) {

+						freecon(previous);

+					}

+					return NULL;

+				}

+				sprintf(genpath, "%s/%s", wd, pathname);

+				free(wd);

+				fullpath = genpath;

+			} else {

+				fullpath = pathname;

+			}

+#ifdef DEBUG

+			if (isatty(fileno(stderr))) {

+				fprintf(stderr, "Looking up context for "

+					"\"%s\"(%05o).\n", fullpath, mode);

+			}

+#endif

+			configuredsc = NULL;

+#ifdef HAVE_SELINUX_LABEL_H

+			if ((selabel_ctx != NULL) ||

+			    (selabel_last_changed == 0)) {

+				const char *cpath;

+				struct stat st;

+				int i = -1;

+				cpath = selinux_file_context_path();

+				if ((cpath == NULL) ||

+				    ((i = stat(cpath, &st)) != 0) ||

+				    (st.st_mtime != selabel_last_changed)) {

+					if (selabel_ctx != NULL) {

+						selabel_close(selabel_ctx);

+						selabel_ctx = NULL;

+					}

+					selabel_last_changed = i ?

+							       time(NULL) :

+							       st.st_mtime;

+				}

+			}

+			if (selabel_ctx == NULL) {

+				selabel_ctx = selabel_open(SELABEL_CTX_FILE,

+							   NULL, 0);

+			}

+			if (selabel_ctx != NULL) {

+				if (selabel_lookup(selabel_ctx, &configuredsc,

+						   fullpath, mode) != 0) {

+					free(genpath);

+					if (previous != NULL) {

+						freecon(previous);

+					}

+					return NULL;

+				}

+			}

+#else

+			if (matchpathcon(fullpath, mode, &configuredsc) != 0) {

+				free(genpath);

+				if (previous != NULL) {

+					freecon(previous);

+				}

+				return NULL;

+			}

+#endif

+			free(genpath);

+			if (configuredsc == NULL) {

+				if (previous != NULL) {

+					freecon(previous);

+				}

+				return NULL;

+			}

+			currentsc = NULL;

+			getcon(&currentsc);

+			if (currentsc != NULL) {

+				derived = context_new(configuredsc);

+				if (derived != NULL) {

+					current = context_new(currentsc);

+					if (current != NULL) {

+						currentuser = context_user_get(current);

+						if (currentuser != NULL) {

+							if (context_user_set(derived,

+									     currentuser) == 0) {

+								derivedsc = context_str(derived);

+								if (derivedsc != NULL) {

+									freecon(configuredsc);

+									configuredsc = strdup(derivedsc);

+								}

+							}

+						}

+						context_free(current);

+					}

+					context_free(derived);

+				}

+				freecon(currentsc);

+			}

+#ifdef DEBUG

+			if (isatty(fileno(stderr))) {

+				fprintf(stderr, "Setting file creation context "

+					"to \"%s\".\n", configuredsc);

+			}

+#endif

+			if (setfscreatecon(configuredsc) != 0) {

+				freecon(configuredsc);

+				if (previous != NULL) {

+					freecon(previous);

+				}

+				return NULL;

+			}

+			freecon(configuredsc);

+#ifdef DEBUG

+		} else {

+			if (isatty(fileno(stderr))) {

+				fprintf(stderr, "Unable to determine "

+					"current context.\n");

+			}

+#endif

+		}

+	}

+	return previous;

+}

+

+static void

+pop_fscreatecon(security_context_t previous)

+{

+	if (is_selinux_enabled()) {

+#ifdef DEBUG

+		if (isatty(fileno(stderr))) {

+			if (previous != NULL) {

+				fprintf(stderr, "Resetting file creation "

+					"context to \"%s\".\n", previous);

+			} else {

+				fprintf(stderr, "Resetting file creation "

+					"context to default.\n");

+			}

+		}

+#endif

+		setfscreatecon(previous);

+		if (previous != NULL) {

+			freecon(previous);

+		}

+	}

+}

+

+void *

+krb5int_push_fscreatecon_for(const char *pathname)

+{

+	struct stat st;

+	void *retval;

+	k5_once(&labeled_once, label_mutex_init);

+	if (k5_mutex_lock(&labeled_mutex) == 0) {

+		if (stat(pathname, &st) != 0) {

+			st.st_mode = S_IRUSR | S_IWUSR;

+		}

+		retval = push_fscreatecon(pathname, st.st_mode);

+		return retval ? retval : (void *) -1;

+	} else {

+		return NULL;

+	}

+}

+

+void

+krb5int_pop_fscreatecon(void *con)

+{

+	if (con != NULL) {

+		pop_fscreatecon((con == (void *) -1) ? NULL : con);

+		k5_mutex_unlock(&labeled_mutex);

+	}

+}

+

+FILE *

+krb5int_labeled_fopen(const char *path, const char *mode)

+{

+	FILE *fp;

+	int errno_save;

+	security_context_t ctx;

+

+	if ((strcmp(mode, "r") == 0) ||

+	    (strcmp(mode, "rb") == 0)) {

+		return fopen(path, mode);

+	}

+

+	k5_once(&labeled_once, label_mutex_init);

+	if (k5_mutex_lock(&labeled_mutex) == 0) {

+		ctx = push_fscreatecon(path, 0);