pam/pam-0.99.8.1-selinux-permit.patch

Written-by: Tomas Mraz <tmraz@redhat.com>
Reviewed-by: Karel Zak <kzak@redhat.com>

diff -up /dev/null Linux-PAM-0.99.8.1/modules/pam_selinux/pam_selinux_permit.8.xml
--- /dev/null	2007-09-17 08:57:19.474470099 +0200
+++ Linux-PAM-0.99.8.1/modules/pam_selinux/pam_selinux_permit.8.xml	2007-09-19 19:37:26.000000000 +0200
@@ -0,0 +1,182 @@
+<?xml version="1.0" encoding='UTF-8'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+	"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd">
+
+<refentry id="pam_selinux_permit">
+
+  <refmeta>
+    <refentrytitle>pam_selinux_permit</refentrytitle>
+    <manvolnum>8</manvolnum>
+    <refmiscinfo class="sectdesc">Linux-PAM Manual</refmiscinfo>
+  </refmeta>
+
+  <refnamediv id="pam_selinux_permit-name">
+    <refname>pam_selinux_permit</refname>
+    <refpurpose>PAM module to allow/deny login depending on SELinux enforcement state</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <cmdsynopsis id="pam_selinux_permit-cmdsynopsis">
+      <command>pam_selinux_permit.so</command>
+      <arg choice="opt">
+	debug
+      </arg>
+      <arg choice="opt">
+	conf=<replaceable>/path/to/config/file</replaceable>
+      </arg>
+    </cmdsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1 id="pam_selinux_permit-description">
+    <title>DESCRIPTION</title>
+    <para>
+      The pam_selinux module allows or denies login depending on SELinux enforcement
+      state.
+    </para>
+    <para>
+      When the user which is logging in matches an entry in the config file
+      he is allowed access only when the SELinux is in enforcing mode. Otherwise
+      he is denied access. For users not matching any entry in the config file
+      the pam_selinux_permit module returns PAM_IGNORE return value.
+    </para>
+    <para>
+      The config file contains a simple list of user names one per line. If the
+      <replaceable>name</replaceable> is prefixed with @ character it means that all
+      users in the group <replaceable>name</replaceable> match. If it is prefixed
+      with a % character the SELinux user is used to match against the <replaceable>name</replaceable>
+      instead of the account name. Note that when SELinux is disabled the
+      SELinux user assigned to the account cannot be determined. This means that
+      such entries are never matched when SELinux is disabled and pam_selinux_permit
+      will return PAM_IGNORE.
+    </para>
+  </refsect1>
+
+  <refsect1 id="pam_selinux_permit-options">
+    <title>OPTIONS</title>
+    <variablelist>
+      <varlistentry>
+        <term>
+          <option>debug</option>
+        </term>
+        <listitem>
+          <para>
+           Turns on debugging via
+	    <citerefentry>
+              <refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum>
+            </citerefentry>.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>
+          <option>conf=<replaceable>/path/to/config/file</replaceable></option>
+        </term>
+        <listitem>
+          <para>
+            Path to alternative config file overriding the default.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+
+  <refsect1 id="pam_selinux_permit-services">
+    <title>MODULE SERVICES PROVIDED</title>
+    <para>
+      Only the <option>auth</option> and <option>account</option>
+      services are supported.
+    </para>
+  </refsect1>
+
+  <refsect1 id='pam_selinux_permit-return_values'>
+    <title>RETURN VALUES</title>
+    <variablelist>
+      <varlistentry>
+        <term>PAM_AUTH_ERR</term>
+        <listitem>
+          <para>
+            SELinux is disabled or in the permissive mode and the user
+            matches.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>PAM_SUCCESS</term>
+        <listitem>
+          <para>
+            SELinux is in the enforcing mode and the user matches.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>PAM_IGNORE</term>
+        <listitem>
+          <para>
+            The user does not match any entry in the config file.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>PAM_USER_UNKNOWN</term>
+        <listitem>
+          <para>
+            The module was unable to determine the user's name.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>PAM_SERVICE_ERR</term>
+        <listitem>
+          <para>
+            Error during reading or parsing the config file.
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+
+  <refsect1 id="pam_selinux_permit-files">
+    <title>FILES</title>
+    <variablelist>
+      <varlistentry>
+        <term><filename>/etc/security/sepermit.conf</filename></term>
+        <listitem>
+          <para>Default configuration file</para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+
+  <refsect1 id='pam_selinux_permit-examples'>
+    <title>EXAMPLES</title>
+    <programlisting>
+auth     [success=done ignore=ignore default=bad] pam_selinux_permit.so
+auth     required  pam_unix.so
+account  required  pam_unix.so
+session  required  pam_permit.so
+    </programlisting>
+  </refsect1>
+
+  <refsect1 id='pam_selinux_permit-see_also'>
+    <title>SEE ALSO</title>
+    <para>
+      <citerefentry>
+	<refentrytitle>pam.conf</refentrytitle><manvolnum>5</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+	<refentrytitle>pam.d</refentrytitle><manvolnum>8</manvolnum>
+      </citerefentry>,
+      <citerefentry>
+	<refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum>
+      </citerefentry>
+    </para>
+  </refsect1>
+
+  <refsect1 id='pam_selinux_permit-author'>
+    <title>AUTHOR</title>
+      <para>
+        pam_selinux_permit was written by Tomas Mraz &lt;tmraz@redhat.com&gt;.
+      </para>
+  </refsect1>
+
+</refentry>
diff -up /dev/null Linux-PAM-0.99.8.1/modules/pam_selinux/pam_selinux_permit.c
--- /dev/null	2007-09-17 08:57:19.474470099 +0200
+++ Linux-PAM-0.99.8.1/modules/pam_selinux/pam_selinux_permit.c	2007-09-19 20:29:47.000000000 +0200
@@ -0,0 +1,222 @@
+/******************************************************************************
+ * A module for Linux-PAM that allows/denies acces based on SELinux state.
+ *
+ * Copyright (c) 2007 Red Hat, Inc.
+ * Written by Tomas Mraz <tmraz@redhat.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 2. 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.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * ALTERNATIVELY, this product may be distributed under the terms of
+ * the GNU Public License, in which case the provisions of the GPL are
+ * required INSTEAD OF the above restrictions.  (This clause is
+ * necessary due to a potential bad interaction between the GPL and
+ * the restrictions contained in a BSD-style copyright.)
+ *
+ * THIS SOFTWARE IS PROVIDED ``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 AUTHOR 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.
+ *
+ */
+
+#include "config.h"
+
+#include <errno.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <ctype.h>
+
+#define PAM_SM_AUTH
+#define PAM_SM_ACCOUNT
+
+#include <security/pam_modules.h>
+#include <security/_pam_macros.h>
+#include <security/pam_modutil.h>
+#include <security/pam_ext.h>
+
+#include <selinux/selinux.h>
+
+/* return 0 when matched, -1 when unmatched, pam error otherwise */
+static int
+sepermit_match(pam_handle_t *pamh, const char *cfgfile, const char *user,
+	       const char *seuser, int debug)
+{
+	FILE *f;
+	char *line = NULL;
+	char *start;
+	size_t len = 0;
+	int matched = 0;
+	
+	f = fopen(cfgfile, "r");
+	
+	if (!f) {
+		pam_syslog(pamh, LOG_ERR, "Failed to open config file %s: %m", cfgfile);
+		return PAM_SERVICE_ERR;
+	}
+
+	while (!matched && getline(&line, &len, f) != -1) {
+		size_t n;
+
+		if (line[0] == '#')
+			continue;
+
+		start = line;
+		while (isspace(*start))
+			++start;
+		n = strlen(start);
+		while (n > 0 && isspace(start[n-1])) {
+			--n;
+		}
+		if (n == 0)
+			continue;
+
+		start[n] = '\0';
+
+		switch (start[0]) {
+			case '@': 
+				++start;
+				if (debug)
+					pam_syslog(pamh, LOG_NOTICE, "Matching user %s against group %s", user, start);
+				if (pam_modutil_user_in_group_nam_nam(pamh, user, start)) {
+					matched = 1;
+				}
+				break;
+			case '%':
+				++start;
+				if (debug)
+					pam_syslog(pamh, LOG_NOTICE, "Matching seuser %s against seuser %s", seuser, start);
+				if (strcmp(seuser, start) == 0) {
+					matched = 1;					
+				}
+				break;
+			default:
+				if (debug)
+					pam_syslog(pamh, LOG_NOTICE, "Matching user %s against user %s", user, start);
+				if (strcmp(user, start) == 0) {
+					matched = 1;
+				}
+		}
+	}
+
+	free(line);
+	fclose(f);
+	return matched ? 0 : -1;
+}
+
+PAM_EXTERN int
+pam_sm_authenticate(pam_handle_t *pamh, int flags UNUSED,
+		    int argc, const char **argv)
+{
+	int i;
+	int rv;
+	int debug = 0;
+	int sense = PAM_AUTH_ERR;
+	const char *user = NULL;
+	char *seuser = NULL;
+	char *level = NULL;
+	const char *cfgfile = SEPERMIT_CONF_FILE;
+
+	/* Parse arguments. */
+	for (i = 0; i < argc; i++) {
+		if (strcmp(argv[i], "debug") == 0) {
+			debug = 1;
+		}
+		if (strcmp(argv[i], "conf=") == 0) {
+			cfgfile = argv[i] + 5;
+		}
+	}
+
+	if (debug)
+		pam_syslog(pamh, LOG_NOTICE, "Parsing config file: %s", cfgfile);
+
+	if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS || user == NULL
+		|| *user == '\0') {
+		pam_syslog(pamh, LOG_ERR, "Cannot determine the user's name");
+		return PAM_USER_UNKNOWN;
+	}
+
+	if (is_selinux_enabled() > 0) {
+		if (security_getenforce() == 1) {
+			if (debug)
+				pam_syslog(pamh, LOG_NOTICE, "Enforcing mode, access will be allowed on match");
+			sense = PAM_SUCCESS;
+		}
+
+		if (getseuserbyname(user, &seuser, &level) != 0) {
+			seuser = NULL;
+			level = NULL;
+			pam_syslog(pamh, LOG_ERR, "getseuserbyname failed: %m");
+		}
+	}
+
+	if (debug && sense != PAM_SUCCESS)
+		pam_syslog(pamh, LOG_NOTICE, "Access will not be allowed on match");
+
+	rv = sepermit_match(pamh, cfgfile, user, seuser, debug);
+
+	if (debug)
+		pam_syslog(pamh, LOG_NOTICE, "sepermit_match returned: %d", rv);
+
+	free(seuser);
+	free(level);
+
+	switch (rv) {
+		case -1:
+			return PAM_IGNORE;
+		case 0:
+			return sense;
+	}
+
+	return rv;
+}
+
+PAM_EXTERN int
+pam_sm_setcred (pam_handle_t *pamh UNUSED, int flags UNUSED,
+                int argc UNUSED, const char **argv UNUSED)
+{
+	return PAM_IGNORE;
+}
+
+PAM_EXTERN int
+pam_sm_acct_mgmt(pam_handle_t *pamh, int flags,
+		     int argc, const char **argv)
+{
+	return pam_sm_authenticate(pamh, flags, argc, argv);
+}
+
+#ifdef PAM_STATIC
+    
+/* static module data */
+    
+struct pam_module _pam_access_modstruct = {
+    "pam_access",
+    pam_sm_authenticate,
+    pam_sm_setcred,
+    pam_sm_acct_mgmt,
+    NULL,
+    NULL,
+    NULL
+};
+#endif
+
diff -up /dev/null Linux-PAM-0.99.8.1/modules/pam_selinux/sepermit.conf
--- /dev/null	2007-09-17 08:57:19.474470099 +0200
+++ Linux-PAM-0.99.8.1/modules/pam_selinux/sepermit.conf	2007-09-19 19:37:26.000000000 +0200
@@ -0,0 +1,6 @@
+# /etc/security/sepermit.conf
+#
+# Each line contains either:
+#        - an user name
+#        - a group name, with @group syntax
+#        - a SELinux user name, with %seuser syntax
diff -up Linux-PAM-0.99.8.1/modules/pam_selinux/Makefile.am.permit Linux-PAM-0.99.8.1/modules/pam_selinux/Makefile.am
--- Linux-PAM-0.99.8.1/modules/pam_selinux/Makefile.am.permit	2007-01-23 11:09:25.000000000 +0100
+++ Linux-PAM-0.99.8.1/modules/pam_selinux/Makefile.am	2007-09-19 19:37:26.000000000 +0200
@@ -5,20 +5,21 @@
 CLEANFILES = *~
 
 EXTRA_DIST = README $(XMLS) pam_selinux.8 pam_selinux_check.8 \
-		tst-pam_selinux
+		pam_seliux_permit.8 sepermit.conf tst-pam_selinux
 
 if HAVE_LIBSELINUX
   TESTS = tst-pam_selinux
-  man_MANS = pam_selinux.8 
+  man_MANS = pam_selinux.8 pam_selinux_permit.8
 endif
 
-XMLS = README.xml pam_selinux.8.xml
+XMLS = README.xml pam_selinux.8.xml pam_selinux_permit.8.xml
 
 securelibdir = $(SECUREDIR)
 secureconfdir = $(SCONFIGDIR)
 
 AM_CFLAGS = -I$(top_srcdir)/libpam/include -I$(top_srcdir)/libpamc/include \
-	-I$(top_srcdir)/libpam_misc/include
+	-I$(top_srcdir)/libpam_misc/include \
+	-D SEPERMIT_CONF_FILE=\"$(SCONFIGDIR)/sepermit.conf\"
 AM_LDFLAGS = -no-undefined \
 	-L$(top_builddir)/libpam -lpam @LIBSELINUX@
 
@@ -30,12 +31,16 @@ if HAVE_VERSIONING
 	-Wl,--version-script=$(srcdir)/../modules.map
 endif
 
+pam_selinux_permit_la_LDFLAGS= $(pam_selinux_la_LDFLAGS)
+
+secureconf_DATA = sepermit.conf
+
 if HAVE_LIBSELINUX
-  securelib_LTLIBRARIES = pam_selinux.la
+  securelib_LTLIBRARIES = pam_selinux.la pam_selinux_permit.la
   noinst_PROGRAMS = pam_selinux_check
 endif
 if ENABLE_REGENERATE_MAN
-noinst_DATA = README pam_selinux.8
+noinst_DATA = README pam_selinux.8 pam_selinux_permit.8
 README: pam_selinux.8.xml
 -include $(top_srcdir)/Make.xml.rules
 endif