Tests for Kerberos/GSSAPI authentication

Like the LDAP and SSL tests, these are not run by default but can be
selected via PG_TEST_EXTRA.
Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>

configure

@@ -709,7 +709,9 @@ with_systemd
 with_selinux
 with_openssl
 with_ldap
+with_krb_srvnam
 krb_srvtab
+with_gssapi
 with_python
 with_perl
 with_tcl
@@ -5788,6 +5790,7 @@ $as_echo "$with_gssapi" >&6; }
 
 
 
+
 #
 # Kerberos configuration parameters
 #
@@ -5815,6 +5818,7 @@ fi
 
 
 
+
 cat >>confdefs.h <<_ACEOF
 #define PG_KRB_SRVNAM "$with_krb_srvnam"
 _ACEOF

configure.in

@@ -638,6 +638,7 @@ PGAC_ARG_BOOL(with, gssapi, no, [build with GSSAPI support],
   krb_srvtab="FILE:\$(sysconfdir)/krb5.keytab"
 ])
 AC_MSG_RESULT([$with_gssapi])
+AC_SUBST(with_gssapi)
 
 
 AC_SUBST(krb_srvtab)
@@ -650,6 +651,7 @@ PGAC_ARG_REQ(with, krb-srvnam,
              [NAME], [default service principal name in Kerberos (GSSAPI) [postgres]],
              [],
              [with_krb_srvnam="postgres"])
+AC_SUBST(with_krb_srvnam)
 AC_DEFINE_UNQUOTED([PG_KRB_SRVNAM], ["$with_krb_srvnam"],
                    [Define to the name of the default PostgreSQL service principal in Kerberos (GSSAPI). (--with-krb-srvnam=NAME)])
 

doc/src/sgml/regress.sgml

@@ -220,10 +220,20 @@ make installcheck-world
    <varname>PG_TEST_EXTRA</varname> to a whitespace-separated list, for
    example:
 <programlisting>
-make check-world PG_TEST_EXTRA='ldap ssl'
+make check-world PG_TEST_EXTRA='kerberos ldap ssl'
 </programlisting>
    The following values are currently supported:
    <variablelist>
+    <varlistentry>
+     <term><literal>kerberos</literal></term>
+     <listitem>
+      <para>
+       Runs the test suite under <filename>src/test/kerberos</filename>.  This
+       requires an MIT Kerberos installation and opens TCP/IP listen sockets.
+      </para>
+     </listitem>
+    </varlistentry>
+
     <varlistentry>
      <term><literal>ldap</literal></term>
      <listitem>

src/Makefile.global.in

@@ -186,6 +186,8 @@ with_tcl	= @with_tcl@
 with_openssl	= @with_openssl@
 with_selinux	= @with_selinux@
 with_systemd	= @with_systemd@
+with_gssapi	= @with_gssapi@
+with_krb_srvnam	= @with_krb_srvnam@
 with_ldap	= @with_ldap@
 with_libxml	= @with_libxml@
 with_libxslt	= @with_libxslt@

src/test/Makefile

@@ -17,6 +17,11 @@ SUBDIRS = perl regress isolation modules authentication recovery subscription
 # Test suites that are not safe by default but can be run if selected
 # by the user via the whitespace-separated list in variable
 # PG_TEST_EXTRA:
+ifeq ($(with_gssapi),yes)
+ifneq (,$(filter kerberos,$(PG_TEST_EXTRA)))
+SUBDIRS += kerberos
+endif
+endif
 ifeq ($(with_ldap),yes)
 ifneq (,$(filter ldap,$(PG_TEST_EXTRA)))
 SUBDIRS += ldap
@@ -32,7 +37,7 @@ endif
 # clean" etc to recurse into them.  (We must filter out those that we
 # have conditionally included into SUBDIRS above, else there will be
 # make confusion.)
-ALWAYS_SUBDIRS = $(filter-out $(SUBDIRS),examples ldap locale thread ssl)
+ALWAYS_SUBDIRS = $(filter-out $(SUBDIRS),examples kerberos ldap locale thread ssl)
 
 # We want to recurse to all subdirs for all standard targets, except that
 # installcheck and install should not recurse into the subdirectory "modules".

src/test/kerberos/.gitignore

+# Generated by test suite
+/tmp_check/

src/test/kerberos/Makefile

+#-------------------------------------------------------------------------
+#
+# Makefile for src/test/kerberos
+#
+# Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
+# Portions Copyright (c) 1994, Regents of the University of California
+#
+# src/test/kerberos/Makefile
+#
+#-------------------------------------------------------------------------
+
+subdir = src/test/kerberos
+top_builddir = ../../..
+include $(top_builddir)/src/Makefile.global
+
+export with_gssapi with_krb_srvnam
+
+check:
+	$(prove_check)
+
+installcheck:
+	$(prove_installcheck)
+
+clean distclean maintainer-clean:
+	rm -rf tmp_check

src/test/kerberos/README

+src/test/kerberos/README
+
+Tests for Kerberos/GSSAPI functionality
+=======================================
+
+This directory contains a test suite for Kerberos/GSSAPI
+functionality.  This requires a full MIT Kerberos installation,
+including server and client tools, and is therefore kept separate and
+not run by default.
+
+Also, this test suite creates a KDC server that listens for TCP/IP
+connections on localhost without any real access control, so it is not
+safe to run this on a system where there might be untrusted local
+users.
+
+Running the tests
+=================
+
+    make check
+
+or
+
+    make installcheck
+
+Requirements
+============
+
+MIT Kerberos server and client tools are required.  Heimdal is not
+supported.
+
+Debian/Ubuntu packages: krb5-admin-server krb5-kdc krb5-user
+
+RHEL/CentOS packages: krb5-server krb5-workstation
+
+FreeBSD port: krb5 (base system has Heimdal)

src/test/kerberos/t/001_auth.pl

+use strict;
+use warnings;
+use TestLib;
+use PostgresNode;
+use Test::More;
+
+if ($ENV{with_gssapi} eq 'yes')
+{
+	plan tests => 4;
+}
+else
+{
+	plan skip_all => 'GSSAPI/Kerberos not supported by this build';
+}
+
+my ($krb5_bin_dir, $krb5_sbin_dir);
+
+if ($^O eq 'darwin')
+{
+	$krb5_bin_dir = '/usr/local/opt/krb5/bin';
+	$krb5_sbin_dir = '/usr/local/opt/krb5/sbin';
+}
+elsif ($^O eq 'freebsd')
+{
+	$krb5_bin_dir = '/usr/local/bin';
+	$krb5_sbin_dir = '/usr/local/sbin';
+}
+elsif ($^O eq 'linux')
+{
+	$krb5_sbin_dir = '/usr/sbin';
+}
+
+my $krb5_config = 'krb5-config';
+my $kinit = 'kinit';
+my $kdb5_util = 'kdb5_util';
+my $kadmin_local = 'kadmin.local';
+my $krb5kdc = 'krb5kdc';
+
+if ($krb5_bin_dir && -d $krb5_bin_dir)
+{
+	$krb5_config = $krb5_bin_dir . '/' . $krb5_config;
+	$kinit = $krb5_bin_dir . '/' . $kinit;
+}
+if ($krb5_sbin_dir && -d $krb5_sbin_dir)
+{
+	$kdb5_util = $krb5_sbin_dir . '/' . $kdb5_util;
+	$kadmin_local = $krb5_sbin_dir . '/' . $kadmin_local;
+	$krb5kdc = $krb5_sbin_dir . '/' . $krb5kdc;
+}
+
+my $realm = 'EXAMPLE.COM';
+
+my $krb5_conf = "${TestLib::tmp_check}/krb5.conf";
+my $kdc_conf = "${TestLib::tmp_check}/kdc.conf";
+my $krb5_log = "${TestLib::tmp_check}/krb5libs.log";
+my $kdc_log = "${TestLib::tmp_check}/krb5kdc.log";
+my $kdc_port = int(rand() * 16384) + 49152;
+my $kdc_datadir = "${TestLib::tmp_check}/krb5kdc";
+my $kdc_pidfile = "${TestLib::tmp_check}/krb5kdc.pid";
+my $keytab = "${TestLib::tmp_check}/krb5.keytab";
+
+note "setting up Kerberos";
+
+my ($stdout, $krb5_version);
+run_log [ $krb5_config, '--version' ], '>', \$stdout or BAIL_OUT("could not execute krb5-config");
+BAIL_OUT("Heimdal is not supported") if $stdout =~ m/heimdal/;
+$stdout =~ m/Kerberos 5 release ([0-9]+\.[0-9]+)/ or BAIL_OUT("could not get Kerberos version");
+$krb5_version = $1;
+
+append_to_file($krb5_conf,
+qq![logging]
+default = FILE:$krb5_log
+kdc = FILE:$kdc_log
+
+[libdefaults]
+default_realm = $realm
+
+[realms]
+$realm = {
+    kdc = localhost:$kdc_port
+}!);
+
+append_to_file($kdc_conf,
+qq![kdcdefaults]
+!);
+# For new-enough versions of krb5, use the _listen settings rather
+# than the _ports settings so that we can bind to localhost only.
+if ($krb5_version >= 1.15)
+{
+	append_to_file($kdc_conf,
+qq!kdc_listen = localhost:$kdc_port
+kdc_tcp_listen = localhost:$kdc_port
+!);
+}
+else
+{
+	append_to_file($kdc_conf,
+qq!kdc_ports = $kdc_port
+kdc_tcp_ports = $kdc_port
+!);
+}
+append_to_file($kdc_conf,
+qq!
+[realms]
+$realm = {
+    database_name = $kdc_datadir/principal
+    admin_keytab = FILE:$kdc_datadir/kadm5.keytab
+    acl_file = $kdc_datadir/kadm5.acl
+    key_stash_file = $kdc_datadir/_k5.$realm
+}!);
+
+mkdir $kdc_datadir or die;
+
+$ENV{'KRB5_CONFIG'} = $krb5_conf;
+$ENV{'KRB5_KDC_PROFILE'} = $kdc_conf;
+
+my $service_principal = "$ENV{with_krb_srvnam}/localhost";
+
+system_or_bail $kdb5_util, 'create', '-s', '-P', 'secret0';
+
+my $test1_password = 'secret1';
+system_or_bail $kadmin_local, '-q', "addprinc -pw $test1_password test1";
+
+system_or_bail $kadmin_local, '-q', "addprinc -randkey $service_principal";
+system_or_bail $kadmin_local, '-q', "ktadd -k $keytab $service_principal";
+
+system_or_bail $krb5kdc, '-P', $kdc_pidfile;
+
+END
+{
+    kill 'INT', `cat $kdc_pidfile` if -f $kdc_pidfile;
+}
+
+note "setting up PostgreSQL instance";
+
+my $node = get_new_node('node');
+$node->init;
+$node->append_conf('postgresql.conf', "listen_addresses = 'localhost'");
+$node->append_conf('postgresql.conf', "krb_server_keyfile = '$keytab'");
+$node->start;
+
+$node->safe_psql('postgres', 'CREATE USER test1;');
+
+note "running tests";
+
+sub test_access
+{
+	my ($node, $role, $expected_res, $test_name) = @_;
+
+	# need to connect over TCP/IP for Kerberos
+	my $res = $node->psql('postgres', 'SELECT 1',
+						  extra_params => [ '-d', $node->connstr('postgres').' host=localhost',
+											'-U', $role ]);
+	is($res, $expected_res, $test_name);
+}
+
+unlink($node->data_dir . '/pg_hba.conf');
+$node->append_conf('pg_hba.conf', qq{host all all localhost gss map=mymap});
+$node->restart;
+
+test_access($node, 'test1', 2, 'fails without ticket');
+
+run_log [ $kinit, 'test1' ], \$test1_password or BAIL_OUT($?);
+
+test_access($node, 'test1', 2, 'fails without mapping');
+
+$node->append_conf('pg_ident.conf', qq{mymap  /^(.*)\@$realm\$  \\1});
+$node->restart;
+
+test_access($node, 'test1', 0, 'succeeds with mapping');
+
+truncate($node->data_dir . '/pg_ident.conf', 0);
+unlink($node->data_dir . '/pg_hba.conf');
+$node->append_conf('pg_hba.conf', qq{host all all localhost gss include_realm=0});
+$node->restart;
+
+test_access($node, 'test1', 0, 'succeeds with include_realm=0');