[Koha-patches] [PATCH] Bug 6012 : MT 2270: CAS proxy

Chris Cormack chrisc at catalyst.net.nz
Wed Mar 30 22:58:22 CEST 2011


From: Matthias Meusburger <matthias.meusburger at biblibre.com>

CAS Proxy
Examples included are now really usable

Signed-off-by: Chris Cormack <chrisc at catalyst.net.nz>
---
 C4/Auth.pm                                       |   26 ++++---
 C4/Auth_with_cas.pm                              |   52 ++++++++++++-
 docs/CAS/CASProxy/README                         |    9 ++
 docs/CAS/CASProxy/examples/casSession.tmp        |  Bin 0 -> 134 bytes
 docs/CAS/CASProxy/examples/koha_webservice.pl    |   58 ++++++++++++++
 docs/CAS/CASProxy/examples/proxy_cas.pl          |   91 ++++++++++++++++++++++
 docs/CAS/CASProxy/examples/proxy_cas_callback.pl |   62 +++++++++++++++
 docs/CAS/CASProxy/examples/proxy_cas_data.pl     |   80 +++++++++++++++++++
 8 files changed, 367 insertions(+), 11 deletions(-)
 create mode 100644 docs/CAS/CASProxy/README
 create mode 100644 docs/CAS/CASProxy/examples/casSession.tmp
 create mode 100755 docs/CAS/CASProxy/examples/koha_webservice.pl
 create mode 100755 docs/CAS/CASProxy/examples/proxy_cas.pl
 create mode 100755 docs/CAS/CASProxy/examples/proxy_cas_callback.pl
 create mode 100755 docs/CAS/CASProxy/examples/proxy_cas_data.pl

diff --git a/C4/Auth.pm b/C4/Auth.pm
index 2c6809b..387b465 100644
--- a/C4/Auth.pm
+++ b/C4/Auth.pm
@@ -52,7 +52,7 @@ BEGIN {
     }
     if ($cas) {
         require C4::Auth_with_cas;             # no import
-        import  C4::Auth_with_cas qw(checkpw_cas login_cas logout_cas login_cas_url);
+        import  C4::Auth_with_cas qw(check_api_auth_cas checkpw_cas login_cas logout_cas login_cas_url);
     }
 
 }
@@ -1046,7 +1046,7 @@ sub check_api_auth {
     unless ($query->param('userid')) {
         $sessionID = $query->cookie("CGISESSID");
     }
-    if ($sessionID) {
+    if ($sessionID && not $cas) {
         my $session = get_session($sessionID);
         C4::Context->_new_userenv($sessionID);
         if ($session) {
@@ -1096,18 +1096,24 @@ sub check_api_auth {
         # new login
         my $userid = $query->param('userid');
         my $password = $query->param('password');
-        unless ($userid and $password) {
-            # caller did something wrong, fail the authenticateion
-            return ("failed", undef, undef);
-        }
-	my ($return, $cardnumber);
-	if ($cas && $query->param('ticket')) {
+       	my ($return, $cardnumber);
+
+	# Proxy CAS auth
+	if ($cas && $query->param('PT')) {
 	    my $retuserid;
-	    ( $return, $cardnumber, $retuserid ) = checkpw( $dbh, $userid, $password, $query );
-	    $userid = $retuserid;
+	    $debug and print STDERR "## check_api_auth - checking CAS\n";
+	    # In case of a CAS authentication, we use the ticket instead of the password
+	    my $PT = $query->param('PT');
+	    ($return,$cardnumber,$userid) = check_api_auth_cas($dbh, $PT, $query);    # EXTERNAL AUTH
 	} else {
+	    # User / password auth
+	    unless ($userid and $password) {
+		# caller did something wrong, fail the authenticateion
+		return ("failed", undef, undef);
+	    }
 	    ( $return, $cardnumber ) = checkpw( $dbh, $userid, $password, $query );
 	}
+
         if ($return and haspermission(  $userid, $flagsrequired)) {
             my $session = get_session("");
             return ("failed", undef, undef) unless $session;
diff --git a/C4/Auth_with_cas.pm b/C4/Auth_with_cas.pm
index f9a03a3..0b66f5d 100644
--- a/C4/Auth_with_cas.pm
+++ b/C4/Auth_with_cas.pm
@@ -34,7 +34,7 @@ BEGIN {
 	$VERSION = 3.03;	# set the version for version checking
 	$debug = $ENV{DEBUG};
 	@ISA    = qw(Exporter);
-	@EXPORT = qw(checkpw_cas login_cas logout_cas login_cas_url);
+	@EXPORT = qw(check_api_auth_cas checkpw_cas login_cas logout_cas login_cas_url);
 }
 
 
@@ -107,6 +107,56 @@ sub checkpw_cas {
     return 0;
 }
 
+# Proxy CAS auth
+sub check_api_auth_cas {
+    $debug and warn "check_api_auth_cas";
+    my ($dbh, $PT, $query) = @_;
+    my $retnumber;
+    my $url = $query->url();
+    my $cas = Authen::CAS::Client->new($casserver);
+    
+    # If we have a Proxy Ticket
+    if ($PT) {
+	my $r = $cas->proxy_validate( $url, $PT );
+
+	# If the PT is valid
+	if( $r->is_success ) {
+
+	    # We've got a username ! 
+	    $debug and warn "User authenticated as: ", $r->user, "\n";
+	    $debug and warn "Proxied through:\n";
+	    $debug and warn "  $_\n"
+	      for $r->proxies;
+
+	    my $userid = $r->user;
+	    
+	    # Does it match one of our users ?
+    	    my $sth = $dbh->prepare("select cardnumber from borrowers where userid=?");
+    	    $sth->execute($userid);
+    	    if ( $sth->rows ) {
+		$retnumber = $sth->fetchrow;
+		return (1, $retnumber, $userid);
+	    }
+	    my $sth = $dbh->prepare("select userid from borrowers where cardnumber=?");
+	    return $r->user;
+	    $sth->execute($userid);
+	    if ( $sth->rows ) {
+	    	$retnumber = $sth->fetchrow;
+		return (1, $retnumber, $userid);
+	    }
+	    
+	    # If we reach this point, then the user is a valid CAS user, but not a Koha user
+	    $debug and warn "User $userid is not a valid Koha user";
+
+	} else {
+	    $debug and warn "Proxy Ticket authentication failed";
+	    return 0;
+	}
+    }
+    return 0;
+}
+
+
 1;
 __END__
 
diff --git a/docs/CAS/CASProxy/README b/docs/CAS/CASProxy/README
new file mode 100644
index 0000000..b1c882c
--- /dev/null
+++ b/docs/CAS/CASProxy/README
@@ -0,0 +1,9 @@
+As CAS Proxying is not an obvious authentication to set up, here are
+some documented examples showing how a foreign application can query
+koha webservices, being CAS authenticated.
+
+The starting point is proxy_cas.pl
+
+To find more about how CAS Proxy works :
+http://afs.berkeley.edu/~lr/presentations/cas-auth/
+http://www.ja-sig.org/wiki/display/CAS/Proxy+CAS+Walkthrough
diff --git a/docs/CAS/CASProxy/examples/casSession.tmp b/docs/CAS/CASProxy/examples/casSession.tmp
new file mode 100644
index 0000000000000000000000000000000000000000..ca78c338972f592560a68146fc7c534e3ebca685
GIT binary patch
literal 134
zcmXRYE-_$bXJ%kvVC1q4a1YTnwA78Ts7!To^a=9!DoZId3JUY_NzO6IG&L^>H#V&Z
zb1 at 0^H8ApwvIz1|E;KevODZ!p0BW}ZYWDOG)it!xO{($^NzODch|0 at z^Y#c2u?TPv
jjVgCbO06i2NX<*JOiC<DH#f=g^h>VF_e=Av3dsWinw}@#

literal 0
HcmV?d00001

diff --git a/docs/CAS/CASProxy/examples/koha_webservice.pl b/docs/CAS/CASProxy/examples/koha_webservice.pl
new file mode 100755
index 0000000..cb161f7
--- /dev/null
+++ b/docs/CAS/CASProxy/examples/koha_webservice.pl
@@ -0,0 +1,58 @@
+#!/usr/bin/perl
+
+# Copyright 2009 SARL BibLibre
+#
+# This file is part of Koha.
+#
+# Koha 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.
+#
+# Koha 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
+# Koha; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
+# Suite 330, Boston, MA  02111-1307 USA
+
+=head1 DESCRIPTION
+
+# Here is an exemple of a simple phony webservice, returning "Hello World" if the user is authenticated
+# The purpose is to show how CAS Proxy can work with koha
+# In this configuration, this page acts as a CAS Client, instead of the user's browser.
+# This page is meant to be called from a foreign application
+
+=head1 CGI PARAMETERS
+
+=item PT
+The Proxy Ticket, needed for check_api_auth, that will try to make the CAS Server validate it.
+
+=cut 
+
+use utf8;
+use strict;
+use warnings;
+binmode(STDOUT, ":utf8");
+
+use C4::Auth qw(check_api_auth);
+use C4::Output;
+use C4::Context;
+use CGI;
+
+my $cgi = new CGI;
+
+print CGI::header('-type'=>'text/plain', '-charset'=>'utf-8');
+
+# The authentication : if $cgi contains a PT parameter, and CAS is enabled (casAuthentication syspref),
+# a CAS Proxy authentication will take place
+my ( $status, $cookie_, $sessionID ) = check_api_auth( $cgi, {circulate => 'override_renewals'});
+
+if ($status ne 'ok') {
+    print "Authentication failed : $status";
+} else {
+    print "Hello World!";
+}
+exit 0;
+
diff --git a/docs/CAS/CASProxy/examples/proxy_cas.pl b/docs/CAS/CASProxy/examples/proxy_cas.pl
new file mode 100755
index 0000000..85085d7
--- /dev/null
+++ b/docs/CAS/CASProxy/examples/proxy_cas.pl
@@ -0,0 +1,91 @@
+#!/usr/bin/perl
+
+# Copyright 2009 SARL BibLibre
+#
+# This file is part of Koha.
+#
+# Koha 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.
+#
+# Koha 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
+# Koha; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
+# Suite 330, Boston, MA  02111-1307 USA
+
+=head1 DESCRIPTION
+
+# Here is an exemple of a CAS Proxy
+# The proxy is a foreign application that will authenticate the user against CAS
+# Once authenticated as a proxy, the foreign application will be able to call some
+# Koha webservices, proving authentication only by giving a proxy ticket
+
+# Note: please keep in mind that all url's must be https and their certificates must be trusted
+
+=cut
+
+use strict;
+use warnings;
+use CGI;
+use Authen::CAS::Client;
+
+# URL Of the CAS Server
+my $casServerUrl = 'https://localhost:8443/cas/';
+my $cas = Authen::CAS::Client->new($casServerUrl);
+my $cgi = new CGI;
+
+# URL of the service we're requesting a Service Ticket for (typically this very same page)
+my $proxy_service = $cgi->url;
+
+
+# Callback URL (this is an URL the CAS Server will query, providing the Proxy Ticket we'll need 
+# to query the koha webservice). It can be this page or another. In this example, another page will be 
+# called back
+my $pgtUrl = "https://.../proxy_cas_callback.pl";
+
+print $cgi->header({-type  =>  'text/html'});
+print $cgi->start_html("proxy cas");
+
+# If we already have a service ticket
+if ($cgi->param('ticket')) {
+
+    print "Got a ticket :" . $cgi->param('ticket') . "<br>\n";
+  
+    # We validate it against the CAS Server, providing the callback URL
+    my $r = $cas->service_validate( $proxy_service, $cgi->param('ticket'), pgtUrl => $pgtUrl);
+
+    # If it is sucessful, we are authenticated
+    if( $r->is_success() ) {
+	print "User authenticated as: ", $r->user(), "<br>\n";
+    } else {
+	print "User authentication failed<br />\n";
+    }
+
+    # If we have a PGTIou ticket, the proxy validation was sucessful 
+    if (defined $r->iou) {
+      print "Proxy granting ticket IOU: ", $r->iou, "<br />\n";
+      my $pgtIou = $r->iou;
+
+      print '<a href="proxy_cas_data.pl?PGTIOU=', $r->iou, '">Next</a>';
+
+      
+     	    
+    } else {
+      print "Service validation for proxying failed\n";
+   }
+
+# If we don't have a Service Ticket, we ask for one (ie : the user will be redirected to the CAS Server for authentication)
+} else {
+
+    my $url = $cas->login_url($proxy_service);
+    print "<a href=\"$url\">Please log in</a>";
+}
+
+print $cgi->end_html;
+
+
+
diff --git a/docs/CAS/CASProxy/examples/proxy_cas_callback.pl b/docs/CAS/CASProxy/examples/proxy_cas_callback.pl
new file mode 100755
index 0000000..3c2c9ef
--- /dev/null
+++ b/docs/CAS/CASProxy/examples/proxy_cas_callback.pl
@@ -0,0 +1,62 @@
+#!/usr/bin/perl
+
+# Copyright 2009 SARL BibLibre
+#
+# This file is part of Koha.
+#
+# Koha 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.
+#
+# Koha 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
+# Koha; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
+# Suite 330, Boston, MA  02111-1307 USA
+
+=head1 DESCRIPTION
+
+# Here is an exemple of a callback page for a CAS Proxy
+# This is the page the CAS server will call back with a Proxy Ticket, allowing us (the foreign application)
+# to query koha webservices, being CAS authenticated 
+
+=cut
+
+use strict;
+use warnings;
+use CGI;
+use Authen::CAS::Client;
+use Storable qw(nstore_fd);
+
+my $casServerUrl = 'https://localhost:8443/cas/';
+my $cas = Authen::CAS::Client->new($casServerUrl);
+
+my $cgi = new CGI;
+
+my $proxy_service = $cgi->url;
+
+print $cgi->header({-type  =>  'text/html'});
+print $cgi->start_html("proxy cas callback");
+
+# If we have a pgtId, it means the cas server called us back
+if ($cgi->param('pgtId')) {
+    warn "Got a pgtId :" . $cgi->param('pgtId');
+    warn "Got a pgtIou :" . $cgi->param('pgtIou');
+    my $pgtIou =  $cgi->param('pgtIou');
+    my $pgtId =  $cgi->param('pgtId');
+
+    # Now we store the pgtIou and the pgtId in the application vars (in our case a storable object in a file), 
+    # so that the page requesting the webservice can retrieve the pgtId matching it's PgtIou 
+    open FILE, ">", "casSession.tmp" or die "Unable to open file";
+    nstore_fd({$pgtIou => $pgtId}, \*FILE);
+    close FILE;
+
+} else {
+    warn "Failed to get a Proxy Ticket\n";
+}
+
+print $cgi->end_html;
+
diff --git a/docs/CAS/CASProxy/examples/proxy_cas_data.pl b/docs/CAS/CASProxy/examples/proxy_cas_data.pl
new file mode 100755
index 0000000..92c61a5
--- /dev/null
+++ b/docs/CAS/CASProxy/examples/proxy_cas_data.pl
@@ -0,0 +1,80 @@
+#!/usr/bin/perl
+
+# Copyright 2009 SARL BibLibre
+#
+# This file is part of Koha.
+#
+# Koha 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.
+#
+# Koha 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
+# Koha; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
+# Suite 330, Boston, MA  02111-1307 USA
+
+=head1 DESCRIPTION
+
+# This page will display the result of the call to the koha webservice
+
+=head1 CGI PARAMETERS
+
+=item PGTIOU
+
+The Proxy Granting Ticket IOU the CAS Server returned to us when we gave him the Service Ticket
+This PGTIOU will allow us to retrive the matching PGTID
+
+=cut 
+
+use strict;
+use warnings;
+use CGI;
+use Authen::CAS::Client;
+use Storable qw(fd_retrieve);
+use LWP::Simple;
+use URI::Escape;
+
+my $casServerUrl = 'https://localhost:8443/cas/';
+my $cas = Authen::CAS::Client->new($casServerUrl);
+
+# URL of the service we'd like to be proxy for (typically the Koha webservice we want to query)
+my $target_service = "https://.../koha_webservice.pl";
+
+my $cgi = new CGI;
+
+print $cgi->header({-type  =>  'text/html'});
+print $cgi->start_html("proxy cas");
+
+
+if ($cgi->param('PGTIOU')) {
+
+      # At this point, we must retrieve the PgtId by matching the PgtIou we
+      # just received and the PgtIou given by the CAS Server to the callback URL
+      # The callback page stored it in the application vars (in our case a storable object in a file)
+      open FILE, "casSession.tmp" or die "Unable to open file";
+      my $hashref = fd_retrieve(\*FILE);
+      my $pgtId = %$hashref->{$cgi->param('PGTIOU')};
+      close FILE;
+
+      # Now that we have a PgtId, we can ask the cas server for a proxy ticket...
+      my $rp = $cas->proxy( $pgtId, $target_service );
+      if( $rp->is_success ) {
+        print "Proxy Ticket issued: ", $rp->proxy_ticket, "<br />\n";
+
+	# ...which we will provide to the target service (the koha webservice) for authentication !
+	my $data = get($target_service . "?PT=" . $rp->proxy_ticket);
+	
+	# And finally, we can display the data gathered from the koha webservice !
+	print "This is the output of the koha webservice we just queried, CAS authenticated : <br/>";
+	print "<code>$data</code>";
+
+      } else {
+	print "Cannot get Proxy Ticket";
+      }
+
+
+}
-- 
1.7.1



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