C4/Auth_with_shibboleth.pm

   1 package C4::Auth_with_shibboleth;
   2
   3 # Copyright 2014 PTFS Europe
   4 #
   5 # This file is part of Koha.
   6 #
   7 # Koha is free software; you can redistribute it and/or modify it
   8 # under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 3 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # Koha is distributed in the hope that it will be useful, but
  13 # WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with Koha; if not, see <http://www.gnu.org/licenses>.
  19
  20 use Modern::Perl;
  21
  22 use C4::Debug;
  23 use C4::Context;
  24 use Koha::AuthUtils qw(get_script_name);
  25 use Koha::Database;
  26 use C4::Members qw( AddMember_Auto );
  27 use C4::Members::Messaging;
  28 use Carp;
  29 use CGI;
  30
  31 use vars qw(@ISA @EXPORT @EXPORT_OK %EXPORT_TAGS $debug);
  32
  33 BEGIN {
  34     require Exporter;
  35     $debug   = $ENV{DEBUG};
  36     @ISA     = qw(Exporter);
  37     @EXPORT =
  38       qw(shib_ok logout_shib login_shib_url checkpw_shib get_login_shib);
  39 }
  40
  41 # Check that shib config is not malformed
  42 sub shib_ok {
  43     my $config = _get_shib_config();
  44
  45     if ($config) {
  46         return 1;
  47     }
  48
  49     return 0;
  50 }
  51
  52 # Logout from Shibboleth
  53 sub logout_shib {
  54     my ($query) = @_;
  55     my $uri = _get_uri();
  56     print $query->redirect( $uri . "/Shibboleth.sso/Logout?return=$uri" );
  57 }
  58
  59 # Returns Shibboleth login URL with callback to the requesting URL
  60 sub login_shib_url {
  61     my ($query) = @_;
  62
  63     my $param = _get_uri() . get_script_name();
  64     if ( $query->query_string() ) {
  65         $param = $param . '%3F' . $query->query_string();
  66     }
  67     my $uri = _get_uri() . "/Shibboleth.sso/Login?target=$param";
  68     return $uri;
  69 }
  70
  71 # Returns shibboleth user login
  72 sub get_login_shib {
  73
  74 # In case of a Shibboleth authentication, we expect a shibboleth user attribute
  75 # to contain the login match point of the shibboleth-authenticated user. This match
  76 # point is configured in koha-conf.xml
  77
  78 # Shibboleth attributes are mapped into http environmement variables, so we're getting
  79 # the match point of the user this way
  80
  81     # Get shibboleth config
  82     my $config = _get_shib_config();
  83
  84     my $matchAttribute = $config->{mapping}->{ $config->{matchpoint} }->{is};
  85     $debug and warn $matchAttribute . " value: " . $ENV{$matchAttribute};
  86
  87     return $ENV{$matchAttribute} || '';
  88 }
  89
  90 # Checks for password correctness
  91 # In our case : does the given attribute match one of our users ?
  92 sub checkpw_shib {
  93     $debug and warn "checkpw_shib";
  94
  95     my ( $match ) = @_;
  96     my $config = _get_shib_config();
  97     $debug and warn "User Shibboleth-authenticated as: $match";
  98
  99     # Does the given shibboleth attribute value ($match) match a valid koha user ?
 100     my $borrower =
 101       Koha::Database->new()->schema()->resultset('Borrower')
 102       ->find( { $config->{matchpoint} => $match } );
 103     if ( defined($borrower) ) {
 104         return ( 1, $borrower->get_column('cardnumber'), $borrower->get_column('userid') );
 105     }
 106
 107     if ( $config->{'autocreate'} ) {
 108         return _autocreate( $config, $match );
 109     } else {
 110         # If we reach this point, the user is not a valid koha user
 111         $debug and warn "User $userid is not a valid Koha user";
 112         return 0;
 113     }
 114 }
 115
 116 sub _autocreate {
 117     my ( $config, $match ) = @_;
 118
 119     my %borrower = ( $shibbolethMatchField => $match );
 120
 121     while ( my ( $key, $entry ) = each %{$config->{'mapping'}} ) {
 122         $borrower{$key} = ( $entry->{'is'} && $ENV{ $entry->{'is'} } ) || $entry->{'content'} || '';
 123     }
 124
 125     %borrower = AddMember_Auto( %borrower );
 126     C4::Members::Messaging::SetMessagingPreferencesFromDefaults( { borrowernumber => $borrower{'borrowernumber'}, categorycode => $borrower{'categorycode'} } );
 127
 128     return ( 1, $borrower{'cardnumber'}, $borrower{'userid'} );
 129 }
 130
 131 sub _get_uri {
 132
 133     my $protocol = "https://";
 134
 135     my $uri = C4::Context->preference('OPACBaseURL') // '';
 136     if ($uri eq '') {
 137         $debug and warn 'OPACBaseURL not set!';
 138     }
 139     if ($uri =~ /(.*):\/\/(.*)/) {
 140         my $oldprotocol = $1;
 141         if ($oldprotocol ne 'https') {
 142             $debug
 143                 and warn
 144                   'Shibboleth requires OPACBaseURL to use the https protocol!';
 145         }
 146         $uri = $2;
 147     }
 148
 149     my $return = $protocol . $uri;
 150     return $return;
 151 }
 152
 153 sub _get_shib_config {
 154     my $config = C4::Context->config('shibboleth');
 155
 156     if ( !$config ) {
 157         carp 'shibboleth config not defined';
 158         return 0;
 159     }
 160
 161     if ( $config->{matchpoint}
 162         && defined( $config->{mapping}->{ $config->{matchpoint} }->{is} ) )
 163     {
 164         if ($debug) {
 165             warn "koha borrower field to match: " . $config->{matchpoint};
 166             warn "shibboleth attribute to match: "
 167               . $config->{mapping}->{ $config->{matchpoint} }->{is};
 168         }
 169         return $config;
 170     }
 171     else {
 172         if ( !$config->{matchpoint} ) {
 173             carp 'shibboleth matchpoint not defined';
 174         }
 175         else {
 176             carp 'shibboleth matchpoint not mapped';
 177         }
 178         return 0;
 179     }
 180 }
 181
 182 1;
 183 __END__
 184
 185 =head1 NAME
 186
 187 C4::Auth_with_shibboleth
 188
 189 =head1 SYNOPSIS
 190
 191 use C4::Auth_with_shibboleth;
 192
 193 =head1 DESCRIPTION
 194
 195 This module is specific to Shibboleth authentication in koha and relies heavily upon the native shibboleth service provider package in your operating system.
 196
 197 =head1 CONFIGURATION
 198
 199 To use this type of authentication these additional packages are required:
 200
 201 =over
 202
 203 =item *
 204
 205 libapache2-mod-shib2
 206
 207 =item *
 208
 209 libshibsp5:amd64
 210
 211 =item *
 212
 213 shibboleth-sp2-schemas
 214
 215 =back
 216
 217 We let the native shibboleth service provider packages handle all the complexities of shibboleth negotiation for us, and configuring this is beyond the scope of this documentation.
 218
 219 But to sum up, to get shibboleth working in koha, as a minimum you will need to:
 220
 221 =over
 222
 223 =item 1.
 224
 225 Create some metadata for your koha instance (if you're in a single instance setup then the default metadata available at https://youraddress.com/Shibboleth.sso/Metadata should be adequate)
 226
 227 =item 2.
 228
 229 Swap metadata with your Identidy Provider (IdP)
 230
 231 =item 3.
 232
 233 Map their attributes to what you want to see in koha
 234
 235 =item 4.
 236
 237 Tell apache that we wish to allow koha to authenticate via shibboleth.
 238
 239 This is as simple as adding the below to your virtualhost config:
 240
 241  <Location />
 242    AuthType shibboleth
 243    Require shibboleth
 244  </Location>
 245
 246 =item 5.
 247
 248 Configure koha to listen for shibboleth environment variables.
 249
 250 This is as simple as enabling B<useshibboleth> in koha-conf.xml:
 251
 252  <useshibboleth>1</useshibboleth>
 253
 254 =item 6.
 255
 256 Map shibboleth attributes to koha fields, and configure authentication match point in koha-conf.xml.
 257
 258  <shibboleth>
 259    <matchpoint>userid<matchpoint> <!-- koha borrower field to match upon -->
 260    <mapping>
 261      <userid is="eduPersonID"></userid> <!-- koha borrower field to shibboleth attribute mapping -->
 262    </mapping>
 263  </shibboleth>
 264
 265 Note: The minimum you need here is a <matchpoint> block, containing a valid column name from the koha borrowers table, and a <mapping> block containing a relation between the chosen matchpoint and the shibboleth attribute name.
 266
 267 =back
 268
 269 It should be as simple as that; you should now be able to login via shibboleth in the opac.
 270
 271 If you need more help configuring your B<S>ervice B<P>rovider to authenticate against a chosen B<Id>entity B<P>rovider then it might be worth taking a look at the community wiki L<page|http://wiki.koha-community.org/wiki/Shibboleth_Configuration>
 272
 273 =head1 FUNCTIONS
 274
 275 =head2 logout_shib
 276
 277 Sends a logout signal to the native shibboleth service provider and then logs out of koha.  Depending upon the native service provider configuration and identity provider capabilities this may or may not perform a single sign out action.
 278
 279   logout_shib($query);
 280
 281 =head2 login_shib_url
 282
 283 Given a query, this will return a shibboleth login url with return code to page with given given query.
 284
 285   my $shibLoginURL = login_shib_url($query);
 286
 287 =head2 get_login_shib
 288
 289 Returns the shibboleth login attribute should it be found present in the http session
 290
 291   my $shib_login = get_login_shib();
 292
 293 =head2 checkpw_shib
 294
 295 Given a shib_login attribute, this routine checks for a matching local user and if found returns true, their cardnumber and their userid.  If a match is not found, then this returns false.
 296
 297   my ( $retval, $retcard, $retuserid ) = C4::Auth_with_shibboleth::checkpw_shib( $shib_login );
 298
 299 =head2 _autocreate
 300
 301   my ( $retval, $retcard, $retuserid ) = _autocreate( $config, $match );
 302
 303 Given a database handle, a shibboleth attribute reference and a userid this internal routine will add the given user to koha and return their user credentials
 304
 305 This routine is NOT exported
 306
 307 =head1 SEE ALSO
 308
 309 =cut