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::Database;
  25 use Carp;
  26 use CGI;
  27
  28 use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS $debug);
  29
  30 BEGIN {
  31     require Exporter;
  32     $VERSION = 3.03;           # set the version for version checking
  33     $debug   = $ENV{DEBUG};
  34     @ISA     = qw(Exporter);
  35     @EXPORT =
  36       qw(shib_ok logout_shib login_shib_url checkpw_shib get_login_shib);
  37 }
  38
  39 # Check that shib config is not malformed
  40 sub shib_ok {
  41     my $config = _get_shib_config();
  42
  43     if ($config) {
  44         return 1;
  45     }
  46
  47     return 0;
  48 }
  49
  50 # Logout from Shibboleth
  51 sub logout_shib {
  52     my ($query) = @_;
  53     my $uri = _get_uri();
  54     print $query->redirect( $uri . "/Shibboleth.sso/Logout?return=$uri" );
  55 }
  56
  57 # Returns Shibboleth login URL with callback to the requesting URL
  58 sub login_shib_url {
  59     my ($query) = @_;
  60
  61     my $param = _get_uri() . $query->script_name();
  62     if ( $query->query_string() ) {
  63         $param = $param . '%3F' . $query->query_string();
  64     }
  65     my $uri = _get_uri() . "/Shibboleth.sso/Login?target=$param";
  66     return $uri;
  67 }
  68
  69 # Returns shibboleth user login
  70 sub get_login_shib {
  71
  72 # In case of a Shibboleth authentication, we expect a shibboleth user attribute
  73 # to contain the login match point of the shibboleth-authenticated user. This match
  74 # point is configured in koha-conf.xml
  75
  76 # Shibboleth attributes are mapped into http environmement variables, so we're getting
  77 # the match point of the user this way
  78
  79     # Get shibboleth config
  80     my $config = _get_shib_config();
  81
  82     my $matchAttribute = $config->{mapping}->{ $config->{matchpoint} }->{is};
  83     $debug and warn $matchAttribute . " value: " . $ENV{$matchAttribute};
  84
  85     return $ENV{$matchAttribute} || '';
  86 }
  87
  88 # Checks for password correctness
  89 # In our case : does the given attribute match one of our users ?
  90 sub checkpw_shib {
  91     $debug and warn "checkpw_shib";
  92
  93     my ( $match ) = @_;
  94     my $config = _get_shib_config();
  95     $debug and warn "User Shibboleth-authenticated as: $match";
  96
  97     # Does the given shibboleth attribute value ($match) match a valid koha user ?
  98     my $borrower =
  99       Koha::Database->new()->schema()->resultset('Borrower')
 100       ->find( { $config->{matchpoint} => $match } );
 101     if ( defined($borrower) ) {
 102         return ( 1, $borrower->get_column('cardnumber'), $borrower->get_column('userid') );
 103     }
 104
 105     # If we reach this point, the user is not a valid koha user
 106     $debug
 107       and warn
 108       "User with $config->{matchpoint} of $match is not a valid Koha user";
 109     return 0;
 110 }
 111
 112 sub _get_uri {
 113
 114     my $protocol = "https://";
 115
 116     my $return = $protocol . C4::Context->preference('OPACBaseURL');
 117     return $return;
 118 }
 119
 120 sub _get_shib_config {
 121     my $config = C4::Context->config('shibboleth');
 122
 123     if ( !$config ) {
 124         carp 'shibboleth config not defined';
 125         return 0;
 126     }
 127
 128     if ( $config->{matchpoint}
 129         && defined( $config->{mapping}->{ $config->{matchpoint} }->{is} ) )
 130     {
 131         if ($debug) {
 132             warn "koha borrower field to match: " . $config->{matchpoint};
 133             warn "shibboleth attribute to match: "
 134               . $config->{mapping}->{ $config->{matchpoint} }->{is};
 135         }
 136         return $config;
 137     }
 138     else {
 139         if ( !$config->{matchpoint} ) {
 140             carp 'shibboleth matchpoint not defined';
 141         }
 142         else {
 143             carp 'shibboleth matchpoint not mapped';
 144         }
 145         return 0;
 146     }
 147 }
 148
 149 1;
 150 __END__
 151
 152 =head1 NAME
 153
 154 C4::Auth_with_shibboleth
 155
 156 =head1 SYNOPSIS
 157
 158 use C4::Auth_with_shibboleth;
 159
 160 =head1 DESCRIPTION
 161
 162 This module is specific to Shibboleth authentication in koha and relies heavily upon the native shibboleth service provider package in your operating system.
 163
 164 =head1 CONFIGURATION
 165
 166 To use this type of authentication these additional packages are required:
 167
 168 =over
 169
 170 =item *
 171
 172 libapache2-mod-shib2
 173
 174 =item *
 175
 176 libshibsp5:amd64
 177
 178 =item *
 179
 180 shibboleth-sp2-schemas
 181
 182 =back
 183
 184 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.
 185
 186 But to sum up, to get shibboleth working in koha, as a minimum you will need to:
 187
 188 =over
 189
 190 =item 1.
 191
 192 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)
 193
 194 =item 2.
 195
 196 Swap metadata with your Identidy Provider (IdP)
 197
 198 =item 3.
 199
 200 Map their attributes to what you want to see in koha
 201
 202 =item 4.
 203
 204 Tell apache that we wish to allow koha to authenticate via shibboleth.
 205
 206 This is as simple as adding the below to your virtualhost config:
 207
 208  <Location />
 209    AuthType shibboleth
 210    Require shibboleth
 211  </Location>
 212
 213 =item 5.
 214
 215 Configure koha to listen for shibboleth environment variables.
 216
 217 This is as simple as enabling B<useshibboleth> in koha-conf.xml:
 218
 219  <useshibboleth>1</useshibboleth>
 220
 221 =item 6.
 222
 223 Map shibboleth attributes to koha fields, and configure authentication match point in koha-conf.xml.
 224
 225  <shibboleth>
 226    <matchpoint>userid<matchpoint> <!-- koha borrower field to match upon -->
 227    <mapping>
 228      <userid is="eduPersonID"></userid> <!-- koha borrower field to shibboleth attribute mapping -->
 229    </mapping>
 230  </shibboleth>
 231
 232 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.
 233
 234 =back
 235
 236 It should be as simple as that; you should now be able to login via shibboleth in the opac.
 237
 238 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>
 239
 240 =head1 FUNCTIONS
 241
 242 =head2 logout_shib
 243
 244 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.
 245
 246   logout_shib($query);
 247
 248 =head2 login_shib_url
 249
 250 Given a query, this will return a shibboleth login url with return code to page with given given query.
 251
 252   my $shibLoginURL = login_shib_url($query);
 253
 254 =head2 get_login_shib
 255
 256 Returns the shibboleth login attribute should it be found present in the http session
 257
 258   my $shib_login = get_login_shib();
 259
 260 =head2 checkpw_shib
 261
 262 Given a database handle and 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.
 263
 264   my ( $retval, $retcard, $retuserid ) = C4::Auth_with_shibboleth::checkpw_shib( $shib_login );
 265
 266 =head1 SEE ALSO
 267
 268 =cut