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SWITCH WAYF
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Copyright 2010 SWITCH - Serving Swiss Universities
Contact: aai@switch.ch or go to http://www.switch.ch/aai/wayf
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Version: See head of file 'WAYF' in the same directory
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Project web site: https://forge.switch.ch/redmine/projects/wayf
Bug reports/feature requests: https://forge.switch.ch/redmine/projects/wayf/issues
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-------------------------------------------------------------------------------

Description:
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The SWITCHwayf is an implementation of the Shibboleth WAYF and SAML2 Discovery 
Service protocol for use withing a Shibboleth architecture.

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Security Note (25. October 2010):
The current implementation of the Discovery Service protocol as defined in 
http://docs.oasis-open.org/security/saml/Post2.0/sstc-saml-idp-discovery.pdf 
states that the protocol creates opportunities for phishing attacks as do all
SSO protocols that make use of redirection. Therefore, the specification states
that an implementation should examine the 'return' parameter used in a 
Discovery Service request and match it against the <idpdisc:DiscoveryResponse> 
extension in SAML metadata. The implementation of the Discovery Service protocol
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in the SWITCHwayf prior to version 1.14 does NOT verify the return parameter 
even if SAML metadata was used to generate the list of Identity Provider.
Version 1.14 or newer fixes this problem.
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Thanks to Tom Scavo for making us aware of this issue.
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Features:
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Some of the features include

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- Preselecting entry in drop down list by
  - SAML common domain cookie that contains selected Identity Providers 
  - resource path info hint (e.g. 
    /WAYF/unige.ch?shire=https://... selects University  of Geneva, depends 
    of course on the ID scheme a federation uses)
  - Kerberos preselection
  - IP range preselection
  - IP reverse DNS lookup preselection
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- Transparent redirection mode, e.g. /WAYF/unige.ch/redirect?shire=https://...
- Support for SAML2 metadata files
- Various customizations optionas for header, footer, language strings etc.
- HTML code generation for embedding the WAYF directly into a web page
- Support for remembering IdP selection permanently
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- I18N support, currently language packs for en, de, it, fr and pt are included
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- Support for templates
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Requirements:
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- The web server must support PHP5
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- If the configuration and the backup configuration differ, you have to make 
  sure the user that runs the php script has write access for the configuration
  files.

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Installation:

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Unpack the Zip archive into an arbitrary directory on a host that has a deployed
Apache (IIS also should work though). Make sure that permissions for the files 
'SProvider.metadata.php' and 'IDProvider.metadata.php' are set such that the 
web server user (e.g. www-data, www or httpd) has write access on the files:
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If you use Apache 2, add the following statement to the Apache configugration:
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--
<Location /path/to/WAYF>
  SetHandler php5-script
</Location>
--

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In some clustered environments with FastCGI it may be necessary to use something
like

--
Options +FollowSymLinks

<IfModule mod_rewrite.c>
  RewriteEngine On
  RewriteRule ^WAYF/(.*)$ WAYF.php/$1 [QSA,L]
  RewriteRule ^WAYF$ WAYF.php [QSA,L]
</IfModule>
--

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Alternatively, one also could rename the file 'WAYF' to 'WAYF.php'.
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When using the embedded WAYF feature it might be necessary to add a line to 
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the Apache configuration like below in order to prevent certain web browsers 
from not displaying the Embedded WAYF or parts of it:
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--
Header set P3P "CP=\"NOI CUR DEVa OUR IND COM NAV PRE\""
--

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For that to work, the Apache header extension must also be enabled
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with a command like:

--
a2enmod headers
/etc/init.d/apache2 reload
--

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See http://www.w3.org/P3P/ for more details on P3P.
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-------------------------------------------------------------------------------

Update from versions before 1.8:
This version has a slightly different structure than previous versions. 
Therefore, it is recommended to start with a clean installation. 
However, you should be able to take over most of your old config.php 
functions and use them in the new template.php file again to keep your 
customized look and feel.

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-------------------------------------------------------------------------------

Troubleshooting:
Generall, if there is an error or an exception, the WAYF will log the to syslog. 
In case there is a problem and you see only a white page without any output, 
open config.php in a text editor, go to the bottom of the file and set:

$developmentMode = true;

This will output PHP warning messages which are otherwise supressed.

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-------------------------------------------------------------------------------

Customizations:
Since version 1.12 any graphical aspects of this WAYF/DS implementation can be 
customized such that these changes survive an upgrade. In particular, the 
following customizations can be applied:

HTML header:   custom-header.php
Customize page header

HTML Footer:   custom-footer.php
Customize page footer 

HTML Body:     custom-body.php
Customize WAYF/DS body

HTML Body:     custom-settings.php
Customize WAYF/DS permanent settings body

HTML Body:     custom-notice.php
Customize WAYF/DS permanent settings notice body

HTML Body:     custom-embedded-wayf.php
Customize WAYF/DS body

HTML Error:    custom-error.php
Customize error messages

Languages:     custom-languages.php
Can be used to change default or add new language strings. In contrast to the 
above template files, this won't replace the default-languages.php but extend or
modify it.

If the above files don't exist, the default templates and settings 
will be used. To create a custom template, copy of the default files with 
cp default-{$template}.php custom-{$template}.php 
where {$template} stands for the file you want to customize.

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Logging:

The general log where errors are written to is syslog. This log file will 
contain error messages for example in case files cannot be read or written.

If the configuration option $useLogging is true, a log file will be written to 
the path specified in $WAYFLogFile. This log file is an audit log file where 
each line is an entry of the form:

#DATE# #TIME# #IP# #IDP_SELECTION# #REQUEST_TYPE# #IDP_ENTITYID# #FORWARDING_URL#

Log entries are only created if the user was forwarded to an Identity Provider.

#DATE#            Date of request, e.g. 2010-11-02
#TIME#            Time of request, e.g. 06:25:13
#IP#              IP of requester, e.g. 127.0.0.1
#IDP_SELECTION#   How the IdP was selected: Cookie or Request
#REQUEST_TYPE#    Type of request: DS, WAYF, Embedded-DS, Embedded-WAYF
#IDP_ENTITYID#    EntityID of the IdP the user was forwarded to.
#FORWARDING_URL#  URL the user was redirected to

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Optimizations:

If your instance of the SWITCHwayf has many requests and the load is becoming 
higher and higher, you might want to think about using a PHP opcode cacher like 
XCache, apc,  eaccelerator,  phpa,  truck-mmcache or similar.  
Using such a tool can decrease the processing time of the PHP code almost by 
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half. However, internal tests have shown that the bottleneck in general is not 
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the PHP processing but the TLS handshake, which has nothing to do with PHP 
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itself. Benchmark tests conducted by SWITCH demonstrated that generating the 
Javascript WAYF/embedded-wayf.js can be speed up by 100% if the script provided
the script is accessed via HTTP (without TLS). However, if the script is 
accessed via HTTPS (default in SWITCHaai), the overall speed gain by using 
XCache is less than 1% because the TLS hand-shake is what consumes most CPU time.
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SAML2 Metadata support:
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In case you want the WAYF/DS to display the list of IdPs by parsing them from a
SAML2 Medatadata file that is used by Shibboleth

- Set $useSAML2Metadata in config.php to true
- Specify the path to the metadata file that shall be read in $metadataFile
  and make sure this file is updated regularely by Shibboleth or a cron job
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- Make sure the files specified in $metadataIDPFile and $metadataSPFile can be 
  written by the userthat executes the PHP script (the web server user, 
  e.g. www-data or _www)

The parsend IDP and SP entries will be stored in $metadataIDPFile and 
$metadataSPFile as executable PHP code. Storing parsed information in JSON or 
PHP serialized format would allow faster reading and executing in general. 
However, for large numbers of entities an opcode cacher might speed up execution 
time considerably (see chapter "Optimization" above) thanks to this format. 

If you want to change, remove or extend an entry from this automatically 
generated file, you  can extend the IDP definitions by modifying them in 
the $IDPConfigFile. In case you want to overwrite some IDP values with entries in 
the $IDPConfigFile, make sure the entry $SAML2MetaOverLocalConf is set to false;
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For example you could change the displayed name of an IdP by adding an entry in
the file $IDPConfigFile like:

$IDProviders["urn:mace:switch.ch:SWITCHaai:switch.ch"]["Name"] = "Foobar";

You could also manually force the IdP list being upgraded by running the 
readMetadata.php in command line mode, e.g. by executing a cron script like:
5 * * * * /usr/bin/php readMetadata.php > /dev/null

This feature has been initially developed in the framework of GRNET's project 
VNOC by Pavlos Drandakis.

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Embedded WAYF support:
With the embedded WAYF support you as an administrator of an application that is
protected by Shibboleth, can easily integrate a Discovery Service on the home 
page of your application just by copying and adapting the HTML code snippet at 
the bottom of this file.

The embedded WAYF then will display on the remote site a drop-down list with the
same Identity  Providers as if you were on this instance of the WAYF directly.

However, you can also configure the embedded WAYF for your site by hiding or 
adding certain Identity Providers (even from remote federations) or adapt the
look and feel of the embedded wayf. This can be done by simpling modifying the
JavaScript variables in the HTML snippet that can be found at the bottom of 
the page.


Note:
If you operate a WAYF for your federation, you must carefully protect the 
host this WAYF is operated on when you activate this feature. If your WAYF 
host gets compromised, an attacker could modify the JavaScript that is embedded
on the remote site in a malicous wayf (e.g. phish the user's password, redirect
users to malicous pages, steal their sessions etc). You also have to make sure
that your central WAYF has a very high availability because a lot of third-party
services will depend on it.

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Kerberos support:
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Your web server needs to support Negotiate/SPNEGO Kerberos protocol. For 
example by using mod_auth_kerb.
- Make a symlink of the file 'WAYF' and name it like configured in the variable 
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  $kerberosRedirectURL
- Protect file $kerberosRedirectURL with Kerberos. The Kerberos realm must be
  specified in "IDProvider.conf.php" for each IdP. Each IdP's KDC must also
  establish a Kerberos cross-realm trust with the WAYF's KDC. This was tested 
  with a Windows 2000 KDC, with the WAYF running on RHEL4. 

Credits for this feature go to Josh Howlett from Bristol University.

-------------------------------------------------------------------------------

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Configuration file format:
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Checkout the file 'IDProvider.conf.php' for an example of the file format. It's 
supposed to be mostly self-explanatory. Basically the file format is PHP code 
that defines an array of arrays called $IDProviders.

The keys of the array $IDProviders must correspond to the entityIDs of the 
Identity Providers or a unique value in case of a cascaded WAYF/DS or 
a category. The entityID must be a valid URI (URL or URN) where in the
case of a URN the last component must be a valid hostname.

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If metadata is not parsed from SAML2 metadta (using the setting 
$useSAML2Metadata = false), the IdPs and category entries will be displayed 
in order as defined in the configuration file and no sorting is done.

If metadata is used ($useSAML2Metadata = true) to generate the list of Identity 
Providers, the Identity Providers will first be sorted according to their 
type/category, their Index value (see below) and then alphabetically after their 
(local) Name within the same type category. 
If an IdP does not have a type, its category is 'unknown'.
If there exists a type for an IdP that does not have a corresponding category 
it will be displayed in the category 'unknown' at the end of the drop down list 
but will keep its type value (this is important for the Embedded Discovery 
Service).

A general entry for an Identity Provider, a cascaded WAYF/DS or a category is 
of the following form:
$IDProviders[#key#] = #entry#

#key# is a unique value that must correspond to the entity's entityID in case 
the entry stands for an Identity Provider. For entries of Type category, the
#key# should be an identifier that corresponds to a 'Type' of an IdP.

#entry# is another hash array with the following keys: 
['Type']:   Optional        Type that is used for the embedded wayf to hide
                            or show certain categories. Default type will 
                            be 'unknown' if not specified.
                            An entry for another WAYF/DS that the user shall be 
                            redirected to should have ['Type'] ='wayf
                            The Type values 'category' and 'wayf' are reserved 
                            words that are not allowed to be assigned to 
                            entries for Identity Providers.
['Name']:   Mandatory       Default name to display in drop-down list
['en'|'it'|'fr'|'de'|'pt']['Name']:
            Optional        Display name in other languages
['SSO']:    Mandatory       Should be the SAML1 SSO endpoint of the IdP
['Realm']:  Optional        Kerberos Realm
['IP'][]:   Optional        IP ranges of that organizations that can be used to 
                            guess a user's Identity Provider
['Index']:  Optional        An alphanumerical value that is used for sorting 
                            categories and Identity Provider in ascending order 
                            if the Identity Providers are parsed from metadata.
                            This is only relevant if 
                            $includeLocalConfEntries = true

For category entries, only Type, (local) Name and Index are relevant.
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Version History:
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1.14.1 - Corrected behaviour of $enableDSReturnParamCheck and 
         $useACURLsForReturnParamCheck. There won't be an error anymore if an SP 
         has no <idpdisc:DiscoveryResponse> extension defined. In such a case
         there will only be a check if $useACURLsForReturnParamCheck is enabled.
       - Fixed a bug in readMetadata.php that prevented CLI execution
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1.14   - Added the configuration option wayf_force_remember_for_session to
         the Embedded WAYF on request of Wolgang Lierz from ETH Zurich. This
         option allows setting the remember for session checkbox to true
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       - The 'return' parameter of a Discovery Service request can now be 
         checked using the idp-discovery-protocol extension or using the FQDN 
         of all the Service Provider's assertion consumer URLs. The latter 
         alternative is less secure but still offers better security against 
         phising attacks. Have a look at config.dist.php and the README for 
         more detailed explanations on these feature.
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       - Metadata parsing now uses DOM XML for PHP5 instead of Simple XML
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       - Fixed a minor HTML error in template for Embedded WAYF
       - Sorting within categories works now correctly if SAML2 metadata is 
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         used to generate Identity Provider drop-down list. Thanks to 
         Kazutsuna Yamaji from the Japanese National Institute of 
         Informatics (NII) for reporting this issue.
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       - Fixed a minor bug in templates.php that cause PHP warnings to show up
         in case an invalid IdP was stored in the cookie.
       - Fixed a bug affecting the Kerberos authentication.
         Thanks to Robert Basch from MIT for reporting these bugs and for 
         submitting patches.
       - Fixed a bug where hidden IdPs would still be shown in Embedded WAYF
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1.13   - Added Favourite IdPs to Embedded WAYF
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       - Fixed a bug where the state of the "Remember for session" checkbox was
         not remembered.
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1.12.2 - Fixed a XSS security vulnerability
       - Fixed an error in function appendValueToIdPArray
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         Thanks to Martins Purins from Latvijas Universitates for reporting this
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       - Improved description for setting PHP handler on WAYF script. 
       - Removed newly introduced PHP short tag in default-body.php
       - Fixed inconsistency in default Embedded WAYF snippet
         Thanks to Huân Thebault from Centre de Calcul de l'IN2P3 for 
         reporting most of the above issues
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1.12.1 - Fixed a bug in the the getToplevelDomain function. 
         Thanks to Olivier Salaün. 
1.12   - Added code contributions from CRU. Thanks to Olivier Salaün and co.
       - Added hooks for persistent customizations that should survive upgrades
       - Fixed a bug where the last used SP's entityID is not stored for DS 
         requests
       - Changed behaviour for WAYF requests to store providerId/entityID
         in _saml_sp cookie instead of assertion consumer URL
       - Optimized JavaScript code
1.11.1 - Fixed a Javascript HTML entities issue
1.11   - Replaced deprecated PHP 4/5 functions with current ones
       - Reworked JSON handler in order to output a harmonized data structure
         that will be compatible with the Internet2 Discovery Service
1.10.1 - Fixed a minor bug that resulted in PHP warnings when using SAML2 
         metadata directly. Added a default type for the IDPs when SAML2
         metadata is used in combination with Embedded WAYF.
         Thanks to Lourival Pereira Vieira Neto from RNP (Brasil) for reporting.
1.10   - Added new settings of embedded wayf to set custom texts and to 
         hide the logo
       - Added feature to force embedded wayf to use a specific language
       - Added JSON, PHP, Text export handler of IdP list and guessed IdP
       - Added cookie deletion handler to clear all settings
       - Most elements drawn by the Embedded WAYF now have a CSS ID to further
         customize their appearance although this should be done only at own risk
       - Added a setting that allows to define a function that checks whether a
         user is logged in or not
       - Changed the wayf_use_small_logo default setting to true because most 
         deployments use this setting
       - Fixed a bug that occurred when additional IdPs were defined and
         some IdPs were hidden.
       - Removed language file setting because this probably was not used anyway
       - Replaced all non ASCII strings in languages.php with their entities
         to prevent problems in Embedded WAYF
       - Rearranged and refactored some code
       
1.9.5  - Added explicit script name for form action parameter to fix issues with
         some test and monitoring web utilities
1.9.5  - Added category support for the embedded WAYF
       - The embedded WAYF submit button now is an input element instead of an
         image surrounded by a button element. This has the advantage that the
         CSS rules of the embedding page are also applied to the embedded WAYF.
       - Made sure that there are no JS escaping errors anymore
       - Fixed a bug in readMetadata.php that resulted in the wront SSOService 
         URLs being parsed if they were in a certain order. Thanks to 
         Olivier Salaun from CRU for reporting this bug.
 
1.9    - Added three more settings to the embedded WAYF configuration
       - Fixed some JavaScript warnings
       - Fixed some minor bugs in the embedded WAYF
       - Changed button in embedded WAYF to submit input button
       - Added category support
       - readMetadata is now more tolerant and flexible when reading SAML 2 metadata
       - Embedded WAYF now stores cookie itself if IdP from other 
         federation is used
 
1.8    - SAML2 metadata can now be read and displayed
         This feature has been developed in the framework of GRNET's project 
         VNOC by Pavlos Drandakis from University of Athens
       - WAYF/DS can be embedded on remote site using JavaScript
       - There now is a setting to hide the permanent setting checkbox
       - Added logging support for statistics generation
       - Changed character encoding to UTF-8
       - Added Portuegese language translation provided by 
         Nuno Gonçalves from FCCN
       - Cascading of other WAYFs is now possible when Type is set accordingly
 
1.7.2  - Fixed a small JavaScript Bug reportet by Franz Kuster from ETHZ
 
1.7.1  - Added back-wards patch mode for older WAYF version that didn't use 
         transparent GET arguments in all requests
       - Removed RelyingParty configuration option because it is not needed in general
       - Changed Home Organization to Home Organisation and corrected various typos
       - Added support for multilingual IdP names. 
         Thanks go to Pavlos Drandakis from University of Athens 
 
1.7    - Added part of the OASIS Directory Service protocol for SAML2/Shibboleth 2.
         For now, the Service Provider must set the return parameters because 
         metadata lookup is not implemented. Also, the optional policy 
         paramenter currently is ignored. These two limitations shouldn't 
         affect the behaviour negatively for Shibboleth  -based environments.
       - Fixed some typos in the language strings and some HTML code
 
1.6    - Added Reverse  -DNS Lookup to find out users IdP. It is assumed that the
         reverse DNS lookup hostname is part of the IdPs URN values.
       - Running several instance of the WAYF in the same domain
         In this case, you should set the $cookiePrefix variable so that your 
         differents instances do not share the same cookies. Patch by Florent Guilleux
         from CRU
       - Redirect path info together with a resource hint also sets the 
         redirect cookie now
 
1.5.2  - More French corrections by Nicolas Dunand from Uni Lausanne 
 
1.5.1  - Added French language corrections by Florent Guilleux from CRU
       - Made code more resistent against PHP configuration issues
       - Fixed a small typo in the english translation found by Michael R. Gettes 
         from Internet2
       - Adapted SWITCH tagline in License and README
       - Removed SwissSign certificate notice
 
1.5    - State of checkbox to remember session is now stored in a cookie too
       - Determination of user language now has a more reasonable precedence
 
1.4    - Added IP preselection hint by Mika Suvanto CSC (Finland)
 
1.3.1  - Corrected two minor inconsistencies
       - Deactivated Kerberos in default configuration
 
1.3    - Configuration is now in a separate file
       - Kerberos automatic redirection by Josh Howlett from University of Bristol
       - Some structural code changes
       - checkConfig now doesn't need shell access anymore
       - GET parameters received by WAYF are now unchanged appended to each request 
       - Easier customization options
1.2    - Added permanent redirect cookie
       - Cleaned up the code a bit.
 
1.1    - Added (BSD) license
       - Removed and optimized some code
     

-------------------------------------------------------------------------------
Embedded WAYF code snippet:
To get a valid HTML snippet to embedd in a web page, please access your WAYF 
with a URL like:

https://#HOSTNAME#/#PATH_TO_WAYF#/WAYF/embedded-wayf.js/snippet.html

The script then should return some HTML code that can be embedded together
with short descriptions of the available settings.

Embedded WAYF code limitations:
If the embedded WAYF is placed on the right side or at the bottom of a web page,
it may be that the web browser cannot expand and render the complete drop-down
list of Identity Providers.

-------------------------------------------------------------------------------
Path Info parameters and files:
Modifying the WAYF's URL it is possible to influence its behaviour. This can be
done by appending certain Path Info extension to the URL. The Path Info 
components can also be combined. The allowed syntax is:

[/#i18n string#][/redirect][/#entityID hostname#]
[/#i18n string#][/embedded-wayf.js]
[/embedded-wayf.js/snippet.html]
[/IDProviders.json]
[/IDProviders.php]
[/IDProviders.txt]

Note: Your web server must support the use of Path Info.

Hinted Identity Provider and transparent redirects
--------------------------------------------------
Path Info Extensions: [/redirect][/#entityID hostname#]

#entityID hostname# must be the host name of an entityId or the last component 
of a URN. Examples:
https://aai-login.switch.ch/idp/shibboleth         -> aai-login.switch.ch
urn:mace:switch.ch:aaitest:aai-demo-idp.switch.ch  -> aai-demo-idp.switch.ch

If the '/redirect' is included in the Path Info as well, the web browser is 
redirected transparently to the specified entityID hostname.

Note: One must make sure that the entityID hostname is not the same as one of
      the reserved keywords like 'redirect', the below mentioned file types
      or a i18n langauge abbreviation.

Language preselection:
----------------------
Path Info Extensions: [/#i18n string#]

Examples of i18n strings are 'en', 'de_CH' or 'fr_CH.ISO8859-1' etc. However, in
the default distribution only 'en', 'de', 'fr', 'it' and 'pt' are available and 
supported. But it would be easy to create sub types of existing languages  for
country/region support by adding something like this to languages.php:

--
// Create a country specific copy of the German language strings
$langStrings['de_CH'] = $langStrings['de'];

// Overwrite a specific string
$langStrings['de_CH']['title'] = 'Auswahl der Heimorganisation';
--


Special handlers:
-----------------
In order for the Embedded WAYF feature to work there are some special files that
need to be generated. The following Path Info Extensions must be the last 
components of the Path Info URL.

Path Info Extensions:
[/deleteSettings]                  As the name suggests, this handler deletes
                                   all settings cookies that were stored by the 
                                   WAYF service in cookies.
                                   Unless there is a 'return' GET argument 
                                   provided the user is sent to the settings 
                                   page.
[/embedded-wayf.js]                Generates the JavaScript for the Embedded WAYF
[/embedded-wayf.js/snippet.html]   Generates HTML snippet for the Embedded WAYF
[/idps-and-state.json]             Returns JSON data structure that contains
                                   the content of the IDProviders array. The last
                                   element of that array will be a key called 
                                   'preselectedIDP', which contains the 
                                   Identity Provider that would be preselected
                                   in the drop-down list for that user.
[/IDProviders.txt]                 Same as above but in human readable form.
[/IDProviders.php]                 Same as above but as PHP code