Copyright 2012 SWITCH - Serving Swiss Universities. See LICENSE file for details. ------------------------------------------------------------------------------- SWITCHwayf Contact: aai@switch.ch or go to http://www.switch.ch/aai/wayf Version: See head of file 'WAYF' in the same directory Project web site: https://forge.switch.ch/redmine/projects/wayf Bug reports/feature requests: https://forge.switch.ch/redmine/projects/wayf/issues ------------------------------------------------------------------------------- Description: The SWITCHwayf is an implementation of the Shibboleth WAYF and SAML2 Discovery Service protocol for use withing a Shibboleth architecture. Some of the Features: - 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 - Transparent redirection mode, e.g. /WAYF/unige.ch/redirect?shire=https://... - Can read SAML2 metadata files - Supports Discovery Service and the Shibboleth authentication request protocol - Various customizations options for header, footer, language strings etc. - HTML code generation for embedding the WAYF directly into a web page - Support for templates - Support for remembering IdP selection permanently - I18N support, currently language packs for en, de, it, fr and pt are included ------------------------------------------------------------------------------- Customization Options: Since version 1.12 any graphical aspects of this WAYF/DS implementation can be customized such that these changes survive a minor version upgrade. Files whose names start with 'default-' can be copied and renamed to start with 'custom-' in order to customize the file's behaviour. 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 CSS Styles: css/custom-styles.css Customize CSS styles that are printed inline in header. The custom styles are loaded in addition to the default styles. Therefore, they can be used to overwrite the default CSS styles. Languages: custom-languages.php Can be used to change default or add new language strings. The custom languages strings in addition to the default styles. Therefore, they can be used to overwrite the default CSS styles. 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. ------------------------------------------------------------------------------- Logging: Errors are generally written to syslog. Error messages might be cases where files cannot be read or written due to permission problems. 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 ------------------------------------------------------------------------------- Optimizations: If your instance of the SWITCHwayf has to deal with 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 half. However, own tests have shown that the bottleneck in general is not the PHP processing but the TLS handshake, which has nothing to do with PHP or the SWITCHwayf itself. Benchmark tests conducted by SWITCH demonstrated that generating the Javascript WAYF/embedded-wayf.js can be speed up usign XCache by 100% if 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. ------------------------------------------------------------------------------- SAML2 Metadata support: In case the WAYF/DS shall 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 - 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 slightly 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 an entry shall be changed, removed or extended in this automatically generated file, one can extend the IDP definitions by modifying them in the $IDPConfigFile. To overwrite IDP values with entries in the $IDPConfigFile, make sure the entry $SAML2MetaOverLocalConf is set to 'false'; For example one could change the displayed name of an IdP by adding an entry in the file $IDPConfigFile like: $IDProviders["https://sso.example.org/idp/shibboleth"]["Name"] = "Foobar"; It is also possible to 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. ------------------------------------------------------------------------------- Embedded WAYF support: With the embedded WAYF support administrators of a Shibboleth protected application can easily integrate a Discovery Service on the any page of their application just by copying and adapting the HTML code snippet generated by the SWITCHwayf via the URL /WAYF/embedded-wayf.js/snippet.html The embedded WAYF then will display on the remote site a drop-down list with the Identity Provider to authenticate. One can also configure the embedded WAYF to hide or add 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. Note: When activating the Embedded WAYF, carefully protect the host where the WAYF is operated on. 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. Also, please be aware that using the Embedded WAYF allows anybody to guess a user's Home Organisation without much effort. This information then could be used for phising attacks for example! ------------------------------------------------------------------------------- Embedded WAYF code snippet: To get a valid HTML snippet to embedd in a web page, please access the WAYF with a URL like: https://#HOSTNAME#/#PATH_TO_WAYF#/WAYF/embedded-wayf.js/snippet.html The script should return 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. If placed on a host where no Service Provider is installed, the Embedded WAYF might not be able to detect wheter a user is logged in or not. Also, the wayf_use_disco_feed might not be used. ------------------------------------------------------------------------------- Kerberos support: If this features shall be used the 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 $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. ------------------------------------------------------------------------------- Configuration file format: Have a look at the file 'IDProvider.conf.php' for an example of the file format that is used to configure the list of Identity Provider to display. 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. 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 a 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'|...] Language dependent: ['Name']: Optional Display name ['Keywords']: Optional Keywords associated with the Identity Provider. Used for search-as-you-type feature of improved drop-down list. Space delimited. ['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. The format for the file $metadataSPFile looks very similar: A general entry for an Identity Provider, a cascaded WAYF/DS or a category is of the following form: $metadataSProviders[#key#] = #entry# #key# is a unique value that must correspond to the Service Provider's entityID. #entry# is a hash array with the following keys: ['Name']: Mandatory Default name to display in drop-down list. By default the MDUI:DisplayName, the ServiceName or the entityID is used. If there is a display name available in the WAYF's default language that one will be used. Otherwise English or the only available DisplayName is used. ['en'|'it'|'fr'|'de'|'pt']['Name']: Optional Display name in other languages ['DSURL']: Optional List of DiscoveryService endpoints of the SP. ['ACURL']: Mandatory List of Assertion Consumer endpoints of the SP. ['Protocols']: Mandatory Protocols supported by the SP, e.g. : urn:oasis:names:tc:SAML:2.0:protocol urn:oasis:names:tc:SAML:1.1:protocol ------------------------------------------------------------------------------- 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: The 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