Shibboleth Origin Deployment Guide

Shibboleth Origin Deployment Guide
draft-internet2-mace-shibboleth-shib-origin-deploy-26.html
Nate Klingenstein
8 March, 2003
Comments should be directed to ndk@internet2.edu.

This version of the deploy guide is for Shibboleth v0.8. Unfortunately, in order to progress with the full implementation of the Shibboleth specification, Shibboleth v0.8 DOES NOT interoperate with v0.7. Every effort has been made to include any and all changes which will break future interoperability into this release. For documentation related to Shibboleth v0.7, consult the head of that branch in the Shibboleth CVS.

Shibboleth v0.8 has some limitations and lacks certain security provisions which will be present in the final version. It is strongly advised that this version not be used to protect any sensitive data. Some sections of the deploy guide have not yet been populated with text. This document describes additional functionality which will be present in the final version, but which is not implemented in the v0.8, including but not limited to:

Functionality which has been added since the previous version (v0.7) includes:

Before starting, please sign up for all applicable mailing lists. Announcements pertinent to Shibboleth deployments and developments and resources for deployment assistance can be found here.

Please send any questions, concerns, or eventual confusion to mace-shib-users@internet2.edu. This should include, but not be limited to, questions about the documentation, undocumented problems, installation or operational issues, and anything else that arises. Please ensure that you have the appropriate .tarball for your operating system. Thank you for your help in testing Shibboleth.





Shibboleth Origin -- Table of Contents


  1. Shibboleth Overview

    1. Origin
    2. Target
    3. WAYF
    4. Clubs
  2. Planning

    1. Requirements
    2. Join a Club
    3. Security Considerations
    4. Server Certs
    5. Attribute Release Policies
    6. Designate Contacts
    7. Browser Requirements
    8. Clocks
    9. Other Considerations
  3. Installation

    1. Software Requirements
    2. Deploy HS and AA
  4. Getting Running

    1. Basic Configuration
    2. Key Generation and Certificate Installation
      1. Sharing certificate/key pairs between Apache and Java keystores (optional)
    3. Linking the Authentication System to the HS
      1. Enabling client certificate authentication (optional)
    4. Deploying AA plug-ins for attributes(Java API)
    5. Establishing default ARP's for the origin community
  5. Advanced Configuration

    1. ARP Overview
      1. ARP Processing
      2. ARP Syntax
  6. Troubleshooting

    1. Basic Testing
    2. Logging
    3. Common Problems



License Information


Before proceeding with any installation of, implementation of, or any other use of Shibboleth or its code, read and agree to the usage terms put forth in the LICENSE file included in the tarballs. Note that Shibboleth is based on the Security Assertion Markup Language (SAML), a proposed standard in the OASIS organization. There are intellectual property claims on SAML technology that are published on the OASIS site. Shibboleth deployers are encouraged to evaluate these claims and respond to them as they see fit.




1. Shibboleth Overview

Shibboleth is a system designed to exchange attributes across realms for the primary purpose of authorization. It provides a secure framework for one organization to transmit attributes about a web-browsing individual across security domains to another institution. In the primary usage case, when a user attempts to access a resource at a remote domain, the user's own home security domain can send certain information about that user to the target site in a trusted exchange. These attributes can then be used by the resource to help determine whether to grant the user access to the resource. The user may have the ability to decide whether to release specific attributes to certain sites by specifying personal Attribute Release Policies (ARP's), effectively preserving privacy while still granting access based on trusted information.

When a user first tries to access a resource protected by Shibboleth, they are redirected to a service which asks the user to specify the organization from which they want to authenticate. If the user has not yet locally authenticated to a WebISO service, the user will then be redirected to their home institution's authentication system. After the user authenticates, the Shibboleth components at the local institution will generate a temporary reference to the user, known as a handle, for the individual and send this to the target site. The target site can then use the handle to ask for attributes about this individual. Based on these attributes, the target can decide whether or not to grant access to the resource. The user may then be allowed to access the requested materials.

There are several controls on privacy in Shibboleth, and mechanisms are provided to allow users to determine exactly which information about them is released. A user's actual identity isn't necessary for many access control decisions, so privacy often is needlessly compromised. Instead, the resource often utilizes other attributes such as faculty member or member of a certain class. While these are commonly determined using the identity of the user, Shibboleth provides a way to mutually refer to the same principal without revealing that principal's identity. Because the user is initially known to the target site only by a randomly generated temporary handle, if sufficient, the target site might know no more about the user than that the user is a member of the origin organization. This handle should never be used to decide whether or not to grant access, and is intended only as a temporary reference for requesting attributes.

1.a. Origin

There are four primary components to the origin side in Shibboleth: the Attribute Authority (AA), the Handle Service (HS), the directory service, and the local sign-on system (SSO). The AA and HS are provided with Shibboleth, and an open-source WebISO solution Pubcookie can be obtained from www.pubcookie.org; the directory is provided by the origin site. Shibboleth is able to interface with a directory exporting an LDAP interface containing user attributes, and is designed such that programming interfaces to other repositories should be readily implemented. Shibboleth relies on standard web server mechanisms to trigger local authentication. A .htaccess file can be easily used to trigger either the local WebISO system or the web server's own Basic Auth mechanism, which will likely utilize an enterprise authentication system, such as Kerberos.

From the origin site's point of view, the first contact will be the redirection of a user to the handle service, which will then consult the SSO system to determine whether the user has already been authenticated. If not, then the browser user will be asked to authenticate, and then sent back to the target URL with a handle bundled in an attribute assertion. Next, a request from the Shibboleth Attribute Requester (SHAR) will arrive at the AA which will include the previously mentioned handle. The AA then consults the ARP's for the directory entry corresponding to the handle, queries the directory for these attributes, and releases to the SHAR all attributes the SHAR is entitled to know about that user.

1.b. Target

There are three primary components to the target side in Shibboleth: the Shibboleth Indexical Reference Establisher (SHIRE), the Shibboleth Attribute Requester (SHAR), and the resource manager (RM). An implementation of each of these is included in the standard Shibboleth distribution. These components are intended to run on the same web server.

From the target's point of view, a browser will hit the RM with a request for a Shibboleth-protected resource. The RM then allows the SHIRE to step in, which will use the WAYF to acquire the name of a handle service to ask about the user. The handle service (HS) will then reply with a SAML authentication assertion containing a handle, which the SHIRE then hands off to the SHAR. The SHAR uses the handle and the supplied address of the corresponding attribute authority (AA) to request all attributes it is allowed to know about the handle. The SHAR performs some basic validation and analysis based on attribute acceptance policies (AAP's). These attributes are then handed off to the RM, which is responsible for using these attributes to decide whether to grant access.

1.c. Where are you from? (WAYF)

The WAYF service can be either outsourced and operated by a club or deployed as part of the SHIRE. It is responsible for allowing a user to associate themself with an institution of their specification, then redirecting the user to the known address for the handle service of that institution.

1.d. Clubs

A Shibboleth club provides part of the underlying trust required for function of the Shibboleth architecture. A club is a group of organizations(universities, corporations, content providers, etc.) who agree to exchange attributes using the SAML/Shibboleth protocols and abide by a common set of policies and practices. In so doing, they must implicitly or explicitly agree to a common set of guidelines. Joining a club is not explicitly necessary for operation of Shibboleth, but it dramatically expands the number of targets and origins that can interact without defining bilateral agreements between all these parties.

A club can be created in a variety of formats and trust models, but must provide a certain set of services to club members. It needs to supply a registry to process applications to the club and distribute membership information to the origin and target sites. This must include distribution of the PKI components necessary for trust between origins and targets. There also needs to be a set of agreements and best practices defined by the club governing the exchange, use, and population of attributes before and after transit, and there should be a way to find information on local authentication and authorization practices for club members.






2. Planning

There are several essential elements that must be present in the environment to ensure Shibboleth functions well, both political and technical. Shibboleth is entirely written in Java on the origin side. These are the recommendations and requirements for a successful implementation of a Shibboleth origin.

2.a. Requirements

2.b. Join a Club

While it is not necessary for a target or origin to join a club, doing so greatly facilitates the implementation of multilateral trust relationships. Each club will have a different application process.

To join InCommon for the v0.8 test period, please submit a basic application to shib-support@internet2.edu containing the following information:

To interoperate with other sites in InCommon, the HS will need to have a private key and associated certificate generated. When generating the certificate, the subject field will contain a CN attribute. Often, this will be the hostname of your Handle Service, particularly if the same key-pair and certificate will be used for SSL as well. While any name may be assigned that is acceptible to the signer of your certificate, using the hostname is strongly encouraged.

If, for some reason, the HS's URL is not yet known, but its hostname and CN have been determined, the URL may be supplied later. In the meantime, the WAYF will be unable to direct users to that HS, but any assertions from the site will still be accepted by club SHIRE's.

When the site is accepted into the Club, its information is added to the sites file used by the WAYF and target sites.

For more information on Clubs, refer to 1.d or the Shibboleth v1.0 architectural document.

2.c. Security Considerations

Shibboleth's protocols and software have been extensively engineered to provide protection against many attacks. However, the most secure protocol can be compromised if it is placed in an insecure environment. To ensure Shibboleth is as secure as possible, there are several recommended security precautions which should be in place at local sites.

  1. SSL use is optional for origin sites. Club guidelines should be considered when determining whether to implement SSL, and, in general, SSL should be used for interactions with client machines to provide the necessary authentication and encryption to ensure protection from man-in-the-middle attacks. It is strongly suggested that all password traffic or similarly sensitive data should be SSL-protected. Assessment of the risk tradeoff against possible performance degradation should be performed for all applications.

  2. Many other attacks can be made on the several redirection steps that Shibboleth takes to complete attribute transfer. The best protection against this is safeguarding the WAYF service and ensuring that rogue targets and origins are not used, generally by development of the trust model underneath Shibboleth. Shibboleth also leverages DNS for security, which is not uncommon, but attacks concerning bad domain information should be considered.

  3. Information regarding origin users is generally provided by the authoritative enterprise directory, and the acceptance of requests from target applications can be carefully restricted to ensure that all requests the SHAR performs are authorized and all information the origin provides is accurate. Proper security measures should also be in place on directory access and population(see Access Control in the LDAP recipe for more information). Use of plaintext passwords is strongly advised against.

  4. Server platforms should be properly secured, commensurate with the level that would be expected for a campus' other security services, and cookie stores on client machines should be well protected.

2.d. Server Certs

In the Shibboleth architecture, the SHIRE, SHAR, HS, and AA must all have various client and/or server certificates for use in signing assertions and creating SSL channels. These should be issued by a commonly accepted CA, which may be stipulated by some Club rules. For the Shibboleth v0.8 testing, the following root CA's will be recognized by InCommon:

* The certificates issued by these CA's will expire fairly quickly and should only be used for testing.

OSU will also provide a test CA to be used during Shibboleth development. Thawte presently issues certificates with extKeyUsage restrictions that make them incompatible with Shibboleth.

2.e. Attribute Release Policies

The Attribute Authority maintains a set of policies called Attribute Release Policies (or ARP's) that govern the sharing of user attributes with Shibboleth target sites. When a user attempts to access a Shibboleth-protected resource, that resource's SHAR queries the user's AA for all attributes to which it is entitled. The SHAR provides its own name and the URL of the resource on behalf of which it is making the request. The AA finds the attributes associated with the browser user, determines an "Effective ARP" for this user, and then sends to the SHAR only the attributes/values allowed in this policy.

An ARP may be thought of as a sort of filter for outbound attributes; it cannot create attributes or data that aren't originally present, but it can limit the attributes released and the values those attributes may have when released. It does not change the information in the data sources in any way.

Each ARP is comprised of one or more rules that specify which attributes and values may be released to a target or set of targets. The assignment of rules to various targets is quite flexible and includes mechanisms for specifying: that a rule should affect all targets (default rule), exact SHAR names for which a rule is applicable, regular expressions against which SHAR names should be matched to determine if a rule is applicable, URL trees for which a rule is applicable.

For each request, an Effective ARP is determined by locating all ARP's applicable to the designated user and extracting each rule that matches the querying SHAR and resource. Attributes and values that are specified for release are included in the effective ARP, while those specified for denial are blocked from release. See section 5.a.i for details on how ARP's are processed.

Various ARP's may be combined in forming the Effective ARP. For instance, the Site ARP is administratively maintained and applies to all users for which the AA is answerable. User ARP's apply to a specific user only, and can be maintained either administratively or by the users themselves. All ARP's are specified using the same syntax and semantics.

2.f. Designate Contacts

Since Shibboleth deals both with daily technical and operational issues and also with contractual issues, a set of contacts should be set up to support the user base and to facilitate interactions with other Shibboleth sites and club members. It is recommended that at least technical and administrative contacts be designated.

2.g. Browser Requirements

A primary Shibboleth design consideration was to require very little or no modification to client machines. The only requirement is that a browser is used which supports cookies, redirection and SSL. Browser users will have to perform an additional click to submit the authentication assertion if JavaScript is not functional.

2.h. Clocks

NTP should be run on all web servers. Shibboleth employs a short handle issuance time to protect against replay attacks. Because of this, any significant degree of clock skew can hinder the ability of users to access sites successfully.

2.i. Other Considerations

Especially for higher education, there are a handful of laws enacted which may have important ramifications on the disclosure of personal information and attributes. Since Shibboleth does not necessarily need to transmit identity, it is an ideal solution for many higher education situations. Nevertheless, all parties within the United States of America are strongly advised to consult the Family Educational Rights and Privacy Act of 1974(FERPA), and all other relevant state and federal legislation before deploying Shibboleth.





3. Installation

3.a. Software Requirements

The following requirements are primarily recommendations based on the most common ways to run Shibboleth. However, the origin should be able to run under any servlet container supporting Servlet API v2.3 and JSP specification 1.2.

3.b. Deploy HS and AA

  1. Ensure you have already obtained the proper .tarball.

  2. The archive will expand into a shibboleth-origin-0.8/ directory(/usr/local/ recommended).

  3. Run the following command to move the Java files into Tomcat's tree:

    cp /usr/local/shibboleth-origin-0.8/dist/shibboleth.war /usr/local/tomcat/webapps/
  4. Restart Tomcat, which will automatically detect that there has been a new .war file added. This file will by default be expanded into /usr/local/tomcat/webapps/shibboleth.

  5. Apache must be told to map the URL's for the Shibboleth HS and AA to Tomcat. Two popular ways of doing this are to include the following text directly in httpd.conf, or to place Include conf/mod_jk.conf in httpd.conf, and place the following lines in /etc/httpd/conf/mod_jk.conf:

    --------- begin ---------
    <IfModule !mod_jk.c>
     LoadModule jk_module libexec/mod_jk.so
    </IfModule>

    JkWorkersFile "/usr/local/tomcat/conf/jk/workers.properties"
    JkLogFile "/usr/local/apache/logs/mod_jk.log"

    JkLogLevel emerg

    JkMount /shibboleth/* ajp13

    --------- end ---------
  6. Tomcat's /conf/server.xml ships by default with the Coyote/JK2 connector enabled, which fails with Shibboleth due to the lack of support for REMOTE_USER. This connector must be commented out. Then, uncomment and modify the traditional AJP 1.3 connector as follows:

    1. Add address="127.0.0.1" inside the <Ajp13Connector> configuration element to prevent off-host access.

    2. Add tomcatAuthentication="false" to the <Ajp13Connector> configuration element to ensure that the user's identity is passed from Apache to the servlet environment.




4. Getting Running

4.a. Basic Configuration

The main configuration file for Shibboleth's origin side is located in /webapps/shibboleth/WEB-INF/classes/conf/origin.properties. properties. This file contains configuration information for the origin side in several sections. The configuration must be consistent with values elsewhere in the deployment, such as the HS' certificate and with directory access bindings, etc., or access errors may occur.

All pathnames are relative, and have an effective root path of $TOMCAT_HOME/webapps/shibboleth/WEB-INF/classes/. To specify files outside of the webapp, specify a full URI, such as file:///usr/local/shibboleth/.

Fields that are purple are optional; grey fields are mandatory.

These are the variables that may be specified for each component of origin.properties:


General Configuration:

edu.internet2.middleware.shibboleth.hs.HandleServlet.issuer = <domain name>

Specifies the DNS name the HS should use for itself in issuing assertions.

edu.internet2.middleware.shibboleth.hs.HandleServlet.authenticationDomain = <domain>

Specifies the domain in which the HS is located, e.g. internet2.edu. Used to populate the Subject NameQualifier in issued attribute assertions.

edu.internet2.middleware.shibboleth.hs.HandleServlet.AAUrl = <url>

Specifies the URL at which the HS' corresponding AA may be contacted.

edu.internet2.middleware.shibboleth.hs.HandleServlet.keyStorePath = <pathname>

Specifies the location of the Java keystore containing the x.509 certificate and matching private key to be used by the HS.

edu.internet2.middleware.shibboleth.hs.HandleServlet.keyStorePassword = <password>

Specifies the password to the referenced keystore.

edu.internet2.middleware.shibboleth.hs.HandleServlet.keyStoreKeyAlias = <alias>

Specifies the alias used for accessing the private key.

edu.internet2.middleware.shibboleth.hs.HandleServlet.keyStoreKeyPassword = <password>

Specifies the password used to retrieve the private key.

edu.internet2.middleware.shibboleth.hs.HandleServlet.certAlias = <alias>

Specifies the alias for the certificate corresponding to the private key used by the HS. Defaults to the private key's alias.


General AA Configuration:

edu.internet2.middleware.shibboleth.aa.AAServlet.authorityName = <domain name>

Specifies the name of the AA, which is typically the domain name of the server running it.

java.naming.factory.initial = <string>

Specifies the JNDI Context implementation used to retrieve a principal's attributes. If unspecified, defaults to com.sun.jndi.ldap.LdapCtxFactory, a Context for querying an LDAP directory that is included in the Sun JNDI provider.

An echo setting is provided for testing by specifying the parameter edu.internet2.middleware.shibboleth.aaLocal. EchoCtxFactory which will automatically return eduPersonAffiliation=member and eduPersonPrincipalName populated with the name of the principal that is referenced in the query.

LDAP (must be populated if java.naming.factory.initial is com.sun.jndi.ldap.LdapCtxFactory)

java.naming.provider.url = <url>

This is the URL of the LDAP directory used to store attributes, containing the hostname and search base. An example query URL would be ldap://shib2.internet2.edu/ou=People,dc=internet2,dc=edu.

java.naming.security.principal = <DN>

This parameter allows for specification of a DN to be used if you want the HS to BIND to the LDAP server before issuing the query.

java.naming.security.credentials = <password>

This parameter defines the password used for the LDAP BIND.

edu.internet2.middleware.shibboleth.aa.AAServlet.ldapUserDnPhrase = <attribute name>

Specifies the syntax to be used for querying the LDAP directory for an object from which to acquire attribute values. Two separate cases are supported:

  1. The principal name that was used to authenticate the user is contained in the DN of the user's object.

    The name of the attribute used in the principal's RDN should be specified, followed by =, e.g. uid=.
  2. The principal name that was used to authenticate the user is contained in an attribute of the user's object other than the DN.

    The name of the attribute should be specified, followed by =%s, e.g. uuid=%s.

ARP Configuration:

edu.internet2.middleware.shibboleth.aa.arp.ArpRepository.implementation = <string>

References the type of ARP repository implemented. Shibboleth provides a built-in ARP repository specified by edu.internet2.middleware.shibboleth.aa.arp. provider.FileSystemArpRepository.

Note that the set of principals that an ARP applies to is not expressed by the ARP itself, but rather the implementation of the ARP repository. For example, if the ARP repository were implemented in LDAP, the ARP's that apply to a user would be attributes of that user's personal LDAP entry, and the site ARP would be an attribute of an entry representing the site. While not performed by the built-in ARP repository, a repository implementation might also implement group ARP's; for example, in an LDAP directory, the user entry might have some group membership attributes that refer to group entries, and those group entries would have ARP attributes, and all those ARP's would be applicable.

LdapCtxFactory (must be populated if java.naming.factory.initial is com.sun.jndi.ldap.LdapCtxFactory)

edu.internet2.middleware.shibboleth.aa.arp.provider.FileSystemArpRepository.Path = <pathname>

Specifies the path to the directory from which the engine should acquire ARP's.

edu.internet2.middleware.shibboleth.aa.arp.BaseArpRepository.ArpTTL = <milliseconds>

Specifies the number of milliseconds that ARP's should be cached for. Defaults to 0 milliseconds, implying no caching.

Handle Configuration:

edu.internet2.middleware.shibboleth.hs.HandleRepository.implementation = <string>

Specifies the method by which the HS and AA share handles. These are by default passed by memory(which can be specified explicitly using edu.internet2.middleware.shibboleth.hs.provider. MemoryHandleRepository), and may also be passed using symmetric encryption with edu.internet2.middleware.shibboleth.hs.provider.CryptoHandleRepository.

edu.internet2.middleware.shibboleth.hs.provider. MemoryHandleRepository (specify if edu.internet2.middleware.shibboleth.hs.HandleRepository. implementation is MemoryHandleRepository)

edu.internet2.middleware.shibboleth.hs.BaseHandleRepository.handleTTL = <milliseconds>

Specifies the time in milliseconds for which issued handles are valid. Defaults to 1800000, or 30 minutes. The time should be long enough to allow for clock skew and short enough to protect against various attacks. Consult your club guidelines for further advice.

edu.internet2.middleware.shibboleth.hs.provider.CryptoHandleRepository (specify if edu.internet2.middleware.shibboleth.hs.HandleRepository. implementation is CryptoHandleRepository)

In order to use the crypto repository implementation, you must have a DESede secret key in a keystore of type JCEKS. The origin distribution includes a program that will automatically generate such a key. In order to invoke it, run ./ant genSecret, which will create a keystore in $SHIB_HOME/src/conf/handle.jks that includes the key, with an alias of handleKey and a password of shibhs. If ./ant dist is run subsequently, this keystore will be included in the webapp archive that is created.

edu.internet2.middleware.shibboleth.hs.provider.CryptoHandleRepository.keyStorePath = <pathname>

Specifies the path to the keystore containing the key used to encrypt passed principal identifiers.

edu.internet2.middleware.shibboleth.hs.provider.CryptoHandleRepository.keyStorePassword = <password>

Specifies the password for the keystore.

edu.internet2.middleware.shibboleth.hs.provider.CryptoHandleRepository.keyStoreKeyAlias = <password>

Specifies the alias for the appropriate encryption key within the keystore.

edu.internet2.middleware.shibboleth.hs.provider.CryptoHandleRepository.keyStoreKeyPassword = <password>

Specifies the password used to retrieve the key.

edu.internet2.middleware.shibboleth.hs.CryptoHandleRepository.handleTTL = <milliseconds>

Specifies the time in milliseconds for which issued handles are valid. Defaults to 1800000, or 30 minutes. The time should be long enough to allow for clock skew and short enough to protect against various attacks. Consult your club guidelines for further advice.


4.b. Key Generation and Certificate Installation

The SAML messages generated by the HS must be digitally signed. Each HS must be issued a private and public keypair, which is stored in a Java keystore. The current implementation of Shibboleth requires the use of an ordinary file-based keystore. The keytool program is included with the Java development and runtime kits. Access parameters to the keystore will need to be consistent with those specified in origin.properties.

A sample keystore is included in the distribution and can be found in /usr/local/tomcat/webapps/shibboleth/WEB-INF/classes/conf/keystore .jks with a password of shibhs. It is intended to serve as an example and not as a production keystore.

The following commands will generate a new RSA keypair and store it in the keystore.jks file, with a keyentry alias of hs and new passwords of your choosing:

$ cd /usr/local/tomcat/webapps/shibboleth/WEB-INF/classes/conf
$ keytool -storepasswd -keystore keystore.jks -new <newpassword>
$ keytool -genkey -keystore keystore.jks -alias hs -keyalg rsa -keysize 2048

You will be prompted for passwords during key generation as needed, to access the keystore and assign the key itself its own password. You will also be prompted for the distinguished name components to associate with the key. This DN will be placed in a self-signed certificate and will be the name that is associated with your HS by Shibboleth. In particular, the first component you enter for Name will be the Common Name(when keytool asks for first and last name, common name is intended), which in most cases should be the hostname of the HS system. Note that a specific club of sites may dictate what type of key algorithm, key size, or validity period is appropriate. For InCommon, RSA should be used with a minimum keysize of 2048 bits.

Once you have a keypair generated, the self-signed certificate must be replaced with a certificate signed by a CA acceptable to the club you will be joining. Shibboleth is now typically able to climb trust chains to reach an intermediate CA's root CA, and it is no longer necessary for the intermediate to be recognized as a trusted root by InCommon members. Note that the intermediate CA's signing certificate must still be signed by a recognized InCommon root CA.

To generate a certificate signing request for a CA, use the following command:

$ keytool -certreq -keystore keystore.jks -alias hs -file <csr-file>

The contents of <csr-file> can then be sent to a CA for signing. You will receive a signed certificate in return in a file. To install the new certificate into your keystore, use the following command:

$ keytool -import -keystore keystore.jks -alias hs -file <cert-file>

Note that if the signing CA's certificate is not already installed in your keystore as a trusted signer, you may need to download the CA's root certificate and import it into the keystore file under a different alias, using a command similar to the above.

4.b.i. Sharing certificate/key pairs between Apache and Java keystores (optional)

The JDK includes the command line program keytool for managing Java keystores. This utility cannot import or export private key information, making it difficult to use the same private key and certificate for Apache and Java-based applications. The Shibboleth distribution includes extkeytool, a program that can be used in conjunction with keytool to perform these tasks. Select the appropriate step-by-step procedure for your situation from the following guides.

Before running extkeytool, the variable SHIB_HOME must be set to the path to the directory where the Shibboleth tarball was exploded(typically /usr/local/shibboleth-origin-0.8/).

If you have a pre-exiting RSA key/certificate combination in a keystore and you would like to use it with Apache:

  1. Determine the alias of the keystore keyEntry containing the key you would like to use in your Apache setup. Assuming that your keystore is named yourstore, the following command should present a list of the entries in the keystore.

    $ keytool -list -v -keystore yourstore

  2. Assuming that you identified the appropriate alias as youralias and the password for the keystore is yourpass, enter the following command to export the key in Base64-encoded pkcs8 format.

    $ extkeytool -exportkey -keystore yourstore -alias youralias -storepass yourpass -rfc -file yourkey.pkcs8

  3. In order to use this key with Apache, you must convert it to PEM-encoded RSA native format. You have the option of storing the key unencrypted or encrypted:

    1. To use the unencrypted format, enter the following command for the conversion:

      $ openssl pkcs8 -in yourkey.pkcs8 -nocrypt|openssl rsa -out yourkey.key

    2. To use the encrypted format, enter the following command for the conversion:

      $ openssl pkcs8 -in yourkey.pkcs8 -nocrypt|openssl rsa -des3 -out yourkey.enckey

  4. The following command will export the corresponding certificate.

    $ keytool -export -keystore yourstore -alias youralias -rfc -file yourcert

  5. Set the mod_ssl SSLCertificateKeyFile and SSLCertificateFile directives to point to the two files you have just created. Take care to remove any temporary files you created (i.e. yourkey.pkcs8) and set appropriate file permissions, especially if you chose to store the key in an unencrypted format.

If you have a pre-existing RSA key/certificate combination that you use with Apache and would like to import it into a java keystore:

  1. Convert the private key to unencrypted DER-encoded pkcs8 format. Assuming your PEM-encoded key is stored in a file named yourkey.enckey, enter the following command.

    $ openssl pkcs8 -in yourkey.enckey -topk8 -nocrypt -outform DER -out yourkey.der.pkcs8

  2. Create a certificate bundle file. This file should include a series of PEM-encoded X509 certificates representing a complete trust chain, from the root CA certificate to the certificate that matches your private key. If your certificate is stored in a file named mycert and the CA signer certificate is stored in a file named ca.cert, you might enter the following command to create the bundle.

    $ cat mycert ca.cert > cert.bundle

    Note: mod_ssl-enabled Apache installations include a number of commonly recognized CA certificates in the ca-bundle.crt file under the $ServerRoot/conf/ssl.crt/ directory.
  3. Import the key and certificate into the keystore. Assuming you have already created a keystore named yourstore with a password of of yourpass, enter the following command to store the data under the alias youralias.

    $ ./extkeytool -importkey -keystore yourstore -alias youralias -storepass yourpass -keyfile yourkey.der.pkcs8 -certfile cert.bundle -provider org.bouncycastle.jce.provider.BouncyCastleProvider

  4. You can verify that the import was successful by listing entry. Use the command below.

    $ keytool -list -v -keystore yourstore -alias youralias

  5. Remember to delete yourkey.der.pkcs8, as it contains your unencrypted private key.

If you are starting from scratch and do not yet have a certificate/key pair:

  1. Generate an RSA private key. Use the command below, substituting yourkey with an appropriate name to use to refer to the key.

    $ openssl genrsa -des3 -out yourkey.enckey 1024

  2. The following command generates a Certificate Signing Request, which should be communicated to a Certificate Authority.

    $ openssl req -new -key yourkey.enckey

  3. The Certificate Authority should respond with a PEM-encoded X509 certificate. Set the mod_ssl SSLCertificateKeyFile directive to point to the key file you just created and the SSLCertificateFile directive to point to file containing the certificate issued by the Certificate Authority. Previous sections explaion how to share the key/certificate pair with a Java keystore.

4.c. Linking the Authentication System to the HS

The interaction between the HS and the local authentication system is implemented by supplying the HS with the identity of the browser user. Most often, this will mean protecting the HS servlet with some form of local authentication that populates REMOTE_USER. Location blocks can be added to httpd.conf, associating the appropriate authentication mechanism with the URL of the HS servlet. The following example demonstrates association of a very basic authentication method with the HS:

<Location /shibboleth/HS>
AuthType Basic
AuthName "Internet2 Handle Service"
AuthUserFile /usr/local/apache/conf/user.db
require valid-user
</Location>

Note that .htaccess files cannot be used for this purpose because URL's are "virtualized" by Tomcat.

It is recommended that the origin be tested at the end of this process using the process described in section 6.a.

4.c.i. Enabling client certificate authentication (optional)

Shibboleth supports client certificate authentication by utilization of a filter that relies on the web server to do all processing to ensure that the certificate is both valid and appropriate for the application. An example deployment descriptor is included with the Shibboleth distribution at $SHIB_HOME/webAppConfig/origin-client-cert.xml. To enable the filter, add the following to the deployment descriptor (web.xml):

  <filter>
    <filter-name>
      Client Cert AuthN Filter
    </filter-name>
    <filter-class>
      edu.internet2.middleware.shibboleth.utils.ClientCertTrustFilter
    </filter-class>
  </filter>


  <filter-mapping>
    <filter-name>
      Client Cert AuthN Filter
    </filter-name>
    <url-pattern>
      /HS
    </url-pattern>
  </filter-mapping>

By default, the filter pulls the principal name out of the CN of the cert's Subject by using regular expression grouping. This may be done using patterns such as:

regex: '.*CN=([^,/]+).*' match group: 1

The servlet filter will accept two initialization parameters, regex and matchGroup that can be used to extract the principal name differently.

4.d. Deploying AA plug-ins for attributes(Java API)

Under development and extremely likely to fluctuate with future implementation.

4.e. Establishing default ARP's for the origin community

For a more basic introduction to ARP's, please refer to section 2.e.

An ARP determines which attributes are released to a SHAR when a user tries to access a resource. It acts as a sort of filter on user information contained in the authoritative directory, deciding what can be released to whom, but not modifying or creating information itself. ARP's are generally administered by the site, but Shibboleth will provide for users to broker control of their own information and privacy by allowing them to create ARP's pertaining to themselves.

It is recommended that a set of policies be established between an origin and frequently accessed targets to specify default releases of expected attributes. Club guidelines may provide more information on population of ARP's.

Currently, there is no direct mechanism for users to create their own ARP's besides direct XML writing. In future versions, a GUI will be provided for simpler management of ARP's. Care should be given to balancing giving sufficient control over information to users and avoiding access problems. For example, users may decide to restrict the release of their personal information to such a degree that access to a site for a class may become impossible because Shibboleth cannot release enough information to grant access.

For more precise information regarding how ARP's are processed or syntactically formed, please refer to section 5.a.i.





5. Advanced Configuration

5.a. ARP Overview

This section applies primarily to the syntactic and technical details of ARP's. For basic information on and explanation of what an ARP is and how it should be managed, please refer to sections 2.e and 4.e.

Every ARP file contains one ARP. ARP's may be specified either as the site ARP or user ARP's. The site ARP pertains to every principal for whom the AA retrieves information; a user ARP applies only to the individual user for whom it is defined. The set of principals to whom the ARP applies is defined by the name of the ARP file: the site ARP is stored in arp.site.xml and user ARP's are stored as arp.user.$PRINCIPALNAME.xml. Up to two ARP's will apply to a principal: the site ARP, and the user ARP for that principal.

Each ARP acts as a container that holds a set of ARP rules that are applicable to the principals that ARP is effective for. Each ARP rule specifies a single release policy within the ARP container pertaining to a specific set of targets. This set of targets may be specified as a specific SHAR, a SHAR tree, or a regular expression, and becomes the ARP rule's target definition. Each ARP rule may contain specifications regarding the release of any number of attribute values to requests matching that ARP rule for that user. ARP rules may be flagged as default, implying that they are always applied to any user matched by the ARP container. Note that ARP's may also be used to restrict specific attribute/value pairs in addition to restricting or releasing individual attributes.

When a query is received, the AA generates an effective ARP, which is the fully evaluated set of ARP rules regarding that SHAR based on all ARP containers applicable to the principal. This effective ARP is then applied to attribute values retrieved from the directory and the appropriate assertion is constructed. Default rules are always included in construction of the effective ARP.

5.a.i. ARP Processing

When a request arrives from a particular SHAR, the applicable set of ARP rules are parsed into an effective ARP. This parsing is done as follows:

  1. Identify all ARP's that should be applied to a particular principal. This is done by isolating the files in the folder specified by edu.internet2.middleware.shibboleth.aa.arp.provider.FileSystemArpRepository.Path that have the name either arp.site.xml or arp.user.$PRINCIPALNAME.xml.
  2. Find all ARP rules relevant to the query:
    1. Any ARP rules within the identified ARP's designated as defaults are automatically included in the effective ARP without performing any matching functions.
    2. For each non-default rule in each identified ARP, the matching functions specified in the rule's target definition are performed. A separate matching function is performed for the requesting SHAR and the resource on behalf of which the SHAR is making the request.
    3. Each matching function evaluates to TRUE if the match is successful or FALSE if it is unsuccessful. If both functions evaluate to TRUE, the rule is included in the Effective ARP.
  3. Construct the Attribute Filter:
    1. For each attribute, compile a temporary list of associated rules that includes all values with a release qualifier of permit.
    2. Subtract from this list all attribute values with rules specifying a release qualifier of deny. The resulting list represents the allowable release values for the attribute and is used as a mask for the values which are returned from the Attribute Resolver.
    3. If a statement specifies that all values should be permitted, then specific deny qualifiers for specific values should still be enforced. If a statement specifies that all values should be denied, then permit qualifiers for specific values will be ignored.
  4. Using the mask and attributes returned from the Attribute Resolver, an assertion is constructed.

5.a.ii. ARP Syntax

Each ARP is described by an XML file based on a standard .xsd schema. It consists of a standard AttributeReleasePolicy element referencing the appropriate xsi:schemaLocation and a self-explanatory Description element followed by any number of Rule elements. Each Rule element must consist of a Target element and one or more Attribute elements. The Target element specifies the rules by which the target definition is formed. The Attribute elements specifies the name and values of the attributes that may be released.

The simplest possible ARP is as follows, which releases eduPersonScopedAffiliation to any target for the users the ARP applies to:

<?xml version="1.0"?>
<AttributeReleasePolicy xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="urn:mace:shibboleth:arp:1.0" xsi:schemaLocation="urn:mace:shibboleth:arp:1.0 shibboleth-arp-1.0.xsd">
         <Description>Simplest possible ARP.</Description>
         <Rule>
                 <Target>
                         <AnyTarget/>
                 </Target>
                 <Attribute name="urn:mace:eduPerson:1.0:eduPersonScopedAffiliation">
                         <AnyValue release= "permit"/>
                 </Attribute >
        </Rule >
</AttributeReleasePolicy>

All ARP's must take the same basic form. A detailed description of how each element of the Rule element may be sub-populated follows:

The Target element:

Target may contain either the AnyTarget element, which will cause the Target to always return TRUE, or both the Requester element, which provides for matches to be performed against the SHAR name and the Resource element, which provides for matches to be performed against the requested URL.

There are three matches that may be performed by the AA in evaluating ARP's by using the matchFunction component of the Requester and Resource elements. The following match patterns may be specified directly following the Requester or Resource elements, such as <Requester matchFunction="urn:mace:shibboleth:arp:matchFunction:regexMatch">:

The Attribute element:

The Attribute element must always specify the URN of the attribute whose release parameters it specifies. Additionally, it must contain either the AnyValue element or one or more Value elements. These elements, in turn, must specify either release = permit or deny. The Value element must then contain one value for which the rule applies. Examples:

<Attribute name="urn:mace:eduPerson:1.0:eduPersonPrincipalName">
  <AnyValue release="Permit">
</Attribute>

Permits the release of eduPersonPrincipalName with any value.

<Attribute name="urn:mace:eduPerson:1.0:eduPersonScopedAffiliation">
  <Value release="deny">member@example.edu</Value>
</Attribute>

Denies the release of eduPersonScopedAffiliation value member@example.edu. Other values of the attribute may still be released if so specified by a permit ARP.




6. Troubleshooting

This section provides basic information about testing, logging, and error handling for Shibboleth origins. This information is not intended to be comprehensive, but instead rudimentary guidelines for basic configuration tests and problems. For more detailed information or answers to specific problems not addressed in this section, please mail mace-shib-users@internet2.edu with a thorough description of errors and configurations used.

6.a. Basic Testing

Internet2 provides a basic target that can be used to test origin setup functionality. After your origin is recognized by InCommon, simply use any browser to access https://wayf.internet2.edu/shibboleth/sample.jsp. Select your origin's name and follow the login process as a user would. Note that SSL must be used, and both the HS and AA must be fully configured.

The test target will then display a simple page which includes the basic information sent to it by your origin and the authentication rules it is using.

For information regarding specific error messages that may be generated if the origin does not work successfully, please refer to section 6.c.

6.b. Logging

Shibboleth's origin components log various operations which may prove useful for auditing, testing, and security purposes. This data is sent through log4j's standard mechanism. The location of the log file, the level at which the log is output, the formatting of the logs, and many more options may be configured by editing /WEB-INF/classes/conf/log4j.properties. By default, it is setup to log to the console of the servlet container, with a level of WARN, but there is also a commented out example in the file to give a possible alternate configuration.

6.c. Common Problems

A knowledge base is being developed in the Shibboleth Deployer's FAQ. Please mail mace-shib-users@ internet2.edu with any additional questions or problems encountered that are not answered by this basic guide.