overview of voyager external patron authentication michael doran, systems librarian ex libris...

Overview of VoyagerOverview of VoyagerExternal Patron AuthenticationExternal Patron Authentication

Michael Doran, Systems Librarian

Ex Libris Southwest Users GroupFebruary 6, 2008 – Santa Ana College

Michael Doran, Systems Librarian [email protected]

Standard Patron Authentication- User Perspective -

The user clicks the “Login” (or “Patron”, etc.) button...

... gets a login form...

... enters credentials and submits...


Once logged in, the user has access to their patron information, requests, MyOPAC functionality, etc.

Standard Patron Authentication- User Perspective -


The user clicks the “Login” (or “Patron”, etc.) button...

... gets a login form...

... enters credentials and submits...

External Patron Authentication- User Perspective -


Once logged in, the user has access to their patron information, requests, MyOPAC functionality, etc.

External Patron Authentication- User Perspective -


What’s the Difference?

From a user perspective the login experience is pretty much the same, regardless of whether he/she uses standard Voyager patron authentication or an external authentication system.

A sharp-eyed user might notice that another web application comes into play during external authentication....


Standard Patron Authentication

Everything is handled by WebVoyáge (i.e. Pwebrecon.cgi)


External Patron Authentication

query string

WebVoyáge hands over control... ... to an “adaptor”...


External Patron Authentication

... and then returns control to WebVoyáge

... the adaptor does the authentication...


WebVoyáge to Adaptor Hand Off

WebVoyáge[Pwebrecon.cgi]

Authentication Adaptor[customer-adaptor.cgi]

PAGE=pbLogonPatron&PID=2063&SEQ=20040921144400

“query string”

What determines whether this hand off occurs? ...


ExtAuthenticationSystem stanza

[ExtAuthenticationSystem]ExtAuthSystemEnabled=YExtAuthBypassLoginScreen=YExtAuthSubmitText=Login with NetIDExtAuthSystemURL=/cgi-bin/customer-adaptor.cgiExtAuthButtonMethod=GET

The opac.ini configuration file contains a stanza called ExtAuthenticationSystem. The parameters in this stanza control the initial hand-off to a patron authentication adaptor.



To totally bypass the WebVoyáge login screen:

[ExtAuthenticationSystem]ExtAuthSystemEnabled=YExtAuthBypassLoginScreen=YExtAuthSubmitText=Login with NetIDExtAuthSystemURL=/cgi-bin/customer-adaptor.cgiExtAuthButtonMethod=GET

Takes userdirectly to external

authenticationlogin screen.



To give users the option of logging in using the standard WebVoyáge or the external authentication:

[ExtAuthenticationSystem]ExtAuthSystemEnabled=YExtAuthBypassLoginScreen=NExtAuthSubmitText=Login with NetIDExtAuthSystemURL=/cgi-bin/customer-adaptor.cgiExtAuthButtonMethod=GET

Takes user tostandard

WebVoyágelogin screen...

...which includesa button linking to the adaptor login

screen.


Now where did I put that adaptor?

Patron authentication adaptor feature“functionality that allows WebVoyáge to communicate with an external authentication program, via a customer-developed authentication adaptor”

Patron authentication adaptor“the customer-developed adaptor which provides the communications bridge between WebVoyáge and the external authentication program”

The patron authentication adaptor referred to is a computer program. Customer-developed means you get to write it.


Authentication Adaptor Tasks


When first called:

• Parse and store WebVoyáge query stringThe query string contains the data such as the PID (“process ID”) which identifies the session and is necessary for maintaining session state.

• Generate HTML code for a patron login form in order to gather desired user credentials




• Query external authentication system Get “yea” or “nay” on user Retrieve “Institution ID”

• If yea, insert a record into the WOPAC_PID_PATRON_KEYS table:

PID (saved from query string) Institution ID

• Return control to WebVoyáge via a redirect to Pwebrecon.cgi URL appended with:

Original (saved) query string, plus Authentication key-value pair

After user credentials are submitted:


Authentication Systems

There are many authentication systems... LDAP (Lightweight Directory Access Protocol) Kerberos NIS/NIS+ (Network Information Service) SMB (Windows) Shibboleth RADIUS (Remote Authentication Dial In User Service) etc...

In addition, authentication systems such as LDAP will differ in internal data structure from one organization to another.

Time out!


Which means...

The multitude of authentication systems, as well as the fact that the systems can vary in internal data structure, are the principle reasons why Voyager comes with a WebVoyáge patron authentication adaptor feature, but not an actual patron authentication adaptor.

And which are also why the feature is entirely authentication-system neutral, but the adaptor itself is by necessity, authentication-system specific.

Systems Librarian


Query External Authentication System


1. Adaptor sends formatted query containing username and password

2. Authentication system replies with success/failure response plus user information if success

Authentication System[e.g. LDAP]


Plus user information?

dn:cedarid=10856915705,cn=people,dc=uta,dc=edu

objectClass: top person inetOrgPerson utaPerson cedarid: 10856915705 utaSSN: 123456789 mail: [email protected] utaDiscloseInfo: email utaMiddleName: d cn: michael d doran sn: doran givenName: michael displayName: doran, michael dutaPrevAccountName: doran utaAccountName: doran uid: doranmd

Example response from

UTA OpenLDAP server

(a “people” record)


Needed: Institution ID

dn:cedarid=10856915705,cn=people,dc=uta,dc=edu

objectClass: top person inetOrgPerson utaPerson cedarid: 10856915705 utaSSN: 123456789 mail: [email protected] utaDiscloseInfo: email utaMiddleName: d cn: michael d doran sn: doran givenName: michael displayName: doran, michael dutaPrevAccountName: doran utaAccountName: doran uid: doranmd

The authenticator response needs to be parsed for a value (preferably the Institution ID) that can be used to identify that user’s Voyager patron record.



XXXDB.PATRON

PATRON_ID SSAN NORMAL_LAST_NAME NORMAL_INSTITUTION_ID

XXXDB.PATRON_BARCODE

PATRON_ID PATRON_BARCODE

Voyager Tables

Authentication confirms an identity. The standard WebVoyáge login process authenticates a user by matching the user input (last name and identifier) against patron records to identify a unique patron record.


Provide a Unique Patron Identifier

Although you’ve confirmed the user’s identity within the external system, WebVoyáge needs to be able to identify a unique patron record internal to the Voyager database. The Patron Authentication Adaptor feature is designed to use the Institution ID to match on the Voyager patron record for that user. The customer adaptor must insert that value as well as the PID value into a Voyager database table (via an SQL DML statement).

cedarid: 10856915705 utaSSN: 123456789 mail: [email protected]

PID value fromsaved query string

Institution ID value fromauthenticator response

insert into XXXDB.WOPAC_PID_PATRON_KEYS (PID, PATRON_KEY) values (‘2063','123456789')


Adaptor to WebVoyáge Hand Off



PAGE=pbLogonPatron&PID=2063&SEQ=20040921144400&authenticate=Y

“query string”


WebVoyáge Back on the Job



authenticate=Y

A successful external authentication (“Y”) results in WebVoyáge retrieving the record inserted into the WOPAC_PID_PATRON_KEYS table by the adaptor.

authenticate=N

An authentication failure (“N”) results in WebVoyáge displaying an error message, and returning the user to a login screen.


Retrieving Unique Identifier


The query string PID value lets Voyager know which WOPAC record to retrieve.

XXXDB.WOPAC_PID_PATRON_KEYS

PID PATRON_KEY ------- ----------- 2049 555339876 2063 123456789 2068 333221234 ...

Voyager grabs the PATRON_KEY value for that PID and then deletes that record in the WOPAC table.



Looking Up Patron Record


WebVoyáge compares the PATRON_KEY value with normalized Institution ID values in the patron table.

XXXDB.PATRON

PATRON_ID 123456789 NORMAL_INSTITUTION_ID

A successful match means that Voyager has identified the user, and the user can then be logged in and the requested page provided.

If no match is found, WebVoyáge displays an error message and returns the user to the login screen.


The “Institution ID” Blues

This can be a problem if:

1) Your organization doesn’t use Institution IDs and/or your library doesn’t populate that field in the Voyager PATRON table, or...

2) You have Institution IDs in the Voyager PATRON table, but the external authorization system doesn’t return an attribute containing a user’s Institution ID.

The PATRON_KEY value inserted into the Voyager “WOPAC” table has to be the Institution ID since that is the field in the patron record that it will be matched against. Barcodes and social security numbers (that aren’t also Institution IDs) will not work.

Systems Librarian


Work-Arounds

Systems Librarian

The bottom line is that the Institution ID field of the patron record has to be populated with unique identifiers in order to use the WebVoyáge external patron authentication feature.

If your organization uses social security numbers as the de facto institution IDs, then patron update SIF files must include social security numbers in the Institution ID field in addition to the SSAN field.

If the external authentication system doesn’t return the Institution ID values that you have in your Voyager patron records, but returns another unique identifier included in your patron records, it may be possible to have the authentication adaptor query Voyager for the appropriate Institution ID prior to inserting a record into the WOPAC table.


Ex Libris Documentation

The Voyager Technical User’s Guide, Appendix C contains “WebVoyáge Patron Authentication Adaptor feature”.

Note: Ex Libris has substantially revised the WebVoyáge Patron Authentication Adaptor documentation since the initial release.

Always the best place to start...


Constructing an adaptor

There are no real restrictions on the programming language used...

• Perl• Java/JSP• C/C++• Shell script• whatever

However... it saves a lot of work to have pre-built components/modules for: 1) parsing CGI form data, 2) interfacing with an Oracle database, and 3) interfacing with the desired authentication

system.


Perl is a good choice

CGI.pm module or cgi-lib.pl library for processing CGI forms DBI and DBD::Oracle modules for interfacing with the

Voyager database Net::LDAP or Net::LDAPS modules for interfacing with an

LDAP server Plus many other authentication modules available on CPAN


Authentication adaptorsfor LDAP written in Perl

Flatten out the learning curve by adapting these two Perl scripts created by other Voyager customers.

“Adaptor Example Source Code”A production-worthy Voyager third-party patron authentication

adaptor script using Perl to query an LDAP serverby Michael Doran, University of Texas at Arlingtonhttp://rocky.uta.edu/doran/adaptor/

“login”An authentication script used to authenticate access to Voyager's MyOPAC [This is also a production level script, in Perl]by Steve Thomas, University of Adelaidehttp://staff.library.adelaide.edu.au/sthomas/scripts/voyager/login.html


An authentication adaptorfor Kerberos written in Java Or if Java is more your cup of tea, take a look at this EndUser presentation:

“External Patron Authentication”EndUser 2004, Session 35 by Jeff Barnett, Gail Barnett, and Kalee Sprague, Yale Universityhttp://support.endinfosys.com/cust/community/vgroup/eu2004/tech.html orhttp://www.library.yale.edu/~jbarnett/EndUser2004/session35.ppt

Yale University Library developed an external patron authentication adaptor written in Java. It authenticates against a Kerberos server. For more info see: http://www.library.yale.edu/~jbarnett/EndUser2004/


Some Voyager sites usingexternal patron authentication Columbia University Tarrant County College Monash University University of Adelaide University of British Columbia University of Texas at Arlington Washington Research Library Consortium Worcester Polytechnic Institute Yale University

Get a fuller list of implementing libraries at: http://rocky.uta.edu/doran/adaptor/voysites.html


This presentation…

Creating an LDAP Patron Authentication Adaptor (using Perl)

…was an overview

You might also want to take a look at…


Any questions?

overview of voyager external patron authentication michael doran, systems librarian ex libris...

Documents

patron information

external authentication

sharpeyed user

adaptor loginscreen

webvoyge login screen

standard webvoyge

login form

login experience