Overview of VoyagerOverview of VoyagerExternal Patron AuthenticationExternal Patron Authentication
EndUser Session #20 – Thursday 4:15-5:15pm
Michael Doran, Systems LibrarianUniversity of Texas at Arlington
April 28, 2005 - Endeavor Users Group Meeting - Chicago, IL
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Standard Patron Authentication- User Perspective -
The user clicks the “Login” (or “Patron”, etc.) button...
... gets a login form...
... enters credentials and submits...
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Once logged in, the user has access to their patron information, requests, MyOPAC functionality, etc.
Standard Patron Authentication- User Perspective -
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External Patron Authentication- User Perspective -
The user clicks the “Login” (or “Patron”, etc.) button...
... gets a login form...
... enters credentials and submits...
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External Patron Authentication- User Perspective -
Once logged in, the user has access to their patron information, requests, MyOPAC functionality, etc.
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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....
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Standard Patron AuthenticationEverything is handled by WebVoyáge (i.e. Pwebrecon.cgi)
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Standard Patron Authentication
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External Patron Authentication
query string
WebVoyáge hands over control... ... to an “adaptor”...
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External Patron Authentication
... and then returns control to WebVoyáge
... the adaptor does the authentication...
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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? ...
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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.
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ExtAuthenticationSystem stanzaTo 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.
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ExtAuthenticationSystem stanzaTo 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.
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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.
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Authentication Adaptor Tasks
Authentication Adaptor[customer-adaptor.cgi]
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
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Authentication Adaptor Tasks
Authentication Adaptor[customer-adaptor.cgi]
• 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:
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Authentication Adaptor Tasks
Authentication Adaptor[customer-adaptor.cgi]
• 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:
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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!
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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
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Authentication Adaptor Tasks
Authentication Adaptor[customer-adaptor.cgi]
• 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:
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Query External Authentication System
Authentication Adaptor[customer-adaptor.cgi]
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)
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Needed: Institution IDdn: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.
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Standard Patron Authentication
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.
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Authentication Adaptor Tasks
Authentication Adaptor[customer-adaptor.cgi]
• 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:
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Provide a Unique Patron IdentifierAlthough 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')
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Authentication Adaptor Tasks
Authentication Adaptor[customer-adaptor.cgi]
• 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:
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Adaptor to WebVoyáge Hand Off
WebVoyáge[Pwebrecon.cgi]
Authentication Adaptor[customer-adaptor.cgi]
PAGE=pbLogonPatron&PID=2063&SEQ=20040921144400&authenticate=Y
“query string”
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WebVoyáge Back on the Job
WebVoyáge[Pwebrecon.cgi]
PAGE=pbLogonPatron&PID=2063&SEQ=20040921144400&authenticate=Y
authenticate=YA successful external authentication (“Y”) results in WebVoyáge retrieving the record inserted into the WOPAC_PID_PATRON_KEYS table by the adaptor.
authenticate=NAn authentication failure (“N”) results in WebVoyáge displaying an error message, and returning the user to a login screen.
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Retrieving Unique IdentifierPAGE=pbLogonPatron&PID=2063&SEQ=20040921144400&authenticate=Y
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.
WebVoyáge[Pwebrecon.cgi]
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Looking Up Patron Record
WebVoyáge[Pwebrecon.cgi]
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.
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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
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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.
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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.
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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
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Authentication adaptorsfor LDAP written in Perl
Flatten out the learning curve by adapting these two Perl scripts created by other Voyager customers.
“Authentication Adaptor”Proof-of-concept Voyager third-party patron authentication
using Perl to query an LDAP server [includes source code]by 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 a production script]by Steve Thomas, University of Adelaidehttp://staff.library.adelaide.edu.au/~sthomas/scripts/voyager/login.html
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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
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/
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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
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Endeavor Documentation
The Voyager Technical User’s Guide contains “WebVoyáge Patron Authentication Adaptor feature” in Appendix D - Voyager 2001.2 Appendix C - Voyager with Unicode
Note: Endeavor has substantially revised the WebVoyáge Patron Authentication Adaptor documentation since the initial release and I highly recommend you get the latest version.
Always the best place to start...
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Any questions?
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Thanks for attending!
The End
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