Hi Paul,

I've done an integration of Openathens with Koha using the mod_auth_mellon Apache module https://github.com/latchset/mod_auth_mellon (rather than using the EBSCO plugin).


The workflow I did is:

1. Checked out the master branch of mod_auth_mellon

2. Navigated into mod_auth_mellon

3. Generated the Koha SP (Service Provider) XML metadata endpoint, cert and key file. 

./mellon_create_metadata.sh <full_opac_test_site_url> <full_opac_test_site_url>/saml

4. Moved those files into a new directory /etc/koha/sites/<instance>/saml

5. Sent the metadata XML file I'd made to EBSCO and received their one back and put it in /etc/koha/sites/<instance>/saml

6. Edit Apache conf file ( /etc/apache2/sites-available/<instance>.conf ):

<Location />
       MellonEnable "auth"
       MellonUser "NameID"
       MellonSPPrivateKeyFile /etc/koha/sites/<instance>/saml/<opac_test_site_url>.key
       MellonSPCertFile /etc/koha/sites/<instance>/saml/<opac_test_site_url>.cert
       MellonSPMetadataFile /etc/koha/sites/<instance>/saml/<opac_test_site_url>.xml
       MellonIdPMetadataFile /etc/koha/sites/<instance>/saml/<client_supplied_metadata>.xml
       MellonEndpointPath /saml
       # Set environment variables with the values of IdP attributes
       MellonSetEnv "principalname" "<IdP_UPN_attribute_name>"
       MellonSetEnv "givenname" "<IdP_firstaname_attribute_name>"
       MellonSetEnv "surname" "<IdP_surname_attribute_name>"
       MellonSetEnv "email" "<IdP_email_attribute_name>"
       
       # Unset and reset X_REMOTE_UPN
       Header unset X_REMOTE_UPN
       RequestHeader unset X_REMOTE_UPN
       RequestHeader set X_REMOTE_UPN %{MELLON_principalname}e 

       # Unset and reset the X_REMOTE_GIVENNAME
       Header unset X_REMOTE_GIVENNAME
       RequestHeader unset X_REMOTE_GIVENNAME
       RequestHeader set X_REMOTE_GIVENNAME %{MELLON_givenname}e
       
       # Unset and reset the X_REMOTE_SURNAME
       Header unset X_REMOTE_SURNAME
       RequestHeader unset X_REMOTE_SURNAME
       RequestHeader set X_REMOTE_SURNAME %{MELLON_surname}e
       
       # Unset and reset the X_REMOTE_EMAIL
       Header unset X_REMOTE_EMAIL
       RequestHeader unset X_REMOTE_EMAIL
       RequestHeader set X_REMOTE_EMAIL %{MELLON_email}e
 </location>

Here the IdP_UPN_attribute_name is the attribute (claim) that Openathens is sending to Koha in the SAML POST request, we're assigning it to the Mellon environment variable "principalname" and then putting it in the header as X_REMOTE_UPN


7. Install the following packages:

sudo apt-get install libapache2-mod-auth-mellon

sudo s2enmod expires

sudo systemctl restart apache2

sudo apachectl configtest

sudo apachectl restart

apt-cache policy libapache2-mod-auth-mellon

sudo apt-get install liblasso3

sudo apachectl restart

8. Amend the koha-conf.xml file adding the following tags:
<trusted_header_upn>X_REMOTE_UPN</trusted_header_upn>
<trusted_header_givenname>X_REMOTE_GIVENNAME</trusted_header_givenname>
<trusted_header_surname>X_REMOTE_SURNAME</trusted_header_surname>
<trusted_header_email>X_REMOTE_EMAIL</trusted_header_email>
9. Somethings to note is that using mod_auth_mellon is that plack user runs as www-data so you will need to change the AssignUserID in the Apache conf to be:
AssignUserID www-data <instance>-koha

You'll also need to amend your debian/scripts/koha-plack script to replace:
instance_user="${instancename}-koha"

With:
instance_user="www-data"

Also please note when using mod_auth_mellon you'll need to make sure the Koha instance your setting this up for is on a standalone server (i.e. no other Koha instance on the server) because the changing of the user that Plack runs as introduces a security risk on a multi-instance server.

10. Change the ownership of /var/cache/koha/<instance> file, because Plack now running as www-data can not read the file:
sudo chown www-data -R /var/cache/koha/<instance>

11. You'll need to introduce a customization in C4/Auth.pm now (though I am shortly going to be upstreaming this customization so you'll see a bug report from me for it soon):


11a. Add a new subroutine get_header() - This retrieves the Openathens values stored in the header in the Apache conf:

sub get_header {
    my ($header) = @_;
     my $q = CGI->new();
     # Prepend HTTP_ as that's how they come through
    my $h_val = $q->http('HTTP_' . $header);
     return $h_val;
 }


11b. Amend C4::Auth->checkauth():

my $trusted_header = C4::Context->config('trusted_header');
my $trust_head_val = get_header($trusted_header) if $trusted_header; #Store the header values returned from get_header subroutine which are: UPN, givenname, surname and email in $trust_head_val hash.

....

Now above this line (elsif ( $emailaddress) { ) add in a new elsif:


} elsif ($trust_head_val && $trust_head_val ne '(null)') {
        $userid=$trust_head_val;
        # This uses something like
        # <trusted_header>X_REMOTE_USER</trusted_header>
        # in koha-conf.xml, and checks that header on the incoming request.
        # If it is there and contains a user ID, we believe it and log the
        # user in with that. This is intended for things like plack behind a
        # reverse proxy that does auth, and puts the user ID into a header.
        #
        # Basically, we treat it just like basic auth.
         $cookie = $query->cookie(
             -name     => 'CGISESSID',
             -value    => '',
             -expires  => '',
             -HttpOnly => 1,
         );
         C4::Context->_new_userenv(undef);
         $loggedin = check_user_exists($userid); #Call check_user_exists subroutine and check if there is a borrower.userid matching the UPN
 
   }


Note: This is assuming the UPN Openathens is sending Koha matches/is stored in the borrower.userid. If Openathens wants to only use email i.e. the email address Openathens sends Koha in POST request matches borrowers.email then you'll need to amend the SQL query in check_user_exists.



A couple more things to note:

1. If your Koha server is behind a load balancer then you need to include the https:// directive in the  servername e.g. Servername https://demo.koha.com

This is because SAML requires the web server to identify as the same server in the SP metadata (e.g. https://<URL>). But when a Koha server is behind a LB it does not identify itself including the https protocol so you need to include it.

There is more detail on that here: https://jdennis.fedorapeople.org/doc/mellon-user-guide/mellon_user_guide.html#_server_name

I know that is for Fedora (I can't find the documentation link I had discussing it in a Ubuntu context) but it is the same principal.


I hope all this helps and if you need any more information please let me know!

Thanks,
Alex




On 25/03/20 5:00 am, Chris Cormack wrote:


From: Paul Poulain <paul.poulain@biblibre.com>
Sent: 25 March 2020 4:57:14 AM NZDT
To: "koha-devel@lists.koha-community.org" <koha-devel@lists.koha-community.org>
Subject: [Koha-devel] Koha and Ebsco OpenAthens

Hello,

does anyone have experience in setting OpenAthens for Koha. There's an 
Ebsco plugin (https://github.com/ebsco/openathens-koha-plugin), but it 
seems to be for old versions of Koha.

any feedback highly appreciated !

-- 
Paul Poulain, Associé-gérant / co-owner
BibLibre, Services en logiciels libres pour les bibliothèques
BibLibre, Open Source software and services for libraries
Koha-devel mailing list
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bugs : http://bugs.koha-community.org/

--
Sent from my Android device with K-9 Mail. Please excuse my brevity. 
-- 
Alex Buckley
Koha Developer

Catalyst IT - Expert Open Source Solutions
DDI: +64 4 803 2378 | Mob: +64 22 429 6157 | www.catalyst.net.nz


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