Difference between revisions of "LDAP user login.pl"

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m (bootstrapping admins: use SQL)
(Redirecting to LDAP)
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== LDAP Authentication and Provisioning example ==
Here's an example of a customized <tt>/opt/eprints3/archives/ARCHIVEID/cfg/cfg.d/user_login.pl</tt>
* allowing LDAP accounts to login, using the "Advanced LDAP Configuration" example
* allowing the local eprints admin account to login w/ database authentication
* creating eprints accounts for all successfully authenticated LDAP users ''on the fly''
Most of the code is from the default <tt>user_login.pl</tt> and from the [http://files.eprints.org/27/1/update_users update_users] script.
Be sure to only use this over [[HTTPS]]!
$c->{check_user_password} = sub {
    my( $session, $username, $password ) = @_;
    # LDAP authentication for "user", "editor" and "admin" types (roles)
    use Net::LDAP; # IO::Socket::SSL also required
    # LDAP tunables
    my $ldap_host = "ldap.example.org";
    my $base      = "dc=example,dc=org";
    my $dn        = "cn=someProxyAccount,ou=accounts,$base";
    my $ldap      = Net::LDAP->new ( $ldap_host, version => 3 );
    unless( $ldap )
        print STDERR "LDAP error: $@\n";
        return 0;
    # Start secure connection (not needed if using LDAPS)
    my $ssl = $ldap->start_tls();
    if( $ssl->code() )
        print STDERR "LDAP SSL error: " . $ssl->error() . "\n";
        return 0;
    # Get password for the search-bind-account
    my $repository = $session->get_repository;
    my $id        = $repository->get_id;
    my $ldappass  = `cat /opt/eprints3/archives/$id/cfg/ldap.passwd`;
    my $mesg = $ldap->bind( $dn, password=>$password );
    if( $mesg->code() )
        print STDERR "LDAP Bind error: " . $mesg->error() . "\n";
        return 0;
    # Distinguished name (and attribues needed later on) for this user
    my $result = $ldap->search (
        base    => "$base",
        scope  => "sub",
        filter  => "(&(uid=$username)(objectclass=inetOrgPerson))",
        attrs  =>  ['1.1', 'uid', 'sn', 'givenname', 'mail'],
    my $entr = $result->pop_entry;
    unless( defined $entr )
        # Allow local EPrints authentication for admins (accounts not found in LDAP)
        my $user = EPrints::DataObj::User::user_with_username( $session, $username );
        return 0 unless $user;
        my $user_type = $user->get_type;
        if( $user_type eq "admin" )
            # internal authentication for "admin" type
            return $session->get_database->valid_login( $username, $password );
        return 0;
    my $ldap_dn = $entr->dn;
    # Check password
    my $mesg = $ldap->bind( $ldap_dn, password => $password );
    if( $mesg->code() )
        return 0;
    # Does account already exist?
    my $user = EPrints::DataObj::User::user_with_username( $session, $username );
    if( !defined $user )
        # New account
        $user = EPrints::DataObj::User::create( $session, "user" );
        $user->set_value( "username", $username );
    # Set metadata
    my $name = {};
    $name->{family} = $entr->get_value( "sn" );
    $name->{given} = $entr->get_value( "givenName" );
    $user->set_value( "name", $name );
    $user->set_value( "username", $username );
    $user->set_value( "email", $entr->get_value( "mail" ) );
    $ldap->unbind if $ldap;
    return 1;
== things to note ==
* This script uses a dedicated proxy account which must exist in your LDAP tree and has appropriate permissions (ACL settings) to search for users and read their <tt>uid,givenname,sn,mail</tt> attributes.
* It get's this proxy accounts' password from a file inside the repository configuration. this file needs to have read permissions for the user your webserver runs as (e.g. <tt>www-data</tt> on Debian).  Use file system permissions to protect this (e.g. <tt>chmod 400 ldap.passwd</tt>).
* It changes the flow of <tt>user_login.pl</tt> a little to only check for local ''admin'' accounts (no users or editors; we have them all in our LDAP tree) and only when no user is found for ldap authentication. This allows you to have your admins in LDAP (if you want) but still use the local admin for "promoting" other users to admins, among other things (which could also be done with a simple SQL <code>update</code> directly in the RDBMS). If you don't need the local admin, remove those lines and just <tt>return 0</tt> since no user was found in LDAP.
* you could change the default role for generated user accounts from <tt>user</tt>, if you really wanted.
== possible enhancements ==
=== removing stale accounts ===
Currently this script does not remove local eprints accounts from the database: when accounts get deleted from the LDAP database the corresponding local EPrints accounts sit around forever. But since login isn't possible anymore this is not a risk or of high priority.
Depending on your situation it may be enough to run some kind of cleanup script, e.g. once a year, that get's a list of all local EPrints accounts, loops over them and <code>$user->remove</code>s all those, which cannot be found in LDAP anymore (except for those where <code>$user_type eq 'admin'</code>, so you don't risk losing your local admins).

Latest revision as of 11:45, 12 August 2009

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