## @file
# Common SAML functions

## @class
# Common SAML functions
package Lemonldap::NG::Portal::_SAML;

use strict;
use base qw(Exporter);
use XML::Simple;
use MIME::Base64;

our @EXPORT = qw(
  loadLasso checkLassoError createServer addIDP addProvider getOrganizationName
  createAuthnRequest createLogin getHttpMethod initAuthnRequest
  buildAuthnRequestMsg processAuthnResponseMsg getNameIdentifier
  createIdentity createSession acceptSSO extractRelayState
  getAssertion getAttributeValue validateConditions
);

our $VERSION = '0.01';
our $_samlCache;

BEGIN {

    # Load Glib if available
    eval 'use Glib;';
    if ($@) {
        print STDERR
          "Glib Lasso messages will not be catched (require Glib module)\n";
        eval "use constant GLIB => 0";
    }
    else {
        eval "use constant GLIB => 1";
    }

    # Load Lasso.pm
    eval 'use Lasso;';
    if ($@) {
        print STDERR "Lasso.pm not loaded :$@";
        eval 'use constant LASSO => 0;use constant BADLASSO => 0;';
    }
    else {
        no strict 'subs';
        eval 'use constant LASSO => 1';

        # Check Lasso version >= 2.2.91
        my $lasso_check_version_mode = Lasso::Constants::CHECK_VERSION_NUMERIC;
        my $check_version =
          Lasso::check_version( 2, 2, 91, $lasso_check_version_mode );
        unless ($check_version) {
            eval 'use constant BADLASSO => 1';
        }
        else {
            eval 'use constant BADLASSO => 0';
        }
    }

}

## @method boolean loadLasso()
# Load Lasso module
# @return boolean result
sub loadLasso {
    my $self = shift;

    # Catch GLib Lasso messages (require Glib)
    if (GLIB) {
        Glib::Log->set_handler(
            "Lasso",
            [qw/ error critical warning message info debug /],
            sub {
                $self->lmLog( $_[0] . " error " . $_[1] . ": " . $_[2],
                    'debug' );
            }
        );
    }

    unless (LASSO) {
        $self->lmLog( "Module Lasso not loaded (see bellow)", 'error' );
        return 0;
    }

    if (BADLASSO) {
        $self->lmLog( 'Lasso version >= 2.2.91 required', 'error' );
        return 0;
    }

    return 1;
}

## @method boolean checkLassoError(Lasso::Error error, string level)
# Log Lasso error code and message if this is actually a Lasso::Error with code > 0
# @param Lasso::Error Lasso error object
# @param string optional log level (debug by default)
# @return 1 if no error
sub checkLassoError {
    my ( $self, $error, $level ) = splice @_;
    $level ||= 'debug';

    # If $error is not a Lasso::Error object, display error string
    unless ( ref($error) and $error->isa("Lasso::Error") ) {
        return 1 unless $error;
        $self->lmLog( "Lasso error: $error", $level );
        return 0;
    }

    # Else check error code and error message
    if ( $error->{code} ) {
        $self->lmLog(
            "Lasso error code " . $error->{code} . ": " . $error->{message},
            $level );
        return 0;
    }

    return 1;
}

## @method Lasso::Server createServer(string metadata, string private_key, string private_key_password, string certificate)
# Load service metadata and create Lasso::Server object
# @param string metadata
# @param string private key
# @param string optional private key password
# @param string optional certificate
# @return Lasso::Server object
sub createServer {
    my ( $self, $metadata, $private_key, $private_key_password, $certificate ) =
      splice @_;
    my $server = $_samlCache->{$metadata};
    return $server if ($server);

    eval {
        $server = Lasso::Server::new_from_buffers( $metadata, $private_key,
            $private_key_password, $certificate );
    };

    if ($@) {
        $self->checkLassoError($@);
        return;
    }

    return $server;
}

## @method boolean addIDP(Lasso::Server server, string metadata, string public_key, string ca_cert_chain)
# Add IDP to an existing Lasso::Server
# @param Lasso::Server Lasso::Server object
# @param string metadata IDP metadata
# @param string optional public key
# @param string optional ca cert chain
# @return boolean result
sub addIDP {
    my ( $self, $server, $metadata, $public_key, $ca_cert_chain ) = splice @_;

    return 0 unless ( $server->isa("Lasso::Server") and defined $metadata );

    no strict 'subs';
    return $self->addProvider( $server, Lasso::Constants::PROVIDER_ROLE_IDP,
        $metadata, $public_key, $ca_cert_chain );
}

## @method boolean addProvider(Lasso::Server server, int role, string metadata, string public_key, string ca_cert_chain)
# Add provider to an existing Lasso::Server
# @param Lasso::Server Lasso::Server object
# @param int role (IDP, SP or Both)
# @param string metadata IDP metadata
# @param string optional public key
# @param string optional ca cert chain
# @return boolean result
sub addProvider {
    my ( $self, $server, $role, $metadata, $public_key, $ca_cert_chain ) =
      splice @_;

    return 0
      unless ( $server->isa("Lasso::Server")
        and defined $role
        and defined $metadata );

    eval {
        Lasso::Server::add_provider_from_buffer( $server, $role, $metadata,
            $public_key, $ca_cert_chain );
    };

    return $self->checkLassoError($@);

}

## @method string getOrganizationName(Lasso::Server server, string idp)
# Return name of organization picked up from metadata
#@param server Lasso::Server object
#@param string entityID
#@return string organization name
sub getOrganizationName {
    my ( $self, $server, $idp ) = splice @_;
    my ( $provider, $node );

    # Get provider from server
    eval { $provider = Lasso::Server::get_provider( $server, $idp ); };

    if ($@) {
        $self->checkLassoError($@);
        return;
    }

    # Get organization node
    eval { $node = Lasso::Provider::get_organization($provider); };

    if ($@) {
        $self->checkLassoError($@);
        return;
    }

    # Return if node is empty
    return unless $node;

    # Extract organization name
    my $xs   = XML::Simple->new();
    my $data = $xs->XMLin($node);
    return $data->{OrganizationName}->{content};
}

## @method Lasso::Login createAuthnRequest(Lasso::Server server, string idp)
# Create authentication request for selected IDP
# @param Lasso::Server server
# @param string entityID
# @return Lasso::Login object
sub createAuthnRequest {
    my ( $self, $server, $idp ) = splice @_;

    # Create Lasso Login
    my $login = $self->createLogin($server);

    unless ($login) {
        $self->lmLog( 'Unable to create Lasso login', 'error' );
        return;
    }

    # Get HTTP method for selected IDP
    my $method = $self->getHttpMethod( $server, $idp );

    $self->lmLog( "Use HTTP method $method", 'debug' );

    # Init authentication request
    unless ( $self->initAuthnRequest( $login, $idp, $method ) ) {
        $self->lmLog( "Could not initiate authentication request on $idp",
            'error' );
        return;
    }

    # Set RelayState as key1;value1;key2;value2;... encoded in base 64
    my $relaystate;
    foreach (qw /_idp urldc/) {
        $relaystate .= $_ . ";" . $self->{$_} . ";" if $self->{$_};
    }
    $relaystate =~ s/;$//;
    $relaystate = encode_base64( $relaystate, '' );
    $login->msg_relayState($relaystate);
    $self->lmLog( "Set $relaystate in RelayState", 'debug' );

    # Customize request
    my $request = $login->request();
    $request->NameIDPolicy()
      ->Format(Lasso::Constants::SAML2_NAME_IDENTIFIER_FORMAT_EMAIL);
    $request->NameIDPolicy()->AllowCreate(1);

    # Build authentication request
    unless ( $self->buildAuthnRequestMsg($login) ) {
        $self->lmLog( "Could not build authentication request on $idp",
            'error' );
        return;
    }

    return $login;
}

## @method Lasso::Login createLogin(Lasso::Server server)
# Create Lasso::Login object
# @param Lasso::Server server
# @return Lasso::Login object
sub createLogin {
    my ( $self, $server ) = splice @_;
    my $login;

    eval { $login = Lasso::Login->new($server); };

    if ($@) {
        $self->checkLassoError($@);
        return;
    }

    return $login;
}

## @method int getHttpMethod(Lasso::Server server, string idp)
# Find a compatible HTTP method
# @param Lasso::Server server
# @param string entityID
# @return int HTTP method
sub getHttpMethod {
    my ( $self, $server, $idp ) = splice @_;

    # TODO

    # By default, use HTTP REDIRECT
    no strict 'subs';
    return Lasso::Constants::HTTP_METHOD_REDIRECT;
}

## @method boolean initAuthnRequest(Lasso::Login login, string idp, int method)
# Init authentication request
# @param Lasso::Login login
# @param string entityID
# @param int HTTP method
# @return boolean result
sub initAuthnRequest {
    my ( $self, $login, $idp, $method ) = splice @_;

    eval { Lasso::Login::init_authn_request( $login, $idp, $method ); };

    return $self->checkLassoError($@);
}

## @method boolean buildAuthnRequestMsg(Lasso::Login login)
# Build authentication request message
# @param Lasso::Login login
# @return boolean result
sub buildAuthnRequestMsg {
    my ( $self, $login ) = splice @_;

    eval { Lasso::Login::build_authn_request_msg($login); };

    return $self->checkLassoError($@);
}

## @method boolean processAuthnResponseMsg(Lasso::Login login, string response)
# Process authentication response message
# @param login Lasso::Login object
# @param response SAML response
# @return result
sub processAuthnResponseMsg {
    my ( $self, $login, $response ) = splice @_;

    eval { Lasso::Login::process_authn_response_msg( $login, $response ); };

    return $self->checkLassoError($@);
}

## @method Lasso::Saml2NameID getNameIdentifer(Lasso::Profile profile)
# Get NameID from Lasso Profile
# @param profile Lasso::Profile object
# @return result or NULL if error
sub getNameIdentifier {
    my ( $self, $profile ) = splice @_;
    my $nameid;

    eval { $nameid = Lasso::Profile::get_nameIdentifier($profile); };

    if ($@) {
        $self->checkLassoError($@);
        return;
    }

    return $nameid;
}

## @method Lasso::Identity createIdentity(string dump)
# Create Lasso::Identity object
# @param dump optional Identity dump
# @return Lasso::Identity object
sub createIdentity {
    my ( $self, $dump ) = splice @_;
    my $identity;

    if ($dump) {
        eval { $identity = Lasso::Identity::new_from_dump($dump); };
    }
    else {
        eval { $identity = Lasso::Identity->new(); };
    }

    if ($@) {
        $self->checkLassoError($@);
        return;
    }

    return $identity;
}

## @method Lasso::Session createSession(string dump)
# Create Lasso::Session object
# @param dump optional Session dump
# @return Lasso::Session object
sub createSession {
    my ( $self, $dump ) = splice @_;
    my $session;

    if ($dump) {
        eval { $session = Lasso::Session::new_from_dump($dump); };
    }
    else {
        eval { $session = Lasso::Session->new(); };
    }

    if ($@) {
        $self->checkLassoError($@);
        return;
    }

    return $session;
}

## @method boolean acceptSSO(Lasso::Login login)
# Accept SSO from IDP
# @param login Lasso::Login object
# @return result
sub acceptSSO {
    my ( $self, $login ) = splice @_;

    eval { Lasso::Login::accept_sso($login); };

    return $self->checkLassoError($@);
}

## @method boolean extractRelayState(Lasso::Login login)
# Extract RelayState information into $self
## @param login Lasso::Login object
## @return result
sub extractRelayState {
    my ( $self, $login ) = splice @_;

    # Get relayState in assertion
    my $relaystate = $login->msg_relayState;

    return 0 unless $relaystate;

    # Decode base64
    $relaystate = decode_base64($relaystate);

    # Recover values
    my @values = split( /;/, $relaystate );

    # Push values in $self
    my $i;
    for ( $i = 0, $i < $#values, $i++ ) {
        $self->{ $values[$i] } = $values[ $i++ ];
    }

    return 1;
}

## @method Lasso::Node getAssertion(Lasso::Login login)
# Get assertion in Lasso::Login object
# @param login Lasso::Login object
# @return assertion Lasso::Node object
sub getAssertion {
    my ( $self, $login ) = splice @_;
    my $assertion;

    eval { $assertion = Lasso::Login::get_assertion($login); };

    if ($@) {
        $self->checkLassoError($@);
        return;
    }

    return $assertion;
}

## @method string getAttributeValue(string name, string format, string friendly_name, array_ref attributes)
# Get SAML attribute value corresponding to name, format and friendly_name
# Multivaluated values are separated by ';'
# @param name SAML attribute name
# @param format optional SAML attribute format
# @param friendly_name optional SAML attribute friendly name
# @return attribute value
sub getAttributeValue {
    my ( $self, $name, $format, $friendly_name, $attributes ) = splice @_;
    my $value;

    # Loop on attributes
    foreach (@$attributes) {
        my $attr_name   = $_->Name();
        my $attr_format = $_->NameFormat();
        my $attr_fname  = $_->FriendlyName();

        # Skip if name does not correspond to attribute name
        next if ( $name ne $attr_name );

        # Verify format and friendly name if given
        next if ( $format        and $format        ne $attr_format );
        next if ( $friendly_name and $friendly_name ne $attr_fname );

        # Attribute is found, return its content
        my @attr_values = $_->AttributeValue();

        foreach (@attr_values) {
            my $xs      = XML::Simple->new();
            my $data    = $xs->XMLin( $_->dump() );
            my $content = $data->{content};
            $value .= $content . ";" if $content;
        }
        $value =~ s/;$//;
    }

    return $value;
}

## @method boolean validateConditions(Lasso::Saml2::Assertion assertion, string entityID)
# Validate conditions
# @param assertion SAML2 assertion
# @param entityID relaying party entity ID
# @return result
sub validateConditions {
    my ( $self, $assertion, $entityID ) = splice @_;
    my $status;

    eval {
        $status =
          Lasso::Saml2Assertion::validate_conditions( $assertion, $entityID );
    };

    if ($@) {
        $self->checkLassoError($@);
        return 0;
    }

    unless ( $status eq Lasso::Constants::SAML2_ASSERTION_VALID ) {
        $self->lmLog( "Conditions validations result: $status", 'error' );
        return 0;
    }

    return 1;
}

1;

__END__

=head1 NAME

=encoding utf8

Lemonldap::NG::Portal::_SAML

=head1 SYNOPSIS

use Lemonldap::NG::Portal::_SAML;

=head1 DESCRIPTION

This module contains common methods for SAML authentication
and user information loading

=head1 METHODS

=head2 loadLasso

Load Lasso module

=head2 checkLassoError

Log Lasso error code and message if this is actually a Lasso::Error with code > 0

=head2 createServer

Load service metadata and create Lasso::Server object

=head2 addIDP

Add IDP to an existing Lasso::Server

=head2 addProvider

Add provider to an existing Lasso::Server

=head2 getOrganizationName

Return name of organization picked up from metadata

=head2 createAuthnRequest

Create authentication request for selected IDP

=head2 createLogin

Create Lasso::Login object

=head2 getHttpMethod

Find a compatible HTTP method

=head2 initAuthnRequest

Init authentication request

=head2 buildAuthnRequestMsg

Build authentication request message

=head2 processAuthnResponseMsg

Process authentication response message

=head2 getNameIdentifier

Get NameID from Lasso Profile

=head2 createIdentity

Create Lasso::Identity object

=head2 createSession

Create Lasso::Session object

=head2 acceptSSO

Accept SSO from IDP

=head2 extractRelayState

Extract RelayState information into $self

=head2 getAssertion

Get assertion in Lasso::Login object

=head2 getAttributeValue

Get SAML attribute value corresponding to name, format and friendly_name
Multivaluated values are separated by ';'

=head2 validateConditions

Validate conditions

=head1 SEE ALSO

L<Lemonldap::NG::Portal::AuthSAML>, L<Lemonldap::NG::Portal::UserDBSAML>

=head1 AUTHOR

Xavier Guimard, E<lt>x.guimard@free.frE<gt>,
Clement Oudot, E<lt>coudot@linagora.comE<gt>

=head1 COPYRIGHT AND LICENSE

Copyright (C) 2009 by Xavier Guimard, Clement Oudot

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.10.0 or,
at your option, any later version of Perl 5 you may have available.

=cut