# The LearningOnline Network with CAPA
# Launch External Tool Provider (LTI)
#
# $Id: lonexttool.pm,v 1.7 2017/11/30 14:41:20 raeburn Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#
=pod
=head1 NAME
Apache::lonexttool - Tool Provider launcher
=head1 SYNOPSIS
=head1 OVERVIEW
=cut
package Apache::lonexttool;
use strict;
use Apache::Constants qw(:common :http);
use Net::OAuth;
use Encode;
use Digest::SHA;
use UUID::Tiny ':std';
use HTML::Entities;
use Apache::lonlocal;
use Apache::lonnet;
use Apache::loncommon;
sub handler {
my $r=shift;
&Apache::loncommon::content_type($r,'text/html');
$r->send_http_header;
return OK if $r->header_only;
my $target=$env{'form.grade_target'};
# ------------------------------------------------------------ Print the screen
if ($target eq 'tex') {
$r->print(&Apache::lonprintout::print_latex_header($env{'form.latex_type'}));
}
# Is this even in a course?
unless ($env{'request.course.id'}) {
if ($target ne 'tex') {
&Apache::loncommon::simple_error_page($r,'','Not in a course');
} else {
$r->print('\textbf{Not in a course}\end{document}');
}
return OK;
}
my ($marker,$exttool) = (split(m{/},$r->uri))[4,5];
$marker=~s/\D//g;
if (!$marker) {
if ($target ne 'tex') {
$r->print(&mt('Invalid Call'));
} else {
$r->print('\textbf{'&mt('Invalid Call').'}\end{document}');
}
return OK;
}
my $cdom = $env{'course.'.$env{'request.course.id'}.'.domain'};
my $cnum = $env{'course.'.$env{'request.course.id'}.'.num'};
my $chome = $env{'course.'.$env{'request.course.id'}.'.home'};
my $is_tool;
if ($r->uri eq "/adm/$cdom/$cnum/$marker/$exttool") {
my %toolsettings=&Apache::lonnet::dump('exttool_'.$marker,$cdom,$cnum);
if ($toolsettings{'id'}) {
my $idx = $toolsettings{'id'};
my %ltitools = &Apache::lonnet::get_domain_lti($cdom,'consumer');
if (ref($ltitools{$idx}) eq 'HASH') {
my %toolhash = %{$ltitools{$idx}};
$toolhash{'display'} = {
target => $toolsettings{'target'},
width => $toolsettings{'width'},
height => $toolsettings{'height'},
};
$toolhash{'crslabel'} = $toolsettings{'crslabel'};
$toolhash{'crstitle'} = $toolsettings{'crstitle'};
$toolhash{'crsappend'} = $toolsettings{'crsappend'};
$is_tool = 1;
my $launchok = 1;
if ($target eq 'tex') {
$r->print(&mt('External Tool'));
} else {
my $now = time;
if ($toolhash{'passback'}) {
unless (&set_callback_secret($cdom,$cnum,$marker,'grade',$now,
\%toolsettings,\%toolhash) eq 'ok') {
undef($launchok);
}
}
if ($toolhash{'roster'}) {
&set_callback_secret($cdom,$cnum,$marker,'roster',$now,
\%toolsettings,\%toolhash);
}
my $submittext = &mt('Launch [_1]',$toolhash{'title'});
if (($toolhash{'key'} ne '') && ($toolhash{'secret'} ne '') &&
($toolhash{'url'} ne '') && ($launchok)) {
my %lti = <i_params($r,$cnum,$cdom,$idx,$submittext,\%toolhash);
my $url = $toolhash{'url'};
if ($toolhash{'crsappend'} ne '') {
$url .= $toolhash{'crsappend'};
}
$r->print(&launch_html($url,$toolhash{'key'},$toolhash{'secret'},
$submittext,\%lti));
} else {
$r->print('<div>'.&mt('External Tool Unavailable').'</div>');
}
}
}
}
}
unless ($is_tool) {
if ($target ne 'tex') {
$r->print('<div>'.&mt('Invalid Call').'</div>');
} else {
$r->print('\textbf{'.&mt(Invalid Call).'}\end{document}');
}
}
return OK;
}
sub set_callback_secret {
my ($cdom,$cnum,$marker,$name,$now,$toolsettings,$toolhash) = @_;
return unless ((ref($toolsettings) eq 'HASH') && (ref($toolhash) eq 'HASH'));
my $warning;
my ($needsnew,$oldsecret,$lifetime);
if ($name eq 'grade') {
$lifetime = $toolhash->{'passbackvalid'}
} elsif ($name eq 'roster') {
$lifetime = $toolhash->{'rostervalid'};
}
if ($toolsettings->{$name} eq '') {
$needsnew = 1;
} elsif (($toolsettings->{$name.'date'} + $lifetime) < $now) {
$oldsecret = $toolsettings->{$name.'secret'};
$needsnew = 1;
}
if ($needsnew) {
if (&get_tool_lock($cdom,$cnum,$marker,$now) eq 'ok') {
my $secret = UUID::Tiny::create_uuid_as_string(UUID_V4);
$toolhash->{$name.'secret'} = $secret;
my %secrethash = (
$name.'secret' => $secret,
$name.'secretdate' => $now,
);
if ($oldsecret ne '') {
$secrethash{'old'.$name.'secret'} = $oldsecret;
}
my $putres = &Apache::lonnet::put('exttool_'.$marker,
\%secrethash,$cdom,$cnum);
my $delresult = &release_tool_lock($cdom,$cnum,$marker);
if ($delresult ne 'ok') {
$warning = $delresult ;
}
if ($putres eq 'ok') {
return 'ok';
}
} else {
$warning = '<span class="LC_error">'.
&mt('Could not obtain exclusive lock').
'</span>';
}
} else {
$toolhash->{$name.'secret'} = $toolsettings->{$name.'secret'};
return 'ok';
}
return;
}
sub lti_params {
my ($r,$cnum,$cdom,$idx,$submittext,$toolsref) = @_;
my ($version,$context_type,$msgtype,$toolname,$passback,$roster,$locale,
$crslabel,$crstitle,$gradesecret,$rostersecret,%fields,%rolesmap,
%display,%custom,@userlangs);
if (ref($toolsref) eq 'HASH') {
$version = $toolsref->{'version'};
$toolname = $toolsref->{'title'};
$passback = $toolsref->{'passback'};
$gradesecret = $toolsref->{'gradesecret'};
$roster = $toolsref->{'roster'};
$rostersecret = $toolsref->{'rostersecret'};
$msgtype = $toolsref->{'messagetype'};
if (ref($toolsref->{'fields'}) eq 'HASH') {
%fields = %{$toolsref->{'fields'}};
}
if (ref($toolsref->{'roles'}) eq 'HASH') {
%rolesmap = %{$toolsref->{'roles'}};
}
if (ref($toolsref->{'display'}) eq 'HASH') {
%display = %{$toolsref->{'display'}};
}
if (ref($toolsref->{'custom'}) eq 'HASH') {
%custom = %{$toolsref->{'custom'}};
}
$crslabel = $toolsref->{'crslabel'};
$crstitle = $toolsref->{'crstitle'};
}
if ($version eq '') {
$version = 'LTI-1p0';
}
if ($context_type eq '') {
$context_type = 'CourseSection';
}
if ($msgtype eq '') {
$msgtype = 'basic-lti-launch-request';
}
if ($crslabel eq '') {
$crslabel = $env{'course.'.$env{'request.course.id'}.'.internal.coursecode'},
}
if ($crstitle eq '') {
$crstitle = $env{'course.'.$env{'request.course.id'}.'.description'},;
}
my $lonhost = $r->dir_config('lonHostID');
my $loncaparev = $r->dir_config('lonVersion');
my $uname = $env{'user.name'};
my $udom = $env{'user.domain'};
my @possroles = qw(Instructor ContentDeveloper TeachingAssistant Learner);
my ($roleprefix) = ($env{'request.role'} =~ /^(\w+)\./);
my $ltirole = $rolesmap{$roleprefix};
unless (grep(/^\Q$ltirole\E$/,@possroles)) {
$ltirole = 'Learner';
}
my $digest_user = &Encode::decode_utf8($uname.':'.$udom);
$digest_user = &Digest::SHA::sha1_hex($digest_user);
if ($env{'course.'.$env{'request.course.id'}.'.languages'} ne '') {
@userlangs=(@userlangs,split(/\s*(\,|\;|\:)\s*/,
$env{'course.'.$env{'request.course.id'}.'.languages'}));
} else {
my %langhash = &Apache::loncommon::getlangs($uname,$udom);
if ($langhash{'languages'} ne '') {
@userlangs = split(/\s*(\,|\;|\:)\s*/,$langhash{'languages'});
} else {
my %domdefs = &Apache::lonnet::get_domain_defaults($udom);
if ($domdefs{'lang_def'} ne '') {
@userlangs = ($domdefs{'lang_def'});
}
}
}
if (scalar(@userlangs) == 1) {
$locale = $userlangs[0];
}
my ($title,$digest_symb);
my ($symb) = &Apache::lonnet::whichuser();
if ($symb) {
$digest_symb = &Encode::decode_utf8($symb);
$digest_symb = &Digest::SHA::sha1_hex($digest_symb);
my $navmap = Apache::lonnavmaps::navmap->new();
if (ref($navmap)) {
my $res = $navmap->getBySymb($symb);
if (ref($res)) {
$title = $res->compTitle();
}
}
}
my $domdesc = &Apache::lonnet::domain($cdom);
my $primary_id = &Apache::lonnet::domain($cdom,'primary');
my $int_dom = &Apache::lonnet::internet_dom($primary_id);
my $portal_url = &Apache::lonnet::course_portal_url($cnum,$cdom);
my %ltiparams = (
lti_version => $version,
lti_message_type => $msgtype,
resource_link_title => $title,
resource_link_id => $digest_symb,
tool_consumer_instance_guid => $lonhost,
tool_consumer_instance_description => $domdesc,
tool_consumer_info_product_family_code => 'loncapa',
tool_consumer_instance_name => $int_dom,
tool_consumer_instance_url => $portal_url,
tool_consumer_info_version => $loncaparev,
user_id => $digest_user,
roles => $ltirole,
context_id => $env{'request.course.id'},
context_type => $context_type,
context_label => $crslabel,
context_title => $crstitle,
launch_presentation_locale => $locale,
);
my $crshome = $env{'course.'.$env{'request.course.id'}.'.home'};
my $crshostname = &Apache::lonnet::hostname($crshome);
if ($crshostname) {
my $crsprotocol = $Apache::lonnet::protocol{$crshome};
unless ($crsprotocol eq 'https') {
$crsprotocol = 'http';
}
if (($passback) || ($roster)) {
if ($passback) {
$ltiparams{'lis_outcome_service_url'} = $crsprotocol.'//'.$crshostname.'/adm/service/passback';
$ltiparams{'ext_ims_lis_basic_outcome_url'} = $ltiparams{'lis_outcome_service_url'};
if ($gradesecret) {
my $result_sig =
Digest::SHA::sha1_hex($gradesecret.':::'.$digest_symb.':::'.$digest_user.':::'.$env{'request.course.id'});
$ltiparams{'lis_result_sourcedid'} =
$result_sig.':::'.$digest_symb.':::'.$digest_user.':::'.$env{'request.course.id'};
}
}
if ($roster) {
if (&Apache::lonnet::allowed('opa',$env{'request.course.id'})) {
$ltiparams{'ext_ims_lis_memberships_url'} = $crsprotocol.'//'.$crshostname.'/adm/service/roster';
if ($rostersecret) {
my $roster_sig = Digest::SHA::sha1_hex($gradesecret.':::'.$digest_symb.':::'.$env{'request.course.id'});
$ltiparams{'ext_ims_lis_memberships_id'} = $roster_sig.':::'.$digest_symb.':::'.$env{'request.course.id'};
}
}
}
my %digesthash;
if ($ltiparams{'lis_result_sourcedid'}) {
$digesthash{$ltiparams{'lis_result_sourcedid'}} = "$idx\0".time;
}
if ($ltiparams{'ext_ims_lis_memberships_id'}) {
$digesthash{$ltiparams{'ext_ims_lis_memberships_id'}} = "$idx\0".time;
}
if (($digest_symb) && ($gradesecret || $rostersecret)) {
$digesthash{$digest_symb} = $symb;
}
if (($passback) && ($gradesecret)) {
$digesthash{$digest_user} = $uname.':'.$udom;
}
if (keys(%digesthash)) {
&Apache::lonnet::put('exttools',\%digesthash,$cdom,$cnum);
}
}
}
if ($display{'target'}) {
$ltiparams{'launch_presentation_document_target'} = $display{'target'};
}
if ($display{'width'}) {
$ltiparams{'launch_presentation_width'} = $display{'width'};
}
if ($display{'height'}) {
$ltiparams{'launch_presentation_height'} = $display{'height'};
}
if ($fields{'firstname'}) {
$ltiparams{'lis_person_name_given'} = $env{'environment.firstname'};
}
if ($fields{'lastname'}) {
$ltiparams{'lis_person_name_family'} = $env{'environment.lastname'};
}
if ($fields{'fullname'}) {
$ltiparams{'lis_person_name_full'} = &Apache::loncommon::plainname($uname,$udom);
}
if ($fields{'email'}) {
my %emails = &Apache::loncommon::getemails($uname,$udom);
my $contact_email;
foreach my $type ('permanentemail','critnotification','notification') {
if ($emails{$type} =~ /\@/) {
$contact_email = $emails{$type};
last;
}
}
$ltiparams{'lis_person_contact_email_primary'} = $contact_email;
}
if ($fields{'user'}) {
$ltiparams{'lis_person_sourcedid'} = $uname.':'.$udom;
}
if (keys(%custom)) {
foreach my $key (keys(%custom)) {
my $value = $custom{$key};
$value =~ s/^\s+|\s+\$//g;
if ($value =~ /^\QLONCAPA::env{\E([^\}]+)\}$/) {
if (exists($env{$1})) {
$value = $env{$1};
}
}
$ltiparams{'custom_'.$key} = $value;
}
}
foreach my $key (keys(%ltiparams)) {
$ltiparams{$key} = &Encode::decode_utf8($ltiparams{$key});
}
$ltiparams{'basiclti_submit'} = $submittext;
return %ltiparams;
}
sub launch_html {
my ($url,$key,$secret,$submittext,$paramsref) = @_;
my $hashref = &sign_params($url,$key,$secret,$paramsref);
my $action = &HTML::Entities::encode($url,'<>&"');
my $form = <<"END";
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
<body>
<div id="LCltiLaunch">
<form name="LCltiLaunchForm" id="LCltiLaunchFormId" action="$action" method="post" encType="application/x-www-form-urlencoded">
END
if (ref($hashref) eq 'HASH') {
foreach my $item (keys(%{$hashref})) {
my $type = 'hidden';
if ($item eq 'basiclti_submit') {
$type = 'submit';
}
$form .= '<input type="'.$type.'" name="'.$item.'" value="'.$hashref->{$item}.'" id="id_'.$item.'" />'."\n";
}
}
$form .= "</form></div>\n";
$form .= <<"ENDJS";
<script type="text/javascript">
document.getElementById("LCltiLaunch").style.display = "none";
nei = document.createElement('input');
nei.setAttribute('type','hidden');
nei.setAttribute('name','basiclti_submit');
nei.setAttribute('value','$submittext');
document.getElementById("LCltiLaunchFormId").appendChild(nei);
document.LCltiLaunchForm.submit();
</script>
ENDJS
$form .= "</body></html>\n";
return $form;
}
sub sign_params {
my ($url,$key,$secret,$paramsref) = @_;
my $nonce = Digest::SHA::sha1_hex(sprintf("%06x%06x",rand(0xfffff0),rand(0xfffff0)));
my $request = Net::OAuth->request("request token")->new(
consumer_key => $key,
consumer_secret => $secret,
request_url => $url,
request_method => 'POST',
signature_method => 'HMAC-SHA1',
timestamp => time,
nonce => $nonce,
callback => 'about:blank',
extra_params => $paramsref,
version => '1.0',
);
$request->sign;
return $request->to_hash();
}
sub get_tool_lock {
my ($cdom,$cnum,$marker,$now) = @_;
# get lock for tool for which gradesecret is being set
my $lockhash = {
$marker."\0".'lock' => $now.':'.$env{'user.name'}.
':'.$env{'user.domain'},
};
my $tries = 0;
my $gotlock = &Apache::lonnet::newput('exttools',$lockhash,$cdom,$cnum);
while (($gotlock ne 'ok') && $tries <3) {
$tries ++;
sleep(1);
$gotlock = &Apache::lonnet::newput('exttools',$lockhash,$cdom,$cnum);
}
return $gotlock;
}
sub release_tool_lock {
my ($cdom,$cnum,$marker) = @_;
# remove lock
my @del_lock = ($marker."\0".'lock');
my $dellockoutcome=&Apache::lonnet::del('exttools',\@del_lock,$cdom,$cnum);
if ($dellockoutcome ne 'ok') {
return ('<div class="LC_error">'
.&mt('Warning: failed to release lock for exttool: [_1].','<tt>'.$marker.'</tt>')
.'</div>'
);
} else {
return 'ok';
}
}
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