# The LearningOnline Network with CAPA
# Utility functions for managing LON-CAPA LTI interactions
#
# $Id: ltiutils.pm,v 1.21 2024/02/27 04:04:06 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/
#
package LONCAPA::ltiutils;
use strict;
use Net::OAuth;
use Digest::SHA;
use Digest::MD5 qw(md5_hex);
use Encode;
use UUID::Tiny ':std';
use Apache::lonnet;
use Apache::loncommon;
use Apache::loncoursedata;
use Apache::lonuserutils;
use Apache::lonenc();
use Apache::longroup();
use Apache::lonlocal;
use Math::Round();
use LONCAPA::Lond;
use LONCAPA qw(:DEFAULT :match);
#
# LON-CAPA as LTI Consumer or LTI Provider
#
# Determine if a nonce in POSTed data has expired.
# If unexpired, confirm it has not already been used.
#
# When LON-CAPA is operating as a Consumer, nonce checking
# occurs when a Tool Provider launched from an instance of
# an external tool in a LON-CAPA course makes a request to
# (a) /adm/service/roster or (b) /adm/service/passback to,
# respectively, retrieve a roster or store the grade for
# the original launch by a specific user.
#
# When LON-CAPA is operating as a Provider, nonce checking
# occurs when a user in course context in another LMS (the
# Consumer) launches an external tool to access a LON-CAPA URL:
# /adm/lti/ with LON-CAPA symb, map, or deep-link ID appended.
#
sub check_nonce {
my ($nonce,$timestamp,$lifetime,$domain,$ltidir) = @_;
if (($ltidir eq '') || ($timestamp eq '') || ($timestamp =~ /^\D/) ||
($lifetime eq '') || ($lifetime =~ /\D/) || ($domain eq '')) {
return;
}
my $now = time;
if (($timestamp) && ($timestamp < ($now - $lifetime))) {
return;
}
if ($nonce eq '') {
return;
}
if (-e "$ltidir/$domain/$nonce") {
return;
} else {
unless (-e "$ltidir/$domain") {
unless (mkdir("$ltidir/$domain",0755)) {
return;
}
}
if (open(my $fh,'>',"$ltidir/$domain/$nonce")) {
print $fh $now;
close($fh);
return 1;
}
}
return;
}
#
# LON-CAPA as LTI Consumer
#
# Determine the domain and the courseID of the LON-CAPA course
# for which access is needed by a Tool Provider -- either to
# retrieve a roster or store the grade for an instance of an
# external tool in the course.
#
sub get_loncapa_course {
my ($lonhost,$cid,$errors) = @_;
return unless (ref($errors) eq 'HASH');
my ($cdom,$cnum);
if ($cid =~ /^($match_domain)_($match_courseid)$/) {
my ($posscdom,$posscnum) = ($1,$2);
my $cprimary_id = &Apache::lonnet::domain($posscdom,'primary');
if ($cprimary_id eq '') {
$errors->{5} = 1;
return;
} else {
my @intdoms;
my $internet_names = &Apache::lonnet::get_internet_names($lonhost);
if (ref($internet_names) eq 'ARRAY') {
@intdoms = @{$internet_names};
}
my $cintdom = &Apache::lonnet::internet_dom($cprimary_id);
if (($cintdom ne '') && (grep(/^\Q$cintdom\E$/,@intdoms))) {
$cdom = $posscdom;
} else {
$errors->{6} = 1;
return;
}
}
my $chome = &Apache::lonnet::homeserver($posscnum,$posscdom);
if ($chome =~ /(con_lost|no_host|no_such_host)/) {
$errors->{7} = 1;
return;
} else {
$cnum = $posscnum;
}
} else {
$errors->{8} = 1;
return;
}
return ($cdom,$cnum);
}
#
# LON-CAPA as LTI Consumer
#
# Determine the symb and (optionally) LON-CAPA user for an
# instance of an external tool in a course -- either to
# to retrieve a roster or store a grade.
#
# Use the digested symb to lookup the real symb in exttools.db
# and the digested userID to lookup the real userID (if needed).
# and extract the exttool instance and symb.
#
sub get_tool_instance {
my ($cdom,$cnum,$digsymb,$diguser,$errors) = @_;
return unless (ref($errors) eq 'HASH');
my ($marker,$symb,$uname,$udom);
my @keys = ($digsymb);
if ($diguser) {
push(@keys,$diguser);
}
my %digesthash = &Apache::lonnet::get('exttools',\@keys,$cdom,$cnum);
if ($digsymb) {
$symb = $digesthash{$digsymb};
if ($symb) {
my ($map,$id,$url) = split(/___/,$symb);
$marker = (split(m{/},$url))[3];
$marker=~s/\D//g;
} else {
$errors->{9} = 1;
}
}
if ($diguser) {
if ($digesthash{$diguser} =~ /^($match_username):($match_domain)$/) {
($uname,$udom) = ($1,$2);
} else {
$errors->{10} = 1;
}
return ($marker,$symb,$uname,$udom);
} else {
return ($marker,$symb);
}
}
#
# LON-CAPA as LTI Consumer
#
# Retrieve data needed to validate a request from a Tool Provider
# for a roster or to store a grade for an instance of an external
# tool in a LON-CAPA course.
#
# Retrieve the Consumer key and Consumer secret from the domain
# configuration or the Tool Provider ID stored in the
# exttool_$marker db file and compare the Consumer key with the
# one in the POSTed data.
#
# Side effect is to populate the $toolsettings hashref with the
# contents of the .db file (instance of tool in course) and the
# $ltitools hashref with the configuration for the tool (at
# domain level).
#
sub get_tool_secret {
my ($key,$marker,$symb,$cdom,$cnum,$toolsettings,$ltitools,$errors) = @_;
return unless ((ref($toolsettings) eq 'HASH') && (ref($ltitools) eq 'HASH') &&
(ref($errors) eq 'HASH'));
my ($consumer_secret,$nonce_lifetime);
if ($marker) {
%{$toolsettings}=&Apache::lonnet::dump('exttool_'.$marker,$cdom,$cnum);
if ($toolsettings->{'id'}) {
my $idx = $toolsettings->{'id'};
my ($crsdef,$ltinum);
if ($idx =~ /^c(\d+)$/) {
$ltinum = $1;
$crsdef = 1;
my %crslti = &Apache::lonnet::get_course_lti($cnum,$cdom,'consumer');
if (ref($crslti{$ltinum}) eq 'HASH') {
%{$ltitools} = %{$crslti{$ltinum}};
} else {
undef($ltinum);
}
} elsif ($idx =~ /^\d+$/) {
my %lti = &Apache::lonnet::get_domain_lti($cdom,'consumer');
if (ref($lti{$idx}) eq 'HASH') {
%{$ltitools} = %{$lti{$idx}};
$ltinum = $idx;
}
}
if ($ltinum ne '') {
my $loncaparev = &Apache::lonnet::get_server_loncaparev($cdom);
my $keynum = $ltitools->{'cipher'};
my ($poss_key,$poss_secret) =
&LONCAPA::Lond::get_lti_credentials($cdom,$cnum,$crsdef,'tools',$ltinum,$keynum,$loncaparev);
if ($poss_key eq $key) {
$consumer_secret = $poss_secret;
$nonce_lifetime = $ltitools->{'lifetime'};
} else {
$errors->{11} = 1;
return;
}
} else {
$errors->{12} = 1;
return;
}
} else {
$errors->{13} = 1;
return;
}
} else {
$errors->{14};
return;
}
return ($consumer_secret,$nonce_lifetime);
}
#
# LON-CAPA as LTI Consumer
#
# Verify a signed request using the consumer_key and
# secret for the specific LTI Provider.
#
# FIXME Move to Lond.pm and perform on course's homeserver
sub verify_request {
my ($oauthtype,$protocol,$hostname,$requri,$reqmethod,$consumer_secret,$params,
$authheaders,$errors) = @_;
unless (ref($errors) eq 'HASH') {
$errors->{15} = 1;
return;
}
my $request;
if ($oauthtype eq 'consumer') {
my $oauthreq = Net::OAuth->request('consumer');
$oauthreq->add_required_message_params('body_hash');
$request = $oauthreq->from_authorization_header($authheaders,
request_url => $protocol.'://'.$hostname.$requri,
request_method => $reqmethod,
consumer_secret => $consumer_secret,);
} else {
$request = Net::OAuth->request('request token')->from_hash($params,
request_url => $protocol.'://'.$hostname.$requri,
request_method => $reqmethod,
consumer_secret => $consumer_secret,);
}
unless ($request->verify()) {
$errors->{15} = 1;
return;
}
}
#
# LON-CAPA as LTI Consumer
#
# Verify that an item identifier (either roster request:
# ext_ims_lis_memberships_id, or grade store:
# lis_result_sourcedid) has not been tampered with, and
# the secret used to create the unique identifier has not
# expired.
#
# Prepending the current secret (if still valid),
# or the previous secret (if current one is no longer valid),
# to a string composed of the :::-separated components
# must generate the result signature in the lis item ID
# sent by the Tool Provider.
#
sub verify_lis_item {
my ($sigrec,$context,$digsymb,$diguser,$cdom,$cnum,$toolsettings,$ltitools,$errors) = @_;
return unless ((ref($toolsettings) eq 'HASH') && (ref($ltitools) eq 'HASH') &&
(ref($errors) eq 'HASH'));
my ($has_action, $valid_for);
if ($context eq 'grade') {
$has_action = $ltitools->{'passback'};
$valid_for = $ltitools->{'passbackvalid'} * 86400; # convert days to seconds
} elsif ($context eq 'roster') {
$has_action = $ltitools->{'roster'};
$valid_for = $ltitools->{'rostervalid'};
}
if ($has_action) {
my $secret;
if (($toolsettings->{$context.'secretdate'} + $valid_for) > time) {
$secret = $toolsettings->{$context.'secret'};
} else {
$secret = $toolsettings->{'old'.$context.'secret'};
}
if ($secret) {
my $expected_sig;
if ($context eq 'grade') {
my $uniqid = $digsymb.':::'.$diguser.':::'.$cdom.'_'.$cnum;
$expected_sig = (split(/:::/,&get_service_id($secret,$uniqid)))[0];
if ($expected_sig eq $sigrec) {
return 1;
} else {
$errors->{18} = 1;
}
} elsif ($context eq 'roster') {
my $uniqid = $digsymb.':::'.$cdom.'_'.$cnum;
$expected_sig = (split(/:::/,&get_service_id($secret,$uniqid)))[0];
if ($expected_sig eq $sigrec) {
return 1;
} else {
$errors->{19} = 1;
}
}
} else {
$errors->{20} = 1;
}
} else {
$errors->{21} = 1;
}
return;
}
#
# LON-CAPA as LTI Consumer
#
# Sign a request used to launch an instance of an external
# tool in a LON-CAPA course, using the key and secret supplied
# by the Tool Provider.
#
sub sign_params {
my ($url,$key,$secret,$paramsref,$sigmethod,$type,$callback,$post) = @_;
return unless (ref($paramsref) eq 'HASH');
if ($sigmethod eq '') {
$sigmethod = 'HMAC-SHA1';
}
if ($type eq '') {
$type = 'request token';
}
if ($callback eq '') {
$callback = 'about:blank',
}
srand( time() ^ ($$ + ($$ << 15)) ); # Seed rand.
my $nonce = Digest::SHA::sha1_hex(sprintf("%06x%06x",rand(0xfffff0),rand(0xfffff0)));
my $request = Net::OAuth->request($type)->new(
consumer_key => $key,
consumer_secret => $secret,
request_url => $url,
request_method => 'POST',
signature_method => $sigmethod,
timestamp => time,
nonce => $nonce,
callback => $callback,
extra_params => $paramsref,
version => '1.0',
);
$request->sign();
if ($post) {
return $request->to_post_body();
} else {
return $request->to_hash();
}
}
#
# LON-CAPA as LTI Consumer
#
# Generate a signature for a unique identifier (roster request:
# ext_ims_lis_memberships_id, or grade store: lis_result_sourcedid)
#
sub get_service_id {
my ($secret,$id) = @_;
my $sig = Digest::SHA::sha1_hex($secret.':::'.$id);
return $sig.':::'.$id;
}
#
# LON-CAPA as LTI Consumer
#
# Generate and store the time-limited secret used to create the
# signature in a service request identifier (roster request or
# grade store). An existing secret past its expiration date
# will be stored as old<service name>secret, and a new secret
# <service name>secret will be stored.
#
# Secrets are specific to service name and to the tool instance
# (and are stored in the exttool_$marker db file).
# The time period a secret remains valid is determined by the
# domain configuration for the specific tool and the service.
#
sub set_service_secret {
my ($cdom,$cnum,$marker,$name,$now,$toolsettings,$ltitools) = @_;
return unless ((ref($toolsettings) eq 'HASH') && (ref($ltitools) eq 'HASH'));
my $warning;
my ($needsnew,$oldsecret,$lifetime);
if ($name eq 'grade') {
$lifetime = $ltitools->{'passbackvalid'} * 86400; # convert days to seconds
} elsif ($name eq 'roster') {
$lifetime = $ltitools->{'rostervalid'};
}
if ($toolsettings->{$name.'secret'} eq '') {
$needsnew = 1;
} elsif (($toolsettings->{$name.'secretdate'} + $lifetime) < $now) {
$oldsecret = $toolsettings->{$name.'secret'};
$needsnew = 1;
}
if ($needsnew) {
if (&get_tool_lock($cdom,$cnum,$marker,$name,$now) eq 'ok') {
my $secret = UUID::Tiny::create_uuid_as_string(UUID_V4);
$toolsettings->{$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,$name);
if ($delresult ne 'ok') {
$warning = $delresult ;
}
if ($putres eq 'ok') {
return 'ok';
}
} else {
$warning = 'Could not obtain exclusive lock';
}
} else {
return 'ok';
}
return;
}
#
# LON-CAPA as LTI Consumer
#
# Add a lock key to exttools.db for the instance of an external tool
# when generating and storing a service secret.
#
sub get_tool_lock {
my ($cdom,$cnum,$marker,$name,$now) = @_;
# get lock for tool for which secret is being set
my $lockhash = {
$name."\0".$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 $gotlock;
}
#
# LON-CAPA as LTI Consumer
#
# Remove a lock key from exttools.db for the instance of an external
# tool created when generating and storing a service secret.
#
sub release_tool_lock {
my ($cdom,$cnum,$marker,$name) = @_;
# remove lock
my @del_lock = ($name."\0".$marker."\0".'lock');
my $dellockoutcome=&Apache::lonnet::del('exttools',\@del_lock,$cdom,$cnum);
if ($dellockoutcome ne 'ok') {
return 'Warning: failed to release lock for exttool';
} else {
return 'ok';
}
}
#
# LON-CAPA as LTI Consumer
#
# Parse XML containing grade data sent by an LTI Provider
#
sub parse_grade_xml {
my ($xml) = @_;
my %data = ();
my $count = 0;
my @state = ();
my $p = HTML::Parser->new(
xml_mode => 1,
start_h =>
[sub {
my ($tagname, $attr) = @_;
push(@state,$tagname);
if ("@state" eq "imsx_POXEnvelopeRequest imsx_POXBody replaceResultRequest resultRecord") {
$count ++;
}
}, "tagname, attr"],
text_h =>
[sub {
my ($text) = @_;
if ("@state" eq "imsx_POXEnvelopeRequest imsx_POXBody replaceResultRequest resultRecord sourcedGUID sourcedId") {
$data{$count}{sourcedid} = $text;
} elsif ("@state" eq "imsx_POXEnvelopeRequest imsx_POXBody replaceResultRequest resultRecord result resultScore textString") {
$data{$count}{score} = $text;
}
}, "dtext"],
end_h =>
[sub {
my ($tagname) = @_;
pop @state;
}, "tagname"],
);
$p->parse($xml);
$p->eof;
return %data;
}
#
# LON-CAPA as LTI Provider
#
# Use the part of the launch URL after /adm/lti to determine
# the scope for the current session (i.e., restricted to a
# single resource, to a single folder/map, or to an entire
# course).
#
# Returns an array containing scope: resource, map, or course
# and the LON-CAPA URL that is displayed post-launch, including
# accommodation of URL encryption, and translation of a tiny URL
# to the actual URL
#
sub lti_provider_scope {
my ($tail,$cdom,$cnum,$getunenc) = @_;
my ($scope,$realuri,$passkey,$unencsymb);
if ($tail =~ m{^/?uploaded/$cdom/$cnum/(?:default|supplemental)(?:|_\d+)\.(?:sequence|page)(|___\d+___.+)$}) {
my $rest = $1;
if ($rest eq '') {
$scope = 'map';
$realuri = $tail;
} else {
my $symb = $tail;
$symb =~ s{^/}{};
my ($map,$resid,$url) = &Apache::lonnet::decode_symb($symb);
$realuri = &Apache::lonnet::clutter($url);
if ($url =~ /\.sequence$/) {
$scope = 'map';
} else {
$scope = 'resource';
$realuri .= '?symb='.$symb;
$passkey = $symb;
if ($getunenc) {
$unencsymb = $symb;
}
}
}
} elsif ($tail =~ m{^/?res/$match_domain/$match_username/.+\.(?:sequence|page)(|___\d+___.+)$}) {
my $rest = $1;
if ($rest eq '') {
$scope = 'map';
$realuri = $tail;
} else {
my $symb = $tail;
$symb =~ s{^/?res/}{};
my ($map,$resid,$url) = &Apache::lonnet::decode_symb($symb);
$realuri = &Apache::lonnet::clutter($url);
if ($url =~ /\.sequence$/) {
$scope = 'map';
} else {
$scope = 'resource';
$realuri .= '?symb='.$symb;
$passkey = $symb;
if ($getunenc) {
$unencsymb = $symb;
}
}
}
} elsif ($tail =~ m{^/tiny/$cdom/(\w+)$}) {
my $key = $1;
my $tinyurl;
my ($result,$cached)=&Apache::lonnet::is_cached_new('tiny',$cdom."\0".$key);
if (defined($cached)) {
$tinyurl = $result;
} else {
my $configuname = &Apache::lonnet::get_domainconfiguser($cdom);
my %currtiny = &Apache::lonnet::get('tiny',[$key],$cdom,$configuname);
if ($currtiny{$key} ne '') {
$tinyurl = $currtiny{$key};
&Apache::lonnet::do_cache_new('tiny',$cdom."\0".$key,$currtiny{$key},600);
}
}
if ($tinyurl ne '') {
my ($cnum,$symb) = split(/\&/,$tinyurl,2);
my ($map,$resid,$url) = &Apache::lonnet::decode_symb($symb);
if ($url =~ /\.(page|sequence)$/) {
$scope = 'map';
} else {
$scope = 'resource';
}
$passkey = $symb;
if ((&Apache::lonnet::EXT('resource.0.encrypturl',$symb) =~ /^yes$/i) &&
(!$env{'request.role.adv'})) {
$realuri = &Apache::lonenc::encrypted(&Apache::lonnet::clutter($url));
if ($scope eq 'resource') {
$realuri .= '?symb='.&Apache::lonenc::encrypted($symb);
}
} else {
$realuri = &Apache::lonnet::clutter($url);
if ($scope eq 'resource') {
$realuri .= '?symb='.$symb;
}
}
if ($getunenc) {
$unencsymb = $symb;
}
}
} elsif (($tail =~ m{^/$cdom/$cnum$}) || ($tail eq '')) {
$scope = 'course';
$realuri = '/adm/navmaps';
$passkey = '';
}
if ($scope eq 'map') {
$passkey = $realuri;
}
if (wantarray) {
return ($scope,$realuri,$unencsymb);
} else {
return $passkey;
}
}
#
# LON-CAPA as LTI Provider
#
# Obtain a list of course personnel and students from
# the LTI Consumer which launched this instance.
#
sub get_roster {
my ($cdom,$cnum,$ltinum,$keynum,$id,$url) = @_;
my %ltiparams = (
lti_version => 'LTI-1p0',
lti_message_type => 'basic-lis-readmembershipsforcontext',
ext_ims_lis_memberships_id => $id,
);
my %info = ();
my ($status,$hashref) =
&Apache::lonnet::sign_lti($cdom,$cnum,'','lti','roster',$url,$ltinum,$keynum,\%ltiparams,\%info);
if (($status eq 'ok') && (ref($hashref) eq 'HASH')) {
my $request=new HTTP::Request('POST',$url);
$request->content(join('&',map {
my $name = escape($_);
"$name=" . ( ref($hashref->{$_}) eq 'ARRAY'
? join("&$name=", map {escape($_) } @{$hashref->{$_}})
: &escape($hashref->{$_}) );
} keys(%{$hashref})));
my $response = &LONCAPA::LWPReq::makerequest('',$request,'','',10);
my $message=$response->status_line;
if (($response->is_success) && ($response->content ne '')) {
my %data = ();
my $count = 0;
my @state = ();
my @items = ('user_id','roles','person_sourcedid','person_name_given','person_name_family',
'person_contact_email_primary','person_name_full','lis_result_sourcedid');
my $p = HTML::Parser->new
(
xml_mode => 1,
start_h =>
[sub {
my ($tagname, $attr) = @_;
push(@state,$tagname);
if ("@state" eq "message_response memberships member") {
$count ++;
}
}, "tagname, attr"],
text_h =>
[sub {
my ($text) = @_;
foreach my $item (@items) {
if ("@state" eq "message_response memberships member $item") {
$data{$count}{$item} = $text;
}
}
}, "dtext"],
end_h =>
[sub {
my ($tagname) = @_;
pop @state;
}, "tagname"],
);
$p->parse($response->content);
$p->eof;
return %data;
}
}
return;
}
#
# LON-CAPA as LTI Provider
#
# Passback a grade for a user to the LTI Consumer which originally
# provided the lis_result_sourcedid
#
sub send_grade {
my ($cdom,$cnum,$crsdef,$type,$ltinum,$keynum,$id,$url,$scoretype,$sigmethod,$msgformat,$total,$possible) = @_;
my $score;
if ($possible > 0) {
if ($scoretype eq 'ratio') {
$score = Math::Round::round($total).'/'.Math::Round::round($possible);
} elsif ($scoretype eq 'percentage') {
$score = (100.0*$total)/$possible;
$score = Math::Round::round($score);
} else {
$score = $total/$possible;
$score = sprintf("%.4f",$score);
}
}
if ($sigmethod eq '') {
$sigmethod = 'HMAC-SHA1';
}
my $request;
if ($msgformat eq '1.0') {
my $date = &Apache::loncommon::utc_string(time);
my %ltiparams = (
lti_version => 'LTI-1p0',
lti_message_type => 'basic-lis-updateresult',
sourcedid => $id,
result_resultscore_textstring => $score,
result_resultscore_language => 'en-US',
result_resultvaluesourcedid => $scoretype,
result_statusofresult => 'final',
result_date => $date,
);
my %info = (
method => $sigmethod,
);
my ($status,$hashref) =
&Apache::lonnet::sign_lti($cdom,$cnum,$crsdef,$type,'grade',$url,$ltinum,$keynum,
\%ltiparams,\%info);
if (($status eq 'ok') && (ref($hashref) eq 'HASH')) {
$request=new HTTP::Request('POST',$url);
$request->content(join('&',map {
my $name = escape($_);
"$name=" . ( ref($hashref->{$_}) eq 'ARRAY'
? join("&$name=", map {escape($_) } @{$hashref->{$_}})
: &escape($hashref->{$_}) );
} keys(%{$hashref})));
#FIXME Need to handle case where passback failed.
}
} else {
srand( time() ^ ($$ + ($$ << 15)) ); # Seed rand.
my $uniqmsgid = int(rand(2**32));
my $gradexml = <<END;
<?xml version = "1.0" encoding = "UTF-8"?>
<imsx_POXEnvelopeRequest xmlns = "http://www.imsglobal.org/services/ltiv1p1/xsd/imsoms_v1p0">
<imsx_POXHeader>
<imsx_POXRequestHeaderInfo>
<imsx_version>V1.0</imsx_version>
<imsx_messageIdentifier>$uniqmsgid</imsx_messageIdentifier>
</imsx_POXRequestHeaderInfo>
</imsx_POXHeader>
<imsx_POXBody>
<replaceResultRequest>
<resultRecord>
<sourcedGUID>
<sourcedId>$id</sourcedId>
</sourcedGUID>
<result>
<resultScore>
<language>en</language>
<textString>$score</textString>
</resultScore>
</result>
</resultRecord>
</replaceResultRequest>
</imsx_POXBody>
</imsx_POXEnvelopeRequest>
END
chomp($gradexml);
my $bodyhash = Digest::SHA::sha1_base64($gradexml);
while (length($bodyhash) % 4) {
$bodyhash .= '=';
}
my $reqmethod = 'POST';
my %info = (
body_hash => $bodyhash,
method => $sigmethod,
reqtype => 'consumer',
reqmethod => $reqmethod,
respfmt => 'to_authorization_header',
);
my %params;
my ($status,$authheader) =
&Apache::lonnet::sign_lti($cdom,$cnum,$crsdef,$type,'grade',$url,$ltinum,$keynum,\%params,\%info);
if (($status eq 'ok') && ($authheader ne '')) {
$request = HTTP::Request->new(
$reqmethod,
$url,
[
'Authorization' => $authheader,
'Content-Type' => 'application/xml',
],
$gradexml,
);
my $response = &LONCAPA::LWPReq::makerequest('',$request,'','',10);
my $message=$response->status_line;
#FIXME Handle case where pass back of score to LTI Consumer failed.
}
}
}
sub setup_logout_callback {
my ($cdom,$cnum,$crstool,$idx,$keynum,$uname,$udom,$server,$service_url,$idsdir,$protocol,$hostname) = @_;
if ($service_url =~ m{^https?://[^/]+/}) {
my $digest_user = &Encode::decode('UTF-8',$uname.':'.$udom);
my $loginfile = &Digest::SHA::sha1_hex($digest_user).&md5_hex(&md5_hex(time.{}.rand().$$));
if ((-d $idsdir) && (open(my $fh,'>',"$idsdir/$loginfile"))) {
print $fh "$uname,$udom,$server\n";
close($fh);
my $callback = 'http://'.$hostname.'/adm/service/logout/'.$loginfile;
my %ltiparams = (
callback => $callback,
);
my %info = (
respfmt => 'to_post_body',
);
my ($status,$post) =
&Apache::lonnet::sign_lti($cdom,$cnum,$crstool,'lti','logout',$service_url,$idx,
$keynum,\%ltiparams,\%info);
if (($status eq 'ok') && ($post ne '')) {
my $request=new HTTP::Request('POST',$service_url);
$request->content($post);
my $response = &LONCAPA::LWPReq::makerequest('',$request,'','',10);
}
}
}
return;
}
#
# LON-CAPA as LTI Provider
#
# Create a new user in LON-CAPA. If the domain's configuration
# includes rules for format of "official" usernames, those rules
# will apply when determining if a user is to be created. In
# additional if institutional user information is available that
# will be used when creating a new user account.
#
sub create_user {
my ($ltiref,$uname,$udom,$domdesc,$data,$alerts,$rulematch,$inst_results,
$curr_rules,$got_rules) = @_;
return unless (ref($ltiref) eq 'HASH');
my $checkhash = { "$uname:$udom" => { 'newuser' => 1, }, };
my $checks = { 'username' => 1, };
my ($lcauth,$lcauthparm);
&Apache::loncommon::user_rule_check($checkhash,$checks,$alerts,$rulematch,
$inst_results,$curr_rules,$got_rules);
my ($userchkmsg,$lcauth,$lcauthparm);
my $allowed = 1;
if (ref($alerts->{'username'}) eq 'HASH') {
if (ref($alerts->{'username'}{$udom}) eq 'HASH') {
if ($alerts->{'username'}{$udom}{$uname}) {
if (ref($curr_rules->{$udom}) eq 'HASH') {
$userchkmsg =
&Apache::loncommon::instrule_disallow_msg('username',$domdesc,1).
&Apache::loncommon::user_rule_formats($udom,$domdesc,
$curr_rules->{$udom}{'username'},
'username');
}
$allowed = 0;
}
}
}
if ($allowed) {
if (ref($rulematch->{$uname.':'.$udom}) eq 'HASH') {
my $matchedrule = $rulematch->{$uname.':'.$udom}{'username'};
my ($rules,$ruleorder) =
&Apache::lonnet::inst_userrules($udom,'username');
if (ref($rules) eq 'HASH') {
if (ref($rules->{$matchedrule}) eq 'HASH') {
$lcauth = $rules->{$matchedrule}{'authtype'};
$lcauthparm = $rules->{$matchedrule}{'authparm'};
}
}
}
if ($lcauth eq '') {
$lcauth = $ltiref->{'lcauth'};
if ($lcauth eq 'internal') {
$lcauthparm = &create_passwd();
} else {
$lcauthparm = $ltiref->{'lcauthparm'};
}
}
} else {
return 'notallowed';
}
my @userinfo = ('firstname','middlename','lastname','generation','permanentemail','id');
my (%useinstdata,%info);
if (ref($ltiref->{'instdata'}) eq 'ARRAY') {
map { $useinstdata{$_} = 1; } @{$ltiref->{'instdata'}};
}
foreach my $item (@userinfo) {
if (($useinstdata{$item}) && (ref($inst_results->{$uname.':'.$udom}) eq 'HASH') &&
($inst_results->{$uname.':'.$udom}{$item} ne '')) {
$info{$item} = $inst_results->{$uname.':'.$udom}{$item};
} else {
if ($item eq 'permanentemail') {
if ($data->{'permanentemail'} =~/^[^\@]+\@[^@]+$/) {
$info{$item} = $data->{'permanentemail'};
}
} elsif (($item eq 'firstname') || ($item eq 'lastname')) {
$info{$item} = $data->{$item};
}
}
}
if (($info{'middlename'} eq '') && ($data->{'fullname'} ne '')) {
unless ($useinstdata{'middlename'}) {
my $fullname = $data->{'fullname'};
if ($info{'firstname'}) {
$fullname =~ s/^\s*\Q$info{'firstname'}\E\s*//i;
}
if ($info{'lastname'}) {
$fullname =~ s/\s*\Q$info{'lastname'}\E\s*$//i;
}
if ($fullname ne '') {
$fullname =~ s/^\s+|\s+$//g;
if ($fullname ne '') {
$info{'middlename'} = $fullname;
}
}
}
}
if (ref($inst_results->{$uname.':'.$udom}{'inststatus'}) eq 'ARRAY') {
my @inststatuses = @{$inst_results->{$uname.':'.$udom}{'inststatus'}};
$info{'inststatus'} = join(':',map { &escape($_); } @inststatuses);
}
my $result =
&Apache::lonnet::modifyuser($udom,$uname,$info{'id'},
$lcauth,$lcauthparm,$info{'firstname'},
$info{'middlename'},$info{'lastname'},
$info{'generation'},undef,undef,
$info{'permanentemail'},$info{'inststatus'});
return $result;
}
#
# LON-CAPA as LTI Provider
#
# Create a password for a new user if the authentication
# type to assign to new users created following LTI launch is
# to be LON-CAPA "internal".
#
sub create_passwd {
my $passwd = '';
srand( time() ^ ($$ + ($$ << 15)) ); # Seed rand.
my @letts = ("a".."z");
for (my $i=0; $i<8; $i++) {
my $lettnum = int(rand(2));
my $item = '';
if ($lettnum) {
$item = $letts[int(rand(26))];
my $uppercase = int(rand(2));
if ($uppercase) {
$item =~ tr/a-z/A-Z/;
}
} else {
$item = int(rand(10));
}
$passwd .= $item;
}
return ($passwd);
}
#
# LON-CAPA as LTI Provider
#
# Enroll a user in a LON-CAPA course, with the specified role and (optional)
# section. If this is a self-enroll case, i.e., a user launched the LTI tool
# in the Consumer, user privs will be added to the user's environment for
# the new role.
#
# If this is a self-enroll case, a Course Coordinator role will only be assigned
# if the current user is also the course owner.
#
sub enrolluser {
my ($udom,$uname,$role,$cdom,$cnum,$sec,$start,$end,$selfenroll) = @_;
my $enrollresult;
my $area = "/$cdom/$cnum";
if (($role ne 'cc') && ($role ne 'co') && ($sec ne '')) {
$area .= '/'.$sec;
}
my $spec = $role.'.'.$area;
my $instcid;
if ($role eq 'st') {
$enrollresult =
&Apache::lonnet::modify_student_enrollment($udom,$uname,undef,undef,undef,
undef,undef,$sec,$end,$start,
'ltienroll',undef,$cdom.'_'.$cnum,
$selfenroll,'ltienroll','',$instcid);
} elsif ($role =~ /^(cc|in|ta|ep)$/) {
$enrollresult =
&Apache::lonnet::assignrole($udom,$uname,$area,$role,$end,$start,
undef,$selfenroll,'ltienroll');
}
if ($enrollresult eq 'ok') {
if ($selfenroll) {
my (%userroles,%newrole,%newgroups);
&Apache::lonnet::standard_roleprivs(\%newrole,$role,$cdom,$spec,$cnum,
$area);
&Apache::lonnet::set_userprivs(\%userroles,\%newrole,\%newgroups);
$userroles{'user.role.'.$spec} = $start.'.'.$end;
&Apache::lonnet::appenv(\%userroles,[$role,'cm']);
}
}
return $enrollresult;
}
#
# LON-CAPA as LTI Provider
#
# Batch addition of users following LTI launch by a user
# with LTI Instructor status.
#
# A list of users is obtained by a call to get_roster()
# if the calling Consumer support the LTI extension:
# Context Memberships Service.
#
# If a user included in the retrieved list does not currently
# have a user account in LON-CAPA, an account will be created.
#
# If a user already has an account, and the same role and
# section assigned (currently active), then no change will
# be made for that user.
#
# Information available for new users (besides username and)
# role) may include: first name, last name, full name (from
# which middle name will be extracted), permanent e-mail address,
# and lis_result_sourcedid (for passback of grades).
#
# If grades are to be passed back, the passback url will be
# the same as for the current user's session.
#
# The roles which may be assigned will be determined from the
# LTI roles included in the retrieved roster, and the mapping
# of LTI roles to LON-CAPA roles configured for this LTI Consumer
# in the domain configuration.
#
# Course Coordinator roles will only be assigned if the current
# user is also the course owner.
#
# The domain configuration for the corresponding Consumer can include
# a section to assign to LTI users. If the roster includes students
# any existing student roles with a different section will be expired,
# and a role in the LTI section will be assigned.
#
# For non-student rules (excluding Course Coordinator) a role will be
# assigned with the LTI section )or no section, if one is not rquired.
#
sub batchaddroster {
my ($item) = @_;
return unless((ref($item) eq 'HASH') &&
(ref($item->{'ltiref'}) eq 'HASH'));
my ($cdom,$cnum) = split(/_/,$item->{'cid'});
return if (($cdom eq '') || ($cnum eq ''));
my $udom = $cdom;
my $id = $item->{'id'};
my $url = $item->{'url'};
my $ltinum = $item->{'lti'};
my $keynum = $item->{'ltiref'}->{'cipher'};
my @intdoms;
my $intdomsref = $item->{'intdoms'};
if (ref($intdomsref) eq 'ARRAY') {
@intdoms = @{$intdomsref};
}
my $uriscope = $item->{'uriscope'};
my $section = $item->{'ltiref'}->{'section'};
$section =~ s/\W//g;
if ($section eq 'none') {
undef($section);
} elsif ($section ne '') {
my %curr_groups =
&Apache::longroup::coursegroups($cdom,$cnum);
if (exists($curr_groups{$section})) {
undef($section);
}
}
my (%maproles,@possroles);
if (ref($item->{'ltiref'}->{'maproles'}) eq 'HASH') {
%maproles = %{$item->{'ltiref'}->{'maproles'}};
}
if (ref($item->{'possroles'}) eq 'ARRAY') {
@possroles = @{$item->{'possroles'}};
}
if (($id ne '') && ($url ne '')) {
my %data = &get_roster($cdom,$cnum,$ltinum,$keynum,$id,$url);
if (keys(%data) > 0) {
my (%rulematch,%inst_results,%curr_rules,%got_rules,%alerts,%info);
my %coursehash = &Apache::lonnet::coursedescription($cdom.'_'.$cnum);
my $start = $coursehash{'default_enrollment_start_date'};
my $end = $coursehash{'default_enrollment_end_date'};
my $domdesc = &Apache::lonnet::domain($udom,'description');
my $roster = &Apache::loncoursedata::get_classlist($cdom,$cnum);
my $status = &Apache::loncoursedata::CL_STATUS;
my $cend = &Apache::loncoursedata::CL_END;
my $cstart = &Apache::loncoursedata::CL_START;
my $lockedtype=&Apache::loncoursedata::CL_LOCKEDTYPE;
my $sec=&Apache::loncoursedata::CL_SECTION;
my (@activestudents,@futurestudents,@excludedstudents,@localstudents,%currlist,%advroles);
if (grep(/^st$/,@possroles)) {
foreach my $user (keys(%{$roster})) {
if ($user =~ m/^(.+):$cdom$/) {
my $stuname = $1;
if ($roster->{$user}[$status] eq "Active") {
push(@activestudents,$stuname);
@{$currlist{$stuname}} = @{$roster->{$user}};
push(@localstudents,$stuname);
} elsif (($roster->{$user}[$cstart] > time) && ($roster->{$user}[$cend] > time ||
$roster->{$user}[$cend] == 0 || $roster->{$user}[$cend] eq '')) {
push(@futurestudents,$stuname);
@{$currlist{$stuname}} = @{$roster->{$user}};
push(@localstudents,$stuname);
} elsif ($roster->{$user}[$lockedtype] == 1) {
push(@excludedstudents,$stuname);
}
}
}
}
if ((@possroles > 1) || ((@possroles == 1) && (!grep(/^st$/,@possroles)))) {
my %personnel = &Apache::lonnet::get_course_adv_roles($item->{'cid'},1);
foreach my $item (keys(%personnel)) {
my ($role,$currsec) = split(/:/,$item);
if ($currsec eq '') {
$currsec = 'none';
}
foreach my $user (split(/,/,$personnel{$item})) {
push(@{$advroles{$user}{$role}},$currsec);
}
}
}
if (($end == 0) || ($end > time) || (@localstudents > 0)) {
my (%passback,$pbnum,$numadv);
$numadv = 0;
foreach my $i (sort { $a <=> $b } keys(%data)) {
if (ref($data{$i}) eq 'HASH') {
my $entry = $data{$i};
my $user = $entry->{'person_sourcedid'};
my $uname;
if ($user =~ /^($match_username):($match_domain)$/) {
$uname = $1;
my $possudom = $2;
if ($possudom ne $udom) {
my $uintdom = &Apache::lonnet::domain($possudom,'primary');
if (($uintdom ne '') && (grep(/^\Q$uintdom\E$/,@intdoms))) {
$udom = $possudom;
}
}
} elsif ($uname =~ /^match_username$/) {
$uname = $user;
} else {
next;
}
my $uhome = &Apache::lonnet::homeserver($uname,$udom);
if ($uhome eq 'no_host') {
my %data;
$data{'permanentemail'} = $entry->{'person_contact_email_primary'};
$data{'lastname'} = $entry->{'person_name_family'};
$data{'firstname'} = $entry->{'person_name_given'};
$data{'fullname'} = $entry->{'person_name_full'};
my $addresult =
&create_user($item->{'ltiref'},$uname,$udom,
$domdesc,\%data,\%alerts,\%rulematch,
\%inst_results,\%curr_rules,\%got_rules);
next unless ($addresult eq 'ok');
}
if ($env{'request.lti.passbackurl'}) {
if ($entry->{'lis_result_sourcedid'} ne '') {
unless ($pbnum) {
($pbnum,my $error) = &store_passbackurl($env{'request.lti.login'},
$env{'request.lti.passbackurl'},
$cdom,$cnum);
if ($pbnum eq '') {
$pbnum = $env{'request.lti.passbackurl'};
}
}
$passback{$uname."\0".$uriscope."\0".$env{'request.lti.sourcecrs'}."\0".$env{'request.lti.login'}} =
$pbnum."\0".$entry->{'lis_result_sourcedid'};
}
}
my $rolestr = $entry->{'roles'};
my ($lcrolesref) = &get_lc_roles($rolestr,\@possroles,\%maproles);
my @lcroles = @{$lcrolesref};
if (@lcroles) {
if (grep(/^st$/,@lcroles)) {
my $addstu;
if (!grep(/^\Q$uname\E$/,@excludedstudents)) {
if (grep(/^\Q$uname\E$/,@localstudents)) {
# Check for section changes
if ($currlist{$uname}[$sec] ne $section) {
$addstu = 1;
&Apache::lonuserutils::modifystudent($udom,$uname,$cdom.'_'.$cnum,
undef,undef,'course');
} elsif (grep(/^\Q$uname\E$/,@futurestudents)) {
# Check for access date changes for students with access starting in the future.
my $datechange = &datechange_check($currlist{$uname}[$cstart],
$currlist{$uname}[$cend],
$start,$end);
if ($datechange) {
$addstu = 1;
}
}
} else {
$addstu = 1;
}
}
unless ($addstu) {
pop(@lcroles);
}
}
my @okroles;
if (@lcroles) {
foreach my $role (@lcroles) {
unless (($role eq 'st') || (keys(%advroles) == 0)) {
if (exists($advroles{$uname.':'.$udom})) {
if ((ref($advroles{$uname.':'.$udom}) eq 'HASH') &&
(ref($advroles{$uname.':'.$udom}{$role}) eq 'ARRAY')) {
if (($section eq '') || ($role eq 'cc') || ($role eq 'co')) {
next if (grep(/^none$/,@{$advroles{$uname.':'.$udom}{$role}}));
} else {
next if (grep(/^\Q$sec\E$/,@{$advroles{$uname.':'.$udom}{$role}}));
}
}
}
}
push(@okroles,$role);
}
}
if (@okroles) {
my $permanentemail = $entry->{'person_contact_email_primary'};
my $lastname = $entry->{'person_name_family'};
my $firstname = $entry->{'person_name_given'};
foreach my $role (@okroles) {
my $enrollresult = &enrolluser($udom,$uname,$role,$cdom,$cnum,
$section,$start,$end);
if (($enrollresult eq 'ok') && ($role ne 'st')) {
$numadv ++;
}
}
}
}
}
}
if (keys(%passback)) {
&Apache::lonnet::put('nohist_lti_passback',\%passback,$cdom,$cnum);
}
if ($numadv) {
&Apache::lonnet::flushcourselogs();
}
}
}
}
return;
}
#
# LON-CAPA as LTI Provider
#
# Gather a list of available LON-CAPA roles derived
# from a comma separated list of LTI roles.
#
# Which LON-CAPA roles are assignable by the current user
# and how LTI roles map to LON-CAPA roles (as defined in
# the domain configuration for the specific Consumer) are
# factored in when compiling the list of available roles.
#
# Inputs: 3
# $rolestr - comma separated list of LTI roles.
# $allowedroles - reference to array of assignable LC roles
# $maproles - ref to HASH of mapping of LTI roles to LC roles
#
# Outputs: 2
# (a) reference to array of available LC roles.
# (b) reference to array of LTI roles.
#
sub get_lc_roles {
my ($rolestr,$allowedroles,$maproles) = @_;
my (@ltiroles,@lcroles);
my @ltiroleorder = ('Instructor','TeachingAssistant','Mentor','Learner');
if ($rolestr =~ /,/) {
my @possltiroles = split(/\s*,\s*/,$rolestr);
foreach my $ltirole (@ltiroleorder) {
if (grep(/^\Q$ltirole\E$/,@possltiroles)) {
push(@ltiroles,$ltirole);
}
}
} else {
my $singlerole = $rolestr;
$singlerole =~ s/^\s|\s+$//g;
if ($singlerole ne '') {
if (grep(/^\Q$singlerole\E$/,@ltiroleorder)) {
@ltiroles = ($singlerole);
}
}
}
if (@ltiroles) {
my %possroles;
map { $possroles{$maproles->{$_}} = 1; } @ltiroles;
if (keys(%possroles) > 0) {
if (ref($allowedroles) eq 'ARRAY') {
foreach my $item (@{$allowedroles}) {
if (($item eq 'co') || ($item eq 'cc')) {
if ($possroles{'cc'}) {
push(@lcroles,$item);
}
} elsif ($possroles{$item}) {
push(@lcroles,$item);
}
}
}
}
}
return (\@lcroles,\@ltiroles);
}
#
# LON-CAPA as LTI Provider
#
# Compares current start and dates for a user's role
# with dates to apply for the same user/role to
# determine if there is a change between the current
# ones and the updated ones.
#
sub datechange_check {
my ($oldstart,$oldend,$startdate,$enddate) = @_;
my $datechange = 0;
unless ($oldstart eq $startdate) {
$datechange = 1;
}
if (!$datechange) {
if (!$oldend) {
if ($enddate) {
$datechange = 1;
}
} elsif ($oldend ne $enddate) {
$datechange = 1;
}
}
return $datechange;
}
#
# LON-CAPA as LTI Provider
#
# Store the URL used by a specific LTI Consumer to process grades passed back
# by an LTI Provider.
#
sub store_passbackurl {
my ($ltinum,$pburl,$cdom,$cnum) = @_;
my %history = &Apache::lonnet::restore($ltinum,'passbackurl',$cdom,$cnum);
my ($pbnum,$version,$error);
if ($history{'version'}) {
$version = $history{'version'};
for (my $i=1; $i<=$version; $i++) {
if ($history{$i.':pburl'} eq $pburl) {
$pbnum = $i;
last;
}
}
} else {
$version = 0;
}
if ($pbnum eq '') {
# get lock on passbackurl db
my $now = time;
my $lockhash = {
'lock'."\0".$ltinum."\0".$now => $env{'user.name'}.':'.$env{'user.domain'},
};
my $tries = 0;
my $gotlock = &Apache::lonnet::newput('passbackurl',$lockhash,$cdom,$cnum);
while (($gotlock ne 'ok') && ($tries<3)) {
$tries ++;
sleep 1;
$gotlock = &Apache::lonnet::newput('passbackurl',$lockhash,$cdom.$cnum);
}
if ($gotlock eq 'ok') {
if (&Apache::lonnet::store_userdata({pburl => $pburl},
$ltinum,'passbackurl',$cdom,$cnum) eq 'ok') {
$pbnum = 1+$version;
}
my $dellock = &Apache::lonnet::del('passbackurl',['lock'."\0".$ltinum."\0".$now],$cdom,$cnum);
unless ($dellock eq 'ok') {
$error = &mt('error: could not release lockfile');
}
} else {
$error = &mt('error: could not obtain lockfile');
}
}
return ($pbnum,$error);
}
1;
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