--- loncom/lond	2020/01/13 13:41:24	1.489.2.35
+++ loncom/lond	2020/07/19 19:02:39	1.489.2.35.2.2
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.489.2.35 2020/01/13 13:41:24 raeburn Exp $
+# $Id: lond,v 1.489.2.35.2.2 2020/07/19 19:02:39 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -63,7 +63,7 @@ my $DEBUG = 0;		       # Non zero to ena
 my $status='';
 my $lastlog='';
 
-my $VERSION='$Revision: 1.489.2.35 $'; #' stupid emacs
+my $VERSION='$Revision: 1.489.2.35.2.2 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -4576,6 +4576,44 @@ sub course_lastaccess_handler {
 }
 &register_handler("courselastaccess",\&course_lastaccess_handler, 0, 1, 0);
 
+sub course_sessions_handler {
+    my ($cmd, $tail, $client) = @_;
+    my $userinput = "$cmd:$tail";
+    my ($cdom,$cnum,$lastactivity) = split(':',$tail);
+    my $dbsuffix = '_'.$cdom.'_'.$cnum.'.db';
+    my (%sessions,$qresult);
+    my $now=time;
+    if (opendir(DIR,$perlvar{'lonIDsDir'})) {
+        my $filename;
+        while ($filename=readdir(DIR)) {
+            next if ($filename=~/^\./);
+            next if ($filename=~/^publicuser_/);
+            next if ($filename=~/^[a-f0-9]+_(linked|lti_\d+)\.id$/);
+            if ($filename =~ /^($LONCAPA::match_username)_\d+_($LONCAPA::match_domain)_/) {
+                my ($uname,$udom) = ($1,$2);
+                next unless (-e "$perlvar{'lonDaemons'}/tmp/$uname$dbsuffix");
+                my $mtime = (stat("$perlvar{'lonIDsDir'}/$filename"))[9];
+                if ($lastactivity < 0) {
+                    next if ($mtime-$now > $lastactivity);
+                } else {
+                    next if ($now-$mtime > $lastactivity);
+                }
+                $sessions{$uname.':'.$udom} = $mtime;
+            }
+        }
+        closedir(DIR);
+    }
+    foreach my $user (keys(%sessions)) {
+        $qresult.=&escape($user).'='.$sessions{$user}.'&';
+    }
+    if ($qresult) {
+        chop($qresult);
+    }
+    &Reply($client, \$qresult, $userinput);
+    return 1;
+}
+&register_handler("coursesessions",\&course_sessions_handler, 0, 1, 0);
+
 #
 # Puts an unencrypted entry in a namespace db file at the domain level 
 #
@@ -4646,6 +4684,40 @@ sub get_domain_handler {
 
     my ($udom,$namespace,$what)=split(/:/,$tail,3);
     chomp($what);
+    if ($namespace =~ /^enc/) {
+        &Failure( $client, "refused\n", $userinput);
+    } else {
+        my @queries=split(/\&/,$what);
+        my $qresult='';
+        my $hashref = &tie_domain_hash($udom, "$namespace", &GDBM_READER());
+        if ($hashref) {
+            for (my $i=0;$i<=$#queries;$i++) {
+                $qresult.="$hashref->{$queries[$i]}&";
+            }
+            if (&untie_domain_hash($hashref)) {
+                $qresult=~s/\&$//;
+                &Reply($client, \$qresult, $userinput);
+            } else {
+                &Failure( $client, "error: ".($!+0)." untie(GDBM) Failed ".
+                          "while attempting getdom\n",$userinput);
+            }
+        } else {
+            &Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".
+                     "while attempting getdom\n",$userinput);
+        }
+    }
+
+    return 1;
+}
+&register_handler("getdom", \&get_domain_handler, 0, 1, 0);
+
+sub encrypted_get_domain_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $userinput = "$cmd:$tail";
+
+    my ($udom,$namespace,$what)=split(/:/,$tail,3);
+    chomp($what);
     my @queries=split(/\&/,$what);
     my $qresult='';
     my $hashref = &tie_domain_hash($udom, "$namespace", &GDBM_READER());
@@ -4655,19 +4727,31 @@ sub get_domain_handler {
         }
         if (&untie_domain_hash($hashref)) {
             $qresult=~s/\&$//;
-            &Reply($client, \$qresult, $userinput);
+            if ($cipher) {
+                my $cmdlength=length($qresult);
+                $qresult.="         ";
+                my $encqresult='';
+                for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
+                    $encqresult.= unpack("H16",
+                                         $cipher->encrypt(substr($qresult,
+                                                                 $encidx,
+                                                                 8)));
+                }
+                &Reply( $client, "enc:$cmdlength:$encqresult\n", $userinput);
+            } else {
+                &Failure( $client, "error:no_key\n", $userinput);
+            }
         } else {
             &Failure( $client, "error: ".($!+0)." untie(GDBM) Failed ".
-                      "while attempting getdom\n",$userinput);
+                      "while attempting egetdom\n",$userinput);
         }
     } else {
         &Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".
-                 "while attempting getdom\n",$userinput);
+                 "while attempting egetdom\n",$userinput);
     }
-
     return 1;
 }
-&register_handler("getdom", \&get_domain_handler, 0, 1, 0);
+&register_handler("egetdom", \&encrypted_get_domain_handler, 1, 1, 0);
 
 #
 #  Puts an id to a domains id database.