--- loncom/lond	2019/08/01 18:17:02	1.489.2.32
+++ loncom/lond	2021/06/20 18:41:28	1.489.2.35.2.5
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.489.2.32 2019/08/01 18:17:02 raeburn Exp $
+# $Id: lond,v 1.489.2.35.2.5 2021/06/20 18:41:28 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: 1.489.2.32 $'; #' stupid emacs
+my $VERSION='$Revision: 1.489.2.35.2.5 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -2107,12 +2107,84 @@ sub change_password_handler {
     }
     if($validated) {
 	my $realpasswd  = &get_auth_type($udom, $uname); # Defined since authd.
-	
 	my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
+        my $notunique;
 	if ($howpwd eq 'internal') {
 	    &Debug("internal auth");
             my $ncpass = &hash_passwd($udom,$npass);
-	    if(&rewrite_password_file($udom, $uname, "internal:$ncpass")) {
+            my (undef,$method,@rest) = split(/!/,$contentpwd);
+            if ($method eq 'bcrypt') {
+                my %passwdconf = &Apache::lonnet::get_passwdconf($udom);
+                if (($passwdconf{'numsaved'}) && ($passwdconf{'numsaved'} =~ /^\d+$/)) {
+                    my @oldpasswds;
+                    my $userpath = &propath($udom,$uname);
+                    my $fullpath = $userpath.'/oldpasswds';
+                    if (-d $userpath) {
+                        my @oldfiles;
+                        if (-e $fullpath) {
+                            if (opendir(my $dir,$fullpath)) {
+                                (@oldfiles) = grep(/^\d+$/,readdir($dir));
+                                closedir($dir);
+                            }
+                            if (@oldfiles) {
+                                @oldfiles = sort { $b <=> $a } (@oldfiles);
+                                my $numremoved = 0;
+                                for (my $i=0; $i<@oldfiles; $i++) {
+                                    if ($i>=$passwdconf{'numsaved'}) {
+                                        if (-f "$fullpath/$oldfiles[$i]") {
+                                            if (unlink("$fullpath/$oldfiles[$i]")) {
+                                                $numremoved ++;
+                                            }
+                                        }
+                                    } elsif (open(my $fh,'<',"$fullpath/$oldfiles[$i]")) {
+                                        while (my $line = <$fh>) {
+                                            push(@oldpasswds,$line);
+                                        }
+                                        close($fh);
+                                    }
+                                }
+                                if ($numremoved) {
+                                    &logthis("unlinked $numremoved old password files for $uname:$udom");
+                                }
+                            }
+                        }
+                        push(@oldpasswds,$contentpwd);
+                        foreach my $item (@oldpasswds) {
+                            my (undef,$method,@rest) = split(/!/,$item);
+                            if ($method eq 'bcrypt') {
+                                my $result = &hash_passwd($udom,$npass,@rest);
+                                if ($result eq $item) {
+                                    $notunique = 1;
+                                    last;
+                                }
+                            }
+                        }
+                        unless ($notunique) {
+                            unless (-e $fullpath) {
+                                if (&mkpath("$fullpath/")) {
+                                    chmod(0700,$fullpath);
+                                }
+                            }
+                            if (-d $fullpath) {
+                                my $now = time;
+                                if (open(my $fh,'>',"$fullpath/$now")) {
+                                    print $fh $contentpwd;
+                                    close($fh);
+                                    chmod(0400,"$fullpath/$now");
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            if ($notunique) {
+                my $msg="Result of password change for $uname:$udom - password matches one used before";
+                if ($lonhost) {
+                    $msg .= " - request originated from: $lonhost";
+                }
+                &logthis($msg);
+                &Reply($client, "prioruse\n", $userinput);
+	    } elsif (&rewrite_password_file($udom, $uname, "internal:$ncpass")) {
 		my $msg="Result of password change for $uname: pwchange_success";
                 if ($lonhost) {
                     $msg .= " - request originated from: $lonhost";
@@ -2140,7 +2212,6 @@ sub change_password_handler {
 	    #
 	    &Failure( $client, "auth_mode_error\n", $userinput);
 	}  
-	
     } else {
 	if ($failure eq '') {
 	    $failure = 'non_authorized';
@@ -4505,6 +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 
 #
@@ -4553,7 +4662,7 @@ sub put_domain_handler {
 # domain directory.
 #
 # Parameters:
-#   $cmd             - Command request keyword (get).
+#   $cmd             - Command request keyword (getdom).
 #   $tail            - Tail of the command.  This is a colon separated list
 #                      consisting of the domain and the 'namespace' 
 #                      which selects the gdbm file to do the lookup in,
@@ -4570,34 +4679,52 @@ sub put_domain_handler {
 sub get_domain_handler {
     my ($cmd, $tail, $client) = @_;
 
-
-    my $userinput = "$client:$tail";
+    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, "$namespace", &GDBM_READER());
-    if ($hashref) {
-        for (my $i=0;$i<=$#queries;$i++) {
-            $qresult.="$hashref->{$queries[$i]}&";
-        }
-        if (&untie_domain_hash($hashref)) {
-            $qresult=~s/\&$//;
-            &Reply($client, \$qresult, $userinput);
+    if ($namespace =~ /^enc/) {
+        &Failure( $client, "refused\n", $userinput);
+    } else {
+        my $res = LONCAPA::Lond::get_dom($userinput);
+        if ($res =~ /^error:/) {
+            &Failure($client, \$res, $userinput);
         } else {
-            &Failure( $client, "error: ".($!+0)." untie(GDBM) Failed ".
-                      "while attempting getdom\n",$userinput);
+            &Reply($client, \$res, $userinput);
         }
-    } else {
-        &Failure($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 $res = LONCAPA::Lond::get_dom($userinput);
+    if ($res =~ /^error:/) {
+        &Failure($client, \$res, $userinput);
+    } else {
+        if ($cipher) {
+            my $cmdlength=length($res);
+            $res.="         ";
+            my $encres='';
+            for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
+                $encres.= unpack("H16",
+                                 $cipher->encrypt(substr($res,
+                                                         $encidx,
+                                                         8)));
+            }
+            &Reply( $client,"enc:$cmdlength:$encres\n",$userinput);
+        } else {
+            &Failure( $client, "error:no_key\n",$userinput);
+        }
+    }
+    return 1;
+}
+&register_handler("egetdom", \&encrypted_get_domain_handler, 1, 1, 0);
+
 #
 #  Puts an id to a domains id database. 
 #
@@ -5114,8 +5241,65 @@ sub tmp_del_handler {
 &register_handler("tmpdel", \&tmp_del_handler, 0, 1, 0);
 
 #
+#  Process the updatebalcookie command.  This command updates a
+#  cookie in the lonBalancedir directory on a load balancer node.
+#
+# Parameters:
+#   $cmd      - Command that got us here.
+#   $tail     - Tail of the request (escaped cookie: escaped current entry)
+#
+#   $client   - socket open on the client process.
+#
+# Returns:
+#   1     - Indicating processing should continue.
+# Side Effects:
+#   A cookie file is updated from the lonBalancedir directory
+#   A reply is sent to the client.
+#
+sub update_balcookie_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $userinput= "$cmd:$tail";
+    chomp($tail);
+    my ($cookie,$lastentry) = map { &unescape($_) } (split(/:/,$tail));
+
+    my $updatedone;
+    if ($cookie =~ /^$LONCAPA::match_domain\_$LONCAPA::match_username\_[a-f0-9]{32}$/) {
+        my $execdir=$perlvar{'lonBalanceDir'};
+        if (-e "$execdir/$cookie.id") {
+            my $doupdate;
+            if (open(my $fh,'<',"$execdir/$cookie.id")) {
+                while (my $line = <$fh>) {
+                    chomp($line);
+                    if ($line eq $lastentry) {
+                        $doupdate = 1;
+                        last;
+                    }
+                }
+                close($fh);
+            }
+            if ($doupdate) {
+                if (open(my $fh,'>',"$execdir/$cookie.id")) {
+                    print $fh $clientname;
+                    close($fh);
+                    $updatedone = 1;
+                }
+            }
+        }
+    }
+    if ($updatedone) {
+        &Reply($client, "ok\n", $userinput);
+    } else {
+        &Failure( $client, "error: ".($!+0)."file update failed ".
+                  "while attempting updatebalcookie\n", $userinput);
+    }
+    return 1;
+}
+&register_handler("updatebalcookie", \&update_balcookie_handler, 0, 1, 0);
+
+#
 #  Process the delbalcookie command. This command deletes a balancer
-#  cookie in the lonBalancedir directory created by switchserver
+#  cookie in the lonBalancedir directory on a load balancer node.
 #
 # Parameters:
 #   $cmd      - Command that got us here.
@@ -5133,6 +5317,7 @@ sub del_balcookie_handler {
     my $userinput= "$cmd:$cookie";
 
     chomp($cookie);
+    $cookie = &unescape($cookie);
     my $deleted = '';
     if ($cookie =~ /^$LONCAPA::match_domain\_$LONCAPA::match_username\_[a-f0-9]{32}$/) {
         my $execdir=$perlvar{'lonBalanceDir'};
@@ -5348,6 +5533,39 @@ sub validate_instcode_handler {
 }
 &register_handler("autovalidateinstcode", \&validate_instcode_handler, 0, 1, 0);
 
+#
+#  Validate co-owner for cross-listed institutional code and
+#  institutional course code itself used for a LON-CAPA course.
+#
+# Formal Parameters:
+#   $cmd          - The command request that got us dispatched.
+#   $tail         - The tail of the command.  In this case,
+#                   this is a colon separated string containing:
+#      $dom            - Course's LON-CAPA domain
+#      $instcode       - Institutional course code for the course
+#      $inst_xlist     - Institutional course Id for the crosslisting
+#      $coowner        - Username of co-owner
+#      (values for all but $dom have been escaped).
+#
+#   $client       - Socket open on the client.
+# Returns:
+#    1           - Indicating processing should continue.
+#
+sub validate_instcrosslist_handler  {
+    my ($cmd, $tail, $client) = @_;
+    my $userinput = "$cmd:$tail";
+    my ($dom,$instcode,$inst_xlist,$coowner) = split(/:/,$tail);
+    $instcode = &unescape($instcode);
+    $inst_xlist = &unescape($inst_xlist);
+    $coowner = &unescape($coowner);
+    my $outcome = &localenroll::validate_crosslist_access($dom,$instcode,
+                                                          $inst_xlist,$coowner);
+    &Reply($client, \$outcome, $userinput);
+
+    return 1;
+}
+&register_handler("autovalidateinstcrosslist", \&validate_instcrosslist_handler, 0, 1, 0);
+
 #   Get the official sections for which auto-enrollment is possible.
 #   Since the admin people won't know about 'unofficial sections' 
 #   we cannot auto-enroll on them.
@@ -5472,6 +5690,62 @@ sub validate_class_access_handler {
 &register_handler("autovalidateclass_sec", \&validate_class_access_handler, 0, 1, 0);
 
 #
+#    Modify institutional sections (using customized &instsec_reformat()
+#    routine in localenroll.pm), to either clutter or declutter, for
+#    purposes of ensuring an institutional course section (string) can
+#    be unambiguously separated into institutional course and section.
+#
+# Formal Parameters:
+#    $cmd     - The command request that got us dispatched.
+#    $tail    - The tail of the command.   In this case this is a colon separated
+#               set of values that will be split into:
+#               $cdom        - The LON-CAPA domain of the course.
+#               $action      - Either: clutter or declutter
+#                              clutter adds character(s) to eliminate ambiguity
+#                              declutter removes the added characters (e.g., for
+#                              display of the institutional course section string.
+#               $info        - A frozen hash in which keys are:
+#                              LON-CAPA course number:Institutional course code
+#                              and values are a reference to an array of the
+#                              items to modify -- either institutional sections,
+#                              or institutional course sections (for crosslistings).
+#    $client  - The socket open on the client.
+# Returns:
+#    1 - continue processing.
+#
+
+sub instsec_reformat_handler {
+    my ($cmd, $tail, $client) = @_;
+    my $userinput = "$cmd:$tail";
+    my ($cdom,$action,$info) = split(/:/,$tail);
+    my $instsecref = &Apache::lonnet::thaw_unescape($info);
+    my ($outcome,$result);
+    eval {
+        local($SIG{__DIE__})='DEFAULT';
+        $outcome=&localenroll::instsec_reformat($cdom,$action,$instsecref);
+        if ($outcome eq 'ok') {
+            if (ref($instsecref) eq 'HASH') {
+                foreach my $key (keys(%{$instsecref})) {
+                    $result .= &escape($key).'='.&Apache::lonnet::freeze_escape($instsecref->{$key}).'&';
+                }
+                $result =~ s/\&$//;
+            }
+        }
+    };
+    if (!$@) {
+        if ($outcome eq 'ok') {
+            &Reply( $client, \$result, $userinput);
+        } else {
+            &Reply($client,\$outcome, $userinput);
+        }
+    } else {
+        &Failure($client,"unknown_cmd\n",$userinput);
+    }
+    return 1;
+}
+&register_handler("autoinstsecreformat",\&instsec_reformat_handler, 0, 1, 0);
+
+#
 #   Validate course owner or co-owners(s) access to enrollment data for all sections
 #   and crosslistings for a particular course.
 #
@@ -5599,7 +5873,7 @@ sub auto_export_grades_handler {
     return 1;
 }
 &register_handler("autoexportgrades", \&auto_export_grades_handler,
-                  0, 1, 0);
+                  1, 1, 0);
 
 
 #   Retrieve and remove temporary files created by/during autoenrollment.