--- loncom/lond	2016/07/25 19:49:45	1.523
+++ loncom/lond	2023/12/22 18:50:55	1.580
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.523 2016/07/25 19:49:45 raeburn Exp $
+# $Id: lond,v 1.580 2023/12/22 18:50:55 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -15,7 +15,6 @@
 #
 # 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.
 #
@@ -36,6 +35,7 @@ use LONCAPA;
 use LONCAPA::Configuration;
 use LONCAPA::Lond;
 
+use Socket;
 use IO::Socket;
 use IO::File;
 #use Apache::File;
@@ -65,7 +65,7 @@ my $DEBUG = 0;		       # Non zero to ena
 my $status='';
 my $lastlog='';
 
-my $VERSION='$Revision: 1.523 $'; #' stupid emacs
+my $VERSION='$Revision: 1.580 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -75,7 +75,16 @@ my $clientip;			# IP address of client.
 my $clientname;			# LonCAPA name of client.
 my $clientversion;              # LonCAPA version running on client.
 my $clienthomedom;              # LonCAPA domain of homeID for client. 
-                                # primary library server. 
+my $clientintdom;               # LonCAPA "internet domain" for client.
+my $clientsamedom;              # LonCAPA domain same for this host 
+                                # and client.
+my $clientsameinst;             # LonCAPA "internet domain" same for 
+                                # this host and client.
+my $clientremoteok;             # Current domain permits hosting on client
+                                # (not set if host and client share "internet domain").
+                                # Values are 0 or 1; 1 if allowed.
+my %clientprohibited;           # Commands from client prohibited for domain's
+                                # users.
 
 my $server;
 
@@ -97,6 +106,13 @@ my %managers;			# Ip -> manager names
 
 my %perlvar;			# Will have the apache conf defined perl vars.
 
+my %secureconf;                 # Will have requirements for security 
+                                # of lond connections
+
+my %crlchecked;                 # Will contain clients for which the client's SSL
+                                # has been checked against the cluster's Certificate
+                                # Revocation List.
+
 my $dist;
 
 #
@@ -146,6 +162,169 @@ my @installerrors = ("ok",
 		     );
 
 #
+# The %trust hash classifies commands according to type of trust 
+# required for execution of the command.
+#
+# When clients from a different institution request execution of a
+# particular command, the trust settings for that institution set
+# for this domain (or default domain for a multi-domain server) will
+# be checked to see if running the command is allowed.
+#
+# Trust types which depend on the "Trust" domain configuration
+# for the machine's default domain are:
+#
+# content   ("Access to this domain's content by others")
+# shared    ("Access to other domain's content by this domain")
+# enroll    ("Enrollment in this domain's courses by others")
+# coaurem   ("Co-author roles for this domain's users elsewhere")
+# othcoau   ("Co-author roles in this domain for others")
+# domroles  ("Domain roles in this domain assignable to others")
+# catalog   ("Course Catalog for this domain displayed elsewhere")
+# reqcrs    ("Requests for creation of courses in this domain by others")
+# msg       ("Users in other domains can send messages to this domain")
+# 
+# Trust type which depends on the User Session Hosting (remote) 
+# domain configuration for machine's default domain is: "remote".
+#
+# Trust types which depend on contents of manager.tab in 
+# /home/httpd/lonTabs is: "manageronly".
+# 
+# Trust type which requires client to share the same LON-CAPA
+# "internet domain" (i.e., same institution as this server) is:
+# "institutiononly".
+#
+
+my %trust = (
+               auth => {remote => 1},
+               autocreatepassword => {remote => 1},
+               autocrsreqchecks => {remote => 1, reqcrs => 1},
+               autocrsrequpdate => {remote => 1},
+               autocrsreqvalidation => {remote => 1},
+               autogetsections => {remote => 1},
+               autoinstcodedefaults => {remote => 1, catalog => 1},
+               autoinstcodeformat => {remote => 1, catalog => 1},
+               autonewcourse => {remote => 1, reqcrs => 1},
+               autophotocheck => {remote => 1, enroll => 1},
+               autophotochoice => {remote => 1},
+               autophotopermission => {remote => 1, enroll => 1},
+               autopossibleinstcodes => {remote => 1, reqcrs => 1},
+               autoretrieve => {remote => 1, enroll => 1, catalog => 1},
+               autorun => {remote => 1, enroll => 1, reqcrs => 1},
+               autovalidateclass_sec => {catalog => 1},
+               autovalidatecourse => {remote => 1, enroll => 1},
+               autovalidateinstcode => {domroles => 1, remote => 1, enroll => 1},
+               autovalidateinstcrosslist => {remote => 1, enroll => 1},
+               autoinstsecreformat => {remote => 1, enroll => 1},
+               changeuserauth => {remote => 1, domroles => 1},
+               chatretr => {remote => 1, enroll => 1},
+               chatsend => {remote => 1, enroll => 1},
+               courseiddump => {remote => 1, domroles => 1, enroll => 1},
+               courseidput => {remote => 1, domroles => 1, enroll => 1},
+               courseidputhash => {remote => 1, domroles => 1, enroll => 1},
+               courselastaccess => {remote => 1, domroles => 1, enroll => 1},
+               coursesessions => {institutiononly => 1},
+               currentauth => {remote => 1, domroles => 1, enroll => 1},
+               currentdump => {remote => 1, enroll => 1},
+               currentversion => {remote=> 1, content => 1},
+               dcmaildump => {remote => 1, domroles => 1},
+               dcmailput => {remote => 1, domroles => 1},
+               del => {remote => 1, domroles => 1, enroll => 1, content => 1},
+               delbalcookie => {institutiononly => 1},
+               delusersession => {institutiononly => 1},
+               deldom => {remote => 1, domroles => 1}, # not currently used
+               devalidatecache => {institutiononly => 1},
+               domroleput => {remote => 1, enroll => 1},
+               domrolesdump => {remote => 1, catalog => 1},
+               du => {remote => 1, enroll => 1},
+               du2 => {remote => 1, enroll => 1},
+               dump => {remote => 1, enroll => 1, domroles => 1},
+               edit => {institutiononly => 1},  #not used currently
+               edump => {remote => 1, enroll => 1, domroles => 1},
+               eget => {remote => 1, domroles => 1, enroll => 1}, #not used currently
+               egetdom => {remote => 1, domroles => 1, enroll => 1, },
+               ekey => {anywhere => 1},
+               exit => {anywhere => 1},
+               fetchuserfile => {remote => 1, enroll => 1},
+               get => {remote => 1, domroles => 1, enroll => 1},
+               getdom => {anywhere => 1},
+               home => {anywhere => 1},
+               iddel => {remote => 1, enroll => 1},
+               idget => {remote => 1, enroll => 1},
+               idput => {remote => 1, domroles => 1, enroll => 1},
+               inc => {remote => 1, enroll => 1},
+               init => {anywhere => 1},
+               inst_usertypes => {remote => 1, domroles => 1, enroll => 1},
+               instemailrules => {remote => 1, domroles => 1},
+               instidrulecheck => {remote => 1, domroles => 1,},
+               instidrules => {remote => 1, domroles => 1,},
+               instrulecheck => {remote => 1, enroll => 1, reqcrs => 1, domroles => 1},
+               instselfcreatecheck => {institutiononly => 1},
+               instunamemapcheck => {remote => 1,},  
+               instuserrules => {remote => 1, enroll => 1, reqcrs => 1, domroles => 1},
+               keys => {remote => 1,},
+               load => {anywhere => 1},
+               log => {anywhere => 1},
+               ls => {remote => 1, enroll => 1, content => 1,},
+               ls2 => {remote => 1, enroll => 1, content => 1,},
+               ls3 => {remote => 1, enroll => 1, content => 1,},
+               lti => {institutiononly => 1},
+               makeuser => {remote => 1, enroll => 1, domroles => 1,},
+               mkdiruserfile => {remote => 1, enroll => 1,},
+               newput => {remote => 1, enroll => 1, reqcrs => 1, domroles => 1,},
+               passwd => {remote => 1},
+               ping => {anywhere => 1},
+               pong => {anywhere => 1},
+               pushfile => {manageronly => 1},
+               put => {remote => 1, enroll => 1, domroles => 1, msg => 1, content => 1, shared => 1},
+               putdom => {remote => 1, domroles => 1,},
+               putstore => {remote => 1, enroll => 1},
+               queryreply => {anywhere => 1},
+               querysend => {anywhere => 1},
+               querysend_activitylog => {remote => 1},
+               querysend_allusers => {remote => 1, domroles => 1},
+               querysend_courselog => {remote => 1},
+               querysend_fetchenrollment => {remote => 1},
+               querysend_getinstuser => {remote => 1},
+               querysend_getmultinstusers => {remote => 1},
+               querysend_instdirsearch => {remote => 1, domroles => 1, coaurem => 1},
+               querysend_institutionalphotos => {remote => 1},
+               querysend_portfolio_metadata => {remote => 1, content => 1},
+               querysend_userlog => {remote => 1, domroles => 1},
+               querysend_usersearch => {remote => 1, enroll => 1, coaurem => 1},
+               quit => {anywhere => 1},
+               readlonnetglobal => {institutiononly => 1},
+               reinit => {manageronly => 1}, #not used currently
+               removeuserfile => {remote => 1, enroll => 1},
+               renameuserfile => {remote => 1,},
+               restore => {remote => 1, enroll => 1, reqcrs => 1,},
+               rolesdel => {remote => 1, enroll => 1, domroles => 1, coaurem => 1},
+               rolesput => {remote => 1, enroll => 1, domroles => 1, coaurem => 1},
+               servercerts => {institutiononly => 1},
+               serverdistarch => {anywhere => 1},
+               serverhomeID => {anywhere => 1},
+               serverloncaparev => {anywhere => 1},
+               servertimezone => {remote => 1, enroll => 1},
+               setannounce => {remote => 1, domroles => 1},
+               sethost => {anywhere => 1},
+               signlti => {remote => 1},
+               store => {remote => 1, enroll => 1, reqcrs => 1,},
+               studentphoto => {remote => 1, enroll => 1},
+               sub => {content => 1,},
+               tmpdel => {institutiononly => 1},
+               tmpget => {institutiononly => 1},
+               tmpput => {remote => 1, othcoau => 1},
+               tokenauthuserfile => {anywhere => 1},
+               unamemaprules => {remote => 1,},
+               unsub => {content => 1,},
+               update => {shared => 1},
+               updatebalcookie => {institutiononly => 1},
+               updateclickers => {remote => 1},
+               userhassession => {anywhere => 1},
+               userload => {anywhere => 1},
+               version => {anywhere => 1}, #not used
+            );
+
+#
 #   Statistics that are maintained and dislayed in the status line.
 #
 my $Transactions = 0;		# Number of attempted transactions.
@@ -258,10 +437,19 @@ sub SSLConnection {
     Debug("Approving promotion -> ssl");
     #  And do so:
 
+    my $CRLFile;
+    unless ($crlchecked{$clientname}) {
+        $CRLFile = lonssl::CRLFile();
+        $crlchecked{$clientname} = 1;
+    }
+
     my $SSLSocket = lonssl::PromoteServerSocket($Socket,
 						$CACertificate,
 						$Certificate,
-						$KeyFile);
+						$KeyFile,
+						$clientname,
+                                                $CRLFile,
+                                                $clientversion);
     if(! ($SSLSocket) ) {	# SSL socket promotion failed.
 	my $err = lonssl::LastError();
 	&logthis("<font color=\"red\"> CRITICAL "
@@ -301,8 +489,23 @@ sub InsecureConnection {
     my $Socket  =  shift;
 
     #   Don't even start if insecure connections are not allowed.
-
-    if(! $perlvar{londAllowInsecure}) {	# Insecure connections not allowed.
+    #   return 0 if Insecure connections not allowed.
+    #
+    if (ref($secureconf{'connfrom'}) eq 'HASH') {
+        if ($clientsamedom) {
+            if ($secureconf{'connfrom'}{'dom'} eq 'req') {
+                return 0;
+            } 
+        } elsif ($clientsameinst) {
+            if ($secureconf{'connfrom'}{'intdom'} eq 'req') {
+                return 0;
+            }
+        } else {
+            if ($secureconf{'connfrom'}{'other'} eq 'req') {
+                return 0;
+            }
+        }
+    } elsif (!$perlvar{londAllowInsecure}) {
 	return 0;
     }
 
@@ -602,10 +805,17 @@ sub ConfigFileFromSelector {
     my $selector   = shift;
     my $tablefile;
 
-    my $tabledir = $perlvar{'lonTabDir'}.'/';
-    if (($selector eq "hosts") || ($selector eq "domain") || 
-        ($selector eq "dns_hosts") || ($selector eq "dns_domain")) {
-	$tablefile =  $tabledir.$selector.'.tab';
+    if ($selector eq 'loncapaCAcrl') {
+        my $tabledir = $perlvar{'lonCertificateDirectory'};
+        if (-d $tabledir) {
+            $tablefile =  $tabledir.'/'.$selector.'.pem';
+        }
+    } else {
+        my $tabledir = $perlvar{'lonTabDir'}.'/';
+        if (($selector eq "hosts") || ($selector eq "domain") || 
+            ($selector eq "dns_hosts") || ($selector eq "dns_domain")) {
+	    $tablefile =  $tabledir.$selector.'.tab';
+        }
     }
     return $tablefile;
 }
@@ -629,12 +839,13 @@ sub PushFile {
     my ($command, $filename, $contents) = split(":", $request, 3);
     &Debug("PushFile");
     
-    #  At this point in time, pushes for only the following tables are
-    #  supported:
+    #  At this point in time, pushes for only the following tables and
+    #  CRL file are supported:
     #   hosts.tab  ($filename eq host).
     #   domain.tab ($filename eq domain).
     #   dns_hosts.tab ($filename eq dns_host).
-    #   dns_domain.tab ($filename eq dns_domain). 
+    #   dns_domain.tab ($filename eq dns_domain).
+    #   loncapaCAcrl.pem ($filename eq loncapaCAcrl).
     # Construct the destination filename or reject the request.
     #
     # lonManage is supposed to ensure this, however this session could be
@@ -655,7 +866,8 @@ sub PushFile {
 
     if($filename eq "host") {
 	$contents = AdjustHostContents($contents);
-    } elsif ($filename eq 'dns_host' || $filename eq 'dns_domain') {
+    } elsif (($filename eq 'dns_hosts') || ($filename eq 'dns_domain') ||
+             ($filename eq 'loncapaCAcrl')) {
         if ($contents eq '') {
             &logthis('<font color="red"> Pushfile: unable to install '
                     .$tablefile." - no data received from push. </font>");
@@ -666,8 +878,13 @@ sub PushFile {
             if ($managers{$clientip} eq $clientname) {
                 my $clientprotocol = $Apache::lonnet::protocol{$clientname};
                 $clientprotocol = 'http' if ($clientprotocol ne 'https');
-                my $url = '/adm/'.$filename;
-                $url =~ s{_}{/};
+                my $url;
+                if ($filename eq 'loncapaCAcrl') {
+                    $url = '/adm/dns/loncapaCRL';
+                } else {
+                    $url = '/adm/'.$filename;
+                    $url =~ s{_}{/};
+                }
                 my $request=new HTTP::Request('GET',"$clientprotocol://$clienthost$url");
                 my $response = LONCAPA::LWPReq::makerequest($clientname,$request,'',\%perlvar,60,0);
                 if ($response->is_error()) {
@@ -1424,6 +1641,22 @@ sub du2_handler {
 #    selected directory the filename followed by the full output of
 #    the stat function is returned.  The returned info for each
 #    file are separated by ':'.  The stat fields are separated by &'s.
+#
+#    If the requested path contains /../ or is:
+#
+#    1. for a directory, and the path does not begin with one of:
+#        (a) /home/httpd/html/res/<domain>
+#        (b) /home/httpd/html/userfiles/
+#        (c) /home/httpd/lonUsers/<domain>/<1>/<2>/<3>/<username>/userfiles
+#    or is:
+#
+#    2. for a file, and the path (after prepending) does not begin with one of:
+#        (a) /home/httpd/lonUsers/<domain>/<1>/<2>/<3>/<username>/
+#        (b) /home/httpd/html/res/<domain>/<username>/
+#        (c) /home/httpd/html/userfiles/<domain>/<username>/
+#
+#    the response will be "refused".
+#
 # Parameters:
 #    $cmd        - The command that dispatched us (ls).
 #    $ulsdir     - The directory path to list... I'm not sure what this
@@ -1445,8 +1678,17 @@ sub ls_handler {
     my $rights;
     my $ulsout='';
     my $ulsfn;
+    if ($ulsdir =~m{/\.\./}) {
+        &Failure($client,"refused\n",$userinput);
+        return 1;
+    }
     if (-e $ulsdir) {
 	if(-d $ulsdir) {
+            unless (($ulsdir =~ m{^/home/httpd/html/(res/$LONCAPA::match_domain|userfiles/)}) ||
+                    ($ulsdir =~ m{^/home/httpd/lonUsers/$LONCAPA::match_domain(?:/[\w\-.@]){3}/$LONCAPA::match_name/userfiles})) {
+                &Failure($client,"refused\n",$userinput);
+                return 1;
+            }
 	    if (opendir(LSDIR,$ulsdir)) {
 		while ($ulsfn=readdir(LSDIR)) {
 		    undef($obs);
@@ -1470,6 +1712,11 @@ sub ls_handler {
 		closedir(LSDIR);
 	    }
 	} else {
+            unless (($ulsdir =~ m{^/home/httpd/lonUsers/$LONCAPA::match_domain(?:/[\w\-.@]){3}/$LONCAPA::match_name/}) ||
+                    ($ulsdir =~ m{^/home/httpd/html/(?:res|userfiles)/$LONCAPA::match_domain/$LONCAPA::match_name/})) {
+                &Failure($client,"refused\n",$userinput);
+                return 1;
+            }
 	    my @ulsstats=stat($ulsdir);
 	    $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';
 	}
@@ -1494,6 +1741,22 @@ sub ls_handler {
 #    selected directory the filename followed by the full output of
 #    the stat function is returned.  The returned info for each
 #    file are separated by ':'.  The stat fields are separated by &'s.
+#
+#    If the requested path contains /../ or is:
+#
+#    1. for a directory, and the path does not begin with one of:
+#        (a) /home/httpd/html/res/<domain>
+#        (b) /home/httpd/html/userfiles/
+#        (c) /home/httpd/lonUsers/<domain>/<1>/<2>/<3>/<username>/userfiles
+#    or is:
+#
+#    2. for a file, and the path (after prepending) does not begin with one of:
+#        (a) /home/httpd/lonUsers/<domain>/<1>/<2>/<3>/<username>/
+#        (b) /home/httpd/html/res/<domain>/<username>/
+#        (c) /home/httpd/html/userfiles/<domain>/<username>/
+#
+#    the response will be "refused".
+#
 # Parameters:
 #    $cmd        - The command that dispatched us (ls).
 #    $ulsdir     - The directory path to list... I'm not sure what this
@@ -1514,8 +1777,17 @@ sub ls2_handler {
     my $rights;
     my $ulsout='';
     my $ulsfn;
+    if ($ulsdir =~m{/\.\./}) {
+        &Failure($client,"refused\n",$userinput);
+        return 1;
+    }
     if (-e $ulsdir) {
         if(-d $ulsdir) {
+            unless (($ulsdir =~ m{^/home/httpd/html/(res/$LONCAPA::match_domain|userfiles/)}) ||
+                    ($ulsdir =~ m{^/home/httpd/lonUsers/$LONCAPA::match_domain(?:/[\w\-.@]){3}/$LONCAPA::match_name/userfiles})) {
+                &Failure($client,"refused\n","$userinput");
+                return 1;
+            }
             if (opendir(LSDIR,$ulsdir)) {
                 while ($ulsfn=readdir(LSDIR)) {
                     undef($obs);
@@ -1540,6 +1812,11 @@ sub ls2_handler {
                 closedir(LSDIR);
             }
         } else {
+            unless (($ulsdir =~ m{^/home/httpd/lonUsers/$LONCAPA::match_domain(?:/[\w\-.@]){3}/$LONCAPA::match_name/}) ||
+                    ($ulsdir =~ m{^/home/httpd/html/(?:res|userfiles)/$LONCAPA::match_domain/$LONCAPA::match_name/})) {
+                &Failure($client,"refused\n",$userinput);
+                return 1;
+            }
             my @ulsstats=stat($ulsdir);
             $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';
         }
@@ -1556,6 +1833,25 @@ sub ls2_handler {
 #    selected directory the filename followed by the full output of
 #    the stat function is returned.  The returned info for each
 #    file are separated by ':'.  The stat fields are separated by &'s.
+#
+#    If the requested path (after prepending) contains /../ or is:
+#
+#    1. for a directory, and the path does not begin with one of:
+#        (a) /home/httpd/html/res/<domain>
+#        (b) /home/httpd/html/userfiles/
+#        (c) /home/httpd/lonUsers/<domain>/<1>/<2>/<3>/<username>/userfiles
+#        (d) /home/httpd/html/priv/<domain> and client is the homeserver
+#
+#    or is:
+#
+#    2. for a file, and the path (after prepending) does not begin with one of:
+#        (a) /home/httpd/lonUsers/<domain>/<1>/<2>/<3>/<username>/
+#        (b) /home/httpd/html/res/<domain>/<username>/
+#        (c) /home/httpd/html/userfiles/<domain>/<username>/
+#        (d) /home/httpd/html/priv/<domain>/<username>/ and client is the homeserver
+#
+#    the response will be "refused".
+#
 # Parameters:
 #    $cmd        - The command that dispatched us (ls).
 #    $tail       - The tail of the request that invoked us.
@@ -1595,22 +1891,12 @@ sub ls3_handler {
     }
 
     my $dir_root = $perlvar{'lonDocRoot'};
-    if ($getpropath) {
+    if (($getpropath) || ($getuserdir)) {
         if (($uname =~ /^$LONCAPA::match_name$/) && ($udom =~ /^$LONCAPA::match_domain$/)) {
             $dir_root = &propath($udom,$uname);
             $dir_root =~ s/\/$//;
         } else {
-            &Failure($client,"refused\n","$cmd:$tail");
-            return 1;
-        }
-    } elsif ($getuserdir) {
-        if (($uname =~ /^$LONCAPA::match_name$/) && ($udom =~ /^$LONCAPA::match_domain$/)) {
-            my $subdir=$uname.'__';
-            $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
-            $dir_root = $Apache::lonnet::perlvar{'lonUsersDir'}
-                       ."/$udom/$subdir/$uname";
-        } else {
-            &Failure($client,"refused\n","$cmd:$tail");
+            &Failure($client,"refused\n",$userinput);
             return 1;
         }
     } elsif ($alternate_root ne '') {
@@ -1623,14 +1909,56 @@ sub ls3_handler {
             $ulsdir = $dir_root.'/'.$ulsdir;
         }
     }
+    if ($ulsdir =~m{/\.\./}) {
+        &Failure($client,"refused\n",$userinput);
+        return 1;
+    }
+    my $islocal;
+    my @machine_ids = &Apache::lonnet::current_machine_ids();
+    if (grep(/^\Q$clientname\E$/,@machine_ids)) {
+        $islocal = 1;
+    }
     my $obs;
     my $rights;
     my $ulsout='';
     my $ulsfn;
+
+    my ($crscheck,$toplevel,$currdom,$currnum,$skip);
+    unless ($islocal) {
+        my ($major,$minor) = split(/\./,$clientversion);
+        if (($major < 2) || ($major == 2 && $minor < 12)) {
+            $crscheck = 1;
+        }
+    }
     if (-e $ulsdir) {
         if(-d $ulsdir) {
-            if (opendir(LSDIR,$ulsdir)) {
+            unless (($getpropath) || ($getuserdir) ||
+                    ($ulsdir =~ m{^/home/httpd/html/(res/$LONCAPA::match_domain|userfiles/)}) ||
+                    ($ulsdir =~ m{^/home/httpd/lonUsers/$LONCAPA::match_domain(?:/[\w\-.@]){3}/$LONCAPA::match_name/userfiles}) ||
+                    (($ulsdir =~ m{^/home/httpd/html/priv/$LONCAPA::match_domain}) && ($islocal))) {
+                &Failure($client,"refused\n",$userinput);
+                return 1;
+            }
+            if (($crscheck) &&
+                ($ulsdir =~ m{^/home/httpd/html/res/($LONCAPA::match_domain)(/?$|/$LONCAPA::match_courseid)})) {
+                ($currdom,my $posscnum) = ($1,$2);
+                if (($posscnum eq '') || ($posscnum eq '/')) {
+                    $toplevel = 1;
+                } else {
+                    $posscnum =~ s{^/+}{};
+                    if (&LONCAPA::Lond::is_course($currdom,$posscnum)) {
+                        $skip = 1;
+                    }
+                }
+            }
+            if ((!$skip) && (opendir(LSDIR,$ulsdir))) {
                 while ($ulsfn=readdir(LSDIR)) {
+                    if (($crscheck) && ($toplevel) && ($currdom ne '') &&
+                        ($ulsfn =~ /^$LONCAPA::match_courseid$/) && (-d "$ulsdir/$ulsfn")) {
+                        if (&LONCAPA::Lond::is_course($currdom,$ulsfn)) {
+                            next;
+                        }
+                    }
                     undef($obs);
                     undef($rights);
                     my @ulsstats=stat($ulsdir.'/'.$ulsfn);
@@ -1653,6 +1981,13 @@ sub ls3_handler {
                 closedir(LSDIR);
             }
         } else {
+            unless (($getpropath) || ($getuserdir) ||
+                    ($ulsdir =~ m{^/home/httpd/lonUsers/$LONCAPA::match_domain(?:/[\w\-.@]){3}/$LONCAPA::match_name/}) ||
+                    ($ulsdir =~ m{^/home/httpd/html/(?:res|userfiles)/$LONCAPA::match_domain/$LONCAPA::match_name/}) ||
+                    (($ulsdir =~ m{^/home/httpd/html/priv/$LONCAPA::match_domain/$LONCAPA::match_name/}) && ($islocal))) {
+                &Failure($client,"refused\n",$userinput);
+                return 1;
+            }
             my @ulsstats=stat($ulsdir);
             $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';
         }
@@ -1676,15 +2011,17 @@ sub read_lonnet_global {
                       );
     my %limit_to = (
                     perlvar => {
-                                 lonOtherAuthen => 1,
-                                 lonBalancer    => 1,
-                                 lonVersion     => 1,
-                                 lonSysEMail    => 1,
-                                 lonHostID      => 1,
-                                 lonRole        => 1,
-                                 lonDefDomain   => 1,
-                                 lonLoadLim     => 1,
-                                 lonUserLoadLim => 1,
+                                 lonOtherAuthen  => 1,
+                                 lonBalancer     => 1,
+                                 lonVersion      => 1,
+                                 lonAdmEMail     => 1,
+                                 lonSupportEMail => 1,  
+                                 lonSysEMail     => 1,
+                                 lonHostID       => 1,
+                                 lonRole         => 1,
+                                 lonDefDomain    => 1,
+                                 lonLoadLim      => 1,
+                                 lonUserLoadLim  => 1,
                                }
                   );
     if (ref($requested) eq 'HASH') {
@@ -1703,7 +2040,7 @@ sub read_lonnet_global {
                 }
                 if ($what eq 'perlvar') {
                     if (!exists($packagevars{$what}{'lonBalancer'})) {
-                        if ($dist =~ /^(centos|rhes|fedora|scientific)/) {
+                        if ($dist =~ /^(centos|rhes|fedora|scientific|oracle|rocky|alma)/) {
                             my $othervarref=LONCAPA::Configuration::read_conf('httpd.conf');
                             if (ref($othervarref) eq 'HASH') {
                                 $items->{'lonBalancer'} = $othervarref->{'lonBalancer'};
@@ -1799,8 +2136,8 @@ sub server_distarch_handler {
 sub server_certs_handler {
     my ($cmd,$tail,$client) = @_;
     my $userinput = "$cmd:$tail";
-    my $result;
-    my $result = &LONCAPA::Lond::server_certs(\%perlvar);
+    my $hostname = &Apache::lonnet::hostname($perlvar{'lonHostID'});
+    my $result = &LONCAPA::Lond::server_certs(\%perlvar,$perlvar{'lonHostID'},$hostname);
     &Reply($client,\$result,$userinput);
     return;
 }
@@ -1938,7 +2275,7 @@ sub authenticate_handler {
                 my ($remote,$hosted);
                 my $remotesession = &get_usersession_config($udom,'remotesession');
                 if (ref($remotesession) eq 'HASH') {
-                    $remote = $remotesession->{'remote'}
+                    $remote = $remotesession->{'remote'};
                 }
                 my $hostedsession = &get_usersession_config($clienthomedom,'hostedsession');
                 if (ref($hostedsession) eq 'HASH') {
@@ -2021,12 +2358,84 @@ sub change_password_handler {
     }
     if($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";
@@ -2043,7 +2452,7 @@ sub change_password_handler {
 	    my $result = &change_unix_password($uname, $npass);
             if ($result eq 'ok') {
                 &update_passwd_history($uname,$udom,$howpwd,$context);
-             }
+            }
 	    &logthis("Result of password change for $uname: ".
 		     $result);
 	    &Reply($client, \$result, $userinput);
@@ -2054,7 +2463,6 @@ sub change_password_handler {
 	    #
 	    &Failure( $client, "auth_mode_error\n", $userinput);
 	}  
-	
     } else {
 	if ($failure eq '') {
 	    $failure = 'non_authorized';
@@ -2075,12 +2483,8 @@ sub hash_passwd {
         my $plainsalt = substr($rest[1],0,22);
         $salt = Crypt::Eksblowfish::Bcrypt::de_base64($plainsalt);
     } else {
-        my $defaultcost;
-        my %domconfig =
-            &Apache::lonnet::get_dom('configuration',['password'],$domain);
-        if (ref($domconfig{'password'}) eq 'HASH') {
-            $defaultcost = $domconfig{'password'}{'cost'};
-        }
+        my %domdefaults = &Apache::lonnet::get_domain_defaults($domain);
+        my $defaultcost = $domdefaults{'intauth_cost'};
         if (($defaultcost eq '') || ($defaultcost =~ /D/)) {
             $cost = 10;
         } else {
@@ -2254,6 +2658,36 @@ sub update_passwd_history {
     return;
 }
 
+sub inst_unamemap_check {
+    my ($cmd, $tail, $client)   = @_;
+    my $userinput               = "$cmd:$tail";
+    my %rulecheck;
+    my $outcome;
+    my ($udom,$uname,@rules) = split(/:/,$tail);
+    $udom = &unescape($udom);
+    $uname = &unescape($uname);
+    @rules = map {&unescape($_);} (@rules);
+    eval {
+        local($SIG{__DIE__})='DEFAULT';
+        $outcome = &localenroll::unamemap_check($udom,$uname,\@rules,\%rulecheck);
+    };
+    if (!$@) {
+        if ($outcome eq 'ok') {
+            my $result='';
+            foreach my $key (keys(%rulecheck)) {
+                $result.=&escape($key).'='.&Apache::lonnet::freeze_escape($rulecheck{$key}).'&';
+            }
+            &Reply($client,\$result,$userinput);
+        } else {
+            &Reply($client,"error\n", $userinput);
+        }
+    } else {
+        &Failure($client,"unknown_cmd\n",$userinput);
+    }
+}
+&register_handler("instunamemapcheck",\&inst_unamemap_check,0,1,0);
+
+
 #
 #   Determines if this is the home server for a user.  The home server
 #   for a user will have his/her lon-capa passwd file.  Therefore all we need
@@ -2335,32 +2769,26 @@ sub update_resource_handler {
 		my $transname="$fname.in.transfer";
 		my $remoteurl=&Apache::lonnet::reply("sub:$fname","$clientname");
 		my $response;
-# FIXME: cannot replicate files that take more than two minutes to transfer?
-#		alarm(120);
-# FIXME: this should use the LWP mechanism, not internal alarms.
-                alarm(1200);
-		{
-		    my $request=new HTTP::Request('GET',"$remoteurl");
-                    $response=&LONCAPA::LWPReq::makerequest($clientname,$request,$transname,\%perlvar,1200,0,1);
-		}
-		alarm(0);
+# FIXME: cannot replicate files that take more than two minutes to transfer -- needs checking now 1200s timeout used
+# for LWP request.
+		my $request=new HTTP::Request('GET',"$remoteurl");
+                $response=&LONCAPA::LWPReq::makerequest($clientname,$request,$transname,\%perlvar,1200,0,1);
 		if ($response->is_error()) {
-# FIXME: we should probably clean up here instead of just whine
-		    unlink($transname);
+                    my $reply=&Apache::lonnet::reply("unsub:$fname","$clientname");
+                    &devalidate_meta_cache($fname);
+                    if (-e $transname) {
+                        unlink($transname);
+                    }
+                    unlink($fname);
 		    my $message=$response->status_line;
 		    &logthis("LWP GET: $message for $fname ($remoteurl)");
 		} else {
 		    if ($remoteurl!~/\.meta$/) {
-# FIXME: isn't there an internal LWP mechanism for this?
-			alarm(120);
-			{
-			    my $mrequest=new HTTP::Request('GET',$remoteurl.'.meta');
-                            my $mresponse = &LONCAPA::LWPReq::makerequest($clientname,$mrequest,$fname.'.meta',\%perlvar,120,0,1);
-			    if ($mresponse->is_error()) {
-				unlink($fname.'.meta');
-			    }
+			my $mrequest=new HTTP::Request('GET',$remoteurl.'.meta');
+                        my $mresponse = &LONCAPA::LWPReq::makerequest($clientname,$mrequest,$fname.'.meta',\%perlvar,120,0,1);
+			if ($mresponse->is_error()) {
+			    unlink($fname.'.meta');
 			}
-			alarm(0);
 		    }
                     # we successfully transfered, copy file over to real name
 		    rename($transname,$fname);
@@ -2430,17 +2858,13 @@ sub fetch_user_file_handler {
 	my $remoteurl=$clientprotocol.'://'.$clienthost.'/userfiles/'.$fname;
 	my $response;
 	Debug("Remote URL : $remoteurl Transfername $transname Destname: $destname");
-	alarm(1200);
-	{
-	    my $request=new HTTP::Request('GET',"$remoteurl");
-            my $verifycert = 1;
-            my @machine_ids = &Apache::lonnet::current_machine_ids();
-            if (grep(/^\Q$clientname\E$/,@machine_ids)) {
-                $verifycert = 0;
-            }
-            $response = &LONCAPA::LWPReq::makerequest($clientname,$request,$transname,\%perlvar,1200,$verifycert);
-	}
-	alarm(0);
+	my $request=new HTTP::Request('GET',"$remoteurl");
+        my $verifycert = 1;
+        my @machine_ids = &Apache::lonnet::current_machine_ids();
+        if (grep(/^\Q$clientname\E$/,@machine_ids)) {
+            $verifycert = 0;
+        }
+        $response = &LONCAPA::LWPReq::makerequest($clientname,$request,$transname,\%perlvar,1200,$verifycert);
 	if ($response->is_error()) {
 	    unlink($transname);
 	    my $message=$response->status_line;
@@ -2649,6 +3073,54 @@ sub user_has_session_handler {
 }
 &register_handler("userhassession", \&user_has_session_handler, 0,1,0);
 
+sub del_usersession_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $result;
+    my ($udom, $uname) = map { &unescape($_) } (split(/:/, $tail));
+    if (($udom =~ /^$LONCAPA::match_domain$/) && ($uname =~ /^$LONCAPA::match_username$/)) {
+        my $lonidsdir = $perlvar{'lonIDsDir'};
+        if (-d $lonidsdir) {
+            if (opendir(DIR,$lonidsdir)) {
+                my $filename;
+                while ($filename=readdir(DIR)) {
+                    if ($filename=~/^\Q$uname\E_\d+_\Q$udom\E_/) {
+                        if (tie(my %oldenv,'GDBM_File',"$lonidsdir/$filename",
+                                &GDBM_READER(),0640)) {
+                            my $linkedfile;
+                            if (exists($oldenv{'user.linkedenv'})) {
+                                $linkedfile = $oldenv{'user.linkedenv'};
+                            }
+                            untie(%oldenv);
+                            $result = unlink("$lonidsdir/$filename");
+                            if ($result) {
+                                if ($linkedfile =~ /^[a-f0-9]+_linked$/) {
+                                    if (-l "$lonidsdir/$linkedfile.id") {
+                                        unlink("$lonidsdir/$linkedfile.id");
+                                    }
+                                }
+                            }
+                        } else {
+                            $result = unlink("$lonidsdir/$filename");
+                        }
+                        last;
+                    }
+                }
+            }
+        }
+        if ($result == 1) {
+            &Reply($client, "$result\n", "$cmd:$tail");
+        } else {
+            &Reply($client, "not_found\n", "$cmd:$tail");
+        }
+    } else {
+        &Failure($client, "invalid_user\n", "$cmd:$tail");
+    }
+    return 1;
+}
+
+&register_handler("delusersession", \&del_usersession_handler, 0,1,0);
+
 #
 #  Authenticate access to a user file by checking that the token the user's 
 #  passed also exists in their session file
@@ -3138,7 +3610,8 @@ sub get_profile_entry {
 #
 #  Parameters:
 #     $cmd               - Command keyword of request (eget).
-#     $tail              - Tail of the command.  See GetProfileEntry
#                          for more information about this.
+#     $tail              - Tail of the command.  See GetProfileEntry
+#                          for more information about this.
 #     $client            - File open on the client.
 #  Returns:
 #     1      - Continue processing
@@ -3391,6 +3864,47 @@ sub dump_with_regexp {
 }
 &register_handler("dump", \&dump_with_regexp, 0, 1, 0);
 
+#
+#  Process the encrypted dump request. Original call should
+#  be from lonnet::dump() with seventh arg ($encrypt) set to
+#  1, to ensure that both request and response are encrypted.
+#
+#  Parameters:
+#     $cmd               - Command keyword of request (edump).
+#     $tail              - Tail of the command.
+#                          See &dump_with_regexp for more
+#                          information about this.
+#     $client            - File open on the client.
+#  Returns:
+#     1      - Continue processing
+#     0      - server should exit.
+#
+
+sub encrypted_dump_with_regexp {
+    my ($cmd, $tail, $client) = @_;
+    my $res = LONCAPA::Lond::dump_with_regexp($tail, $clientversion);
+
+    if ($res =~ /^error:/) {
+        Failure($client, \$res, "$cmd:$tail");
+    } else {
+        if ($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:$encres\n","$cmd:$tail");
+        } else {
+            &Failure( $client, "error:no_key\n","$cmd:$tail");
+        }
+    }
+}
+&register_handler("edump", \&encrypted_dump_with_regexp, 0, 1, 0);
+
 #  Store a set of key=value pairs associated with a versioned name.
 #
 #  Parameters:
@@ -3710,7 +4224,7 @@ sub retrieve_chat_handler {
 #  serviced.
 #
 #  Parameters:
-#     $cmd       - COmmand keyword that initiated the request.
+#     $cmd       - Command keyword that initiated the request.
 #     $tail      - Remainder of the command after the keyword.
 #                  For this function, this consists of a query and
 #                  3 arguments that are self-documentingly labelled
@@ -3724,11 +4238,41 @@ sub retrieve_chat_handler {
 sub send_query_handler {
     my ($cmd, $tail, $client) = @_;
 
-
     my $userinput = "$cmd:$tail";
 
     my ($query,$arg1,$arg2,$arg3)=split(/\:/,$tail);
     $query=~s/\n*$//g;
+    if (($query eq 'usersearch') || ($query eq 'instdirsearch')) {
+        my $usersearchconf = &get_usersearch_config($currentdomainid,'directorysrch');
+        my $earlyout;
+        if (ref($usersearchconf) eq 'HASH') {
+            if ($currentdomainid eq $clienthomedom) {
+                if ($query eq 'usersearch') {
+                    if ($usersearchconf->{'lcavailable'} eq '0') {
+                        $earlyout = 1;
+                    }
+                } else {
+                    if ($usersearchconf->{'available'} eq '0') {
+                        $earlyout = 1;
+                    }
+                }
+            } else {
+                if ($query eq 'usersearch') {
+                    if ($usersearchconf->{'lclocalonly'}) {
+                        $earlyout = 1;
+                    }
+                } else {
+                    if ($usersearchconf->{'localonly'}) {
+                        $earlyout = 1;
+                    }
+                }
+            }
+        }
+        if ($earlyout) {
+            &Reply($client, "query_not_authorized\n");
+            return 1;
+        }
+    }
     &Reply($client, "". &sql_reply("$clientname\&$query".
 				"\&$arg1"."\&$arg2"."\&$arg3")."\n",
 	  $userinput);
@@ -4409,6 +4953,44 @@ 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 
 #
@@ -4573,7 +5155,7 @@ sub del_domain_handler {
 # domain directory.
 #
 # Parameters:
-#   $cmd             - Command request keyword (get).
+#   $cmd             - Command request keyword (getdom).
 #   $tail            - Tail of the command.  This is a colon separated list
 #                      consisting of the domain and the 'namespace' 
 #                      which selects the gdbm file to do the lookup in,
@@ -4590,33 +5172,215 @@ sub del_domain_handler {
 sub get_domain_handler {
     my ($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 (($namespace =~ /^enc/) || ($namespace eq 'private')) {
+        &Failure( $client, "refused\n", $userinput);
+    } else {
+        my $res = LONCAPA::Lond::get_dom($userinput);
+        if ($res =~ /^error:/) {
+            &Failure($client, \$res, $userinput);
+        } else {
+            &Reply($client, \$res, $userinput);
         }
-        if (&untie_domain_hash($hashref)) {
-            $qresult=~s/\&$//;
-            &Reply($client, \$qresult, $userinput);
+    }
+
+    return 1;
+}
+&register_handler("getdom", \&get_domain_handler, 0, 1, 0);
+
+#
+# Encrypted get from the namespace database file at the domain level.
+# This function retrieves a keyed item from a specific named database in the
+# domain directory.
+#
+# Parameters:
+#   $cmd             - Command request keyword (egetdom).
+#   $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,
+#                      & separated list of keys to lookup.  Note that
+#                      the values are returned as an & separated list too.
+#   $client          - File descriptor open on the client.
+# Returns:
+#   1       - Continue processing.
+#   0       - Exit.
+#  Side effects:
+#     reply is encrypted before being written to $client.
+#
+sub encrypted_get_domain_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $userinput = "$cmd:$tail";
+
+    my ($udom,$namespace,$what) = split(/:/,$tail,3);
+    if ($namespace eq 'private') {
+        &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",$userinput);
+            if ($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);
+
+#
+# Encrypted get from the namespace database file at the domain level.
+# This function retrieves a keyed item from a specific named database in the
+# domain directory.
+#
+# Parameters:
+#   $cmd             - Command request keyword (lti).
+#   $tail            - Tail of the command.  This is a colon-separated list
+#                      consisting of the domain, coursenum, if for LTI-
+#                      enabled deep-linking to course content using
+#                      link protection configured within a course,
+#                      context (=deeplink) if for LTI-enabled deep-linking
+#                      to course content using LTI Provider settings
+#                      configured within a course's domain, the (escaped)
+#                      launch URL, the (escaped) method (typically POST),
+#                      and a frozen hash of the LTI launch parameters
+#                      from the LTI payload.
+#   $client          - File descriptor open on the client.
+# Returns:
+#   1       - Continue processing.
+#   0       - Exit.
+#  Side effects:
+#     The reply will contain an LTI itemID, if the signed LTI payload
+#     could be verified using the consumer key and the shared secret
+#     available for that key (for the itemID) for either the course or domain,
+#     depending on values for cnum and context. The reply is encrypted before
+#     being written to $client.
+#
+sub lti_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $userinput = "$cmd:$tail";
+
+    my ($cdom,$cnum,$context,$escurl,$escmethod,$items) = split(/:/,$tail);
+    my $url = &unescape($escurl);
+    my $method = &unescape($escmethod);
+    my $params = &Apache::lonnet::thaw_unescape($items);
+    my $res;
+    if ($cnum ne '') {
+        $res = &LONCAPA::Lond::crslti_itemid($cdom,$cnum,$url,$method,$params,$perlvar{'lonVersion'});
     } else {
-        &Failure($client, "error: ".($!+0)." tie(GDBM) Failed ".
-                 "while attempting getdom\n",$userinput);
+        $res = &LONCAPA::Lond::domlti_itemid($cdom,$context,$url,$method,$params,$perlvar{'lonVersion'});
+    }
+    if ($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("lti", \&lti_handler, 1, 1, 0);
 
+#
+# Data for LTI payload (received encrypted) are unencrypted and
+# then signed with the appropriate key and secret, before re-encrypting
+# the signed payload which is sent to the client for unencryption by
+# the caller: lonnet::sign_lti()) before dispatch either to a web browser
+# (launch) or to a remote web service (roster, logout, or grade).  
+#
+# Parameters:
+#   $cmd             - Command request keyword (signlti).
+#   $tail            - Tail of the command.  This is a colon-separated list
+#                      consisting of the domain, coursenum (if for an External
+#                      Tool defined in a course), crsdef (true if defined in
+#                      a course), type (linkprot or lti)
+#                      context (launch, roster, logout, or grade),
+#                      escaped launch URL, numeric ID of external tool,
+#                      version number for encryption key (if tool's LTI secret was
+#                      encrypted before storing), a frozen hash of LTI launch 
+#                      parameters, and a frozen hash of LTI information,
+#                      (e.g., method => 'HMAC-SHA1',
+#                             respfmt => 'to_authorization_header').
+#   $client          - File descriptor open on the client.
+# Returns:
+#   1       - Continue processing.
+#   0       - Exit.
+#  Side effects:
+#     The reply will contain the LTI payload, as & separated key=value pairs,
+#     where value is itself a frozen hash, if the required key and secret
+#     for the specific tool ID are available. The payload data are retrieved from
+#     a call to Lond::sign_lti_payload(), and the reply is encrypted before being
+#     written to $client.
+#
+sub sign_lti_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $userinput = "$cmd:$tail";
+
+    my ($cdom,$cnum,$crsdef,$type,$context,$escurl,
+        $ltinum,$keynum,$paramsref,$inforef) = split(/:/,$tail);
+    my $url = &unescape($escurl);
+    my $params = &Apache::lonnet::thaw_unescape($paramsref);
+    my $info = &Apache::lonnet::thaw_unescape($inforef);
+    my $res =
+        &LONCAPA::Lond::sign_lti_payload($cdom,$cnum,$crsdef,$type,$context,$url,$ltinum,
+                                         $keynum,$perlvar{'lonVersion'},$params,$info);
+    my $result;
+    if (ref($res) eq 'HASH') {
+        foreach my $key (keys(%{$res})) {
+            $result .= &escape($key).'='.&Apache::lonnet::freeze_escape($res->{$key}).'&';
+        }
+        $result =~ s/\&$//;
+    } else {
+        $result = $res;
+    }
+    if ($result =~ /^error:/) {
+        &Failure($client, \$result, $userinput);
+    } else {
+        if ($cipher) {
+            my $cmdlength=length($result);
+            $result.="         ";
+            my $encres='';
+            for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
+                $encres.= unpack("H16",
+                                 $cipher->encrypt(substr($result,
+                                                         $encidx,
+                                                         8)));
+            }
+            &Reply( $client,"enc:$cmdlength:$encres\n",$userinput);
+        } else {
+            &Failure( $client, "error:no_key\n",$userinput);
+        }
+    }
     return 1;
 }
-&register_handler("getdom", \&get_domain_handler, 0, 1, 0);
+&register_handler("signlti", \&sign_lti_handler, 1, 1, 0);
 
 #
 #  Puts an id to a domains id database. 
@@ -5043,15 +5807,23 @@ sub tmp_put_handler {
     }
     my ($id,$store);
     $tmpsnum++;
-    if (($context eq 'resetpw') || ($context eq 'createaccount')) {
-        $id = &md5_hex(&md5_hex(time.{}.rand().$$));
+    my $numtries = 0;
+    my $execdir=$perlvar{'lonDaemons'};
+    if (($context eq 'resetpw') || ($context eq 'createaccount') ||
+        ($context eq 'sso') || ($context eq 'link') || ($context eq 'retry')) {
+        $id = &md5_hex(&md5_hex(time.{}.rand().$$.$tmpsnum));
+        while ((-e "$execdir/tmp/$id.tmp") && ($numtries <10)) {
+            undef($id);
+            $id = &md5_hex(&md5_hex(time.{}.rand().$$.$tmpsnum));
+            $numtries ++;
+        }
     } else {
         $id = $$.'_'.$clientip.'_'.$tmpsnum;
     }
     $id=~s/\W/\_/g;
     $record=~s/\n//g;
-    my $execdir=$perlvar{'lonDaemons'};
-    if ($store=IO::File->new(">$execdir/tmp/$id.tmp")) {
+    if (($id ne '') &&
+        ($store=IO::File->new(">$execdir/tmp/$id.tmp"))) {
 	print $store $record;
 	close $store;
 	&Reply($client, \$id, $userinput);
@@ -5134,6 +5906,116 @@ 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 on a load balancer node.
+#
+# Parameters:
+#   $cmd      - Command that got us here.
+#   $cookie   - Cookie to be deleted.
+#   $client   - socket open on the client process.
+#
+# Returns:
+#   1     - Indicating processing should continue.
+# Side Effects:
+#   A cookie file is deleted from the lonBalancedir directory
+#   A reply is sent to the client.
+sub del_balcookie_handler {
+    my ($cmd, $cookie, $client) = @_;
+
+    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'};
+        if (-e "$execdir/$cookie.id") {
+            if (open(my $fh,'<',"$execdir/$cookie.id")) {
+                my $dodelete;
+                while (my $line = <$fh>) {
+                    chomp($line);
+                    if ($line eq $clientname) {
+                        $dodelete = 1;
+                        last;
+                    }
+                }
+                close($fh);
+                if ($dodelete) {
+                    if (unlink("$execdir/$cookie.id")) {
+                        $deleted = 1;
+                    }
+                }
+            }
+        }
+    }
+    if ($deleted) {
+        &Reply($client, "ok\n", $userinput);
+    } else {
+        &Failure( $client, "error: ".($!+0)."Unlinking cookie file Failed ".
+                  "while attempting delbalcookie\n", $userinput);
+    }
+    return 1;
+}
+&register_handler("delbalcookie", \&del_balcookie_handler, 0, 1, 0);
+
+#
 #   Processes the setannounce command.  This command
 #   creates a file named announce.txt in the top directory of
 #   the documentn root and sets its contents.  The announce.txt file is
@@ -5316,6 +6198,39 @@ 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.
@@ -5412,9 +6327,10 @@ sub validate_course_section_handler {
 # 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 words that will be split into:
+#               set of values that will be split into:
 #               $inst_class  - Institutional code for the specific class section   
-#               $courseowner - The escaped username:domain of the course owner 
+#               $ownerlist   - An escaped comma-separated list of username:domain 
+#                              of the course owner, and co-owner(s).
 #               $cdom        - The domain of the course from the institution's
 #                              point of view.
 #    $client  - The socket open on the client.
@@ -5439,6 +6355,112 @@ 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.
+#
+#
+# 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:
+#               $ownerlist   - An escaped comma-separated list of username:domain
+#                              of the course owner, and co-owner(s).
+#               $cdom        - The domain of the course from the institution's
+#                              point of view.
+#               $classes     - Frozen hash of institutional course sections and
+#                              crosslistings.
+#    $client  - The socket open on the client.
+# Returns:
+#    1 - continue processing.
+#
+
+sub validate_classes_handler {
+    my ($cmd, $tail, $client) = @_;
+    my $userinput = "$cmd:$tail";
+    my ($ownerlist,$cdom,$classes) = split(/:/, $tail);
+    my $classesref = &Apache::lonnet::thaw_unescape($classes);
+    my $owners = &unescape($ownerlist);
+    my $result;
+    eval {
+        local($SIG{__DIE__})='DEFAULT';
+        my %validations;
+        my $response = &localenroll::check_instclasses($owners,$cdom,$classesref,
+                                                       \%validations);
+        if ($response eq 'ok') {
+            foreach my $key (keys(%validations)) {
+                $result .= &escape($key).'='.&Apache::lonnet::freeze_escape($validations{$key}).'&';
+            }
+            $result =~ s/\&$//;
+        } else {
+            $result = 'error';
+        }
+    };
+    if (!$@) {
+        &Reply($client, \$result, $userinput);
+    } else {
+        &Failure($client,"unknown_cmd\n",$userinput);
+    }
+    return 1;
+}
+&register_handler("autovalidateinstclasses", \&validate_classes_handler, 0, 1, 0);
+
+#
 #   Create a password for a new LON-CAPA user added by auto-enrollment.
 #   Only used for case where authentication method for new user is localauth
 #
@@ -5516,7 +6538,7 @@ 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.
 #
@@ -5524,7 +6546,7 @@ sub auto_export_grades_handler {
 #    $cmd      - The command that got us dispatched.
 #    $tail     - The tail of the command.  In our case this is a colon 
 #                separated list that will be split into:
-#                $filename - The name of the file to remove.
+#                $filename - The name of the file to retrieve.
 #                            The filename is given as a path relative to
 #                            the LonCAPA temp file directory.
 #    $client   - Socket open on the client.
@@ -5541,6 +6563,8 @@ sub retrieve_auto_file_handler {
 
     if ($filename =~m{/\.\./}) {
         &Failure($client, "refused\n", $userinput);
+    } elsif ($filename !~ /^$LONCAPA::match_domain\_$LONCAPA::match_courseid\_.+_classlist\.xml$/) {
+        &Failure($client, "refused\n", $userinput);
     } elsif ( (-e $source) && ($filename ne '') ) {
 	my $reply = '';
 	if (open(my $fh,$source)) {
@@ -5890,6 +6914,39 @@ sub get_institutional_selfcreate_rules {
 }
 &register_handler("instemailrules",\&get_institutional_selfcreate_rules,0,1,0);
 
+sub get_unamemap_rules {
+    my ($cmd, $tail, $client)   = @_;
+    my $userinput               = "$cmd:$tail";
+    my $dom = &unescape($tail);
+    my (%rules_hash,@rules_order);
+    my $outcome;
+    eval {
+        local($SIG{__DIE__})='DEFAULT';
+        $outcome = &localenroll::unamemap_rules($dom,\%rules_hash,\@rules_order);
+    };
+    if (!$@) {
+        if ($outcome eq 'ok') {
+            my $result;
+            foreach my $key (keys(%rules_hash)) {
+                $result .= &escape($key).'='.&Apache::lonnet::freeze_escape($rules_hash{$key}).'&';
+            }
+            $result =~ s/\&$//;
+            $result .= ':';
+            if (@rules_order > 0) {
+                foreach my $item (@rules_order) {
+                    $result .= &escape($item).'&';
+                }
+            }
+            $result =~ s/\&$//;
+            &Reply($client,\$result,$userinput);
+        } else {
+            &Reply($client,"error\n", $userinput);
+        }
+    } else {
+        &Failure($client,"unknown_cmd\n",$userinput);
+    }
+}
+&register_handler("unamemaprules",\&get_unamemap_rules,0,1,0);
 
 sub institutional_username_check {
     my ($cmd, $tail, $client)   = @_;
@@ -6178,12 +7235,13 @@ sub get_request {
 #
 # Parameters:
 #    user_input   - The request received from the client (lonc).
+#
 # Returns:
 #    true to keep processing, false if caller should exit.
 #
 sub process_request {
-    my ($userinput) = @_;      # Easier for now to break style than to
-                                # fix all the userinput -> user_input.
+    my ($userinput) = @_; # Easier for now to break style than to
+                          # fix all the userinput -> user_input.
     my $wasenc    = 0;		# True if request was encrypted.
 # ------------------------------------------------------------ See if encrypted
     # for command
@@ -6263,6 +7321,62 @@ sub process_request {
 	    Debug("Client not privileged to do this operation");
 	    $ok = 0;
 	}
+        if ($ok) {
+            my $realcommand = $command;
+            if ($command eq 'querysend') {
+                my ($query,$rest)=split(/\:/,$tail,2);
+                $query=~s/\n*$//g;
+                my @possqueries = 
+                    qw(userlog courselog fetchenrollment institutionalphotos usersearch instdirsearch getinstuser getmultinstusers);
+                if (grep(/^\Q$query\E$/,@possqueries)) {
+                    $command .= '_'.$query;
+                } elsif ($query eq 'prepare activity log') {
+                    $command .= '_activitylog';
+                }
+            }
+            if (ref($trust{$command}) eq 'HASH') {
+                my $donechecks;
+                if ($trust{$command}{'anywhere'}) {
+                   $donechecks = 1;
+                } elsif ($trust{$command}{'manageronly'}) {
+                    unless (&isManager()) {
+                        $ok = 0;
+                    }
+                    $donechecks = 1;
+                } elsif ($trust{$command}{'institutiononly'}) {
+                    unless ($clientsameinst) {
+                        $ok = 0;
+                    }
+                    $donechecks = 1;
+                } elsif ($clientsameinst) {
+                    $donechecks = 1;
+                }
+                unless ($donechecks) {
+                    foreach my $rule (keys(%{$trust{$command}})) {
+                        next if ($rule eq 'remote');
+                        if ($trust{$command}{$rule}) {
+                            if ($clientprohibited{$rule}) {
+                                $ok = 0;
+                            } else {
+                                $ok = 1;
+                                $donechecks = 1;
+                                last;
+                            }
+                        }
+                    }
+                }
+                unless ($donechecks) {
+                    if ($trust{$command}{'remote'}) {
+                        if ($clientremoteok) {
+                            $ok = 1;
+                        } else {
+                            $ok = 0;
+                        } 
+                    }
+                }
+            }
+            $command = $realcommand;
+        }
 
 	if($ok) {
 	    Debug("Dispatching to handler $command $tail");
@@ -6273,8 +7387,7 @@ sub process_request {
 	    Failure($client, "refused\n", $userinput);
 	    return 1;
 	}
-
-    }    
+    }
 
     print $client "unknown_cmd\n";
 # -------------------------------------------------------------------- complete
@@ -6414,8 +7527,8 @@ my $wwwid=getpwnam('www');
 if ($wwwid!=$<) {
    my $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
    my $subj="LON: $currenthostid User ID mismatch";
-   system("echo 'User ID mismatch.  lond must be run as user www.' |\
- mailto $emailto -s '$subj' > /dev/null");
+   system("echo 'User ID mismatch.  lond must be run as user www.' |".
+          " mail -s '$subj' $emailto > /dev/null");
    exit 1;
 }
 
@@ -6531,6 +7644,7 @@ sub UpdateHosts {
     #  will take care of new and changed hosts as connections come into being.
 
     &Apache::lonnet::reset_hosts_info();
+    my %active;
 
     foreach my $child (keys(%children)) {
 	my $childip = $children{$child};
@@ -6540,15 +7654,62 @@ sub UpdateHosts {
 		    ." $child for ip $childip </font>");
 	    kill('INT', $child);
 	} else {
+            $active{$child} = $childip;
 	    logthis('<font color="green"> keeping child for ip '
 		    ." $childip (pid=$child) </font>");
 	}
     }
+
+    my %oldconf = %secureconf;
+    my %connchange;
+    if (lonssl::Read_Connect_Config(\%secureconf,\%perlvar,\%crlchecked) eq 'ok') {
+        logthis('<font color="blue"> Reloaded SSL connection rules and cleared CRL checking history </font>');
+    } else {
+        logthis('<font color="yellow"> Failed to reload SSL connection rules and clear CRL checking history </font>');
+    }
+    if ((ref($oldconf{'connfrom'}) eq 'HASH') && (ref($secureconf{'connfrom'}) eq 'HASH')) {
+        foreach my $type ('dom','intdom','other') {
+            if ((($oldconf{'connfrom'}{$type} eq 'no') && ($secureconf{'connfrom'}{$type} eq 'req')) ||
+                (($oldconf{'connfrom'}{$type} eq 'req') && ($secureconf{'connfrom'}{$type} eq 'no'))) {
+                $connchange{$type} = 1;
+            }
+        }
+    }
+    if (keys(%connchange)) {
+        foreach my $child (keys(%active)) {
+            my $childip = $active{$child};
+            if ($childip ne '127.0.0.1') {
+                my $childhostname  = gethostbyaddr(Socket::inet_aton($childip),AF_INET);
+                if ($childhostname ne '') {
+                    my $childlonhost = &Apache::lonnet::get_server_homeID($childhostname);
+                    my ($samedom,$sameinst) = &set_client_info($childlonhost);
+                    if ($samedom) {
+                        if ($connchange{'dom'}) {
+                            logthis('<font color="blue"> UpdateHosts killing child '
+                                   ." $child for ip $childip </font>");
+                            kill('INT', $child);
+                        }
+                    } elsif ($sameinst) {
+                        if ($connchange{'intdom'}) {
+                            logthis('<font color="blue"> UpdateHosts killing child '
+                                   ." $child for ip $childip </font>");
+                           kill('INT', $child);
+                        }
+                    } else {
+                        if ($connchange{'other'}) {
+                            logthis('<font color="blue"> UpdateHosts killing child '
+                                   ." $child for ip $childip </font>");
+                            kill('INT', $child);
+                        }
+                    }
+                }
+            }
+        }
+    }
     ReloadApache;
     &status("Finished reloading hosts.tab");
 }
 
-
 sub checkchildren {
     &status("Checking on the children (sending signals)");
     &initnewstatus();
@@ -6783,6 +7944,10 @@ if ($arch eq 'unknown') {
     chomp($arch);
 }
 
+unless (lonssl::Read_Connect_Config(\%secureconf,\%perlvar,\%crlchecked) eq 'ok') {
+    &logthis('<font color="blue">No connectionrules table. Will fallback to loncapa.conf</font>');
+}
+
 # --------------------------------------------------------------
 #   Accept connections.  When a connection comes in, it is validated
 #   and if good, a child process is created to process transactions
@@ -6868,7 +8033,7 @@ sub make_new_child {
         &Authen::Krb5::init_context();
 
         my $no_ets;
-        if ($dist =~ /^(?:centos|rhes|scientific)(\d+)$/) {
+        if ($dist =~ /^(?:centos|rhes|scientific|oracle|rocky|alma)(\d+)/) {
             if ($1 >= 7) {
                 $no_ets = 1;
             }
@@ -6941,7 +8106,32 @@ sub make_new_child {
 		# If the connection type is ssl, but I didn't get my
 		# certificate files yet, then I'll drop  back to 
 		# insecure (if allowed).
-		
+
+                if ($inittype eq "ssl") {
+                    my $context;
+                    if ($clientsamedom) {
+                        $context = 'dom';
+                        if ($secureconf{'connfrom'}{'dom'} eq 'no') {
+                            $inittype = "";
+                        }
+                    } elsif ($clientsameinst) {
+                        $context = 'intdom';
+                        if ($secureconf{'connfrom'}{'intdom'} eq 'no') {
+                            $inittype = "";
+                        }
+                    } else {
+                        $context = 'other';
+                        if ($secureconf{'connfrom'}{'other'} eq 'no') {
+                            $inittype = "";
+                        }
+                    }
+                    if ($inittype eq '') {
+                        &logthis("<font color=\"blue\"> Domain config set "
+                                ."to no ssl for $clientname (context: $context)"
+                                ." -- trying insecure auth</font>");
+                    }
+                }
+
 		if($inittype eq "ssl") {
 		    my ($ca, $cert) = lonssl::CertificateFile;
 		    my $kfile       = lonssl::KeyFile;
@@ -6974,7 +8164,7 @@ sub make_new_child {
 			close $client;
 		    }
 		} elsif ($inittype eq "ssl") {
-		    my $key = SSLConnection($client);
+		    my $key = SSLConnection($client,$clientname);
 		    if ($key) {
 			$clientok = 1;
 			my $cipherkey = pack("H32", $key);
@@ -7001,7 +8191,6 @@ sub make_new_child {
 				  ."Attempted insecure connection disallowed </font>");
 			close $client;
 			$clientok = 0;
-			
 		    }
 		}
 	    } else {
@@ -7010,7 +8199,6 @@ sub make_new_child {
 			 ."$clientip failed to initialize: >$remotereq< </font>");
 		&status('No init '.$clientip);
 	    }
-	    
 	} else {
 	    &logthis(
 		     "<font color='blue'>WARNING: Unknown client $clientip</font>");
@@ -7028,15 +8216,13 @@ sub make_new_child {
 # ------------------------------------------------------------ Process requests
 	    my $keep_going = 1;
 	    my $user_input;
-            my $clienthost = &Apache::lonnet::hostname($clientname);
-            my $clientserverhomeID = &Apache::lonnet::get_server_homeID($clienthost);
-            $clienthomedom = &Apache::lonnet::host_domain($clientserverhomeID);
+
 	    while(($user_input = get_request) && $keep_going) {
 		alarm(120);
 		Debug("Main: Got $user_input\n");
 		$keep_going = &process_request($user_input);
 		alarm(0);
-		&status('Listening to '.$clientname." ($keymode)");	   
+		&status('Listening to '.$clientname." ($keymode)");
 	    }
 
 # --------------------------------------------- client unknown or fishy, refuse
@@ -7046,20 +8232,89 @@ sub make_new_child {
 	    &logthis("<font color='blue'>WARNING: "
 		     ."Rejected client $clientip, closing connection</font>");
 	}
-    }            
+    }
     
 # =============================================================================
     
     &logthis("<font color='red'>CRITICAL: "
 	     ."Disconnect from $clientip ($clientname)</font>");    
-    
-    
+
+
     # this exit is VERY important, otherwise the child will become
     # a producer of more and more children, forking yourself into
     # process death.
     exit;
     
 }
+
+#
+#  Used to determine if a particular client is from the same domain
+#  as the current server, or from the same internet domain, and
+#  also if the client can host sessions for the domain's users.
+#  A hash is populated with keys set to commands sent by the client
+#  which may not be executed for this domain.
+#
+#  Optional input -- the client to check for domain and internet domain.
+#  If not specified, defaults to the package variable: $clientname
+#
+#  If called in array context will not set package variables, but will
+#  instead return an array of two values - (a) true if client is in the
+#  same domain as the server, and (b) true if client is in the same 
+#  internet domain.
+#
+#  If called in scalar context, sets package variables for current client:
+#
+#  $clienthomedom    - LonCAPA domain of homeID for client.
+#  $clientsamedom    - LonCAPA domain same for this host and client.
+#  $clientintdom     - LonCAPA "internet domain" for client.
+#  $clientsameinst   - LonCAPA "internet domain" same for this host & client.
+#  $clientremoteok   - If current domain permits hosting on this client: 1
+#  %clientprohibited - Commands prohibited for domain's users for this client.
+#
+#  if the host and client have the same "internet domain", then the value
+#  of $clientremoteok is not used, and no commands are prohibited.
+#
+#  returns 1 to indicate package variables have been set for current client.
+#
+
+sub set_client_info {
+    my ($lonhost) = @_;
+    $lonhost ||= $clientname;
+    my $clienthost = &Apache::lonnet::hostname($lonhost);
+    my $clientserverhomeID = &Apache::lonnet::get_server_homeID($clienthost);
+    my $homedom = &Apache::lonnet::host_domain($clientserverhomeID);
+    my $samedom = 0;
+    if ($perlvar{'lonDefDomain'} eq $homedom) {
+        $samedom = 1;
+    }
+    my $intdom = &Apache::lonnet::internet_dom($clientserverhomeID);
+    my $sameinst = 0;
+    if ($intdom ne '') {
+        my $internet_names = &Apache::lonnet::get_internet_names($currenthostid);
+        if (ref($internet_names) eq 'ARRAY') {
+            if (grep(/^\Q$intdom\E$/,@{$internet_names})) {
+                $sameinst = 1;
+            }
+        }
+    }
+    if (wantarray) {
+        return ($samedom,$sameinst);
+    } else {
+        $clienthomedom = $homedom;
+        $clientsamedom = $samedom;
+        $clientintdom = $intdom;
+        $clientsameinst = $sameinst;
+        if ($clientsameinst) {
+            undef($clientremoteok);
+            undef(%clientprohibited);
+        } else {
+            $clientremoteok = &get_remote_hostable($currentdomainid);
+            %clientprohibited = &get_prohibited($currentdomainid);
+        }
+        return 1;
+    }
+}
+
 #
 #   Determine if a user is an author for the indicated domain.
 #
@@ -7168,15 +8423,25 @@ sub password_filename {
 #    domain    - domain of the user.
 #    name      - User's name.
 #    contents  - New contents of the file.
+#    saveold   - (optional). If true save old file in a passwd.bak file.
 # Returns:
 #   0    - Failed.
 #   1    - Success.
 #
 sub rewrite_password_file {
-    my ($domain, $user, $contents) = @_;
+    my ($domain, $user, $contents, $saveold) = @_;
 
     my $file = &password_filename($domain, $user);
     if (defined $file) {
+        if ($saveold) {
+            my $bakfile = $file.'.bak';
+            if (CopyFile($file,$bakfile)) {
+                chmod(0400,$bakfile);
+                &logthis("Old password saved in passwd.bak for internally authenticated user: $user:$domain");
+            } else {
+                &logthis("Failed to save old password in passwd.bak for internally authenticated user: $user:$domain");
+            }
+        }
 	my $pf = IO::File->new(">$file");
 	if($pf) {
 	    print $pf "$contents\n";
@@ -7263,24 +8528,38 @@ sub validate_user {
             } elsif ((($domdefaults{'auth_def'} eq 'krb4') || 
                       ($domdefaults{'auth_def'} eq 'krb5')) &&
                      ($domdefaults{'auth_arg_def'} ne '')) {
-                $howpwd = $domdefaults{'auth_def'};
-                $contentpwd = $domdefaults{'auth_arg_def'}; 
+                #
+                # Don't attempt authentication for username and password supplied
+                # for user without an account if uername contains @ to avoid
+                # call to &Authen::Krb5::parse_name() which will result in con_lost
+                #
+                unless ($user =~ /\@/) {
+                    $howpwd = $domdefaults{'auth_def'};
+                    $contentpwd = $domdefaults{'auth_arg_def'};
+                }
             }
         }
-    } 
+    }
     if ($howpwd ne 'nouser') {
 	if($howpwd eq "internal") { # Encrypted is in local password file.
             if (length($contentpwd) == 13) {
                 $validated = (crypt($password,$contentpwd) eq $contentpwd);
                 if ($validated) {
-                    my $ncpass = &hash_passwd($domain,$password);
-                    if (&rewrite_password_file($domain,$user,"$howpwd:$ncpass")) {
-                        &update_passwd_history($user,$domain,$howpwd,'conversion');
-                        &logthis("Validated password hashed with bcrypt for $user:$domain");
+                    my %domdefaults = &Apache::lonnet::get_domain_defaults($domain);
+                    if ($domdefaults{'intauth_switch'}) {
+                        my $ncpass = &hash_passwd($domain,$password);
+                        my $saveold;
+                        if ($domdefaults{'intauth_switch'} == 2) {
+                            $saveold = 1;
+                        }
+                        if (&rewrite_password_file($domain,$user,"$howpwd:$ncpass",$saveold)) {
+                            &update_passwd_history($user,$domain,$howpwd,'conversion');
+                            &logthis("Validated password hashed with bcrypt for $user:$domain");
+                        }
                     }
                 }
             } else {
-                $validated = &check_internal_passwd($password,$contentpwd,$domain);
+                $validated = &check_internal_passwd($password,$contentpwd,$domain,$user);
             }
 	}
 	elsif ($howpwd eq "unix") { # User is a normal unix user.
@@ -7350,24 +8629,35 @@ sub validate_user {
 }
 
 sub check_internal_passwd {
-    my ($plainpass,$stored,$domain) = @_;
+    my ($plainpass,$stored,$domain,$user) = @_;
     my (undef,$method,@rest) = split(/!/,$stored);
-    if ($method eq "bcrypt") {
+    if ($method eq 'bcrypt') {
         my $result = &hash_passwd($domain,$plainpass,@rest);
         if ($result ne $stored) {
             return 0;
         }
-        # Upgrade to a larger number of rounds if necessary
-        my $defaultcost;
-        my %domconfig =
-            &Apache::lonnet::get_dom('configuration',['password'],$domain);
-        if (ref($domconfig{'password'}) eq 'HASH') {
-            $defaultcost = $domconfig{'password'}{'cost'};
-        }
-        if (($defaultcost eq '') || ($defaultcost =~ /D/)) {
-            $defaultcost = 10;
+        my %domdefaults = &Apache::lonnet::get_domain_defaults($domain);
+        if ($domdefaults{'intauth_check'}) {
+            # Upgrade to a larger number of rounds if necessary
+            my $defaultcost = $domdefaults{'intauth_cost'};
+            if (($defaultcost eq '') || ($defaultcost =~ /D/)) {
+                $defaultcost = 10;
+            }
+            if (int($rest[0])<int($defaultcost)) {
+                if ($domdefaults{'intauth_check'} == 1) { 
+                    my $ncpass = &hash_passwd($domain,$plainpass);
+                    if (&rewrite_password_file($domain,$user,"internal:$ncpass")) {
+                        &update_passwd_history($user,$domain,'internal','update cost');
+                        &logthis("Validated password hashed with bcrypt for $user:$domain");
+                    }
+                    return 1;
+                } elsif ($domdefaults{'intauth_check'} == 2) {
+                    return 0;
+                }
+            }
+        } else {
+            return 1;
         }
-        return 1 unless($rest[0]<$defaultcost);
     }
     return 0;
 }
@@ -7590,6 +8880,9 @@ sub currentversion {
     if (-e $ulsdir) {
 	if(-d $ulsdir) {
 	    if (opendir(LSDIR,$ulsdir)) {
+                if (-e $fname) {
+                    $version=0;
+                }
 		my $ulsfn;
 		while ($ulsfn=readdir(LSDIR)) {
 # see if this is a regular file (ignore links produced earlier)
@@ -7726,6 +9019,7 @@ sub make_passwd_file {
 	    my $pf = IO::File->new(">$passfilename");
 	    if($pf) {
 		print $pf "localauth:$npass\n";
+                &update_passwd_history($uname,$udom,$umode,$action);
 	    } else {
 		$result = "pass_file_failed_error";
 	    }
@@ -7742,6 +9036,14 @@ sub make_passwd_file {
 		$result = "pass_file_failed_error";
 	    }
 	}
+    } elsif ($umode eq 'lti') {
+        my $pf = IO::File->new(">$passfilename");
+        if($pf) {
+            print $pf "lti:\n";
+            &update_passwd_history($uname,$udom,$umode,$action);
+        } else {
+            $result = "pass_file_failed_error";
+        }
     } else {
 	$result="auth_mode_error";
     }
@@ -7766,6 +9068,7 @@ sub sethost {
 	eq &Apache::lonnet::get_host_ip($hostid)) {
 	$currenthostid  =$hostid;
 	$currentdomainid=&Apache::lonnet::host_domain($hostid);
+        &set_client_info();
 #	&logthis("Setting hostid to $hostid, and domain to $currentdomainid");
     } else {
 	&logthis("Requested host id $hostid not an alias of ".
@@ -7788,16 +9091,85 @@ sub get_usersession_config {
         return $usersessionconf;
     } else {
         my %domconfig = &Apache::lonnet::get_dom('configuration',['usersessions'],$dom);
-        if (ref($domconfig{'usersessions'}) eq 'HASH') {
-            &Apache::lonnet::do_cache_new($name,$dom,$domconfig{'usersessions'},3600);
-            return $domconfig{'usersessions'};
-        }
+        &Apache::lonnet::do_cache_new($name,$dom,$domconfig{'usersessions'},3600);
+        return $domconfig{'usersessions'};
     }
     return;
 }
 
+sub get_usersearch_config {
+    my ($dom,$name) = @_;
+    my ($usersearchconf,$cached)=&Apache::lonnet::is_cached_new($name,$dom);
+    if (defined($cached)) {
+        return $usersearchconf;
+    } else {
+        my %domconfig = &Apache::lonnet::get_dom('configuration',['directorysrch'],$dom);
+        &Apache::lonnet::do_cache_new($name,$dom,$domconfig{'directorysrch'},600);
+        return $domconfig{'directorysrch'};
+    }
+    return;
+}
 
+sub get_prohibited {
+    my ($dom) = @_;
+    my $name = 'trust';
+    my ($trustconfig,$cached)=&Apache::lonnet::is_cached_new($name,$dom);
+    unless (defined($cached)) {
+        my %domconfig = &Apache::lonnet::get_dom('configuration',['trust'],$dom);
+        &Apache::lonnet::do_cache_new($name,$dom,$domconfig{'trust'},3600);
+        $trustconfig = $domconfig{'trust'};
+    }
+    my %prohibited;
+    if (ref($trustconfig)) {
+        foreach my $prefix (keys(%{$trustconfig})) {
+            if (ref($trustconfig->{$prefix}) eq 'HASH') {
+                my $reject;
+                if (ref($trustconfig->{$prefix}->{'exc'}) eq 'ARRAY') {
+                    if (grep(/^\Q$clientintdom\E$/,@{$trustconfig->{$prefix}->{'exc'}})) {
+                        $reject = 1;
+                    }
+                }
+                if (ref($trustconfig->{$prefix}->{'inc'}) eq 'ARRAY') {
+                    if (grep(/^\Q$clientintdom\E$/,@{$trustconfig->{$prefix}->{'inc'}})) {
+                        $reject = 0;
+                    } else {
+                        $reject = 1;
+                    }
+                }
+                if ($reject) {
+                    $prohibited{$prefix} = 1;
+                }
+            }
+        }
+    }
+    return %prohibited;
+}
 
+sub get_remote_hostable {
+    my ($dom) = @_;
+    my $result;
+    if ($clientintdom) {
+        $result = 1;
+        my $remsessconf = &get_usersession_config($dom,'remotesession');
+        if (ref($remsessconf) eq 'HASH') {
+            if (ref($remsessconf->{'remote'}) eq 'HASH') {
+                if (ref($remsessconf->{'remote'}->{'excludedomain'}) eq 'ARRAY') {
+                    if (grep(/^\Q$clientintdom\E$/,@{$remsessconf->{'remote'}->{'excludedomain'}})) {
+                        $result = 0;
+                    }
+                }
+                if (ref($remsessconf->{'remote'}->{'includedomain'}) eq 'ARRAY') {
+                    if (grep(/^\Q$clientintdom\E$/,@{$remsessconf->{'remote'}->{'includedomain'}})) {
+                        $result = 1;
+                    } else {
+                        $result = 0;
+                    }
+                }
+            }
+        }
+    }
+    return $result;
+}
 
 sub distro_and_arch {
     return $dist.':'.$arch;
@@ -8124,7 +9496,6 @@ IO::File
 Apache::File
 POSIX
 Crypt::IDEA
-LWP::UserAgent()
 GDBM_File
 Authen::Krb4
 Authen::Krb5
@@ -8206,7 +9577,7 @@ is closed and the child exits.
 =item Red CRITICAL Can't get key file <error>        
 
 SSL key negotiation is being attempted but the call to
-lonssl::KeyFile  failed.  This usually means that the
+lonssl::KeyFile failed.  This usually means that the
 configuration file is not correctly defining or protecting
 the directories/files lonCertificateDirectory or
 lonnetPrivateKey