--- loncom/interface/courseprefs.pm	2022/02/01 18:23:24	1.98
+++ loncom/interface/courseprefs.pm	2022/02/01 23:13:19	1.99
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Handler to set configuration settings for a course
 #
-# $Id: courseprefs.pm,v 1.98 2022/02/01 18:23:24 raeburn Exp $
+# $Id: courseprefs.pm,v 1.99 2022/02/01 23:13:19 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -365,11 +365,25 @@ sub handler {
     }
 
     my %values=&Apache::lonnet::dump('environment',$cdom,$cnum);
-    my %courselti=&Apache::lonnet::dump('lti',$cdom,$cnum,undef,undef,undef,1);
-    if ($courselti{'lock'}) {
-        delete($courselti{'lock'});
+    my %lti=&Apache::lonnet::dump('lti',$cdom,$cnum,undef,undef,undef,1);
+    my %ltienc = &Apache::lonnet::dump('nohist_ltienc',$cdom,$cnum,undef,undef,undef,1);
+    foreach my $id (keys(%lti)) {
+        if (ref($lti{$id}) eq 'HASH') {
+            if (ref($ltienc{$id}) eq 'HASH') {
+                $values{'linkprotection'}{$id} = { %{$lti{$id}}, %{$ltienc{$id}} };
+            } else {
+                $values{'linkprotection'}{$id} = $lti{$id};
+            }
+        }
+        unless ($phase eq 'process') {
+            if (ref($values{'linkprotection'}{$id}) eq 'HASH') {
+                delete($values{'linkprotection'}{$id}{'secret'});
+            }
+        }
+    }
+    if ($lti{'lock'}) {
+        delete($lti{'lock'});
     }
-    $values{'linkprotection'} = \%courselti;
     my @prefs_order = ('courseinfo','localization','feedback','discussion',
                        'classlists','appearance','grading','printouts',
                        'menuitems','linkprotection','spreadsheet','bridgetasks',
@@ -596,7 +610,7 @@ sub handler {
         my $jscript = &get_jscript($cid,$cdom,$phase,$crstype,\%values,$noedit);
         my @allitems = &get_allitems(%prefs);
         &Apache::lonconfigsettings::display_settings($r,$cdom,$phase,$context,
-            \@prefs_order,\%prefs,\%values,undef,$jscript,\@allitems,$crstype,
+            \@prefs_order,\%prefs,\%values,$cnum,$jscript,\@allitems,$crstype,
             'coursepref',$parm_permission);
     } else {
         &Apache::lonconfigsettings::display_choices($r,$phase,$context,
@@ -649,7 +663,7 @@ sub get_allitems {
 }
 
 sub print_config_box {
-    my ($r,$cdom,$phase,$action,$item,$settings,$allitems,$crstype,$parm_permission) = @_;
+    my ($r,$cdom,$cnum,$phase,$action,$item,$settings,$allitems,$crstype,$parm_permission) = @_;
     my $ordered = $item->{'ordered'};
     my $itemtext = $item->{'itemtext'};
     my $noedit;
@@ -780,7 +794,7 @@ sub print_config_box {
     } elsif ($action eq 'menuitems') {
         $output .= &print_menuitems('bottom',$cdom,$settings,$itemtext,\$rowtotal,$crstype,$noedit);
     } elsif ($action eq 'linkprotection') {
-        $output .= &print_linkprotection($cdom,$settings,\$rowtotal,$crstype,$noedit);
+        $output .= &print_linkprotection($cdom,$cnum,$settings,\$rowtotal,$crstype,$noedit);
     } elsif ($action eq 'other') {
         $output .= &print_other($cdom,$settings,$allitems,\$rowtotal,$crstype,$noedit);
     }
@@ -794,7 +808,7 @@ sub print_config_box {
 
 sub process_changes {
     my ($cdom,$cnum,$action,$values,$item,$changes,$allitems,$disallowed,$crstype) = @_;
-    my (%newvalues,%courselti,$errors);
+    my (%newvalues,%lti,%ltienc,$errors);
     if (ref($item) eq 'HASH') {
         if (ref($changes) eq 'HASH') {
             my @ordered;
@@ -812,12 +826,12 @@ sub process_changes {
                     }
                 }
             } elsif ($action eq 'linkprotection') {
-                if (ref($values->{'linkprotection'}) eq 'HASH') {
-                    foreach my $id (keys(%{$values->{'linkprotection'}})) {
+                if (ref($values->{$action}) eq 'HASH') {
+                    foreach my $id (keys(%{$values->{$action}})) {
                         if ($id =~ /^\d+$/) {
                             push(@ordered,$id);
-                            unless (ref($values->{'linkprotection'}->{$id}) eq 'HASH') {
-                                $courselti{$id} = '';
+                            unless (ref($values->{$action}->{$id}) eq 'HASH') {
+                                $lti{$id} = '';
                             }
                         }
                     }
@@ -965,6 +979,7 @@ sub process_changes {
                     }
                 } elsif ($action eq 'linkprotection') {
                     my %menutitles = &ltimenu_titles();
+                    my $switchserver = &check_switchserver($cdom,$cnum);
                     my (@items,%deletions,%itemids,%haschanges);
                     if ($env{'form.linkprot_add'}) {
                         my $name = $env{'form.linkprot_name_add'};
@@ -980,18 +995,18 @@ sub process_changes {
                                        '</span>';
                         }
                     }
-                    if (ref($values->{'linkprotection'}) eq 'HASH') {
+                    if (ref($values->{$action}) eq 'HASH') {
                         my @todelete = &Apache::loncommon::get_env_multiple('form.linkprot_del');
                         my $maxnum = $env{'form.linkprot_maxnum'};
                         for (my $i=0; $i<=$maxnum; $i++) {
                             my $itemid = $env{'form.linkprot_id_'.$i};
                             $itemid =~ s/\D+//g;
                             if ($itemid) {
-                                if (ref($values->{'linkprotection'}->{$itemid}) eq 'HASH') {
+                                if (ref($values->{$action}->{$itemid}) eq 'HASH') {
                                     push(@items,$i);
                                     $itemids{$i} = $itemid;
                                     if ((@todelete > 0) && (grep(/^$i$/,@todelete))) {
-                                        $deletions{$itemid} = $values->{'linkprotection'}->{$itemid}->{'name'};
+                                        $deletions{$itemid} = $values->{$action}->{$itemid}->{'name'};
                                     }
                                 }
                             }
@@ -1002,19 +1017,19 @@ sub process_changes {
                         my $itemid = $itemids{$idx};
                         next unless ($itemid);
                         if (exists($deletions{$itemid})) {
-                            $courselti{$itemid} = $deletions{$itemid};
+                            $lti{$itemid} = $deletions{$itemid};
                             $haschanges{$itemid} = 1;
                             next;
                         }
                         my %current;
-                        if (ref($values->{'linkprotection'}) eq 'HASH') {
-                            if (ref($values->{'linkprotection'}->{$itemid}) eq 'HASH') {
-                                foreach my $key (keys(%{$values->{'linkprotection'}->{$itemid}})) {
-                                    $current{$key} = $values->{'linkprotection'}->{$itemid}->{$key};
+                        if (ref($values->{$action}) eq 'HASH') {
+                            if (ref($values->{$action}->{$itemid}) eq 'HASH') {
+                                foreach my $key (keys(%{$values->{$action}->{$itemid}})) {
+                                    $current{$key} = $values->{$action}->{$itemid}->{$key};
                                 }
                             }
                         }
-                        foreach my $inner ('name','key','secret','lifetime','version') {
+                        foreach my $inner ('name','lifetime','version') {
                             my $formitem = 'form.linkprot_'.$inner.'_'.$idx;
                             $env{$formitem} =~ s/(`)/'/g;
                             if ($inner eq 'lifetime') {
@@ -1026,13 +1041,40 @@ sub process_changes {
                                 }
                             }
                             if ($env{$formitem} ne '') {
-                                $courselti{$itemid}{$inner} = $env{$formitem};
+                                $lti{$itemid}{$inner} = $env{$formitem};
+                            }
+                        }
+                        unless ($switchserver) {
+                            my $keyitem = 'form.linkprot_key_'.$idx;
+                            $env{$keyitem} =~ s/(`)/'/g;
+                            unless ($idx eq 'add') {
+                                if ($current{'key'} ne $env{$keyitem}) {
+                                    $haschanges{$itemid} = 1;
+                                }
+                            }
+                            if ($env{$keyitem} ne '') {
+                                $lti{$itemid}{'key'} = $env{$keyitem};
+                            }
+                            my $secretitem = 'form.linkprot_secret_'.$idx;
+                            $env{$secretitem} =~ s/(`)/'/g;
+                            if ($current{'usable'}) {
+                                if ($env{'form.linkprot_changesecret_'.$idx}) {
+                                    if ($env{$secretitem} ne '') {
+                                        $lti{$itemid}{'secret'} = $env{$secretitem};
+                                        $haschanges{$itemid} = 1;
+                                    }
+                                } else {
+                                    $lti{$itemid}{'secret'} = $current{'secret'};
+                                }
+                            } elsif ($env{$secretitem} ne '') {
+                                $lti{$itemid}{'secret'} = $env{$secretitem};
+                                $haschanges{$itemid} = 1;
                             }
                         }
                     }
                     if (keys(%haschanges)) {
                         foreach my $entry (keys(%haschanges)) {
-                            $changes->{$entry} = $courselti{$entry};
+                            $changes->{$entry} = $lti{$entry};
                         }
                     }
                 } else {
@@ -1655,7 +1697,7 @@ sub store_changes {
         if (grep(/^\Q$item\E$/,@{$actions})) {
             $output .= '<h3>'.&mt($prefs->{$item}{'text'}).'</h3>';
             if (ref($changes->{$item}) eq 'HASH') {
-                if ((keys(%{$changes->{$item}}) > 0) || ($item eq 'linkprotection')) {
+                if (keys(%{$changes->{$item}}) > 0) {
                     $output .= &mt('Changes made:').'<ul style="list-style:none;">';
                     if ($item eq 'other') {
                         foreach my $key (sort(keys(%{$changes->{$item}}))) {
@@ -1669,34 +1711,96 @@ sub store_changes {
                             }
                         }
                     } elsif ($item eq 'linkprotection') {
-                        if (&Apache::lonnet::put('lti',$changes->{'linkprotection'},$cdom,$cnum,1) eq 'ok') {
-                            my $hashid=$cdom.'_'.$cnum;
-                            &Apache::lonnet::devalidate_cache_new('courselti',$hashid);
-                            foreach my $itemid (sort { $a <=> $b } %{$changes->{'linkprotection'}}) {
-                                if (ref($changes->{'linkprotection'}->{$itemid}) eq 'HASH') {
-                                    my %values = %{$changes->{'linkprotection'}->{$itemid}};
-                                    my %desc = &linkprot_names();
-                                    my $display;
-                                    foreach my $title ('name','lifetime','version','key','secret') {
-                                        if ($title eq 'secret') {
-                                            my $length = length($values{$title});
-                                            $display .= $desc{$title}.': '.('*' x $length);
-                                        } elsif ($title eq 'version') {
-                                            if ($values{$title} eq 'LTI-1p0') {
-                                                $display .= $desc{$title}.': 1.1, ';
+                        my (%ltienc,$lti_save_error);
+                        if (ref($changes->{$item}) eq 'HASH') {
+                            foreach my $id (sort { $a <=> $b } keys(%{$changes->{$item}})) {
+                                if (ref($changes->{$item}->{$id}) eq 'HASH') {
+                                    if (exists($changes->{$item}->{$id}->{'key'})) {
+                                        $ltienc{$id}{'key'} = $changes->{$item}->{$id}->{'key'};
+                                        delete($changes->{$item}->{$id}->{'key'});
+                                    }
+                                    if (exists($changes->{$item}->{$id}->{'secret'})) {
+                                        $ltienc{$id}{'secret'} = $changes->{$item}->{$id}->{'secret'};
+                                        delete($changes->{$item}->{$id}->{'secret'});
+                                    } elsif (ref($oldlinkprot{$id}) eq 'HASH') {
+                                        if (exists($oldlinkprot{$id}{'usable'})) {
+                                            $changes->{$item}->{$id}->{'usable'} = 1;
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                        if (keys(%ltienc) > 0) {
+                            if (&Apache::lonnet::put('nohist_ltienc',\%ltienc,$cdom,$cnum,1) eq 'ok') {
+                                foreach my $id (keys(%ltienc)) {
+                                    if (exists($ltienc{$id}{'secret'})) {
+                                        $changes->{$item}->{$id}->{'usable'} = 1;
+                                    }
+                                }
+                            } else {
+                                $lti_save_error = 1;
+                            }
+                        }
+                        unless ($lti_save_error) {
+                            if (&Apache::lonnet::put('lti',$changes->{$item},$cdom,$cnum,1) eq 'ok') {
+                                my $hashid=$cdom.'_'.$cnum;
+                                &Apache::lonnet::devalidate_cache_new('courselti',$hashid);
+                                $chome = &Apache::lonnet::homeserver($cnum,$cdom);
+                                unless (($chome eq 'no_host') || ($chome eq '')) {
+                                    my @ids=&Apache::lonnet::current_machine_ids();
+                                    unless (grep(/^\Q$chome\E$/,@ids)) {
+                                        &Apache::lonnet::devalidate_cache_new('courseltienc',$hashid);
+                                    }
+                                }
+                                foreach my $id (sort { $a <=> $b } %{$changes->{$item}}) {
+                                    if (ref($changes->{$item}->{$id}) eq 'HASH') {
+                                        my %values = %{$changes->{$item}->{$id}};
+                                        my %desc = &linkprot_names();
+                                        my $display;
+                                        foreach my $title ('name','lifetime','version','key','secret') {
+                                            if (($title eq 'key') || ($title eq 'secret')) {
+                                                if (ref($ltienc{$id}) eq 'HASH') {
+                                                    if (exists($ltienc{$id}{$title})) {
+                                                        if ($title eq 'secret') {
+                                                            my $length = length($ltienc{$id}{$title});
+                                                            $display .= $desc{$title}.': '.('*' x $length);
+                                                        } else {
+                                                            $display .= $desc{$title}.': '.$ltienc{$id}{$title}.', ';
+                                                        }
+                                                    }
+                                                }
+                                            } elsif ($title eq 'version') {
+                                                if ($values{$title} eq 'LTI-1p0') {
+                                                    $display .= $desc{$title}.': 1.1, ';
+                                                }
+                                            } else {
+                                                $display .= $desc{$title}.': '.$values{$title}.', ';
                                             }
-                                        } else {
-                                            $display .= $desc{$title}.': '.$values{$title}.', ';
                                         }
+                                        $display =~ s/, $//;
+                                        $output .= '<li>'.&Apache::lonhtmlcommon::confirm_success(&mt('[_1] set to [_2]','<i>'.$id.'</i>',
+                                                   "'$display'")).'</li>';
+                                    } elsif (ref($oldlinkprot{$id}) eq 'HASH') {
+                                        my $oldname = $oldlinkprot{$id}{'name'};
+                                        $output .= '<li>'.&Apache::lonhtmlcommon::confirm_success(&mt('Deleted setting for [_1]','<i>'."$id ($oldname)".'</i>')).'</li>';
                                     }
-                                    $output .= '<li>'.&Apache::lonhtmlcommon::confirm_success(&mt('[_1] set to [_2]','<i>'.$itemid.'</i>',
-                                               "'$display'")).'</li>';
-                                } elsif (ref($oldlinkprot{$itemid}) eq 'HASH') {
-                                    my $oldname = $oldlinkprot{$itemid}{'name'};
-                                    $output .= '<li>'.&Apache::lonhtmlcommon::confirm_success(&mt('Deleted setting for [_1]','<i>'."$itemid ($oldname)".'</i>')).'</li>';
                                 }
+                            } else {
+                                $lti_save_error = 1;
                             }
-                        } else {
+                        }
+                        unless ($lti_save_error) {
+                            my @deletions;
+                            foreach my $id (sort { $a <=> $b } keys(%{$changes->{$item}})) {
+                                unless (ref($changes->{$item}->{$id}) eq 'HASH') {
+                                    push (@deletions,$id);
+                                }
+                            }
+                            if (@deletions) {
+                                &Apache::lonnet::del('nohist_ltienc',\@deletions,$cdom,$cnum);
+                            }
+                        }
+                        if ($lti_save_error) {
                             $output .= '<li>'.
                                        '<span class="LC_error">'.
                                        &mt('An error occurred when saving changes to link protection settings, which remain unchanged.').
@@ -2375,11 +2479,45 @@ function toggleAddmenucoll() {
 }
 ENDSCRIPT
     }
+    my $linkprotector_js = <<"ENDSCRIPT";
+function toggleLTI(form,num,item) {
+    var radioname = '';
+    var currdivid = '';
+    var newdivid = '';
+    if ((document.getElementById('linkprot_divcurr'+item+'_'+num)) &&
+        (document.getElementById('linkprot_divchg'+item+'_'+num))) {
+        currdivid = document.getElementById('linkprot_divcurr'+item+'_'+num);
+        newdivid = document.getElementById('linkprot_divchg'+item+'_'+num);
+        radioname = form.elements['linkprot_change'+item+'_'+num];
+        if (radioname) {
+            if (radioname.length > 0) {
+                var setvis;
+                for (var i=0; i<radioname.length; i++) {
+                    if (radioname[i].checked == true) {
+                        if (radioname[i].value == 1) {
+                            newdivid.style.display = 'inline-block';
+                            currdivid.style.display = 'none';
+                            setvis = 1;
+                        }
+                        break;
+                    }
+                }
+                if (!setvis) {
+                    newdivid.style.display = 'none';
+                    currdivid.style.display = 'inline-block';
+                }
+            }
+        }
+    }
+    return;
+}
+ENDSCRIPT
     $jscript = '<script type="text/javascript" language="Javascript">'."\n".
                '// <![CDATA['."\n".  
                $browse_js."\n".$categorize_js."\n".$loncaparev_js."\n".
                $cloners_js."\n".$instcode_js.
-               $syllabus_js."\n".$menuitems_js."\n".'//]]>'."\n".
+               $syllabus_js."\n".$menuitems_js."\n".
+               $linkprotector_js."\n".'//]]>'."\n".
                '</script>'."\n".$stubrowse_js."\n";
     return $jscript;
 }
@@ -5268,7 +5406,7 @@ sub menucollections_display {
 }
 
 sub print_linkprotection {
-    my ($cdom,$settings,$rowtotal,$crstype,$noedit) = @_;
+    my ($cdom,$cnum,$settings,$rowtotal,$crstype,$noedit) = @_;
     unless (ref($settings) eq 'HASH') {
         return;
     }
@@ -5283,6 +5421,8 @@ sub print_linkprotection {
     my %lt = &linkprot_names();
     my $itemcount = 0;
 
+    my $switchserver = &check_switchserver($cdom,$cnum);
+
     if (ref($settings->{'linkprotection'}) eq 'HASH') {
         if (keys(%{$settings->{'linkprotection'}})) {
             my @current = sort { $a <=> $b } keys(%{$settings->{'linkprotection'}});
@@ -5307,20 +5447,65 @@ sub print_linkprotection {
                     '<td><span class="LC_nobreak">'.$lt{'name'}.
                     ':<input type="text" size="15" name="linkprot_name_'.$i.'" value="'.$values{'name'}.'" autocomplete="off"'.$disabled.' /></span> '.
                     ('&nbsp;'x2).
-                    '<span class="LC_nobreak">'.$lt{'version'}.':<select name="linkprot_version_'.$i.'">'.
+                    '<span class="LC_nobreak">'.$lt{'version'}.':<select name="linkprot_version_'.$i.'"'.$disabled.'>'.
                     '<option value="LTI-1p0" '.$selected.'>1.1</option></select></span> '."\n".
                     ('&nbsp;'x2).
                     '<span class="LC_nobreak">'.$lt{'lifetime'}.':<input type="text" name="linkprot_lifetime_'.$i.'"'.
                     'value="'.$values{'lifetime'}.'" size="3"'.$disabled.' /></span>'.
-                    '<br /><br />'.
-                    '<span class="LC_nobreak">'.$lt{'key'}.
-                    ':<input type="text" size="25" name="linkprot_key_'.$i.'" value="'.$values{'key'}.'" autocomplete="off"'.$disabled.' /></span> '.
-                    ('&nbsp;'x2).
-                    '<span class="LC_nobreak">'.$lt{'secret'}.':'.
-                    '<input type="password" size="20" name="linkprot_secret_'.$i.'" value="'.$values{'secret'}.'" autocomplete="off"'.$disabled.' />'.
-                    '<label><input type="checkbox" name="visible" onclick="if (this.checked) { this.form.linkprot_secret_'.$i.'.type='."'text'".' } else { this.form.linkprot_secret_'.$i.'.type='."'password'".' }"'.$disabled.' />'.&mt('Visible input').'</label>'.
-                    '<input type="hidden" name="linkprot_id_'.$i.'" value="'.$num.'" /></span>'.
-                    '</td></tr>';
+                    '<br /><br />';
+                if ($values{'key'} ne '') {
+                    $datatable .= '<span class="LC_nobreak">'.$lt{'key'};
+                    if ($noedit) {
+                        $datatable .= ': ['.&mt('not shown').']';
+                    } elsif ($switchserver) {
+                        $datatable .= ': ['.&mt('[_1] to view/edit',$switchserver).']';
+                    } else {
+                        $datatable .= ':<input type="text" size="25" name="linkprot_key_'.$i.'" value="'.$values{'key'}.'" autocomplete="off"'.$disabled.' />';
+                    }
+                    $datatable .= '</span> '.('&nbsp;'x2);
+                } elsif (!$switchserver) {
+                    $datatable .= '<span class="LC_nobreak">'.$lt{'key'}.':'.
+                                  '<input type="text" size="25" name="linkprot_key_'.$i.'" value="'.$values{'key'}.'" autocomplete="off"'.$disabled.' />'.
+                                  '</span> '.('&nbsp;'x2);
+                }
+                if ($switchserver) {
+                    if ($values{'usable'} ne '') {
+                        $datatable .= '<div id="linkprot_divcurrsecret_'.$i.'" style="display:inline-block" /><span class="LC_nobreak">'.
+                                      $lt{'secret'}.': ['.&mt('not shown').'] '.('&nbsp;'x2).'</span></div>'.
+                                      '<span class="LC_nobreak">'.&mt('Change secret?').
+                                      '<label><input type="radio" value="0" name="linkprot_changesecret_'.$i.'" onclick="javascript:toggleLTI(this.form,'."'$i','secret'".');" checked="checked"'.$disabled.' />'.&mt('No').'</label>'.
+                                      ('&nbsp;'x2).
+                                      '<label><input type="radio" value="1" name="linkprot_changesecret_'.$i.'" onclick="javascript:toggleLTI(this.form,'."'$i','secret'".');" '.$disabled.' />'.&mt('Yes').'</label>'.('&nbsp;'x2).
+                                      '</span><div id="linkprot_divchgsecret_'.$i.'" style="display:none" />'.
+                                      '<span class="LC_nobreak"> - '.&mt("submit from course's home server: [_1].",$switchserver).'</span>'.
+                                      '</div>';
+                    } elsif ($values{'key'} eq '') {
+                        $datatable .= '<span class="LC_nobreak">'.&mt('Key and Secret are required').' - '.&mt("submit from course's home server: [_1].",$switchserver).'</span>'."\n";
+                    } else {
+                        $datatable .= '<span class="LC_nobreak">'.&mt('Secret required').' - '.&mt("submit from course's home server: [_1].",$switchserver).'</span>'."\n";
+                    }
+                } else {
+                    if ($values{'usable'} ne '') {
+                        $datatable .= '<div id="linkprot_divcurrsecret_'.$i.'" style="display:inline-block" /><span class="LC_nobreak">'.
+                                      $lt{'secret'}.': ['.&mt('not shown').'] '.('&nbsp;'x2).'</span></div>'.
+                                      '<span class="LC_nobreak">'.&mt('Change?').
+                                      '<label><input type="radio" value="0" name="linkprot_changesecret_'.$i.'" onclick="javascript:toggleLTI(this.form,'."'$i','secret'".');" checked="checked"'.$disabled.' />'.&mt('No').'</label>'.
+                                      ('&nbsp;'x2).
+                                      '<label><input type="radio" value="1" name="linkprot_changesecret_'.$i.'" onclick="javascript:toggleLTI(this.form,'."'$i','secret'".');"'.$disabled.' />'.&mt('Yes').
+                                      '</label>&nbsp;&nbsp;</span><div id="linkprot_divchgsecret_'.$i.'" style="display:none" />'.
+                                      '<span class="LC_nobreak">'.&mt('New Secret').':'.
+                                      '<input type="password" size="20" name="linkprot_secret_'.$i.'" value="" autocomplete="off"'.$disabled.' />'.
+                                      '<label><input type="checkbox" name="visible" onclick="if (this.checked) { this.form.linkprot_secret_'.$i.'.type='."'text'".' } else { this.form.linkprot_secret_'.$i.'.type='."'password'".' }"'.$disabled.' />'.&mt('Visible input').'</label>'.
+                                      '<input type="hidden" name="linkprot_id_'.$i.'" value="'.$num.'" /></span></div>';
+                    } else {
+                        $datatable .=
+                            '<span class="LC_nobreak">'.$lt{'secret'}.':'.
+                            '<input type="password" size="20" name="linkprot_secret_'.$i.'" value="" autocomplete="off"'.$disabled.' />'.
+                            '<label><input type="checkbox" name="visible" onclick="if (this.checked) { this.form.linkprot_secret_'.$i.'.type='."'text'".' } else { this.form.linkprot_secret_'.$i.'.type='."'password'".' }"'.$disabled.' />'.&mt('Visible input').'</label>'.
+                            '<input type="hidden" name="linkprot_id_'.$i.'" value="'.$num.'" /></span>';
+                    }
+                }
+                $datatable .= '</td></tr>';
                 $itemcount ++;
             }
         }
@@ -5337,12 +5522,16 @@ sub print_linkprotection {
                   '<option value="LTI-1p0" selected="selected">1.1</option></select></span> '."\n".
                   ('&nbsp;'x2).
                   '<span class="LC_nobreak">'.$lt{'lifetime'}.':<input type="text" size="3" name="linkprot_lifetime_add" value="300"'.$disabled.' /></span> '."\n".
-                  '<br /><br />'.
-                  '<span class="LC_nobreak">'.$lt{'key'}.':<input type="text" size="25" name="linkprot_key_add" value="" autocomplete="off"'.$disabled.' /></span> '."\n".
-                  ('&nbsp;'x2).
-                  '<span class="LC_nobreak">'.$lt{'secret'}.':<input type="password" size="20" name="linkprot_secret_add" value="" autocomplete="off"'.$disabled.' />'.
-                  '<label><input type="checkbox" name="visible" onclick="if (this.checked) { this.form.linkprot_secret_add.type='."'text'".' } else { this.form.linkprot_secret_add.type='."'password'".' }"'.$disabled.' />'.&mt('Visible input').'</label></span> '."\n".
-                  '</td></tr>';
+                  '<br /><br />';
+    if ($switchserver) {
+        $datatable .= '<span class="LC_nobreak">'.&mt('Key and Secret are required').' - '.&mt("submit from course's home server: [_1].",$switchserver).'</span>'."\n";
+    } else {
+        $datatable .= '<span class="LC_nobreak">'.$lt{'key'}.':<input type="text" size="25" name="linkprot_key_add" value="" autocomplete="off"'.$disabled.' /></span> '."\n".
+                      ('&nbsp;'x2).
+                      '<span class="LC_nobreak">'.$lt{'secret'}.':<input type="password" size="20" name="linkprot_secret_add" value="" autocomplete="off"'.$disabled.' />'.
+                      '<label><input type="checkbox" name="visible" onclick="if (this.checked) { this.form.linkprot_secret_add.type='."'text'".' } else { this.form.linkprot_secret_add.type='."'password'".' }"'.$disabled.' />'.&mt('Visible input').'</label></span> '."\n";
+    }
+    $datatable .= '</td></tr>';
     $$rowtotal ++;
     return $datatable;;
 }
@@ -5358,6 +5547,22 @@ sub linkprot_names {
     return %lt;
 }
 
+sub check_switchserver {
+    my ($cdom,$cnum) = @_;
+    my ($allowed,$switchserver);
+    my $home = &Apache::lonnet::homeserver($cnum,$cdom);
+    unless ($home eq 'no_host') {
+        my @ids=&Apache::lonnet::current_machine_ids();
+        foreach my $id (@ids) { if ($id eq $home) { $allowed=1; } }
+        if (!$allowed) {
+            $switchserver='<a href="/adm/switchserver?otherserver='.$home.'&amp;role='.
+                          &HTML::Entities::encode($env{'request.role'},'\'<>"&').
+                          '&amp;destinationurl=/adm/courseprefs">'.&mt('Switch Server').'</a>';
+        }
+    }
+    return $switchserver;
+}
+
 sub print_other {
     my ($cdom,$settings,$allitems,$rowtotal,$crstype,$noedit) = @_;
     unless ((ref($settings) eq 'HASH') && (ref($allitems) eq 'ARRAY')) {