--- loncom/auth/lonlogin.pm	2017/02/17 18:37:05	1.169
+++ loncom/auth/lonlogin.pm	2021/11/03 01:04:02	1.193
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Login Screen
 #
-# $Id: lonlogin.pm,v 1.169 2017/02/17 18:37:05 raeburn Exp $
+# $Id: lonlogin.pm,v 1.193 2021/11/03 01:04:02 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -37,7 +37,9 @@ use Apache::lonauth();
 use Apache::lonlocal;
 use Apache::migrateuser();
 use lib '/home/httpd/lib/perl/';
-use LONCAPA;
+use LONCAPA qw(:DEFAULT :match);
+use URI::Escape;
+use HTML::Entities();
 use CGI::Cookie();
  
 sub handler {
@@ -47,26 +49,73 @@ sub handler {
 	(join('&',$ENV{'QUERY_STRING'},$env{'request.querystring'},
 	      $ENV{'REDIRECT_QUERY_STRING'}),
 	 ['interface','username','domain','firsturl','localpath','localres',
-	  'token','role','symb','iptoken']);
-    if (!defined($env{'form.firsturl'})) {
-        &Apache::lonacc::get_posted_cgi($r,['firsturl']);
-    }
+	  'token','role','symb','iptoken','btoken','ltoken','ttoken','linkkey',
+          'saml','sso','retry']); 
 
 # -- check if they are a migrating user
     if (defined($env{'form.token'})) {
-	return &Apache::migrateuser::handler($r);
+        return &Apache::migrateuser::handler($r);
+    }
+
+    my $lonhost = $r->dir_config('lonHostID');
+    if ($env{'form.ttoken'}) {
+        my %info = &Apache::lonnet::tmpget($env{'form.ttoken'});
+        &Apache::lonnet::tmpdel($env{'form.ttoken'});
+        if ($info{'origurl'}) {
+            $env{'form.firsturl'} = $info{'origurl'};
+        }
+        if ($info{'ltoken'}) {
+            $env{'form.ltoken'} = $info{'ltoken'};
+        } elsif ($info{'linkprot'}) {
+            $env{'form.linkprot'} = $info{'linkprot'};
+        } elsif ($info{'linkkey'} ne '') {
+            $env{'form.linkkey'} = $info{'linkkey'};
+        }
+    } elsif (($env{'form.sso'}) || ($env{'form.retry'})) {
+        my $infotoken;
+        if ($env{'form.sso'}) {
+            $infotoken = $env{'form.sso'};
+        } else {
+            $infotoken = $env{'form.retry'};
+        }
+        my $data = &Apache::lonnet::reply('tmpget:'.$infotoken,$lonhost);
+        unless (($data=~/^error/) || ($data eq 'con_lost') ||
+                ($data eq 'no_such_host')) {
+            my %info = &decode_token($data);
+            foreach my $item (keys(%info)) {
+                $env{'form.'.$item} = $info{$item};
+            }
+            &Apache::lonnet::tmpdel($infotoken);
+        }
+    } else {
+        if (!defined($env{'form.firsturl'})) {
+            &Apache::lonacc::get_posted_cgi($r,['firsturl']);
+        }
+        if (!defined($env{'form.firsturl'})) {
+            if ($ENV{'REDIRECT_URL'} =~ m{^/+tiny/+$LONCAPA::match_domain/+\w+$}) {
+                $env{'form.firsturl'} = $ENV{'REDIRECT_URL'};
+            }
+        }
+        if (($env{'form.firsturl'} =~ m{^/+tiny/+$LONCAPA::match_domain/+\w+$}) &&
+            (!$env{'form.ltoken'}) && (!$env{'form.linkprot'}) && (!$env{'form.linkkey'})) {
+            &Apache::lonacc::get_posted_cgi($r,['linkkey']);
+        }
+        if ($env{'form.firsturl'} eq '/adm/logout') {
+            delete($env{'form.firsturl'});
+        }
     }
 
 # For "public user" - remove any exising "public" cookie, as user really wants to log-in
-    my ($handle,$lonidsdir,$expire);
+    my ($handle,$lonidsdir,$expirepub,$userdom);
+    $lonidsdir=$r->dir_config('lonIDsDir');
     unless ($r->header_only) {
-        $handle = &Apache::lonnet::check_for_valid_session($r);
+        $handle = &Apache::lonnet::check_for_valid_session($r,'lonID',undef,\$userdom);
         if ($handle ne '') {
-            $lonidsdir=$r->dir_config('lonIDsDir');
             if ($handle=~/^publicuser\_/) {
                 unlink($r->dir_config('lonIDsDir')."/$handle.id");
                 undef($handle);
-                $expire = 1;
+                undef($userdom);
+                $expirepub = 1;
             }
         }
     }
@@ -74,11 +123,20 @@ sub handler {
     &Apache::loncommon::no_cache($r);
     &Apache::lonlocal::get_language_handle($r);
     &Apache::loncommon::content_type($r,'text/html');
-    if ($expire) {
-        my $c = new CGI::Cookie(-name    => 'lonPublic',
+    if ($expirepub) {
+        my $c = new CGI::Cookie(-name    => 'lonPubID',
                                 -value   => '',
                                 -expires => '-10y',);
         $r->header_out('Set-cookie' => $c);
+    } elsif (($handle eq '') && ($userdom ne '')) {
+        my %cookies=CGI::Cookie->parse($r->header_in('Cookie'));
+        foreach my $name (keys(%cookies)) {
+            next unless ($name =~ /^lon(|S|Link|Pub)ID$/);
+            my $c = new CGI::Cookie(-name    => $name,
+                                    -value   => '',
+                                    -expires => '-10y',);
+            $r->headers_out->add('Set-cookie' => $c);
+        }
     }
     $r->send_http_header;
     return OK if $r->header_only;
@@ -91,7 +149,93 @@ sub handler {
 	return OK;
     }
 
-    $env{'form.firsturl'} =~ s/(`)/'/g;
+# Check if browser sent a LON-CAPA load balancer cookie (and this is a balancer)
+
+    my ($found_server,$balancer_cookie) = &Apache::lonnet::check_for_balancer_cookie($r,1);
+    if ($found_server) {
+        my $hostname = &Apache::lonnet::hostname($found_server);
+        if ($hostname ne '') {
+            my $protocol = $Apache::lonnet::protocol{$found_server};
+            $protocol = 'http' if ($protocol ne 'https');
+            my $dest = '/adm/roles';
+            if ($env{'form.firsturl'} ne '') {
+                $dest = &HTML::Entities::encode($env{'form.firsturl'},'\'"<>&');
+            }
+            my %info = (
+                         balcookie => $lonhost.':'.$balancer_cookie,
+                       );
+            if ($env{'form.role'}) {
+                $info{'role'} = $env{'form.role'};
+            }
+            if ($env{'form.symb'}) {
+                $info{'symb'} = $env{'form.symb'};
+            }
+            my $balancer_token = &Apache::lonnet::tmpput(\%info,$found_server);
+            unless (($balancer_token eq 'con_lost') || ($balancer_token eq 'refused') ||
+                    ($balancer_token eq 'unknown_cmd') || ($balancer_token eq 'no_such_host')) {
+                $dest .=  (($dest=~/\?/)?'&amp;':'?') . 'btoken='.$balancer_token;
+            }
+            if ($env{'form.firsturl'} =~ m{^/tiny/$match_domain/\w+$}) {
+                my %link_info;
+                if ($env{'form.ltoken'}) {
+                    $link_info{'ltoken'} = $env{'form.ltoken'};
+                } elsif ($env{'form.linkprot'}) {
+                    $link_info{'linkprot'} = $env{'form.linkprot'};
+                } elsif ($env{'form.linkkey'} ne '') {
+                    $link_info{'linkkey'} = $env{'form.linkkey'};
+                }
+                if (keys(%link_info)) {
+                    $link_info{'origurl'} = $env{'form.firsturl'};
+                    my $token = &Apache::lonnet::tmpput(\%link_info,$found_server,'link');
+                    unless (($token eq 'con_lost') || ($token eq 'refused') ||
+                            ($token eq 'unknown_cmd') || ($token eq 'no_such_host')) {
+                        $dest .=  (($dest=~/\?/)?'&amp;':'?') . 'ttoken='.$token;
+                    }
+                }
+            }
+            unless ($found_server eq $lonhost) {
+                my $alias = &Apache::lonnet::use_proxy_alias($r,$found_server);
+                $hostname = $alias if ($alias ne '');
+            }
+            my $url = $protocol.'://'.$hostname.$dest;
+            my $start_page =
+                &Apache::loncommon::start_page('Switching Server ...',undef,
+                                               {'redirect'       => [0,$url],});
+            my $end_page   = &Apache::loncommon::end_page();
+            $r->print($start_page.$end_page);
+            return OK;
+        }
+    }
+
+#
+# Check if a LON-CAPA load balancer sent user here because user's browser sent
+# it a balancer cookie for an active session on this server.
+#
+
+    my $balcookie;
+    if ($env{'form.btoken'}) {
+        my %info = &Apache::lonnet::tmpget($env{'form.btoken'});
+        $balcookie = $info{'balcookie'};
+        &Apache::lonnet::tmpdel($env{'form.btoken'});
+        delete($env{'form.btoken'});
+    }
+
+#
+# If browser sent an old cookie for which the session file had been removed
+# check if configuration for user's domain has a portal URL set.  If so
+# switch user's log-in to the portal.
+#
+
+    if (($handle eq '') && ($userdom ne '')) {
+        my %domdefaults = &Apache::lonnet::get_domain_defaults($userdom);
+        if ($domdefaults{'portal_def'} =~ /^https?\:/) {
+            my $start_page = &Apache::loncommon::start_page('Switching Server ...',undef,
+                                          {'redirect' => [0,$domdefaults{'portal_def'}],});
+            my $end_page   = &Apache::loncommon::end_page();
+            $r->print($start_page.$end_page);
+            return OK;
+        }
+    }
 
 # -------------------------------- Prevent users from attempting to login twice
     if ($handle ne '') {
@@ -102,7 +246,63 @@ sub handler {
 	    &Apache::loncommon::end_page();
         my $dest = '/adm/roles';
         if ($env{'form.firsturl'} ne '') {
-            $dest = $env{'form.firsturl'}; 
+            $dest = &HTML::Entities::encode($env{'form.firsturl'},'\'"<>&');
+        }
+        if (($env{'form.ltoken'}) || ($env{'form.linkprot'})) {
+            my $linkprot;
+            if ($env{'form.ltoken'}) {
+                my %info = &Apache::lonnet::tmpget($env{'form.ltoken'});
+                $linkprot = $info{'linkprot'};
+                my $delete = &Apache::lonnet::tmpdel($env{'form.ltoken'});
+            } else {
+                $linkprot = $env{'form.linkprot'};
+            }
+            if ($linkprot) {
+                my ($linkprotector,$deeplink) = split(/:/,$linkprot,2);
+                if ($env{'user.linkprotector'}) {
+                    my @protectors = split(/,/,$env{'user.linkprotector'});
+                    unless (grep(/^\Q$linkprotector\E$/,@protectors)) {
+                        push(@protectors,$linkprotector);
+                        @protectors = sort { $a <=> $b } @protectors;
+                        &Apache::lonnet::appenv({'user.linkprotector' => join(',',@protectors)});
+                    }
+                } else {
+                    &Apache::lonnet::appenv({'user.linkprotector' => $linkprotector });
+                }
+                if ($env{'user.linkproturi'}) {
+                    my @proturis = split(/,/,$env{'user.linkproturi'});
+                    unless (grep(/^\Q$deeplink\E$/,@proturis)) {
+                        push(@proturis,$deeplink);
+                        @proturis = sort @proturis;
+                        &Apache::lonnet::appenv({'user.linkproturi' => join(',',@proturis)});
+                    }
+                } else {
+                    &Apache::lonnet::appenv({'user.linkproturi' => $deeplink});
+                }
+            }
+        } elsif ($env{'form.linkkey'} ne '') {
+            if ($env{'form.firsturl'} =~ m{^/tiny/$match_domain/\w+$}) {
+                my $linkkey = $env{'form.linkkey'};
+                if ($env{'user.deeplinkkey'}) {
+                    my @linkkeys = split(/,/,$env{'user.deeplinkkey'});
+                    unless (grep(/^\Q$linkkey\E$/,@linkkeys)) {
+                        push(@linkkeys,$linkkey);
+                        &Apache::lonnet::appenv({'user.deeplinkkey' => join(',',sort(@linkkeys))});
+                    }
+                } else {
+                    &Apache::lonnet::appenv({'user.deeplinkkey' => $linkkey});
+                }
+                my $deeplink = $env{'form.firsturl'}; 
+                if ($env{'user.keyedlinkuri'}) {
+                    my @keyeduris = split(/,/,$env{'user.keyedlinkuri'});
+                    unless (grep(/^\Q$deeplink\E$/,@keyeduris)) {
+                        push(@keyeduris,$deeplink);
+                        &Apache::lonnet::appenv({'user.keyedlinkuri' => join(',',sort(@keyeduris))});
+                    }
+                } else {
+                    &Apache::lonnet::appenv({'user.keyedlinkuri' => $deeplink});
+                }
+            }
         }
 	$r->print(
                   $start_page
@@ -135,17 +335,16 @@ sub handler {
     $env{'form.interface'}=~s/\W//g;
 
     (undef,undef,undef,undef,undef,undef,my $clientmobile) =
-        &Apache::loncommon::decode_user_agent();
+        &Apache::loncommon::decode_user_agent($r);
 
     my $iconpath= 
 	&Apache::loncommon::lonhttpdurl($r->dir_config('lonIconsURL'));
 
-    my $lonhost = $r->dir_config('lonHostID');
     my $domain = &Apache::lonnet::default_login_domain();
     my $defdom = $domain;
     if ($lonhost ne '') {
         unless ($sessiondata{'sessionserver'}) {
-            my $redirect = &check_loginvia($domain,$lonhost);
+            my $redirect = &check_loginvia($domain,$lonhost,$lonidsdir,$balcookie);
             if ($redirect) {
                 $r->print($redirect);
                 return OK;
@@ -154,7 +353,7 @@ sub handler {
     }
 
     if (($sessiondata{'domain'}) &&
-        (&Apache::lonnet::domain($env{'form.domain'},'description'))) {
+        (&Apache::lonnet::domain($sessiondata{'domain'},'description'))) {
         $domain=$sessiondata{'domain'};
     } elsif (($env{'form.domain'}) && 
 	(&Apache::lonnet::domain($env{'form.domain'},'description'))) {
@@ -229,24 +428,30 @@ sub handler {
     if ($uextkey>2147483647) { $uextkey-=4294967296; }
 
 # -------------------------------------------------------- Store away log token
-    my $tokenextras;
-    if ($env{'form.role'}) {
-        $tokenextras = '&role='.&escape($env{'form.role'});
-    }
-    if ($env{'form.symb'}) {
-        if (!$tokenextras) {
-            $tokenextras = '&';
+    my ($tokenextras,$tokentype);
+    my @names = ('role','symb','iptoken','ltoken','linkprot','linkkey');
+    foreach my $name (@names) {
+        if ($env{'form.'.$name} ne '') {
+            if ($name eq 'ltoken') {
+                my %info = &Apache::lonnet::tmpget($env{'form.'.$name});
+                if ($info{'linkprot'}) {
+                    $tokenextras .= '&linkprot='.&escape($info{'linkprot'});
+                    $tokentype = 'link';
+                    last;
+                }
+            } else {
+                $tokenextras .= '&'.$name.'='.&escape($env{'form.'.$name});
+                if (($name eq 'linkkey') || ($name eq 'linkprot')) {
+                    $tokentype = 'link';
+                }
+            }
         }
-        $tokenextras .= '&symb='.&escape($env{'form.symb'});
     }
-    if ($env{'form.iptoken'}) {
-        if (!$tokenextras) {
-            $tokenextras = '&&';
-        }
-        $tokenextras .= '&iptoken='.&escape($env{'form.iptoken'});
+    if ($tokentype) {
+        $tokenextras .= ":$tokentype";
     }
     my $logtoken=Apache::lonnet::reply(
-       'tmpput:'.$ukey.$lkey.'&'.$firsturl.$tokenextras,
+       'tmpput:'.$ukey.$lkey.'&'.&escape($firsturl).$tokenextras,
        $lonhost);
 
 # -- If we cannot talk to ourselves, or hostID does not map to a hostname
@@ -256,23 +461,41 @@ sub handler {
         if ($logtoken eq 'no_such_host') {
             &Apache::lonnet::logthis('No valid logtoken for log-in page -- unable to determine hostname for hostID: '.$lonhost.'. Check entry in hosts.tab');
         }
+        if ($env{'form.ltoken'}) {
+            &Apache::lonnet::tmpdel($env{'form.ltoken'});
+            delete($env{'form.ltoken'});
+        }
         my $spares='';
-	my $last;
-        foreach my $hostid (sort
-			    {
-				&Apache::lonnet::hostname($a) cmp
-				    &Apache::lonnet::hostname($b);
-			    }
-			    keys(%Apache::lonnet::spareid)) {
+        my (@sparehosts,%spareservers);
+        my $sparesref = &Apache::lonnet::this_host_spares($defdom);
+        if (ref($sparesref) eq 'HASH') {
+            foreach my $key (keys(%{$sparesref})) {
+                if (ref($sparesref->{$key}) eq 'ARRAY') {
+                    my @sorted = sort { &Apache::lonnet::hostname($a) cmp
+                                        &Apache::lonnet::hostname($b);
+                                      } @{$sparesref->{$key}};
+                    if (@sorted) {
+                        if ($key eq 'primary') {
+                            unshift(@sparehosts,@sorted);
+                        } elsif ($key eq 'default') {
+                            push(@sparehosts,@sorted);
+                        }
+                    }
+                }
+            }
+        }
+        foreach my $hostid (@sparehosts) {
             next if ($hostid eq $lonhost);
 	    my $hostname = &Apache::lonnet::hostname($hostid);
-	    next if (($last eq $hostname) || ($hostname eq ''));
-            $spares.='<br /><font size="+1"><a href="http://'.
+	    next if (($hostname eq '') || ($spareservers{$hostname}));
+            $spareservers{$hostname} = 1;
+            my $protocol = $Apache::lonnet::protocol{$hostid};
+            $protocol = 'http' if ($protocol ne 'https');
+            $spares.='<br /><span style="font-size: larger;"><a href="'.$protocol.'://'.
                 $hostname.
                 '/adm/login?domain='.$authdomain.'">'.
                 $hostname.'</a>'.
-                ' '.&mt('(preferred)').'</font>'.$/;
-	    $last=$hostname;
+                ' '.&mt('(preferred)').'</span>'.$/;
         }
         if ($spares) {
             $spares.= '<br />';
@@ -284,23 +507,26 @@ sub handler {
 			    &Apache::lonnet::hostname($b);
 		    }
 		    keys(%all_hostnames)) {
-            next if ($hostid eq $lonhost || $Apache::lonnet::spareid{$hostid});
+            next if ($hostid eq $lonhost);
             my $hostname = &Apache::lonnet::hostname($hostid);
-            next if (($last eq $hostname) || ($hostname eq ''));
-            $spares.='<br /><a href="http://'.
+            next if (($hostname eq '') || ($spareservers{$hostname}));
+            $spareservers{$hostname} = 1;
+            my $protocol = $Apache::lonnet::protocol{$hostid};
+            $protocol = 'http' if ($protocol ne 'https');
+            $spares.='<br /><a href="'.$protocol.'://'.
 	             $hostname.
 	             '/adm/login?domain='.$authdomain.'">'.
 	             $hostname.'</a>';
-            $last=$hostname;
          }
          $r->print(
-   '<html>'
-  .'<head><title>'
+   '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">'
+  .'<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">'
+  .'<head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>'
   .&mt('The LearningOnline Network with CAPA')
   .'</title></head>'
   .'<body bgcolor="#FFFFFF">'
   .'<h1>'.&mt('The LearningOnline Network with CAPA').'</h1>'
-  .'<img src="/adm/lonKaputt/lonlogo_broken.gif" align="right" />'
+  .'<img src="/adm/lonKaputt/lonlogo_broken.gif" alt="broken icon" align="right" />'
   .'<h3>'.&mt('This LON-CAPA server is temporarily not available for login.').'</h3>');
         if ($spares) {
             $r->print('<p>'.&mt('Please attempt to login to one of the following servers:')
@@ -392,17 +618,9 @@ function enableInput() {
 
 ENDSCRIPT
 
-# --------------------------------------------------- Print login screen header
-
-    my %add_entries = (
-	       bgcolor      => "$mainbg",
-	       text         => "$font",
-	       link         => "$link",
-	       vlink        => "$vlink",
-	       alink        => "$alink",
-               onload       => 'javascript:enableInput();',);
-
-    my ($lonhost_in_use,$headextra,$headextra_exempt,@hosts,%defaultdomconf);
+    my ($lonhost_in_use,@hosts,%defaultdomconf,$saml_prefix,$saml_landing,
+        $samlssotext,$samlnonsso,$samlssoimg,$samlssoalt,$samlssourl,$samltooltip);
+    %defaultdomconf = &Apache::loncommon::get_domainconf($defdom);
     @hosts = &Apache::lonnet::current_machine_ids();
     $lonhost_in_use = $lonhost;
     if (@hosts > 1) {
@@ -413,14 +631,74 @@ ENDSCRIPT
             }
         }
     }
-    %defaultdomconf = &Apache::loncommon::get_domainconf($defdom);
+    $saml_prefix = $defdom.'.login.saml_';
+    if ($defaultdomconf{$saml_prefix.$lonhost_in_use}) {
+        $saml_landing = 1;
+        $samlssotext = $defaultdomconf{$saml_prefix.'text_'.$lonhost_in_use};
+        $samlnonsso = $defaultdomconf{$saml_prefix.'notsso_'.$lonhost_in_use};
+        $samlssoimg = $defaultdomconf{$saml_prefix.'img_'.$lonhost_in_use};
+        $samlssoalt = $defaultdomconf{$saml_prefix.'alt_'.$lonhost_in_use};
+        $samlssourl = $defaultdomconf{$saml_prefix.'url_'.$lonhost_in_use};
+        $samltooltip = $defaultdomconf{$saml_prefix.'title_'.$lonhost_in_use};
+    }
+    if ($saml_landing) {
+       if ($samlssotext eq '') {
+           $samlssotext = 'SSO Login';
+       }
+       if ($samlnonsso eq '') {
+           $samlnonsso = 'Non-SSO Login';
+       }
+       $js .= <<"ENDSAMLJS";
+
+<script type="text/javascript">
+// <![CDATA[
+function toggleLClogin() {
+    if (document.getElementById('LC_standard_login')) {
+        if (document.getElementById('LC_standard_login').style.display == 'none') {
+            document.getElementById('LC_standard_login').style.display = 'inline-block';
+            if (document.getElementById('LC_login_text')) {
+                document.getElementById('LC_login_text').innerHTML = '$samlnonsso';
+            }
+            if (document.getElementById('LC_SSO_login')) {
+                document.getElementById('LC_SSO_login').style.display = 'none';
+            }
+        } else {
+            document.getElementById('LC_standard_login').style.display = 'none';
+            if (document.getElementById('LC_login_text')) {
+                document.getElementById('LC_login_text').innerHTML = '$samlssotext';
+            }
+            if (document.getElementById('LC_SSO_login')) {
+                document.getElementById('LC_SSO_login').style.display = 'inline-block';
+            }
+        }
+    }
+    return;
+}
+
+// ]]>
+</script>
+
+ENDSAMLJS
+    }
+
+# --------------------------------------------------- Print login screen header
+
+    my %add_entries = (
+	       bgcolor      => "$mainbg",
+	       text         => "$font",
+	       link         => "$link",
+	       vlink        => "$vlink",
+	       alink        => "$alink",
+               onload       => 'javascript:enableInput();',);
+
+    my ($headextra,$headextra_exempt);
     $headextra = $defaultdomconf{$defdom.'.login.headtag_'.$lonhost_in_use};
     $headextra_exempt = $defaultdomconf{$domain.'.login.headtag_exempt_'.$lonhost_in_use};
     if ($headextra) {
         my $omitextra;
         if ($headextra_exempt ne '') {
             my @exempt = split(',',$headextra_exempt);
-            my $ip = $ENV{'REMOTE_ADDR'};
+            my $ip = &Apache::lonnet::get_requestor_ip();
             if (grep(/^\Q$ip\E$/,@exempt)) {
                 $omitextra = 1;
             }
@@ -458,6 +736,7 @@ ENDSCRIPT
           'helpdesk' => 'Contact Helpdesk',
           'forgotpw' => 'Forgot password?',
           'newuser'  => 'New User?',
+          'change'   => 'Change?',
        );
 # -------------------------------------------------- Change password field name
 
@@ -519,7 +798,7 @@ ENDSERVERFORM
         $mobileargs = 'autocapitalize="off" autocorrect="off"'; 
     }
     my $loginform=(<<LFORM);
-<form name="client" action="" onsubmit="return(send())">
+<form name="client" action="" onsubmit="return(send())" id="lclogin">
   <input type="hidden" name="lextkey" value="$lextkey" />
   <input type="hidden" name="uextkey" value="$uextkey" />
   <b><label for="uname">$lt{'un'}</label>:</b><br />
@@ -540,8 +819,82 @@ LFORM
 </div>
 HEADER
     }
-    $r->print(<<ENDTOP);
-<div style="float:left;margin-top:0;">
+
+    my $stdauthformstyle = 'inline-block';
+    my $ssoauthstyle = 'none';
+    my $logintype;
+    $r->print('<div style="float:left;margin-top:0;">');
+    if ($saml_landing) {
+        $ssoauthstyle = 'inline-block';
+        $stdauthformstyle = 'none';
+        $logintype = $samlssotext;
+        my $ssologin = '/adm/sso';
+        if ($samlssourl  ne '') {
+            $ssologin = $samlssourl;
+        }
+        if (($logtoken eq 'con_lost') || ($logtoken eq 'no_such_host')) {
+            my $querystring;
+            if ($env{'form.firsturl'} ne '') {
+                $querystring = 'origurl=';
+                if ($env{'form.firsturl'} =~ /[^\x00-\xFF]/) {
+                    $querystring .= &uri_escape_utf8($env{'form.firsturl'});
+                } else {
+                    $querystring .= &uri_escape($env{'form.firsturl'});
+                }
+                $querystring = &HTML::Entities::encode($querystring,"'");
+            }
+            if ($env{'form.ltoken'} ne '') {
+                $querystring .= (($querystring eq '')?'':'&amp;') . 'ltoken='.
+                                  &HTML::Entities::encode(&uri_escape($env{'form.ltoken'}));
+            } elsif ($env{'form.linkkey'}) {
+                $querystring .= (($querystring eq '')?'':'&amp;') . 'linkkey='.
+                                  &HTML::Entities::encode(&uri_escape($env{'form.linkkey'}));
+            }
+            if ($querystring ne '') {
+                $ssologin .= (($ssologin=~/\?/)?'&amp;':'?') . $querystring;
+            }
+        } elsif ($logtoken ne '') {
+            $ssologin .= (($ssologin=~/\?/)?'&amp;':'?') . 'logtoken='.$logtoken;
+        }
+        my $ssohref;
+        if ($samlssoimg ne '') {
+            $ssohref = '<a href="'.$ssologin.'" title="'.$samltooltip.'"><img src="'.$samlssoimg.'" alt="'.$samlssoalt.'" /></a>';
+        } else {
+            $ssohref = '<a href="'.$ssologin.'">'.$samlssotext.'</a>';
+        }
+        if (($env{'form.saml'} eq 'no') ||
+            (($env{'form.username'} ne '') && ($env{'form.domain'} ne ''))) {
+            $ssoauthstyle = 'none';
+            $stdauthformstyle = 'inline-block';
+            $logintype = $samlnonsso;
+        }
+        $r->print(<<ENDSAML);
+<p>
+Log-in type:
+<span style="font-weight:bold" id="LC_login_text">$logintype</span><br />
+<span><a href="javascript:toggleLClogin();" style="color:#000000">$lt{'change'}</a></span>
+</p>
+<div style="display:$ssoauthstyle" id="LC_SSO_login">
+<div class="LC_Box" style="padding-top: 10px;">
+$ssohref
+$noscript_warning
+</div>
+<div class="LC_Box" style="padding-top: 10px;">
+$loginhelp
+$contactblock
+$coursecatalog
+</div>
+</div>
+ENDSAML
+    } else {
+        if ($env{'form.ltoken'}) {
+            &Apache::lonnet::tmpdel($env{'form.ltoken'});
+            delete($env{'form.ltoken'});
+        }
+    }
+
+    $r->print(<<ENDLOGIN);
+<div style="display:$stdauthformstyle;" id="LC_standard_login">
 <div class="LC_Box" style="background:$loginbox_bg;">
   $logintitle
   $loginform
@@ -557,8 +910,8 @@ HEADER
 </div>
 </div>
 
-<div>
-ENDTOP
+ENDLOGIN
+    $r->print('</div><div>'."\n");
     if ($showmainlogo) {
         $r->print(' <img src="'.$logo.'" alt="" class="LC_maxwidth" />'."\n");
     }
@@ -653,8 +1006,8 @@ ENDDOCUMENT
 }
 
 sub check_loginvia {
-    my ($domain,$lonhost) = @_;
-    if ($domain eq '' || $lonhost eq '') {
+    my ($domain,$lonhost,$lonidsdir,$balcookie) = @_;
+    if ($domain eq '' || $lonhost eq '' || $lonidsdir eq '') {
         return;
     }
     my %domconfhash = &Apache::loncommon::get_domainconf($domain);
@@ -663,7 +1016,7 @@ sub check_loginvia {
     my $output;
     if ($loginvia ne '') {
         my $noredirect;
-        my $ip = $ENV{'REMOTE_ADDR'};
+        my $ip = &Apache::lonnet::get_requestor_ip();   
         if ($ip eq '127.0.0.1') {
             $noredirect = 1;
         } else {
@@ -683,6 +1036,36 @@ sub check_loginvia {
             }
             if ($newhost ne $lonhost) {
                 if (&Apache::lonnet::hostname($newhost) ne '') {
+                    if ($balcookie) {
+                        my ($balancer,$cookie) = split(/:/,$balcookie);
+                        if ($cookie =~ /^($match_domain)_($match_username)_([a-f0-9]+)$/) {
+                            my ($udom,$uname,$cookieid) = ($1,$2,$3);
+                            unless (&Apache::lonnet::delbalcookie($cookie,$balancer) eq 'ok') {
+                                if ((-d $lonidsdir) && (opendir(my $dh,$lonidsdir))) {
+                                    while (my $filename=readdir($dh)) {
+                                        if ($filename=~/^(\Q$uname\E_\d+_\Q$udom\E_$match_lonid)\.id$/) {
+                                            my $handle = $1;
+                                            my %hash =
+                                                &Apache::lonnet::get_sessionfile_vars($handle,$lonidsdir,
+                                                                                     ['request.balancercookie',
+                                                                                      'user.linkedenv']);
+                                            if ($hash{'request.balancercookie'} eq "$balancer:$cookieid") {
+                                                if (unlink("$lonidsdir/$filename")) {
+                                                    if (($hash{'user.linkedenv'} =~ /^[a-f0-9]+_linked$/) &&
+                                                        (-l "$lonidsdir/$hash{'user.linkedenv'}.id") &&
+                                                        (readlink("$lonidsdir/$hash{'user.linkedenv'}.id") eq "$lonidsdir/$filename")) {
+                                                        unlink("$lonidsdir/$hash{'user.linkedenv'}.id");
+                                                    }
+                                                }
+                                            }
+                                            last;
+                                        }
+                                    }
+                                    closedir($dh);
+                                }
+                            }
+                        }
+                    }
                     $output = &redirect_page($newhost,$path);
                 }
             }
@@ -693,14 +1076,35 @@ sub check_loginvia {
 
 sub redirect_page {
     my ($desthost,$path) = @_;
+    my $hostname = &Apache::lonnet::hostname($desthost);
     my $protocol = $Apache::lonnet::protocol{$desthost};
     $protocol = 'http' if ($protocol ne 'https');
     unless ($path =~ m{^/}) {
         $path = '/'.$path;
     }
-    my $url = $protocol.'://'.&Apache::lonnet::hostname($desthost).$path;
+    my $url = $protocol.'://'.$hostname.$path;
     if ($env{'form.firsturl'} ne '') {
-        $url .='?firsturl='.$env{'form.firsturl'};
+        my $querystring;
+        if ($env{'form.firsturl'} =~ /[^\x00-\xFF]/) {
+            $querystring = &uri_escape_utf8($env{'form.firsturl'});
+        } else {
+            $querystring = &uri_escape($env{'form.firsturl'});
+        }
+        $querystring = &HTML::Entities::encode($querystring,"'");
+        $url .='?firsturl='.$querystring;
+    }
+    if (($env{'form.ltoken'}) || ($env{'form.linkkey'} ne '')) {
+        my %link_info;
+        if ($env{'form.ltoken'}) {
+            $link_info{'ltoken'} = $env{'form.ltoken'};
+        } elsif ($env{'form.linkkey'} ne '') {
+            $link_info{'linkkey'} = $env{'form.linkkey'};
+        }
+        my $token = &Apache::lonnet::tmpput(\%link_info,$desthost,'link');
+        unless (($token eq 'con_lost') || ($token eq 'refused') ||
+                ($token eq 'unknown_cmd') || ($token eq 'no_such_host')) {
+            $url .= (($url=~/\?/)?'&amp;':'?') . 'ttoken='.$token;
+        }
     }
     my $start_page = &Apache::loncommon::start_page('Switching Server ...',undef,
                                                     {'redirect' => [0,$url],});
@@ -776,5 +1180,19 @@ sub newuser_link {
     return '<a href="/adm/createaccount">'.$linkname.'</a>';
 }
 
+sub decode_token {
+    my ($info) = @_;
+    my ($firsturl,@rest)=split(/\&/,$info);
+    my %form;
+    if ($firsturl ne '') {
+        $form{'firsturl'} = &unescape($firsturl);
+    }
+    foreach my $item (@rest) {
+        my ($key,$value) = split(/=/,$item);
+        $form{$key} = &unescape($value);
+    }
+    return %form;
+}
+
 1;
 __END__