--- loncom/interface/loncommon.pm	2019/07/28 14:05:38	1.1075.2.133
+++ loncom/interface/loncommon.pm	2020/02/12 22:06:59	1.1075.2.141.2.3
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # a pile of common routines
 #
-# $Id: loncommon.pm,v 1.1075.2.133 2019/07/28 14:05:38 raeburn Exp $
+# $Id: loncommon.pm,v 1.1075.2.141.2.3 2020/02/12 22:06:59 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -71,6 +71,7 @@ use Apache::lonuserutils();
 use Apache::lonuserstate();
 use Apache::courseclassifier();
 use LONCAPA qw(:DEFAULT :match);
+use HTTP::Request;
 use DateTime::TimeZone;
 use DateTime::Locale;
 use Encode();
@@ -82,6 +83,8 @@ use Crypt::DES;
 use DynaLoader; # for Crypt::DES version
 use File::Copy();
 use File::Path();
+use String::CRC32();
+use Short::URL();
 
 # ---------------------------------------------- Designs
 use vars qw(%defaultdesign);
@@ -427,7 +430,7 @@ sub studentbrowser_javascript {
 <script type="text/javascript" language="Javascript">
 // <![CDATA[
     var stdeditbrowser;
-    function openstdbrowser(formname,uname,udom,clicker,roleflag,ignorefilter,courseadvonly) {
+    function openstdbrowser(formname,uname,udom,clicker,roleflag,ignorefilter,courseadv) {
         var url = '/adm/pickstudent?';
         var filter;
 	if (!ignorefilter) {
@@ -442,7 +445,12 @@ sub studentbrowser_javascript {
                                     '&udomelement='+udom+
                                     '&clicker='+clicker;
 	if (roleflag) { url+="&roles=1"; }
-        if (courseadvonly) { url+="&courseadvonly=1"; }
+        if (courseadv == 'condition') {
+            if (document.getElementById('courseadv')) {
+                courseadv = document.getElementById('courseadv').value;
+            }
+        }
+        if ((courseadv == 'only') || (courseadv == 'none')) { url+="&courseadv="+courseadv; }
         var title = 'Student_Browser';
         var options = 'scrollbars=1,resizable=1,menubar=0';
         options += ',width=700,height=600';
@@ -474,7 +482,7 @@ ENDRESBRW
 }
 
 sub selectstudent_link {
-   my ($form,$unameele,$udomele,$courseadvonly,$clickerid)=@_;
+   my ($form,$unameele,$udomele,$courseadv,$clickerid)=@_;
    my $callargs = "'".&Apache::lonhtmlcommon::entity_encode($form)."','".
                       &Apache::lonhtmlcommon::entity_encode($unameele)."','".
                       &Apache::lonhtmlcommon::entity_encode($udomele)."'";
@@ -485,8 +493,12 @@ sub selectstudent_link {
 	   return '';
        }
        $callargs.=",'".&Apache::lonhtmlcommon::entity_encode($clickerid)."'";
-       if ($courseadvonly)  {
-           $callargs .= ",'',1,1";
+       if ($courseadv eq 'only') {
+           $callargs .= ",'',1,'$courseadv'";
+       } elsif ($courseadv eq 'none') {
+           $callargs .= ",'','','$courseadv'";
+       } elsif ($courseadv eq 'condition') {
+           $callargs .= ",'','','$courseadv'";
        }
        return '<span class="LC_nobreak">'.
               '<a href="javascript:openstdbrowser('.$callargs.');">'.
@@ -1403,7 +1415,7 @@ sub help_menu_js {
         &Apache::loncommon::start_page('Help Menu', undef,
 				       {'frameset'    => 1,
 					'js_ready'    => 1,
-                                        'use_absolute' => $httphost, 
+                                        'use_absolute' => $httphost,
 					'add_entries' => {
 					    'border' => '0',
 					    'rows'   => "110,*",},});
@@ -3170,6 +3182,79 @@ sub get_assignable_auth {
     return ($authnum,%can_assign);
 }
 
+sub check_passwd_rules {
+    my ($domain,$plainpass) = @_;
+    my %passwdconf = &Apache::lonnet::get_passwdconf($domain);
+    my ($min,$max,@chars,@brokerule,$warning);
+    $min = $Apache::lonnet::passwdmin;
+    if (ref($passwdconf{'chars'}) eq 'ARRAY') {
+        if ($passwdconf{'min'} =~ /^\d+$/) {
+            if ($passwdconf{'min'} > $min) {
+                $min = $passwdconf{'min'};
+            }
+        }
+        if ($passwdconf{'max'} =~ /^\d+$/) {
+            $max = $passwdconf{'max'};
+        }
+        @chars = @{$passwdconf{'chars'}};
+    }
+    if (($min) && (length($plainpass) < $min)) {
+        push(@brokerule,'min');
+    }
+    if (($max) && (length($plainpass) > $max)) {
+        push(@brokerule,'max');
+    }
+    if (@chars) {
+        my %rules;
+        map { $rules{$_} = 1; } @chars;
+        if ($rules{'uc'}) {
+            unless ($plainpass =~ /[A-Z]/) {
+                push(@brokerule,'uc');
+            }
+        }
+        if ($rules{'lc'}) {
+            unless ($plainpass =~ /[a-z]/) {
+                push(@brokerule,'lc');
+            }
+        }
+        if ($rules{'num'}) {
+            unless ($plainpass =~ /\d/) {
+                push(@brokerule,'num');
+            }
+        }
+        if ($rules{'spec'}) {
+            unless ($plainpass =~ /[!"#$%&'()*+,\-.\/:;<=>?@[\\\]^_`{|}~]/) {
+                push(@brokerule,'spec');
+            }
+        }
+    }
+    if (@brokerule) {
+        my %rulenames = &Apache::lonlocal::texthash(
+            uc   => 'At least one upper case letter',
+            lc   => 'At least one lower case letter',
+            num  => 'At least one number',
+            spec => 'At least one non-alphanumeric',
+        );
+        $rulenames{'uc'} .= ': ABCDEFGHIJKLMNOPQRSTUVWXYZ';
+        $rulenames{'lc'} .= ': abcdefghijklmnopqrstuvwxyz';
+        $rulenames{'num'} .= ': 0123456789';
+        $rulenames{'spec'} .= ': !&quot;\#$%&amp;\'()*+,-./:;&lt;=&gt;?@[\]^_\`{|}~';
+        $rulenames{'min'} = &mt('Minimum password length: [_1]',$min);
+        $rulenames{'max'} = &mt('Maximum password length: [_1]',$max);
+        $warning = &mt('Password did not satisfy the following:').'<ul>';
+        foreach my $rule ('min','max','uc','lc','num','spec') {
+            if (grep(/^$rule$/,@brokerule)) {
+                $warning .= '<li>'.$rulenames{$rule}.'</li>';
+            }
+        }
+        $warning .= '</ul>';
+    }
+    if (wantarray) {
+        return @brokerule;
+    }
+    return $warning;
+}
+
 ###############################################################
 ##    Get Kerberos Defaults for Domain                 ##
 ###############################################################
@@ -4952,17 +5037,38 @@ sub check_ip_acc {
     if (!defined($acc) || $acc =~ /^\s*$/ || $acc =~/^\s*no\s*$/i) {
         return 1;
     }
-    my $allowed=0;
+    my $allowed;
     my $ip=$ENV{'REMOTE_ADDR'} || $clientip || $env{'request.host'};
 
     my $name;
-    foreach my $pattern (split(',',$acc)) {
-        $pattern =~ s/^\s*//;
-        $pattern =~ s/\s*$//;
+    my %access = (
+                     allowfrom => 1,
+                     denyfrom  => 0,
+                 );
+    my @allows;
+    my @denies;
+    foreach my $item (split(',',$acc)) {
+        $item =~ s/^\s*//;
+        $item =~ s/\s*$//;
+        if ($item =~ /^\!(.+)$/) {
+            push(@denies,$1);
+        } else {
+            push(@allows,$item);
+        }
+    }
+    my $numdenies = scalar(@denies);
+    my $numallows = scalar(@allows);
+    my $count = 0;
+    foreach my $pattern (@denies,@allows) {
+        $count ++;
+        my $acctype = 'allowfrom';
+        if ($count <= $numdenies) {
+            $acctype = 'denyfrom';
+        }
         if ($pattern =~ /\*$/) {
             #35.8.*
             $pattern=~s/\*//;
-            if ($ip =~ /^\Q$pattern\E/) { $allowed=1; }
+            if ($ip =~ /^\Q$pattern\E/) { $allowed=$access{$acctype}; }
         } elsif ($pattern =~ /(\d+\.\d+\.\d+)\.\[(\d+)-(\d+)\]$/) {
             #35.8.3.[34-56]
             my $low=$2;
@@ -4970,7 +5076,7 @@ sub check_ip_acc {
             $pattern=$1;
             if ($ip =~ /^\Q$pattern\E/) {
                 my $last=(split(/\./,$ip))[3];
-                if ($last <=$high && $last >=$low) { $allowed=1; }
+                if ($last <=$high && $last >=$low) { $allowed=$access{$acctype}; }
             }
         } elsif ($pattern =~ /^\*/) {
             #*.msu.edu
@@ -4980,10 +5086,10 @@ sub check_ip_acc {
                 my $netaddr=inet_aton($ip);
                 ($name)=gethostbyaddr($netaddr,AF_INET);
             }
-            if ($name =~ /\Q$pattern\E$/i) { $allowed=1; }
+            if ($name =~ /\Q$pattern\E$/i) { $allowed=$access{$acctype}; }
         } elsif ($pattern =~ /\d+\.\d+\.\d+\.\d+/) {
             #127.0.0.1
-            if ($ip =~ /^\Q$pattern\E/) { $allowed=1; }
+            if ($ip =~ /^\Q$pattern\E/) { $allowed=$access{$acctype}; }
         } else {
             #some.name.com
             if (!defined($name)) {
@@ -4991,9 +5097,16 @@ sub check_ip_acc {
                 my $netaddr=inet_aton($ip);
                 ($name)=gethostbyaddr($netaddr,AF_INET);
             }
-            if ($name =~ /\Q$pattern\E$/i) { $allowed=1; }
+            if ($name =~ /\Q$pattern\E$/i) { $allowed=$access{$acctype}; }
+        }
+        if ($allowed =~ /^(0|1)$/) { last; }
+    }
+    if ($allowed eq '') {
+        if ($numdenies && !$numallows) {
+            $allowed = 1;
+        } else {
+            $allowed = 0;
         }
-        if ($allowed) { last; }
     }
     return $allowed;
 }
@@ -6084,6 +6197,11 @@ td.LC_menubuttons_text {
   background: $tabbg;
 }
 
+td.LC_zero_height {
+  line-height: 0;
+  cellpadding: 0;
+}
+
 table.LC_data_table {
   border: 1px solid #000000;
   border-collapse: separate;
@@ -6674,7 +6792,8 @@ table.LC_prior_tries td {
   padding: 6px;
 }
 
-.LC_answer_unknown {
+.LC_answer_unknown,
+.LC_answer_warning {
   background: orange;
   color: black;
   padding: 6px;
@@ -6756,6 +6875,7 @@ table.LC_data_table tr > td.LC_docs_entr
   color: #990000;
 }
 
+.LC_domprefs_email,
 .LC_docs_reinit_warn,
 .LC_docs_ext_edit {
   font-size: x-small;
@@ -7664,6 +7784,14 @@ ul.LC_funclist li {
 		cursor:pointer;
 }
 
+pre.LC_wordwrap {
+  white-space: pre-wrap;
+  white-space: -moz-pre-wrap;
+  white-space: -pre-wrap;
+  white-space: -o-pre-wrap;
+  word-wrap: break-word;
+}
+
 /*
   styles used by TTH when "Default set of options to pass to tth/m
   when converting TeX" in course settings has been set
@@ -8301,8 +8429,7 @@ sub modal_link {
         $target_attr = 'target="'.$target.'"';
     }
     return <<"ENDLINK";
-<a href="$link" $target_attr title="$title" onclick="javascript:openMyModal('$link',$width,$height,'$scrolling','$transparency','$style'); return false;">
-           $linktext</a>
+<a href="$link" $target_attr title="$title" onclick="javascript:openMyModal('$link',$width,$height,'$scrolling','$transparency','$style'); return false;">$linktext</a>
 ENDLINK
 }
 
@@ -14100,6 +14227,12 @@ defdom (domain for which to retrieve con
 origmail (scalar - email address of recipient from loncapa.conf,
 i.e., predates configuration by DC via domainprefs.pm
 
+$requname username of requester (if mailing type is helpdeskmail)
+
+$requdom domain of requester (if mailing type is helpdeskmail)
+
+$reqemail e-mail address of requester (if mailing type is helpdeskmail)
+
 Returns: comma separated list of addresses to which to send e-mail.
 
 =back
@@ -14109,7 +14242,7 @@ Returns: comma separated list of address
 ############################################################
 ############################################################
 sub build_recipient_list {
-    my ($defmail,$mailing,$defdom,$origmail) = @_;
+    my ($defmail,$mailing,$defdom,$origmail,$requname,$requdom,$reqemail) = @_;
     my @recipients;
     my ($otheremails,$lastresort,$allbcc,$addtext);
     my %domconfig =
@@ -14150,10 +14283,97 @@ sub build_recipient_list {
         } elsif ($origmail ne '') {
             $lastresort = $origmail;
         }
+        if ($mailing eq 'helpdeskmail') {
+            if ((ref($domconfig{'contacts'}{'overrides'}) eq 'HASH') &&
+                (keys(%{$domconfig{'contacts'}{'overrides'}}))) {
+                my ($inststatus,$inststatus_checked);
+                if (($env{'user.name'} ne '') && ($env{'user.domain'} ne '') &&
+                    ($env{'user.domain'} ne 'public')) {
+                    $inststatus_checked = 1;
+                    $inststatus = $env{'environment.inststatus'};
+                }
+                unless ($inststatus_checked) {
+                    if (($requname ne '') && ($requdom ne '')) {
+                        if (($requname =~ /^$match_username$/) &&
+                            ($requdom =~ /^$match_domain$/) &&
+                            (&Apache::lonnet::domain($requdom))) {
+                            my $requhome = &Apache::lonnet::homeserver($requname,
+                                                                      $requdom);
+                            unless ($requhome eq 'no_host') {
+                                my %userenv = &Apache::lonnet::userenvironment($requdom,$requname,'inststatus');
+                                $inststatus = $userenv{'inststatus'};
+                                $inststatus_checked = 1;
+                            }
+                        }
+                    }
+                }
+                unless ($inststatus_checked) {
+                    if ($reqemail =~ /^[^\@]+\@[^\@]+$/) {
+                        my %srch = (srchby     => 'email',
+                                    srchdomain => $defdom,
+                                    srchterm   => $reqemail,
+                                    srchtype   => 'exact');
+                        my %srch_results = &Apache::lonnet::usersearch(\%srch);
+                        foreach my $uname (keys(%srch_results)) {
+                            if (ref($srch_results{$uname}{'inststatus'}) eq 'ARRAY') {
+                                $inststatus = join(',',@{$srch_results{$uname}{'inststatus'}});
+                                $inststatus_checked = 1;
+                                last;
+                            }
+                        }
+                        unless ($inststatus_checked) {
+                            my ($dirsrchres,%srch_results) = &Apache::lonnet::inst_directory_query(\%srch);
+                            if ($dirsrchres eq 'ok') {
+                                foreach my $uname (keys(%srch_results)) {
+                                    if (ref($srch_results{$uname}{'inststatus'}) eq 'ARRAY') {
+                                        $inststatus = join(',',@{$srch_results{$uname}{'inststatus'}});
+                                        $inststatus_checked = 1;
+                                        last;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+                if ($inststatus ne '') {
+                    foreach my $status (split(/\:/,$inststatus)) {
+                        if (ref($domconfig{'contacts'}{'overrides'}{$status}) eq 'HASH') {
+                            my @contacts = ('adminemail','supportemail');
+                            foreach my $item (@contacts) {
+                                if ($domconfig{'contacts'}{'overrides'}{$status}{$item}) {
+                                    my $addr = $domconfig{'contacts'}{'overrides'}{$status};
+                                    if (!grep(/^\Q$addr\E$/,@recipients)) {
+                                        push(@recipients,$addr);
+                                    }
+                                }
+                            }
+                            $otheremails = $domconfig{'contacts'}{'overrides'}{$status}{'others'};
+                            if ($domconfig{'contacts'}{'overrides'}{$status}{'bcc'}) {
+                                my @bccs = split(/,/,$domconfig{'contacts'}{'overrides'}{$status}{'bcc'});
+                                my @ok_bccs;
+                                foreach my $bcc (@bccs) {
+                                    $bcc =~ s/^\s+//g;
+                                    $bcc =~ s/\s+$//g;
+                                    if ($bcc =~ m/^[^\@]+\@[^\@]+$/) {
+                                        if (!(grep(/^\Q$bcc\E$/,@ok_bccs))) {
+                                            push(@ok_bccs,$bcc);
+                                        }
+                                    }
+                                }
+                                if (@ok_bccs > 0) {
+                                    $allbcc = join(', ',@ok_bccs);
+                                }
+                            }
+                            $addtext = $domconfig{'contacts'}{'overrides'}{$status}{'include'};
+                            last;
+                        }
+                    }
+                }
+            }
+        }
     } elsif ($origmail ne '') {
         $lastresort = $origmail;
     }
-
     if (($mailing eq 'helpdeskmail') && ($lastresort ne '')) {
         unless (grep(/^\Q$defdom\E$/,&Apache::lonnet::current_machine_domains())) {
             my $lonhost = $Apache::lonnet::perlvar{'lonHostID'};
@@ -15512,7 +15732,23 @@ sub init_user_environment {
 	    opendir(DIR,$lonids);
 	    while ($filename=readdir(DIR)) {
 		if ($filename=~/^$username\_\d+\_$domain\_$authhost\.id$/) {
-		    unlink($lonids.'/'.$filename);
+                    if (tie(my %oldenv,'GDBM_File',"$lonids/$filename",
+                            &GDBM_READER(),0640)) {
+                        my $linkedfile;
+                        if (exists($oldenv{'user.linkedenv'})) {
+                            $linkedfile = $oldenv{'user.linkedenv'};
+                        }
+                        untie(%oldenv);
+                        if (unlink("$lonids/$filename")) {
+                            if ($linkedfile =~ /^[a-f0-9]+_linked$/) {
+                                if (-l "$lonids/$linkedfile.id") {
+                                    unlink("$lonids/$linkedfile.id");
+                                }
+                            }
+                        }
+                    } else {
+                        unlink($lonids.'/'.$filename);
+                    }
 		}
 	    }
 	    closedir(DIR);
@@ -16645,10 +16881,10 @@ sub symb_to_docspath {
 }
 
 sub captcha_display {
-    my ($context,$lonhost) = @_;
+    my ($context,$lonhost,$defdom) = @_;
     my ($output,$error);
     my ($captcha,$pubkey,$privkey,$version) =
-        &get_captcha_config($context,$lonhost);
+        &get_captcha_config($context,$lonhost,$defdom);
     if ($captcha eq 'original') {
         $output = &create_captcha();
         unless ($output) {
@@ -16664,9 +16900,9 @@ sub captcha_display {
 }
 
 sub captcha_response {
-    my ($context,$lonhost) = @_;
+    my ($context,$lonhost,$defdom) = @_;
     my ($captcha_chk,$captcha_error);
-    my ($captcha,$pubkey,$privkey,$version) = &get_captcha_config($context,$lonhost);
+    my ($captcha,$pubkey,$privkey,$version) = &get_captcha_config($context,$lonhost,$defdom);
     if ($captcha eq 'original') {
         ($captcha_chk,$captcha_error) = &check_captcha();
     } elsif ($captcha eq 'recaptcha') {
@@ -16678,7 +16914,7 @@ sub captcha_response {
 }
 
 sub get_captcha_config {
-    my ($context,$lonhost) = @_;
+    my ($context,$lonhost,$dom_in_effect) = @_;
     my ($captcha,$pubkey,$privkey,$version,$hashtocheck);
     my $hostname = &Apache::lonnet::hostname($lonhost);
     my $serverhomeID = &Apache::lonnet::get_server_homeID($hostname);
@@ -16726,6 +16962,27 @@ sub get_captcha_config {
         } elsif ($domconfhash{$serverhomedom.'.login.captcha'} eq 'original') {
             $captcha = 'original';
         }
+    } elsif ($context eq 'passwords') {
+        if ($dom_in_effect) {
+            my %passwdconf = &Apache::lonnet::get_passwdconf($dom_in_effect);
+            if ($passwdconf{'captcha'} eq 'recaptcha') {
+                if (ref($passwdconf{'recaptchakeys'}) eq 'HASH') {
+                    $pubkey = $passwdconf{'recaptchakeys'}{'public'};
+                    $privkey = $passwdconf{'recaptchakeys'}{'private'};
+                }
+                if ($privkey && $pubkey) {
+                    $captcha = 'recaptcha';
+                    $version = $passwdconf{'recaptchaversion'};
+                    if ($version ne '2') {
+                        $version = 1;
+                    }
+                } else {
+                    $captcha = 'original';
+                }
+            } elsif ($passwdconf{'captcha'} ne 'notused') {
+                $captcha = 'original';
+            }
+        }
     }
     return ($captcha,$pubkey,$privkey,$version);
 }
@@ -16945,6 +17202,284 @@ sub des_decrypt {
     return $plaintext;
 }
 
+sub make_short_symbs {
+    my ($cdom,$cnum,$navmap) = @_;
+    return unless (ref($navmap));
+    my ($numnew,@errors);
+    my @toshorten = &Apache::loncommon::get_env_multiple('form.addtiny');
+    if (@toshorten) {
+        my (%maps,%resources,%titles);
+        &Apache::loncourserespicker::enumerate_course_contents($navmap,\%maps,\%resources,\%titles,
+                                                               'shorturls',$cdom,$cnum);
+        my %tocreate;
+        if (keys(%resources)) {
+            foreach my $item (sort {$a <=> $b} (@toshorten)) {
+                my $symb = $resources{$item};
+                if ($symb) {
+                    $tocreate{$cnum.'&'.$symb} = 1;
+                }
+            }
+        }
+        if (keys(%tocreate)) {
+            my %coursetiny = &Apache::lonnet::dump('tiny',$cdom,$cnum);
+            my $su = Short::URL->new(no_vowels => 1);
+            my $init = '';
+            my (%newunique,%addcourse,%courseonly,%failed);
+            # get lock on tiny db
+            my $now = time;
+            my $lockhash = {
+                                "lock\0$now" => $env{'user.name'}.
+                                                ':'.$env{'user.domain'},
+                            };
+            my $tries = 0;
+            my $gotlock = &Apache::lonnet::newput_dom('tiny',$lockhash,$cdom);
+            my ($code,$error);
+            while (($gotlock ne 'ok') && ($tries<3)) {
+                $tries ++;
+                sleep 1;
+                $gotlock = &Apache::lonnet::newput_dom('tiny',$lockhash,$cdom);
+            }
+            if ($gotlock eq 'ok') {
+                $init = &shorten_symbs($cdom,$init,$su,\%coursetiny,\%tocreate,\%newunique,
+                                       \%addcourse,\%courseonly,\%failed);
+                if (keys(%failed)) {
+                    my $numfailed = scalar(keys(%failed));
+                    push(@errors,&mt('error: could not obtain unique six character URL for [quant,_1,resource]',$numfailed));
+                }
+                if (keys(%newunique)) {
+                    my $putres = &Apache::lonnet::newput_dom('tiny',\%newunique,$cdom);
+                    if ($putres eq 'ok') {
+                        $numnew = scalar(keys(%newunique));
+                        my $newputres = &Apache::lonnet::newput('tiny',\%addcourse,$cdom,$cnum);
+                        unless ($newputres eq 'ok') {
+                            push(@errors,&mt('error: could not store course look-up of short URLs'));
+                        }
+                    } else {
+                        push(@errors,&mt('error: could not store unique six character URLs'));
+                    }
+                }
+            }
+        }
+    }
+    return ($numnew,\@errors);
+}
+
+sub shorten_symbs {
+    my ($cdom,$init,$su,$coursetiny,$tocreate,$newunique,$addcourse,$courseonly,$failed) = @_;
+    return unless ((ref($su)) && (ref($coursetiny) eq 'HASH') && (ref($tocreate) eq 'HASH') &&
+                   (ref($newunique) eq 'HASH') && (ref($addcourse) eq 'HASH') &&
+                   (ref($courseonly) eq 'HASH') && (ref($failed) eq 'HASH'));
+    my (%possibles,%collisions);
+    foreach my $key (keys(%{$tocreate})) {
+        my $num = String::CRC32::crc32($key);
+        my $tiny = $su->encode($num,$init);
+        if ($tiny) {
+            $possibles{$tiny} = $key;
+        }
+    }
+    if (!$init) {
+        $init = 1;
+    } else {
+        $init ++;
+    }
+    if (keys(%possibles)) {
+        my @posstiny = keys(%possibles);
+        my $configuname = &Apache::lonnet::get_domainconfiguser($cdom);
+        my %currtiny = &Apache::lonnet::get('tiny',\@posstiny,$cdom,$configuname);
+        if (keys(%currtiny)) {
+            foreach my $key (keys(%currtiny)) {
+                next if ($currtiny{$key} eq '');
+                if ($currtiny{$key} eq $possibles{$key}) {
+                    my ($tcnum,$tsymb) = split(/\&/,$currtiny{$key});
+                    unless (($coursetiny->{$tsymb} eq $key) || ($addcourse->{$tsymb} eq $key) || ($courseonly->{$tsymb} eq $key)) {
+                        $courseonly->{$tsymb} = $key;
+                    }
+                } else {
+                    $collisions{$possibles{$key}} = 1;
+                }
+                delete($possibles{$key});
+            }
+        }
+        foreach my $key (keys(%possibles)) {
+            $newunique->{$key} = $possibles{$key};
+            my ($tcnum,$tsymb) = split(/\&/,$possibles{$key});
+            unless (($coursetiny->{$tsymb} eq $key) || ($addcourse->{$tsymb} eq $key) || ($courseonly->{$tsymb} eq $key)) {
+                $addcourse->{$tsymb} = $key;
+            }
+        }
+    }
+    if (keys(%collisions)) {
+        if ($init <5) {
+            if (!$init) {
+                $init = 1;
+            } else {
+                $init ++;
+            }
+            $init = &shorten_symbs($cdom,$init,$su,$coursetiny,\%collisions,
+                                   $newunique,$addcourse,$courseonly,$failed);
+        } else {
+            foreach my $key (keys(%collisions)) {
+                $failed->{$key} = 1;
+                $failed->{$key} = 1;
+            }
+        }
+    }
+    return $init;
+}
+
+sub is_nonframeable {
+    my ($url,$absolute,$hostname,$ip,$nocache) = @_;
+    my ($remprotocol,$remhost) = ($url =~ m{^(https?)\://(([a-z0-9]+(-[a-z0-9]+)*\.)+[a-z]{2,})}i);
+    return if (($remprotocol eq '') || ($remhost eq ''));
+
+    $remprotocol = lc($remprotocol);
+    $remhost = lc($remhost);
+    my $remport = 80;
+    if ($remprotocol eq 'https') {
+        $remport = 443;
+    }
+    my ($result,$cached) = &Apache::lonnet::is_cached_new('noiframe',$remhost.':'.$remport);
+    if ($cached) {
+        unless ($nocache) {
+            if ($result) {
+                return 1;
+            } else {
+                return 0;
+            }
+        }
+    }
+    my $uselink;
+    my $request = new HTTP::Request('HEAD',$url);
+    my $ua = LWP::UserAgent->new;
+    $ua->timeout(5);
+    my $response=$ua->request($request);
+    if ($response->is_success()) {
+        my $secpolicy = lc($response->header('content-security-policy'));
+        my $xframeop = lc($response->header('x-frame-options'));
+        $secpolicy =~ s/^\s+|\s+$//g;
+        $xframeop =~ s/^\s+|\s+$//g;
+        if (($secpolicy ne '') || ($xframeop ne '')) {
+            my $remotehost = $remprotocol.'://'.$remhost;
+            my ($origin,$protocol,$port);
+            if ($ENV{'SERVER_PORT'} =~/^\d+$/) {
+                $port = $ENV{'SERVER_PORT'};
+            } else {
+                $port = 80;
+            }
+            if ($absolute eq '') {
+                $protocol = 'http:';
+                if ($port == 443) {
+                    $protocol = 'https:';
+                }
+                $origin = $protocol.'//'.lc($hostname);
+            } else {
+                $origin = lc($absolute);
+                ($protocol,$hostname) = ($absolute =~ m{^(https?:)//([^/]+)$});
+            }
+            if (($secpolicy) && ($secpolicy =~ /\Qframe-ancestors\E([^;]*)(;|$)/)) {
+                my $framepolicy = $1;
+                $framepolicy =~ s/^\s+|\s+$//g;
+                my @policies = split(/\s+/,$framepolicy);
+                if (@policies) {
+                    if (grep(/^\Q'none'\E$/,@policies)) {
+                        $uselink = 1;
+                    } else {
+                        $uselink = 1;
+                        if ((grep(/^\Q*\E$/,@policies)) || (grep(/^\Q$protocol\E$/,@policies)) ||
+                                (($origin ne '') && (grep(/^\Q$origin\E$/,@policies))) ||
+                                (($ip ne '') && (grep(/^\Q$ip\E$/,@policies)))) {
+                            undef($uselink);
+                        }
+                        if ($uselink) {
+                            if (grep(/^\Q'self'\E$/,@policies)) {
+                                if (($origin ne '') && ($remotehost eq $origin)) {
+                                    undef($uselink);
+                                }
+                            }
+                        }
+                        if ($uselink) {
+                            my @possok;
+                            if ($ip ne '') {
+                                push(@possok,$ip);
+                            }
+                            my $hoststr = '';
+                            foreach my $part (reverse(split(/\./,$hostname))) {
+                                if ($hoststr eq '') {
+                                    $hoststr = $part;
+                                } else {
+                                    $hoststr = "$part.$hoststr";
+                                }
+                                if ($hoststr eq $hostname) {
+                                    push(@possok,$hostname);
+                                } else {
+                                    push(@possok,"*.$hoststr");
+                                }
+                            }
+                            if (@possok) {
+                                foreach my $poss (@possok) {
+                                    last if (!$uselink);
+                                    foreach my $policy (@policies) {
+                                        if ($policy =~ m{^(\Q$protocol\E//|)\Q$poss\E(\Q:$port\E|)$}) {
+                                            undef($uselink);
+                                            last;
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            } elsif ($xframeop ne '') {
+                $uselink = 1;
+                my @policies = split(/\s*,\s*/,$xframeop);
+                if (@policies) {
+                    unless (grep(/^deny$/,@policies)) {
+                        if ($origin ne '') {
+                            if (grep(/^sameorigin$/,@policies)) {
+                                if ($remotehost eq $origin) {
+                                    undef($uselink);
+                                }
+                            }
+                            if ($uselink) {
+                                foreach my $policy (@policies) {
+                                    if ($policy =~ /^allow-from\s*(.+)$/) {
+                                        my $allowfrom = $1;
+                                        if (($allowfrom ne '') && ($allowfrom eq $origin)) {
+                                            undef($uselink);
+                                            last;
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+    if ($nocache) {
+        if ($cached) {
+            my $devalidate;
+            if ($uselink && !$result) {
+                $devalidate = 1;
+            } elsif (!$uselink && $result) {
+                $devalidate = 1;
+            }
+            if ($devalidate) {
+                &Apache::lonnet::devalidate_cache_new('noiframe',$remhost.':'.$remport);
+            }
+        }
+    } else {
+        if ($uselink) {
+            $result = 1;
+        } else {
+            $result = 0;
+        }
+        &Apache::lonnet::do_cache_new('noiframe',$remhost.':'.$remport,$result,3600);
+    }
+    return $uselink;
+}
+
 1;
 __END__;