--- loncom/lonenc.pm	2006/05/30 19:47:28	1.16
+++ loncom/lonenc.pm	2006/12/27 17:11:08	1.20
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # URL translation for encrypted filenames
 #
-# $Id: lonenc.pm,v 1.16 2006/05/30 19:47:28 www Exp $
+# $Id: lonenc.pm,v 1.20 2006/12/27 17:11:08 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -35,18 +35,38 @@ use Time::HiRes qw(gettimeofday);
 use LONCAPA;
  
 sub encryptseed {
-    my $seed=$env{'course.'.$env{'request.course.id'}.'.internal.encseed'};
-    $seed=~s/[^0-9a-f]/0/g;
-    $seed.='0123456789abcdef';
-    $seed=substr($seed.$seed,0,32);
-    return pack("H32",$seed);
+    my ($cid) = @_;
+    if (!defined($cid)) {
+        $cid = $env{'request.course.id'};
+    }
+    my $seed;
+    if (defined($cid)) {
+        if (defined$env{'course.'.$cid.'.internal.encseed'}) {
+            $seed = $env{'course.'.$cid.'.internal.encseed'};
+        } else {
+            my %descargs = ( 'one_time' => 1);
+            my %course = 
+               &Apache::lonnet::coursedescription($cid,\%descargs);
+            $seed = $course{'internal.encseed'};
+        }
+    }
+    if (defined($seed)) {
+        $seed=~s/[^0-9a-f]/0/g;
+        $seed.='0123456789abcdef';
+        $seed=substr($seed.$seed,0,32);
+        return pack("H32",$seed);
+    } else {
+        return;
+    }
 }
 
 sub unencrypted {
-    my $uri=shift;
+    my ($uri,$cid) = @_;
     $uri=~s/^\/enc\/(\d+)\///;
     my $cmdlength=$1;
-    my $seed=&encryptseed();
+    # strip any added extension
+    $uri=~s/\.[^.]*//;
+    my $seed=&encryptseed($cid);
     unless ($seed) {
 	return '/'.$uri;
     }
@@ -107,7 +127,12 @@ sub encrypted {
 
 sub check_encrypt {
     my $str=shift;
-    if ($env{'request.enc'}) { return &Apache::lonenc::encrypted($str); }
+    if (ref($str)) {
+        if ($env{'request.enc'}) { $$str = &Apache::lonenc::encrypted($$str); }
+        return;
+    } else {
+        if ($env{'request.enc'}) { return &Apache::lonenc::encrypted($str); }
+    }
     return $str;
 }
 
@@ -129,7 +154,10 @@ sub encrypt_ref {
 	    if (!$value) { next; }
 	    my $href=&Apache::lonnet::hreflocation($Apache::lonxml::pwd[-1],$value);
 	    if ($href !~ /^http:/) {
+		# IE really wants an extension
+		my ($extension) = ($href =~ m/(\.[^.]*)$/);
 		$href = &Apache::lonenc::encrypted($href,$force_enc);
+		$href .= $extension;
 	    }
 	    $token->[2]->{$name}=$href;
 	}