# The LearningOnline Network # URL translation for encrypted filenames # # $Id: lonenc.pm,v 1.4 2004/11/10 22:20:50 albertel Exp $ # # Copyright Michigan State University Board of Trustees # # This file is part of the LearningOnline Network with CAPA (LON-CAPA). # # LON-CAPA is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # LON-CAPA is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with LON-CAPA; if not, write to the Free Software # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA # # /home/httpd/html/adm/gpl.txt # # http://www.lon-capa.org/ # package Apache::lonenc; use strict; use Apache::Constants qw(:common :remotehost); use Apache::lonnet(); use Apache::File(); use Apache::loncommon; use Crypt::IDEA; sub handler { my $r = shift; my %cookies=CGI::Cookie->parse($r->header_in('Cookie')); my $lonid=$cookies{'lonID'}; my $cookie; if ($lonid) { my $handle=$lonid->value; $handle=~s/\W//g; my $lonidsdir=$r->dir_config('lonIDsDir'); $ENV{'request.enc'}=1; if ((-e "$lonidsdir/$handle.id") && ($handle ne '')) { # Initialize Environment &Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle); # Decrypt URL and redirect &Apache::lonnet::logthis("args ".$r->args); &Apache::lonnet::logthis("uri ".$r->uri); $r->internal_redirect(&unencrypted($r->uri).'?'.$r->args); return OK; } } return FORBIDDEN; } 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); } sub unencrypted { my $uri=shift; $uri=~s/^\/enc\/(\d+)\///; my $cmdlength=$1; my $seed=&encryptseed(); unless ($seed) { return '/'.$uri; } $uri=&Apache::lonnet::unescape($uri); my $cipher=new IDEA $seed; my $decuri=''; for (my $encidx=0;$encidxdecrypt( pack("H16",substr($uri,$encidx,16)) ); } return substr($decuri,0,$cmdlength); } sub encrypted { my $uri=shift; if ($ENV{'request.role.adv'}) { return($uri); } my $seed=&encryptseed(); unless ($seed) { return $uri; } my $cmdlength=length($uri); $uri.='00000000'; my $encuri=''; my $cipher=new IDEA $seed; for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) { $encuri.=unpack("H16", $cipher->encrypt(substr($uri,$encidx,8))); } return '/enc/'.$cmdlength.'/'.&Apache::lonnet::escape($encuri); } 1; __END__