1: # The LearningOnline Network
2: # URL translation for encrypted filenames
3: #
4: # $Id: lonenc.pm,v 1.6 2004/11/14 07:54:41 albertel Exp $
5: #
6: # Copyright Michigan State University Board of Trustees
7: #
8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
9: #
10: # LON-CAPA is free software; you can redistribute it and/or modify
11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
28:
29: package Apache::lonenc;
30:
31: use strict;
32: use Apache::Constants qw(:common :remotehost);
33: use Apache::lonnet();
34: use Apache::File();
35: use Apache::loncommon;
36: use Crypt::IDEA;
37:
38: sub handler {
39: my $r = shift;
40: my %cookies=CGI::Cookie->parse($r->header_in('Cookie'));
41: my $lonid=$cookies{'lonID'};
42: my $cookie;
43: if ($lonid) {
44: my $handle=$lonid->value;
45: $handle=~s/\W//g;
46: my $lonidsdir=$r->dir_config('lonIDsDir');
47: $ENV{'request.enc'}=1;
48: if ((-e "$lonidsdir/$handle.id") && ($handle ne '')) {
49: # Initialize Environment
50: &Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle);
51: # Decrypt URL and redirect
52: &Apache::lonnet::logthis("args ".$r->args);
53: &Apache::lonnet::logthis("uri ".$r->uri);
54: $r->internal_redirect(&unencrypted($r->uri).'?'.$r->args);
55: return OK;
56: }
57: }
58: return FORBIDDEN;
59: }
60:
61: sub encryptseed {
62: my $seed=$ENV{'course.'.$ENV{'request.course.id'}.'.internal.encseed'};
63: $seed=~s/[^0-9a-f]/0/g;
64: $seed.='0123456789abcdef';
65: $seed=substr($seed.$seed,0,32);
66: return pack("H32",$seed);
67: }
68:
69: sub unencrypted {
70: my $uri=shift;
71: $uri=~s/^\/enc\/(\d+)\///;
72: my $cmdlength=$1;
73: my $seed=&encryptseed();
74: unless ($seed) {
75: return '/'.$uri;
76: }
77: $uri=&Apache::lonnet::unescape($uri);
78: my $cipher=new IDEA $seed;
79: my $decuri='';
80: for (my $encidx=0;$encidx<length($uri);$encidx+=16) {
81: $decuri.=$cipher->decrypt(
82: pack("H16",substr($uri,$encidx,16))
83: );
84: }
85: $ENV{'request.enc'}=1;
86: return substr($decuri,0,$cmdlength);
87: }
88:
89: sub encrypted {
90: my $uri=shift;
91: if ($ENV{'request.role.adv'}) { return($uri); }
92: my $seed=&encryptseed();
93: unless ($seed) {
94: return $uri;
95: }
96: my $cmdlength=length($uri);
97: $uri.='00000000';
98: my $encuri='';
99: my $cipher=new IDEA $seed;
100: for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
101: $encuri.=unpack("H16",
102: $cipher->encrypt(substr($uri,$encidx,8)));
103: }
104: return '/enc/'.$cmdlength.'/'.&Apache::lonnet::escape($encuri);
105: }
106:
107: sub check_encrypt {
108: my $str=shift;
109: if ($ENV{'request.enc'}) { return &Apache::lonenc::encrypted($str); }
110: return $str;
111: }
112:
113: sub check_decrypt {
114: my ($str)=@_;
115: if ($$str=~m|^/enc/|) { $$str=&Apache::lonenc::unencrypted($$str); }
116: }
117:
118: 1;
119: __END__
120:
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