Return to loncacc.pm CVS log

Up to [LON-CAPA] / loncom / auth

Remainder of fix for bug 262.  Do not allow editing of old versions of
resources in the construction space.

# The LearningOnline Network
# Cookie Based Access Handler for Construction Area
# (lonacc: 5/21/99,5/22,5/29,5/31 Gerd Kortemeyer)
#
# $Id: loncacc.pm,v 1.24 2002/12/10 20:37:21 matthew 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/
#
# YEAR=2000
# 6/15,16/11,22/11,
# YEAR=2001
# 01/06,01/11,6/1,9/25,9/28,11/22,12/25,12/26,
# 01/06/01,05/04,05/05,05/09 Gerd Kortemeyer
# 12/21 Scott Harrison
# YEAR=2002
# 1/4 Gerd Kortemeyer
###

package Apache::loncacc;

use strict;
use Apache::Constants qw(:common :http :methods);
use Apache::File;
use CGI::Cookie();
use Fcntl qw(:flock);

sub constructaccess {
    my ($url,$ownerdomain)=@_;
    my ($ownername)=($url=~/\/(?:\~|priv\/|home\/)(\w+)/);
    unless (($ownername) && ($ownerdomain)) { return ''; }
    # We do not allow editing of previous versions of files.
    if ($url=~/\.(\d+)\.(\w+)$/) { return ''; }
    if (($ownername eq $ENV{'user.name'}) &&
        ($ownerdomain eq $ENV{'user.domain'})) {
	return ($ownername,$ownerdomain);
    }

    my $capriv='user.priv.ca./'.
               $ownerdomain.'/'.$ownername.'./'.
	       $ownerdomain.'/'.$ownername;
    foreach (keys %ENV) {
        if ($_ eq $capriv) {
           return ($ownername,$ownerdomain);
        }
    }

    return '';
}

sub handler {
    my $r = shift;
    my $requrl=$r->uri;
    $ENV{'request.editurl'}=$requrl;
    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');
        if ((-e "$lonidsdir/$handle.id") && ($handle ne '')) {
            my @profile;
	    {
             my $idf=Apache::File->new("$lonidsdir/$handle.id");
             flock($idf,LOCK_SH);
             @profile=<$idf>;
             $idf->close();
	    }
            my $envi;
            for ($envi=0;$envi<=$#profile;$envi++) {
		chomp($profile[$envi]);
		my ($envname,$envvalue)=split(/=/,$profile[$envi]);
                $ENV{$envname} = $envvalue;
            }
            $ENV{'user.environment'} = "$lonidsdir/$handle.id";
            $ENV{'request.state'}    = "construct";
            $ENV{'request.filename'} = $r->filename;

            unless (&constructaccess($requrl,$r->dir_config('lonDefDomain'))) {
                $r->log_reason("Unauthorized $requrl", $r->filename); 
	        return HTTP_NOT_ACCEPTABLE;
            }

# -------------------------------------------------------- Load POST parameters


        my $buffer;

        $r->read($buffer,$r->header_in('Content-length'));

	unless ($buffer=~/^(\-+\w+)\s+Content\-Disposition\:\s*form\-data/si) {
            my @pairs=split(/&/,$buffer);
            my $pair;
            foreach $pair (@pairs) {
               my ($name,$value) = split(/=/,$pair);
               $value =~ tr/+/ /;
               $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
               $name  =~ tr/+/ /;
               $name  =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
	       &Apache::loncommon::add_to_env("form.$name",$value);
            } 
        } else {
	    my $contentsep=$1;
            my @lines = split (/\n/,$buffer);
            my $name='';
            my $value='';
            my $fname='';
            my $fmime='';
            my $i;
            for ($i=0;$i<=$#lines;$i++) {
		if ($lines[$i]=~/^$contentsep/) {
		    if ($name) {
                        chomp($value);
			if ($fname) {
			    $ENV{"form.$name.filename"}=$fname;
                            $ENV{"form.$name.mimetype"}=$fmime;
                        } else {
                            $value=~s/\s+$//s;
                        }
			&Apache::loncommon::add_to_env("form.$name",$value);
                    }
                    if ($i<$#lines) {
			$i++;
                        $lines[$i]=~
		 /Content\-Disposition\:\s*form\-data\;\s*name\=\"([^\"]+)\"/i;
                        $name=$1;
                        $value='';
                        if ($lines[$i]=~/filename\=\"([^\"]+)\"/i) {
			   $fname=$1;
                           if 
                            ($lines[$i+1]=~/Content\-Type\:\s*([\w\-\/]+)/i) {
			      $fmime=$1;
                              $i++;
			   } else {
                              $fmime='';
                           }
                        } else {
			    $fname='';
                            $fmime='';
                        }
                        $i++;
                    }
                } else {
		    $value.=$lines[$i]."\n";
                }
            }
	}
            $ENV{'request.method'}=$ENV{'REQUEST_METHOD'};
            $r->method_number(M_GET);
	    $r->method('GET');
            $r->headers_in->unset('Content-length');

            return OK; 
        } else { 
            $r->log_reason("Cookie $handle not valid", $r->filename) 
        };
    }

# ----------------------------------------------- Store where they wanted to go

    $ENV{'request.firsturl'}=$requrl;
    return FORBIDDEN;
}

1;
__END__

=head1 NAME

Apache::lonacc - Cookie Based Access Handler for Construction Area

=head1 SYNOPSIS

Invoked (for various locations) by /etc/httpd/conf/loncapa_apache.conf:

 PerlAccessHandler       Apache::loncacc

=head1 INTRODUCTION

This module enables cookie based authentication for construction area
and is used to control access for three (essentially equivalent) URIs.

 <LocationMatch "^/priv.*">
 <LocationMatch "^/\~.*">
 <LocationMatch "^/\~.*/$">

Whenever the client sends the cookie back to the server, 
if the cookie is missing or invalid, the user is re-challenged
for login information.

This is part of the LearningOnline Network with CAPA project
described at http://www.lon-capa.org.

=head1 HANDLER SUBROUTINE

This routine is called by Apache and mod_perl.

=over 4

=item *

load POST parameters

=item *

store where they wanted to go (first url entered)

=back

=head1 OTHERSUBROUTINES

=over 4

=item *

constructaccess($url,$ownerdomain) : See if the owner domain and name
in the URL match those in the expected environment.  If so, return 
two element list ($ownername,$ownerdomain).  Else, return null string.

=back

=cut