View of /trunk/webwork-modperl/lib/WeBWorK/Upload.pm

    1 # This package allows a file to be reliably cached on disk and replaced with
    2 # a string that universally and unforgeably represents that file, and then
    3 # retrieved later given that string.
    4 
    5 package WeBWorK::SecureUpload;
    6 
    7 # Everything we need to be confident about the upload
    8 use WeBWorK::Constants qw(SECRET);
    9 use MD5 ();
   10 use Data::UUID;
   11 
   12 
   13 sub store_upload {}
   14 
   15 sub retrieve_upload {}
   16 
   17 sub new {
   18   unless (SECRET) {
   19     die "A secret has not been set in WeBWorK::Constants for this server.";
   20   }
   21   my $invocant = shift;
   22   my $class = ref($invocant) || invocant;
   23   my $self = {
   24     basedir => shift; # The directory into which to place the spool file
   25     uploadObject => shift;  # The Apache::Upload object to deal with
   26   };
   27 
   28   my $ug = Data::UUID->new;   # UUID Generator/Handler
   29   my $uuid = $ug->generate; # Unique identifier for this file, guaranteed to be unique until 3400AD
   30   my $uuid_as_string = $ug->to_string($uuid);
   31   my $mac = MD5->hexhash(SECRET . MD5->hexhash(SECRET . $uuid_as_string); # Message Authentication Check. As long as SECRET stays secret,
   32 
   33 
   34   $self->{
   35   $self->{MAC} = MD5->hexhash(SECRET . MD4->hexhash(SECRET . $self{UUID}->  # Message Authentication Check - An unforgeable checksum
   36   };
   37 }
   38 
   39 1;