NAME
Signature - Generate cryptographic signatures for objects
SYNOPSIS
# In your module
package My::Module
use base 'Object::Signature';
# In outside code
my $Object = My::Module->new;
print "Object Signature: " . $Object->signature;
DESCRIPTION
Object::Signature is an abstract base class that you can inherit from in
order to allow your objects to generate unique cryptographic signatures.
The method used to generate the signature is based on Storable and
Digest::MD5. The object is fed to "Storable::nfreeze" to get a string,
which is then passed to Digest::MD5::md5_hex to get a unique 32
character hexidecimal signature.
METHODS
signature
The "signature" method is the only method added to your class, and will
generate a unique 32 hexidecimal signature for any object it is called
on.
SUPPORT
All bugs should be filed via the bug tracker at
<
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Object-Signature>
For other issues, or commercial enhancement or support, contact the
author.
TO DO
Incremental Generation
Currently has to generate the entire Storable string before digesting
it. Would be nice if there was a way to incrementally Storablise and
Digest in one pass so that it becomes much more memory efficient for
large objects.
Strengthen the Digest Algorithm
Once the current (as of 2005) hashing controversy settles down, consider
selecting a newer and more powerful hashing algorithm to replace MD5. Or
offer alternatives depending on how important the security situation is,
as MD5 is very fast (90 meg a second) and many more secure ones are a
lot slower (worse than 1/10th the speed in some cases).
On our side is the fact we use Storable. It should be much harder to
create collisions when you don't control the string, only the structure
before it goes through Storable.
AUTHORS
Adam Kennedy <
[email protected]>
COPYRIGHT
Copyright (c) 2004 - 2006 Adam Kennedy. All rights reserved. This
program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included
with this module.
