=head1 NAME
Tiger - Perl interface to the Tiger Hash Algorithm
=head1 SYNOPSIS
$context
= new Tiger;
$context
->
reset
();
$context
->add(LIST);
$context
->addfile(HANDLE);
$digest
=
$context
->digest();
$string
=
$context
->hexdigest();
$digest
=
$context
->hash(
$string
);
$string
=
$context
->hexhash(
$string
);
=head1 DESCRIPTION
The B<Tiger> module allows you to
use
the Tiger hash algorithm
developed by Ross Anderson and Eli Biham in Perl programs.
A new Tiger context object is created
with
the B<new> operation.
Multiple simultaneous digest context can be maintained
if
desired.
The context is updated
with
the B<add> operation which adds the
strings contained in the I<LIST> parameter.
The final message digest value is returned by the B<digest> operation
as a 24-byte binary string. This operation delivers the result of
operations since the
last
B<new> or B<
reset
> operation. Once the
operation
has
been performed, the context must be B<
reset
>
before
being used to calculate another digest value.
Several convenience functions are also provided. The B<addfile>
operation takes an
open
file-handle and reads it
until
end-of file in
8192-byte blocks adding the contents to the context. The B<hexdigest>
operation calls B<digest> and returns the result as a printable string
of hexadecimal digits in eight-digit groups. The B<hash> operation
performs the complete series of steps: B<
reset
>, B<add>, B<digest> on
the supplied
scalar
value, and returns the result as a 24-byte binary
string. The B<hexhash> operation does the same thing, but returns the
result in the
format
of the B<hexdigest> operation.
=head1 NOTE
The Tiger extension may be redistributed either under the GPL or the
Perl Artistic License. The Tiger code
has
been appropriated from the
GNU Privacy Guard, and slightly modified to interface
with
Perl.
=head1 AUTHOR
The Tiger interface was written by Rafael Sevilla
(C<dido
@pacific
.net.ph>), shamelessly stealing from the SHA interface
written by Uwe Hollerbach (C<uh
@alumni
.caltech.edu>).
For more information on Tiger see: