121 lines
2.3 KiB
Perl
121 lines
2.3 KiB
Perl
package Crypt::Checksum::CRC32;
|
|
|
|
use strict;
|
|
use warnings;
|
|
our $VERSION = '0.048';
|
|
use Carp;
|
|
use CryptX;
|
|
|
|
sub addfile {
|
|
my ($self, $file) = @_;
|
|
|
|
my $handle;
|
|
if (ref(\$file) eq 'SCALAR') { #filename
|
|
open($handle, "<", $file) || croak "FATAL: cannot open '$file': $!";
|
|
binmode($handle);
|
|
}
|
|
else { #handle
|
|
$handle = $file
|
|
}
|
|
croak "FATAL: invalid handle" unless defined $handle;
|
|
|
|
my $n;
|
|
my $buf = "";
|
|
while (($n = read($handle, $buf, 32*1024))) {
|
|
$self->add($buf)
|
|
}
|
|
croak "FATAL: read failed: $!" unless defined $n;
|
|
|
|
return $self;
|
|
}
|
|
|
|
sub CLONE_SKIP { 1 } # prevent cloning
|
|
|
|
1;
|
|
|
|
=pod
|
|
|
|
=head1 NAME
|
|
|
|
Crypt::Checksum::CRC32 - Compute CRC32 checksum
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
use Crypt::Checksum::CRC32;
|
|
|
|
$d = Crypt::Checksum::CRC32->new;
|
|
$d->add('any data');
|
|
$d->addfile('filename.dat');
|
|
$d->addfile(*FILEHANDLE);
|
|
$checksum_raw = $d->digest; # raw bytes
|
|
$checksum_hex = $d->hexdigest; # hexadecimal form
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
Calculating CRC32 checksums (OO interface);
|
|
|
|
I<Since: CryptX-0.032>
|
|
|
|
=head1 METHODS
|
|
|
|
=head2 new
|
|
|
|
Constructor, returns a reference to the checksum object.
|
|
|
|
$d = Crypt::Checksum::CRC32->new;
|
|
|
|
=head2 clone
|
|
|
|
Creates a copy of the checksum object state and returns a reference to the copy.
|
|
|
|
$d->clone();
|
|
|
|
=head2 reset
|
|
|
|
Reinitialize the checksum object state and returns a reference to the checksum object.
|
|
|
|
$d->reset();
|
|
|
|
=head2 add
|
|
|
|
All arguments are appended to the message we calculate checksum for.
|
|
The return value is the checksum object itself.
|
|
|
|
$d->add('any data');
|
|
#or
|
|
$d->add('any data', 'more data', 'even more data');
|
|
|
|
=head2 addfile
|
|
|
|
The content of the file (or filehandle) is appended to the message we calculate checksum for.
|
|
The return value is the checksum object itself.
|
|
|
|
$d->addfile('filename.dat');
|
|
#or
|
|
$d->addfile(*FILEHANDLE);
|
|
|
|
B<BEWARE:> You have to make sure that the filehandle is in binary mode before you pass it as argument to the addfile() method.
|
|
|
|
=head2 digest
|
|
|
|
Returns the binary checksum (raw bytes).
|
|
|
|
$result_raw = $d->digest();
|
|
|
|
=head2 hexdigest
|
|
|
|
Returns the checksum encoded as a hexadecimal string.
|
|
|
|
$result_hex = $d->hexdigest();
|
|
|
|
=head1 SEE ALSO
|
|
|
|
=over
|
|
|
|
=item * L<CryptX|CryptX>, L<Crypt::Checksum>
|
|
|
|
=item * L<https://en.wikipedia.org/wiki/Cyclic_redundancy_check>
|
|
|
|
=back
|
|
|
|
=cut |