libcryptx-perl/lib/Crypt/Checksum/CRC32.pm
2018-03-22 15:54:03 +01:00

195 lines
4.4 KiB
Perl

package Crypt::Checksum::CRC32;
use strict;
use warnings;
our $VERSION = '0.058_002';
use base qw(Crypt::Checksum Exporter);
our %EXPORT_TAGS = ( all => [qw( crc32_data crc32_data_hex crc32_data_int crc32_file crc32_file_hex crc32_file_int )] );
our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );
our @EXPORT = qw();
use Carp;
$Carp::Internal{(__PACKAGE__)}++;
use CryptX;
sub crc32_file { local $SIG{__DIE__} = \&CryptX::_croak; Crypt::Checksum::CRC32->new->addfile(@_)->digest }
sub crc32_file_hex { local $SIG{__DIE__} = \&CryptX::_croak; Crypt::Checksum::CRC32->new->addfile(@_)->hexdigest }
sub crc32_file_int { local $SIG{__DIE__} = \&CryptX::_croak; Crypt::Checksum::CRC32->new->addfile(@_)->intdigest }
1;
=pod
=head1 NAME
Crypt::Checksum::CRC32 - Compute CRC32 checksum
=head1 SYNOPSIS
### Functional interface:
use Crypt::Checksum::CRC32 ':all';
# calculate CRC32 checksum from string/buffer
$checksum_raw = crc32_data($data);
$checksum_hex = crc32_data_hex($data);
$checksum_int = crc32_data_int($data);
# calculate CRC32 checksum from file
$checksum_raw = crc32_file('filename.dat');
$checksum_hex = crc32_file_hex('filename.dat');
$checksum_int = crc32_file_int('filename.dat');
# calculate CRC32 checksum from filehandle
$checksum_raw = crc32_file(*FILEHANDLE);
$checksum_hex = crc32_file_hex(*FILEHANDLE);
$checksum_int = crc32_file_int(*FILEHANDLE);
### OO interface:
use Crypt::Checksum::CRC32;
$d = Crypt::Checksum::CRC32->new;
$d->add('any data');
$d->add('another data');
$d->addfile('filename.dat');
$d->addfile(*FILEHANDLE);
$checksum_raw = $d->digest; # raw 4 bytes
$checksum_hex = $d->hexdigest; # hexadecimal form
$checksum_int = $d->intdigest; # 32bit unsigned integer
=head1 DESCRIPTION
Calculating CRC32 checksums.
I<Updated: v0.057>
=head1 EXPORT
Nothing is exported by default.
You can export selected functions:
use Crypt::Checksum::CRC32 qw(crc32_data crc32_data_hex crc32_data_int crc32_file crc32_file_hex crc32_file_int);
Or all of them at once:
use Crypt::Checksum::CRC32 ':all';
=head1 FUNCTIONS
=head2 crc32_data
Returns checksum as raw octects.
$checksum_raw = crc32_data('data string');
#or
$checksum_raw = crc32_data('any data', 'more data', 'even more data');
=head2 crc32_data_hex
Returns checksum as a hexadecimal string.
$checksum_hex = crc32_data_hex('data string');
#or
$checksum_hex = crc32_data_hex('any data', 'more data', 'even more data');
=head2 crc32_data_int
Returns checksum as unsigned 32bit integer.
$checksum_int = crc32_data_int('data string');
#or
$checksum_int = crc32_data_int('any data', 'more data', 'even more data');
=head2 crc32_file
Returns checksum as raw octects.
$checksum_raw = crc32_file('filename.dat');
#or
$checksum_raw = crc32_file(*FILEHANDLE);
=head2 crc32_file_hex
Returns checksum as a hexadecimal string.
$checksum_hex = crc32_file_hex('filename.dat');
#or
$checksum_hex = crc32_file_hex(*FILEHANDLE);
=head2 crc32_file_int
Returns checksum as unsigned 32bit integer.
$checksum_int = crc32_file_int('filename.dat');
#or
$checksum_int = crc32_file_int(*FILEHANDLE);
=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();
=head2 intdigest
Returns the checksum encoded as unsigned 32bit integer.
$result_int = $d->intdigest();
=head1 SEE ALSO
=over
=item * L<CryptX|CryptX>
=item * L<https://en.wikipedia.org/wiki/Cyclic_redundancy_check>
=back
=cut