Sponsoring The Perl Toolchain Summit 2025: Help make this important event another success Learn more

 / 
CryptX-0.025_01
River stage three • 72 direct dependents • 284 total dependents
/ Crypt::Mode::CBC

NAME

Crypt::Mode::CBC - Block cipher mode CBC [Cipher-block chaining]

SYNOPSIS


            

              
              
use Crypt::Mode::CBC;
my $m = Crypt::Mode::CBC->new('AES');
#(en|de)crypt at once
my $ciphertext = $m->encrypt($plaintext, $key, $iv);
my $plaintext = $m->decrypt($ciphertext, $key, $iv);
#encrypt more chunks
$m->start_encrypt($key, $iv);
my $ciphertext = $m->add('some data');
$ciphertext .= $m->add('more data');
$ciphertext .= $m->finish;
#decrypt more chunks
$m->start_decrypt($key, $iv);
my $plaintext = $m->add($some_ciphertext);
$plaintext .= $m->add($more_ciphertext);
$plaintext .= $m->finish;

DESCRIPTION

This module implements CBC cipher mode. NOTE: it works only with ciphers from CryptX (Crypt::Cipher::NNNN).

METHODS

new


            

              
              
my $m = Crypt::Mode::CBC->new('AES');
#or
my $m = Crypt::Mode::CBC->new('AES', $padding);
#or
my $m = Crypt::Mode::CBC->new('AES', $padding, $cipher_rounds);
# $padding .... 0 no padding (plaintext size has to be myltiple of block length)
#               1 PKCS5 padding, Crypt::CBC's "standard" - DEFAULT
#               2 Crypt::CBC's "oneandzeroes"
# $cipher_rounds ... optional num of rounds for given cipher

encrypt


            

              
              
my $ciphertext = $m->encrypt($plaintext, $key, $iv);

decrypt


            

              
              
my $plaintext = $m->decrypt($ciphertext, $key, $iv);

start_encrypt

See example below "finish".

start_decrypt

See example below "finish".

add

See example below "finish".

finish


            

              
              
#encrypt more chunks
$m->start_encrypt($key, $iv);
my $ciphertext = '';
$ciphertext .= $m->add('some data');
$ciphertext .= $m->add('more data');
$ciphertext .= $m->finish;
#decrypt more chunks
$m->start_decrypt($key, $iv);
my $plaintext = '';
$plaintext .= $m->add($some_ciphertext);
$plaintext .= $m->add($more_ciphertext);
$plaintext .= $m->finish;

SEE ALSO