Crypt::Mode::CTR(3) | User Contributed Perl Documentation | Crypt::Mode::CTR(3) |
NAME
Crypt::Mode::CTR - Block cipher mode CTR [Counter mode]
SYNOPSIS
use Crypt::Mode::CTR; my $m = Crypt::Mode::CTR->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'); #decrypt more chunks $m->start_decrypt($key, $iv); my $plaintext = $m->add($some_ciphertext); $plaintext .= $m->add($more_ciphertext);
DESCRIPTION
This module implements CTR cipher mode. NOTE: it works only with ciphers from CryptX (Crypt::Cipher::NNNN).
METHODS
new
my $m = Crypt::Mode::CTR->new($cipher_name); #or my $m = Crypt::Mode::CTR->new($cipher_name, $ctr_mode, $ctr_width); #or my $m = Crypt::Mode::CTR->new($cipher_name, $ctr_mode, $ctr_width, $cipher_rounds); # $cipher_name .. one of 'AES', 'Anubis', 'Blowfish', 'CAST5', 'Camellia', 'DES', 'DES_EDE', # 'KASUMI', 'Khazad', 'MULTI2', 'Noekeon', 'RC2', 'RC5', 'RC6', # 'SAFERP', 'SAFER_K128', 'SAFER_K64', 'SAFER_SK128', 'SAFER_SK64', # 'SEED', 'Skipjack', 'Twofish', 'XTEA', 'IDEA', 'Serpent' # simply any <NAME> for which there exists Crypt::Cipher::<NAME> # $ctr_mode ..... 0 little-endian counter (DEFAULT) # 1 big-endian counter # 2 little-endian + RFC3686 incrementing # 3 big-endian + RFC3686 incrementing # $ctr_width .... counter width in bytes (DEFAULT = full block width) # $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
$m->start_encrypt($key, $iv);
start_decrypt
$m->start_decrypt($key, $iv);
add
# in encrypt mode my $plaintext = $m->add($ciphertext); # in decrypt mode my $ciphertext = $m->add($plaintext);
SEE ALSO
- CryptX, Crypt::Cipher
- Crypt::Cipher::AES, Crypt::Cipher::Blowfish, ...
- https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Counter_.28CTR.29
2024-10-20 | perl v5.40.0 |