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CryptX-0.087_002
⭐ Starred 36 / Crypt::Cipher
Security Advisories (2)
CVE-2026-41564 (2026-04-23)

CryptX versions before 0.088 for Perl do not reseed the Crypt::PK PRNG state after forking. The Crypt::PK::RSA, Crypt::PK::DSA, Crypt::PK::DH, Crypt::PK::ECC, Crypt::PK::Ed25519 and Crypt::PK::X25519 modules seed a per-object PRNG state in their constructors and reuse it without fork detection. A Crypt::PK::* object created before `fork()` shares byte-identical PRNG state with every child process, and any randomized operation they perform can produce identical output, including key generation. Two ECDSA or DSA signatures from different processes are enough to recover the signing private key through nonce-reuse key recovery. This affects preforking services such as the Starman web server, where a Crypt::PK::* object loaded at startup is inherited by every worker process.

CVE-2026-41565 (2026-05-28)

CryptX versions before 0.088_001 for Perl have a stack buffer overflow in four AEAD decrypt_verify helpers. The gcm_decrypt_verify, ccm_decrypt_verify, chacha20poly1305_decrypt_verify and eax_decrypt_verify XS routines copied the caller-supplied authentication tag into a fixed 144-byte stack buffer (MAXBLOCKSIZE) without checking the supplied length. A longer tag overwrites the stack past the buffer. Version 0.088 added the clamp to gcm_decrypt_verify, and 0.088_001 added it to the other three. Any caller of an affected helper that forwards an attacker-controlled tag longer than the buffer can trigger the overflow.

NAME

Crypt::Cipher - Generic interface to cipher functions

SYNOPSIS

#### example 1 (encrypting single block)
use Crypt::Cipher;

my $key = '...'; # length has to be valid key size for this cipher
my $c = Crypt::Cipher->new('AES', $key);
my $blocksize  = $c->blocksize;
my $ciphertext = $c->encrypt('plain text block'); #encrypt 1 block
my $plaintext  = $c->decrypt($ciphertext);         #decrypt 1 block

### example 2 (using CBC mode)
use Crypt::Mode::CBC;

my $key = '...'; # length has to be valid key size for this cipher
my $iv = '...';  # 16 bytes
my $cbc = Crypt::Mode::CBC->new('AES');
my $ciphertext = $cbc->encrypt("secret data", $key, $iv);

#### example 3 (compatibility with Crypt::CBC)
use Crypt::CBC;
use Crypt::Cipher;

my $key = '...'; # length has to be valid key size for this cipher
my $iv = '...';  # 16 bytes
my $cipher = Crypt::Cipher('AES', $key);
my $cbc = Crypt::CBC->new( -cipher=>$cipher, -iv=>$iv );
my $ciphertext = $cbc->encrypt("secret data");

DESCRIPTION

Provides an interface to various symmetric cipher algorithms.

BEWARE: This module implements just elementary "one-block-(en|de)cryption" operation - if you want to encrypt/decrypt generic data you have to use some of the cipher block modes - check for example Crypt::Mode::CBC, Crypt::Mode::CTR or Crypt::CBC (which will be slower).

METHODS

new

Constructor, returns a reference to the cipher object.

## basic scenario
$d = Crypt::Cipher->new($name, $key);
# $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>
# $key = binary key (keysize should comply with selected cipher requirements)

## some of the ciphers (e.g. MULTI2, RC5, SAFER) allow one to set number of rounds
$d = Crypt::Cipher->new('MULTI2', $key, $rounds);
# $rounds = positive integer (should comply with selected cipher requirements)

encrypt

Encrypts $plaintext and returns the $ciphertext where $plaintext and $ciphertext should be of blocksize bytes.

$ciphertext = $d->encrypt($plaintext);

decrypt

Decrypts $ciphertext and returns the $plaintext where $plaintext and $ciphertext should be of blocksize bytes.

$plaintext = $d->decrypt($ciphertext);

keysize

Just an alias for max_keysize (needed for Crypt::CBC compatibility).

max_keysize

Returns the maximal allowed key size (in bytes) for given cipher.

$d->max_keysize;
#or
Crypt::Cipher->max_keysize('AES');
#or
Crypt::Cipher::max_keysize('AES');

min_keysize

Returns the minimal allowed key size (in bytes) for given cipher.

$d->min_keysize;
#or
Crypt::Cipher->min_keysize('AES');
#or
Crypt::Cipher::min_keysize('AES');

blocksize

Returns block size (in bytes) for given cipher.

$d->blocksize;
#or
Crypt::Cipher->blocksize('AES');
#or
Crypt::Cipher::blocksize('AES');

default_rounds

Returns default number of rounds for given cipher. NOTE: only some ciphers (e.g. MULTI2, RC5, SAFER) allow one to set number of rounds via new().

$d->default_rounds;
#or
Crypt::Cipher->default_rounds('AES');
#or
Crypt::Cipher::default_rounds('AES');

SEE ALSO