Crypt::Stream::XChaCha(3) User Contributed Perl Documentation
NAME
Crypt::Stream::XChaCha - Stream cipher XChaCha20
SYNOPSIS
use Crypt::Stream::XChaCha;
# encrypt
my $key = "12345678901234567890123456789012"; # 32 bytes
my $nonce = "123456789012345678901234"; # 24 bytes
my $enc_stream = Crypt::Stream::XChaCha->new($key, $nonce);
my $ct = $enc_stream->crypt("plain message");
# decrypt
my $dec_stream = Crypt::Stream::XChaCha->new($key, $nonce);
my $pt = $dec_stream->crypt($ct);
DESCRIPTION
Since: CryptX-0.089
Provides an interface to the XChaCha20 stream cipher, an extended-nonce
variant of ChaCha20 using a 192-bit (24-byte) nonce.
METHODS
Unless noted otherwise, assume $stream is an existing stream object
created via "new", for example:
my $stream = Crypt::Stream::XChaCha->new($key, $nonce);
new
my $stream = Crypt::Stream::XChaCha->new($key, $nonce);
#or
my $stream = Crypt::Stream::XChaCha->new($key, $nonce, $rounds);
# $key .. [binary string] 32 bytes
# $nonce .. [binary string] 24 bytes
# $rounds .. [integer] optional, rounds (DEFAULT: 20)
crypt
Encrypts or decrypts data. The output has the same length as the input.
Returns a binary string (raw bytes).
The input is converted using Perl's usual scalar stringification.
Passing "undef" is treated as an empty string with the usual warning,
and numeric scalars are stringified before processing.
my $ciphertext = $stream->crypt($plaintext);
#or
my $plaintext = $stream->crypt($ciphertext);
keystream
Returns $length bytes of raw keystream as a binary string.
The length is taken using Perl's usual numeric coercion. Values that
coerce to an oversized unsigned length are rejected as too large.
my $random_bytes = $stream->keystream($length);
clone
Returns a copy of the stream cipher object in its current state.
my $stream2 = $stream->clone;
SEE ALSO
o Crypt::Stream::ChaCha(3), Crypt::Stream::XSalsa20(3)
o <https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-xchacha>
perl v5.34.3 2026-05-11 Crypt::Stream::XChaCha(3)
cryptx 0.89.0 - Generated Tue May 12 15:55:22 CDT 2026