# Crypt::Stream::ChaCha - phpMan

## NAME
    [Crypt::Stream::ChaCha] - Stream cipher ChaCha

## SYNOPSIS
       use [Crypt::Stream::ChaCha];

       # encrypt
       $key = "1234567890123456";
       $iv  = "123456789012";
       $stream = [Crypt::Stream::ChaCha]->new($key, $iv);
       $ct = $stream->crypt("plain message");

       # decrypt
       $key = "1234567890123456";
       $iv  = "123456789012";
       $stream = [Crypt::Stream::ChaCha]->new($key, $iv);
       $pt = $stream->crypt($ct);

## DESCRIPTION
    Provides an interface to the ChaCha stream cipher.

## METHODS
  new
     $stream = [Crypt::Stream::ChaCha]->new($key, $iv);
     #or
     $stream = [Crypt::Stream::ChaCha]->new($key, $iv, $counter, $rounds);

     # $key     .. 32 or 16 bytes
     # $iv      .. 8 or 12 bytes
     # $counter .. initial counter value (DEFAULT: 0)
     # $rounds  .. rounds (DEFAULT: 20)

  crypt
     $ciphertext = $stream->crypt($plaintext);
     #or
     $plaintext = $stream->crypt($ciphertext);

  keystream
     $random_key = $stream->keystream($length);

  clone
     $stream->clone();

## SEE ALSO
    *   [Crypt::Stream::RC4], [Crypt::Stream::Sober128], [Crypt::Stream::Salsa20],
        [Crypt::Stream::Sosemanuk]

    *   <<https://tools.ietf.org/html/rfc7539>>