import type { Generator } from '../types.js';
/**
 * ChaCha20 counter-mode PRF for Fortuna's generator slot.
 *
 * The 32-bit counter is read from `counter` as a little-endian u32. Each call
 * to `generate()` encrypts zero blocks to produce keystream output (RFC 8439 §2.3).
 * The nonce is fixed to zero, Fortuna's counter is the only varying input.
 *
 * Pass to `Fortuna.create({ generator: ChaCha20Generator, ... })`, do not
 * call `generate()` directly outside of Fortuna.
 */
export declare const ChaCha20Generator: Generator;