chacha_rng.hpp

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// Copyright (c) 2015-2022 Clearmatics Technologies Ltd
//
// SPDX-License-Identifier: LGPL-3.0+
 
#ifndef __ZETH_CORE_CHACHA_RNG_HPP__
#define __ZETH_CORE_CHACHA_RNG_HPP__
 
#include <cstddef>
#include <cstdint>
 
namespace libzeth
{
 
class chacha_rng
{
public:
    chacha_rng(const void *seed, size_t seed_size);
    void random(void *output, size_t output_size);
 
private:
    void update();
 
    // The key generated from the seed data
    uint32_t key[8];
 
    // 128-bit counter
    uint32_t counter[4];
 
    // Current block of output from chacha
    uint8_t block[64];
 
    // Number of bytes of data already used from block
    size_t data_used;
};
 
} // namespace libzeth
 
#endif // __ZETH_CORE_CHACHA_RNG_HPP__