// Copyright (c) 2014-2016 The Bitcoin Core developers
// Distributed under the GPLv3 software license, see the accompanying
// file COPYING or https://www.gnu.org/licenses/gpl-3.0.en.html

#ifndef BITCOIN_CRYPTO_SHA256_H
#define BITCOIN_CRYPTO_SHA256_H

#include <stdint.h>
#include <stdlib.h>
#include <string>

/** A hasher class for SHA-256. */
class CSHA256
{
public:
    static const size_t OUTPUT_SIZE = 32;
private:
    uint32_t s[8];
    unsigned char buf[64];
    size_t bytes;
    void FinalizeNoPadding(unsigned char hash[OUTPUT_SIZE], bool enforce_compression);
public:
    CSHA256();
    CSHA256& Write(const unsigned char* data, size_t len);
    void Finalize(unsigned char hash[OUTPUT_SIZE]);
    void FinalizeNoPadding(unsigned char hash[OUTPUT_SIZE]) {
    	FinalizeNoPadding(hash, true);
    };
    CSHA256& Reset();
};

/** Autodetect the best available SHA256 implementation.
 *  Returns the name of the implementation.
 */
std::string SHA256AutoDetect();

#endif // BITCOIN_CRYPTO_SHA256_H