js/external/utils/hash.h

/*
 * This file is part of the Flowee project
 * Copyright (C) 2009-2010 Satoshi Nakamoto
 * Copyright (C) 2009-2015 The Bitcoin Core developers
 * Copyright (C) 2021 Tom Zander <tom@flowee.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef FLOWEE_HASH_H
#define FLOWEE_HASH_H

#include "ripemd160.h"
#include "sha256.h"
#include "prevector.h"
#include "serialize.h"
#include "uint256.h"
#include "version.h"

#include <vector>

typedef uint256 ChainCode;

/** A hasher class for Bitcoin's 256-bit hash (double SHA-256). */
class CHash256 {
private:
    CSHA256 sha;
public:
    static constexpr size_t OUTPUT_SIZE = CSHA256::OUTPUT_SIZE;

    void Finalize(unsigned char hash[OUTPUT_SIZE]) {
        unsigned char buf[CSHA256::OUTPUT_SIZE];
        sha.Finalize(buf);
        sha.Reset().Write(buf, CSHA256::OUTPUT_SIZE).Finalize(hash);
    }

    CHash256& Write(const unsigned char *data, size_t len) {
        sha.Write(data, len);
        return *this;
    }

    CHash256& Reset() {
        sha.Reset();
        return *this;
    }
};

/** A hasher class for Bitcoin's 160-bit hash (SHA-256 + RIPEMD-160). */
class CHash160 {
private:
    CSHA256 sha;
public:
    static const size_t OUTPUT_SIZE = CRIPEMD160::OUTPUT_SIZE;

    void Finalize(unsigned char hash[OUTPUT_SIZE]) {
        unsigned char buf[CSHA256::OUTPUT_SIZE];
        sha.Finalize(buf);
        CRIPEMD160().Write(buf, CSHA256::OUTPUT_SIZE).Finalize(hash);
    }

    CHash160& Write(const unsigned char *data, size_t len) {
        sha.Write(data, len);
        return *this;
    }

    CHash160& Reset() {
        sha.Reset();
        return *this;
    }
};

/** Compute the 256-bit hash of an object. */
template<typename T1>
inline uint256 Hash(const T1 pbegin, const T1 pend)
{
    static const unsigned char pblank[1] = {};
    uint256 result;
    CHash256().Write(pbegin == pend ? pblank : (const unsigned char*)&pbegin[0], (pend - pbegin) * sizeof(pbegin[0]))
              .Finalize((unsigned char*)&result);
    return result;
}

/** Compute the 256-bit hash of the concatenation of two objects. */
template<typename T1, typename T2>
inline uint256 Hash(const T1 p1begin, const T1 p1end,
                    const T2 p2begin, const T2 p2end) {
    static const unsigned char pblank[1] = {};
    uint256 result;
    CHash256().Write(p1begin == p1end ? pblank : (const unsigned char*)&p1begin[0], (p1end - p1begin) * sizeof(p1begin[0]))
              .Write(p2begin == p2end ? pblank : (const unsigned char*)&p2begin[0], (p2end - p2begin) * sizeof(p2begin[0]))
              .Finalize((unsigned char*)&result);
    return result;
}

/** Compute the 256-bit hash of the concatenation of three objects. */
template<typename T1, typename T2, typename T3>
inline uint256 Hash(const T1 p1begin, const T1 p1end,
                    const T2 p2begin, const T2 p2end,
                    const T3 p3begin, const T3 p3end) {
    static const unsigned char pblank[1] = {};
    uint256 result;
    CHash256().Write(p1begin == p1end ? pblank : (const unsigned char*)&p1begin[0], (p1end - p1begin) * sizeof(p1begin[0]))
              .Write(p2begin == p2end ? pblank : (const unsigned char*)&p2begin[0], (p2end - p2begin) * sizeof(p2begin[0]))
              .Write(p3begin == p3end ? pblank : (const unsigned char*)&p3begin[0], (p3end - p3begin) * sizeof(p3begin[0]))
              .Finalize((unsigned char*)&result);
    return result;
}

/** Compute the 160-bit hash an object. */
template<typename T1>
inline uint160 Hash160(const T1 pbegin, const T1 pend)
{
    static unsigned char pblank[1] = {};
    uint160 result;
    CHash160().Write(pbegin == pend ? pblank : (const unsigned char*)&pbegin[0], (pend - pbegin) * sizeof(pbegin[0]))
              .Finalize((unsigned char*)&result);
    return result;
}

/** Compute the 160-bit hash of a vector. */
inline uint160 Hash160(const std::vector<unsigned char>& vch)
{
    return Hash160(vch.begin(), vch.end());
}

/** Compute the 160-bit hash of a vector. */
template<unsigned int N>
inline uint160 Hash160(const prevector<N, unsigned char>& vch)
{
    return Hash160(vch.begin(), vch.end());
}

/** A writer stream (for serialization) that computes a 256-bit hash. */
class CHashWriter
{
private:
    CHash256 ctx;

public:
    int nType;
    int nVersion;

    CHashWriter(int nTypeIn, int nVersionIn) : nType(nTypeIn), nVersion(nVersionIn) {}

    CHashWriter& write(const char *pch, size_t size) {
        ctx.Write((const unsigned char*)pch, size);
        return (*this);
    }

    /// This finalizes the data and returns the (double)hashed results.
    // Please note that this invalidates the object.
    uint256 finalizeHash() {
        uint256 result;
        ctx.Finalize((unsigned char*)&result);
        return result;
    }

    template<typename T>
    CHashWriter& operator<<(const T& obj) {
        // Serialize to this stream
        ::Serialize(*this, obj, nType, nVersion);
        return (*this);
    }
};

/** Compute the 256-bit hash of an object's serialization. */
template<typename T>
uint256 SerializeHash(const T& obj, int nType=SER_GETHASH, int nVersion=PROTOCOL_VERSION)
{
    CHashWriter ss(nType, nVersion);
    ss << obj;
    return ss.finalizeHash();
}

unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash);

void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64]);

#endif