base58.h

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2015 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

/**
 * Why base-58 instead of standard base-64 encoding?
 * - Don't want 0OIl characters that look the same in some fonts and
 *      could be used to create visually identical looking data.
 * - A string with non-alphanumeric characters is not as easily accepted as input.
 * - E-mail usually won't line-break if there's no punctuation to break at.
 * - Double-clicking selects the whole string as one word if it's all alphanumeric.
 */
#ifndef BITCOIN_BASE58_H
#define BITCOIN_BASE58_H

// #include <chainparams.h>
// #include <key.h>
#include <pubkey.h>
// #include <script/standard.h>
#include <support/allocators/zeroafterfree.h>

#include <string>
#include <vector>

/**
 * Encode a byte sequence as a base58-encoded string.
 * pbegin and pend cannot be nullptr, unless both are.
 */
std::string EncodeBase58(const unsigned char* pbegin, const unsigned char* pend);

/**
 * Encode a byte vector as a base58-encoded string
 */
std::string EncodeBase58(const std::vector<unsigned char>& vch);

/**
 * Decode a base58-encoded string (psz) into a byte vector (vchRet).
 * return true if decoding is successful.
 * psz cannot be nullptr.
 */
bool DecodeBase58(const char* psz, std::vector<unsigned char>& vchRet);

/**
 * Decode a base58-encoded string (str) into a byte vector (vchRet).
 * return true if decoding is successful.
 */
bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet);

/**
 * Encode a byte vector into a base58-encoded string, including checksum
 */
std::string EncodeBase58Check(const std::vector<unsigned char>& vchIn);

/**
 * Decode a base58-encoded string (psz) that includes a checksum into a byte
 * vector (vchRet), return true if decoding is successful
 */
bool DecodeBase58Check(const char* psz, std::vector<unsigned char>& vchRet);

/**
 * Decode a base58-encoded string (str) that includes a checksum into a byte
 * vector (vchRet), return true if decoding is successful
 */
bool DecodeBase58Check(const std::string& str, std::vector<unsigned char>& vchRet);

/**
 * Base class for all base58-encoded data
 */
class CBase58Data
{
protected:
    //! the version byte(s)
    std::vector<unsigned char> vchVersion;

    //! the actually encoded data
    typedef std::vector<unsigned char, zero_after_free_allocator<unsigned char> > vector_uchar;
    vector_uchar vchData;

    CBase58Data();
    void SetData(const std::vector<unsigned char> &vchVersionIn, const void* pdata, size_t nSize);
    void SetData(const std::vector<unsigned char> &vchVersionIn, const unsigned char *pbegin, const unsigned char *pend);

public:
    bool SetString(const char* psz, unsigned int nVersionBytes = 1);
    bool SetString(const std::string& str);
    std::string ToString() const;
    int CompareTo(const CBase58Data& b58) const;

    bool operator==(const CBase58Data& b58) const { return CompareTo(b58) == 0; }
    bool operator<=(const CBase58Data& b58) const { return CompareTo(b58) <= 0; }
    bool operator>=(const CBase58Data& b58) const { return CompareTo(b58) >= 0; }
    bool operator< (const CBase58Data& b58) const { return CompareTo(b58) <  0; }
    bool operator> (const CBase58Data& b58) const { return CompareTo(b58) >  0; }
};

// /**
//  * A base58-encoded secret key
//  */
// class CBitcoinSecret : public CBase58Data
// {
// public:
//     void SetKey(const CKey& vchSecret);
//     CKey GetKey();
//     bool IsValid() const;
//     bool SetString(const char* pszSecret);
//     bool SetString(const std::string& strSecret);
// 
//     CBitcoinSecret(const CKey& vchSecret) { SetKey(vchSecret); }
//     CBitcoinSecret() {}
// };

enum Base58Type {
    PUBKEY_ADDRESS,
    SCRIPT_ADDRESS,
    SECRET_KEY,
    EXT_PUBLIC_KEY,
    EXT_SECRET_KEY,

    MAX_BASE58_TYPES
};

extern std::vector<std::vector<unsigned char>> base58Prefixes;

inline std::vector<unsigned char> Base58Prefix(Base58Type t) {
    if (base58Prefixes.size() == 0) {
        base58Prefixes.resize(MAX_BASE58_TYPES);
        base58Prefixes[PUBKEY_ADDRESS] = std::vector<unsigned char>(1,0);
        base58Prefixes[SCRIPT_ADDRESS] = std::vector<unsigned char>(1,5);
        base58Prefixes[SECRET_KEY] =     std::vector<unsigned char>(1,128);
        base58Prefixes[EXT_PUBLIC_KEY] = {0x04, 0x88, 0xB2, 0x1E};
        base58Prefixes[EXT_SECRET_KEY] = {0x04, 0x88, 0xAD, 0xE4};
    }
    return base58Prefixes[t];
}

template<typename K, int Size, Base58Type Type> class CBitcoinExtKeyBase : public CBase58Data
{
public:
    void SetKey(const K &key) {
        unsigned char vch[Size];
        key.Encode(vch);
        SetData(Base58Prefix(Type), vch, vch+Size);
    }

    K GetKey() {
        K ret;
        if (vchData.size() == Size) {
            // If base58 encoded data does not hold an ext key, return a !IsValid() key
            ret.Decode(vchData.data());
        }
        return ret;
    }

    CBitcoinExtKeyBase(const K &key) {
        SetKey(key);
    }

    CBitcoinExtKeyBase(const std::string& strBase58c) {
        SetString(strBase58c.c_str(), Base58Prefix(Type).size());
    }

    CBitcoinExtKeyBase() {}
};

// typedef CBitcoinExtKeyBase<CExtKey, BIP32_EXTKEY_SIZE, CChainParams::EXT_SECRET_KEY> CBitcoinExtKey;
// typedef CBitcoinExtKeyBase<CExtPubKey, BIP32_EXTKEY_SIZE, CChainParams::EXT_PUBLIC_KEY> CBitcoinExtPubKey;

// std::string EncodeDestination(const CTxDestination& dest);
// CTxDestination DecodeDestination(const std::string& str);
// bool IsValidDestinationString(const std::string& str);
// bool IsValidDestinationString(const std::string& str, const CChainParams& params);

#endif // BITCOIN_BASE58_H