text: // Copyright (c) 2018. BurnCoin developers
  // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2012 The Bitcoin Developers
  // Distributed under the MIT/X11 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 account numbers.
  // - A string with non-alphanumeric characters is not as easily accepted as an account number.
  // - E-mail usually won't line-break if there's no punctuation to break at.
  // - Double-clicking selects the whole number as one word if it's all alphanumeric.
  //
  #ifndef BITCOIN_BASE58_H
  #define BITCOIN_BASE58_H
  
  #include <string>
  #include <vector>
  #include <openssl/crypto.h> // for OPENSSL_cleanse()
  #include "bignum.h"
  #include "key.h"
  #include "script.h"
  
  // Encode a byte sequence as a base58-encoded string
  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 byte vector vchRet
  // returns true if decoding is successful
  bool DecodeBase58(const char* psz, std::vector<unsigned char>& vchRet);
  
  // Decode a base58-encoded string str into byte vector vchRet
  // returns true if decoding is successful
  bool DecodeBase58(const std::string& str, std::vector<unsigned char>& vchRet);
  
  // Encode a byte vector to 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 byte vector vchRet
  // returns 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 byte vector vchRet
  // returns 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
      unsigned char nVersion;
  
      // the actually encoded data
      std::vector<unsigned char> vchData;
  
      CBase58Data();
      ~CBase58Data();
  
      void SetData(int nVersionIn, const void* pdata, size_t nSize);
      void SetData(int nVersionIn, const unsigned char *pbegin, const unsigned char *pend);
  
  public:
      bool SetString(const char* psz);
      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; }
  };
  
  /** base58-encoded Bitcoin addresses.
   * Public-key-hash-addresses have version 0 (or 111 testnet).
   * The data vector contains RIPEMD160(SHA256(pubkey)), where pubkey is the serialized public key.
   * Script-hash-addresses have version 5 (or 196 testnet).
   * The data vector contains RIPEMD160(SHA256(cscript)), where cscript is the serialized redemption script.
   */
  class CBitcoinAddress;
  class CBitcoinAddressVisitor : public boost::static_visitor<bool>
  {
  private:
      CBitcoinAddress *addr;
  public:
      CBitcoinAddressVisitor(CBitcoinAddress *addrIn) : addr(addrIn) { }
      bool operator()(const CKeyID &id) const;
      bool operator()(const CScriptID &id) const;
      bool operator()(const CNoDestination &no) const;
  };
  
  class CBitcoinAddress : public CBase58Data
  {
  public:
      enum
      {
          PUBKEY_ADDRESS = 25,
          SCRIPT_ADDRESS = 20,
          PUBKEY_ADDRESS_TEST = 111,
          SCRIPT_ADDRESS_TEST = 196,
      };
  
      bool Set(const CKeyID &id);
      bool Set(const CScriptID &id);
      bool Set(const CTxDestination &dest);
      bool IsValid() const;
  
      CBitcoinAddress()
      {
      }
  
      CBitcoinAddress(const CTxDestination &dest)
      {
          Set(dest);
      }
  
      CBitcoinAddress(const std::string& strAddress)
      {
          SetString(strAddress);
      }
  
      CBitcoinAddress(const char* pszAddress)
      {
          SetString(pszAddress);
      }
  
      CTxDestination Get() const;
      bool GetKeyID(CKeyID &keyID) const;
      bool IsScript() const;
  };
  
  bool inline CBitcoinAddressVisitor::operator()(const CKeyID &id) const         { return addr->Set(id); }
  bool inline CBitcoinAddressVisitor::operator()(const CScriptID &id) const      { return addr->Set(id); }
  bool inline CBitcoinAddressVisitor::operator()(const CNoDestination &id) const { return false; }
  
  /** A base58-encoded secret key */
  class CBitcoinSecret : public CBase58Data
  {
  public:
      void SetSecret(const CSecret& vchSecret, bool fCompressed);
      CSecret GetSecret(bool &fCompressedOut);
  
      bool IsValid() const;
  
      bool SetString(const char* pszSecret);
      bool SetString(const std::string& strSecret);
  
      CBitcoinSecret(const CSecret& vchSecret, bool fCompressed);
      CBitcoinSecret()
      {
      }
  };
  
  #endif
  