text: // Copyright (c) 2014-2018 The Dash Core developers 
  // Copyright (c) 2018-2021 The Veco Core developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "base58.h"
  #include "hash.h"
  #include "validation.h" // For strMessageMagic
  #include "messagesigner.h"
  #include "tinyformat.h"
  #include "utilstrencodings.h"
  
  bool CMessageSigner::GetKeysFromSecret(const std::string strSecret, CKey& keyRet, CPubKey& pubkeyRet)
  {
      CBitcoinSecret vchSecret;
  
      if(!vchSecret.SetString(strSecret)) return false;
  
      keyRet = vchSecret.GetKey();
      pubkeyRet = keyRet.GetPubKey();
  
      return true;
  }
  
  bool CMessageSigner::SignMessage(const std::string strMessage, std::vector<unsigned char>& vchSigRet, const CKey key)
  {
      CHashWriter ss(SER_GETHASH, 0);
      ss << strMessageMagic;
      ss << strMessage;
  
      return CHashSigner::SignHash(ss.GetHash(), key, vchSigRet);
  }
  
  bool CMessageSigner::VerifyMessage(const CPubKey pubkey, const std::vector<unsigned char>& vchSig, const std::string strMessage, std::string& strErrorRet)
  {
      CHashWriter ss(SER_GETHASH, 0);
      ss << strMessageMagic;
      ss << strMessage;
  
      return CHashSigner::VerifyHash(ss.GetHash(), pubkey, vchSig, strErrorRet);
  }
  
  bool CHashSigner::SignHash(const uint256& hash, const CKey key, std::vector<unsigned char>& vchSigRet)
  {
      return key.SignCompact(hash, vchSigRet);
  }
  
  bool CHashSigner::VerifyHash(const uint256& hash, const CPubKey pubkey, const std::vector<unsigned char>& vchSig, std::string& strErrorRet)
  {
      CPubKey pubkeyFromSig;
      if(!pubkeyFromSig.RecoverCompact(hash, vchSig)) {
          strErrorRet = "Error recovering public key.";
          return false;
      }
  
      if(pubkeyFromSig.GetID() != pubkey.GetID()) {
          strErrorRet = strprintf("Keys don't match: pubkey=%s, pubkeyFromSig=%s, hash=%s, vchSig=%s",
                      pubkey.GetID().ToString(), pubkeyFromSig.GetID().ToString(), hash.ToString(),
                      EncodeBase64(&vchSig[0], vchSig.size()));
          return false;
      }
  
      return true;
  }
  