text: // Copyright (c) 2009-2009 Satoshi Nakamoto
  // Copyright (c) 2009-2014 The Bitcoin developers
  // Copyright (c) 2014-2015 The Dash developers
  // Copyright (c) 2015-2018 The PIVX developers
  // Copyright (c) 2018-2018 The Jiyo developers
  
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "crypter.h"
  
  #include "script/script.h"
  #include "script/standard.h"
  #include "util.h"
  #include "init.h"
  #include "uint256.h"
  
  #include <boost/foreach.hpp>
  #include <openssl/aes.h>
  #include <openssl/evp.h>
  #include "wallet.h"
  
  bool CCrypter::SetKeyFromPassphrase(const SecureString& strKeyData, const std::vector<unsigned char>& chSalt, const unsigned int nRounds, const unsigned int nDerivationMethod)
  {
      if (nRounds < 1 || chSalt.size() != WALLET_CRYPTO_SALT_SIZE)
          return false;
  
      int i = 0;
      if (nDerivationMethod == 0)
          i = EVP_BytesToKey(EVP_aes_256_cbc(), EVP_sha512(), &chSalt[0],
              (unsigned char*)&strKeyData[0], strKeyData.size(), nRounds, chKey, chIV);
  
      if (i != (int)WALLET_CRYPTO_KEY_SIZE) {
          memory_cleanse(chKey, sizeof(chKey));
          memory_cleanse(chIV, sizeof(chIV));
          return false;
      }
  
      fKeySet = true;
      return true;
  }
  
  bool CCrypter::SetKey(const CKeyingMaterial& chNewKey, const std::vector<unsigned char>& chNewIV)
  {
      if (chNewKey.size() != WALLET_CRYPTO_KEY_SIZE || chNewIV.size() != WALLET_CRYPTO_KEY_SIZE)
          return false;
  
      memcpy(&chKey[0], &chNewKey[0], sizeof chKey);
      memcpy(&chIV[0], &chNewIV[0], sizeof chIV);
  
      fKeySet = true;
      return true;
  }
  
  bool CCrypter::Encrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char>& vchCiphertext)
  {
      if (!fKeySet)
          return false;
  
      // max ciphertext len for a n bytes of plaintext is
      // n + AES_BLOCK_SIZE - 1 bytes
      int nLen = vchPlaintext.size();
      int nCLen = nLen + AES_BLOCK_SIZE, nFLen = 0;
      vchCiphertext = std::vector<unsigned char>(nCLen);
  
      bool fOk = true;
  
      EVP_CIPHER_CTX* ctx = EVP_CIPHER_CTX_new();
      if (fOk) fOk = EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, chKey, chIV) != 0;
      if (fOk) fOk = EVP_EncryptUpdate(ctx, &vchCiphertext[0], &nCLen, &vchPlaintext[0], nLen) != 0;
      if (fOk) fOk = EVP_EncryptFinal_ex(ctx, (&vchCiphertext[0]) + nCLen, &nFLen) != 0;
      EVP_CIPHER_CTX_free(ctx);
  
      if (!fOk) return false;
  
      vchCiphertext.resize(nCLen + nFLen);
      return true;
  }
  
  bool CCrypter::Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext)
  {
      if (!fKeySet)
          return false;
  
      // plaintext will always be equal to or lesser than length of ciphertext
      int nLen = vchCiphertext.size();
      int nPLen = nLen, nFLen = 0;
  
      vchPlaintext = CKeyingMaterial(nPLen);
  
      bool fOk = true;
  
      EVP_CIPHER_CTX* ctx = EVP_CIPHER_CTX_new();
      if (fOk) fOk = EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, chKey, chIV) != 0;
      if (fOk) fOk = EVP_DecryptUpdate(ctx, &vchPlaintext[0], &nPLen, &vchCiphertext[0], nLen) != 0;
      if (fOk) fOk = EVP_DecryptFinal_ex(ctx, (&vchPlaintext[0]) + nPLen, &nFLen) != 0;
      EVP_CIPHER_CTX_free(ctx);
  
      if (!fOk) return false;
  
      vchPlaintext.resize(nPLen + nFLen);
      return true;
  }
  
  
  bool EncryptSecret(const CKeyingMaterial& vMasterKey, const CKeyingMaterial& vchPlaintext, const uint256& nIV, std::vector<unsigned char>& vchCiphertext)
  {
      CCrypter cKeyCrypter;
      std::vector<unsigned char> chIV(WALLET_CRYPTO_KEY_SIZE);
      memcpy(&chIV[0], &nIV, WALLET_CRYPTO_KEY_SIZE);
      if (!cKeyCrypter.SetKey(vMasterKey, chIV))
          return false;
      return cKeyCrypter.Encrypt(*((const CKeyingMaterial*)&vchPlaintext), vchCiphertext);
  }
  
  
  // General secure AES 256 CBC encryption routine
  bool EncryptAES256(const SecureString& sKey, const SecureString& sPlaintext, const std::string& sIV, std::string& sCiphertext)
  {
      // max ciphertext len for a n bytes of plaintext is
      // n + AES_BLOCK_SIZE - 1 bytes
      int nLen = sPlaintext.size();
      int nCLen = nLen + AES_BLOCK_SIZE;
      int nFLen = 0;
  
      // Verify key sizes
      if (sKey.size() != 32 || sIV.size() != AES_BLOCK_SIZE) {
          LogPrintf("crypter EncryptAES256 - Invalid key or block size: Key: %d sIV:%d\n", sKey.size(), sIV.size());
          return false;
      }
  
      // Prepare output buffer
      sCiphertext.resize(nCLen);
  
      // Perform the encryption
      EVP_CIPHER_CTX* ctx;
  
      bool fOk = true;
  
      ctx = EVP_CIPHER_CTX_new();
      if (fOk) fOk = EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, (const unsigned char*)&sKey[0], (const unsigned char*)&sIV[0]);
      if (fOk) fOk = EVP_EncryptUpdate(ctx, (unsigned char*)&sCiphertext[0], &nCLen, (const unsigned char*)&sPlaintext[0], nLen);
      if (fOk) fOk = EVP_EncryptFinal_ex(ctx, (unsigned char*)(&sCiphertext[0]) + nCLen, &nFLen);
      EVP_CIPHER_CTX_free(ctx);
  
      if (!fOk) return false;
  
      sCiphertext.resize(nCLen + nFLen);
      return true;
  }
  
  
  bool DecryptSecret(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCiphertext, const uint256& nIV, CKeyingMaterial& vchPlaintext)
  {
      CCrypter cKeyCrypter;
      std::vector<unsigned char> chIV(WALLET_CRYPTO_KEY_SIZE);
      memcpy(&chIV[0], &nIV, WALLET_CRYPTO_KEY_SIZE);
      if (!cKeyCrypter.SetKey(vMasterKey, chIV))
          return false;
      return cKeyCrypter.Decrypt(vchCiphertext, *((CKeyingMaterial*)&vchPlaintext));
  }
  
  bool DecryptAES256(const SecureString& sKey, const std::string& sCiphertext, const std::string& sIV, SecureString& sPlaintext)
  {
      // plaintext will always be equal to or lesser than length of ciphertext
      int nLen = sCiphertext.size();
      int nPLen = nLen, nFLen = 0;
  
      // Verify key sizes
      if (sKey.size() != 32 || sIV.size() != AES_BLOCK_SIZE) {
          LogPrintf("crypter DecryptAES256 - Invalid key or block size\n");
          return false;
      }
  
      sPlaintext.resize(nPLen);
  
      EVP_CIPHER_CTX* ctx;
  
      bool fOk = true;
  
      ctx = EVP_CIPHER_CTX_new();
      if (fOk) fOk = EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, (const unsigned char*)&sKey[0], (const unsigned char*)&sIV[0]);
      if (fOk) fOk = EVP_DecryptUpdate(ctx, (unsigned char*)&sPlaintext[0], &nPLen, (const unsigned char*)&sCiphertext[0], nLen);
      if (fOk) fOk = EVP_DecryptFinal_ex(ctx, (unsigned char*)(&sPlaintext[0]) + nPLen, &nFLen);
      EVP_CIPHER_CTX_free(ctx);
  
      if (!fOk) return false;
  
      sPlaintext.resize(nPLen + nFLen);
      return true;
  }
  
  
  bool CCryptoKeyStore::SetCrypted()
  {
      LOCK(cs_KeyStore);
      if (fUseCrypto)
          return true;
      if (!mapKeys.empty())
          return false;
      fUseCrypto = true;
      return true;
  }
  
  bool CCryptoKeyStore::Lock()
  {
      if (!SetCrypted())
          return false;
  
      {
          LOCK(cs_KeyStore);
          vMasterKey.clear();
          pwalletMain->zwalletMain->Lock();
      }
  
      NotifyStatusChanged(this);
      return true;
  }
  
  bool CCryptoKeyStore::Unlock(const CKeyingMaterial& vMasterKeyIn)
  {
      {
          LOCK(cs_KeyStore);
          if (!SetCrypted())
              return false;
  
          bool keyPass = false;
          bool keyFail = false;
          CryptedKeyMap::const_iterator mi = mapCryptedKeys.begin();
          for (; mi != mapCryptedKeys.end(); ++mi) {
              const CPubKey& vchPubKey = (*mi).second.first;
              const std::vector<unsigned char>& vchCryptedSecret = (*mi).second.second;
              CKeyingMaterial vchSecret;
              if (!DecryptSecret(vMasterKeyIn, vchCryptedSecret, vchPubKey.GetHash(), vchSecret)) {
                  keyFail = true;
                  break;
              }
              if (vchSecret.size() != 32) {
                  keyFail = true;
                  break;
              }
              CKey key;
              key.Set(vchSecret.begin(), vchSecret.end(), vchPubKey.IsCompressed());
              if (key.GetPubKey() != vchPubKey) {
                  keyFail = true;
                  break;
              }
              keyPass = true;
              if (fDecryptionThoroughlyChecked)
                  break;
          }
          if (keyPass && keyFail) {
              LogPrintf("The wallet is probably corrupted: Some keys decrypt but not all.");
              assert(false);
          }
          if (keyFail || !keyPass)
              return false;
          vMasterKey = vMasterKeyIn;
          fDecryptionThoroughlyChecked = true;
  
          uint256 hashSeed;
          if (CWalletDB(pwalletMain->strWalletFile).ReadCurrentSeedHash(hashSeed)) {
  
              uint256 nSeed;
              if (!GetDeterministicSeed(hashSeed, nSeed)) {
                  return error("Failed to read zJIYO seed from DB. Wallet is probably corrupt.");
              }
              pwalletMain->zwalletMain->SetMasterSeed(nSeed, false);
          } else {
              // First time this wallet has been unlocked with dzJIYO
              // Borrow random generator from the key class so that we don't have to worry about randomness
              CKey key;
              key.MakeNewKey(true);
              uint256 seed = key.GetPrivKey_256();
              LogPrintf("%s: first run of zjiyo wallet detected, new seed generated. Seedhash=%s\n", __func__, Hash(seed.begin(), seed.end()).GetHex());
              pwalletMain->zwalletMain->SetMasterSeed(seed, true);
              pwalletMain->zwalletMain->GenerateMintPool();
          }
      }
  
      NotifyStatusChanged(this);
      return true;
  }
  
  bool CCryptoKeyStore::AddKeyPubKey(const CKey& key, const CPubKey& pubkey)
  {
      {
          LOCK(cs_KeyStore);
          if (!IsCrypted())
              return CBasicKeyStore::AddKeyPubKey(key, pubkey);
  
          if (IsLocked())
              return false;
  
          std::vector<unsigned char> vchCryptedSecret;
          CKeyingMaterial vchSecret(key.begin(), key.end());
          if (!EncryptSecret(vMasterKey, vchSecret, pubkey.GetHash(), vchCryptedSecret))
              return false;
  
          if (!AddCryptedKey(pubkey, vchCryptedSecret))
              return false;
      }
      return true;
  }
  
  
  bool CCryptoKeyStore::AddCryptedKey(const CPubKey& vchPubKey, const std::vector<unsigned char>& vchCryptedSecret)
  {
      {
          LOCK(cs_KeyStore);
          if (!SetCrypted())
              return false;
  
          mapCryptedKeys[vchPubKey.GetID()] = make_pair(vchPubKey, vchCryptedSecret);
      }
      return true;
  }
  
  bool CCryptoKeyStore::GetKey(const CKeyID& address, CKey& keyOut) const
  {
      {
          LOCK(cs_KeyStore);
          if (!IsCrypted())
              return CBasicKeyStore::GetKey(address, keyOut);
  
          CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address);
          if (mi != mapCryptedKeys.end()) {
              const CPubKey& vchPubKey = (*mi).second.first;
              const std::vector<unsigned char>& vchCryptedSecret = (*mi).second.second;
              CKeyingMaterial vchSecret;
              if (!DecryptSecret(vMasterKey, vchCryptedSecret, vchPubKey.GetHash(), vchSecret))
                  return false;
              if (vchSecret.size() != 32)
                  return false;
              keyOut.Set(vchSecret.begin(), vchSecret.end(), vchPubKey.IsCompressed());
              return true;
          }
      }
      return false;
  }
  
  bool CCryptoKeyStore::GetPubKey(const CKeyID& address, CPubKey& vchPubKeyOut) const
  {
      {
          LOCK(cs_KeyStore);
          if (!IsCrypted())
              return CKeyStore::GetPubKey(address, vchPubKeyOut);
  
          CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address);
          if (mi != mapCryptedKeys.end()) {
              vchPubKeyOut = (*mi).second.first;
              return true;
          }
      }
      return false;
  }
  
  bool CCryptoKeyStore::EncryptKeys(CKeyingMaterial& vMasterKeyIn)
  {
      {
          LOCK(cs_KeyStore);
          if (!mapCryptedKeys.empty() || IsCrypted())
              return false;
  
          fUseCrypto = true;
          BOOST_FOREACH (KeyMap::value_type& mKey, mapKeys) {
              const CKey& key = mKey.second;
              CPubKey vchPubKey = key.GetPubKey();
              CKeyingMaterial vchSecret(key.begin(), key.end());
              std::vector<unsigned char> vchCryptedSecret;
              if (!EncryptSecret(vMasterKeyIn, vchSecret, vchPubKey.GetHash(), vchCryptedSecret))
                  return false;
              if (!AddCryptedKey(vchPubKey, vchCryptedSecret))
                  return false;
          }
          mapKeys.clear();
      }
      return true;
  }
  
  bool CCryptoKeyStore::AddDeterministicSeed(const uint256& seed)
  {
      CWalletDB db(pwalletMain->strWalletFile);
      string strErr;
      uint256 hashSeed = Hash(seed.begin(), seed.end());
  
      if(IsCrypted()) {
          if (!IsLocked()) { //if we have password
  
              CKeyingMaterial kmSeed(seed.begin(), seed.end());
              vector<unsigned char> vchSeedSecret;
  
  
              //attempt encrypt
              if (EncryptSecret(vMasterKey, kmSeed, hashSeed, vchSeedSecret)) {
                  //write to wallet with hashSeed as unique key
                  if (db.WriteZJIYOSeed(hashSeed, vchSeedSecret)) {
                      return true;
                  }
              }
              strErr = "encrypt seed";
          }
          strErr = "save since wallet is locked";
      } else { //wallet not encrypted
          if (db.WriteZJIYOSeed(hashSeed, ToByteVector(seed))) {
              return true;
          }
          strErr = "save zjiyoseed to wallet";
      }
                  //the use case for this is no password set seed, mint dzJIYO,
  
      return error("s%: Failed to %s\n", __func__, strErr);
  }
  
  bool CCryptoKeyStore::GetDeterministicSeed(const uint256& hashSeed, uint256& seedOut)
  {
  
      CWalletDB db(pwalletMain->strWalletFile);
      string strErr;
      if (IsCrypted()) {
          if(!IsLocked()) { //if we have password
  
              vector<unsigned char> vchCryptedSeed;
              //read encrypted seed
              if (db.ReadZJIYOSeed(hashSeed, vchCryptedSeed)) {
                  uint256 seedRetrieved = uint256(ReverseEndianString(HexStr(vchCryptedSeed)));
                  //this checks if the hash of the seed we just read matches the hash given, meaning it is not encrypted
                  //the use case for this is when not crypted, seed is set, then password set, the seed not yet crypted in memory
                  if(hashSeed == Hash(seedRetrieved.begin(), seedRetrieved.end())) {
                      seedOut = seedRetrieved;
                      return true;
                  }
  
                  CKeyingMaterial kmSeed;
                  //attempt decrypt
                  if (DecryptSecret(vMasterKey, vchCryptedSeed, hashSeed, kmSeed)) {
                      seedOut = uint256(ReverseEndianString(HexStr(kmSeed)));
                      return true;
                  }
                  strErr = "decrypt seed";
              } else { strErr = "read seed from wallet"; }
          } else { strErr = "read seed; wallet is locked"; }
      } else {
          vector<unsigned char> vchSeed;
          // wallet not crypted
          if (db.ReadZJIYOSeed(hashSeed, vchSeed)) {
              seedOut = uint256(ReverseEndianString(HexStr(vchSeed)));
              return true;
          }
          strErr = "read seed from wallet";
      }
  
      return error("%s: Failed to %s\n", __func__, strErr);
  
  
  //    return error("Failed to decrypt deterministic seed %s", IsLocked() ? "Wallet is locked!" : "");
  }
  