text: // Copyright (c) 2009-2016 The Bitcoin Core developers
  // Copyright (c) 2017-2019 The Raven Core developers
  // Copyright (c) 2020 The Miracle Core 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 "crypto/aes.h"
  #include "crypto/sha512.h"
  #include "script/script.h"
  #include "script/standard.h"
  #include "util.h"
  
  #include <string>
  #include <vector>
  
  int CCrypter::BytesToKeySHA512AES(const std::vector<unsigned char>& chSalt, const SecureString& strKeyData, int count, unsigned char *key,unsigned char *iv) const
  {
      // This mimics the behavior of openssl's EVP_BytesToKey with an aes256cbc
      // cipher and sha512 message digest. Because sha512's output size (64b) is
      // greater than the aes256 block size (16b) + aes256 key size (32b),
      // there's no need to process more than once (D_0).
  
      if(!count || !key || !iv)
          return 0;
  
      unsigned char buf[CSHA512::OUTPUT_SIZE];
      CSHA512 di;
  
      di.Write((const unsigned char*)strKeyData.c_str(), strKeyData.size());
      di.Write(chSalt.data(), chSalt.size());
      di.Finalize(buf);
  
      for(int i = 0; i != count - 1; i++)
          di.Reset().Write(buf, sizeof(buf)).Finalize(buf);
  
      memcpy(key, buf, WALLET_CRYPTO_KEY_SIZE);
      memcpy(iv, buf + WALLET_CRYPTO_KEY_SIZE, WALLET_CRYPTO_IV_SIZE);
      memory_cleanse(buf, sizeof(buf));
      return WALLET_CRYPTO_KEY_SIZE;
  }
  
  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 = BytesToKeySHA512AES(chSalt, strKeyData, nRounds, vchKey.data(), vchIV.data());
  
      if (i != (int)WALLET_CRYPTO_KEY_SIZE)
      {
          memory_cleanse(vchKey.data(), vchKey.size());
          memory_cleanse(vchIV.data(), vchIV.size());
          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_IV_SIZE)
          return false;
  
      memcpy(vchKey.data(), chNewKey.data(), chNewKey.size());
      memcpy(vchIV.data(), chNewIV.data(), chNewIV.size());
  
      fKeySet = true;
      return true;
  }
  
  bool CCrypter::Encrypt(const CKeyingMaterial& vchPlaintext, std::vector<unsigned char> &vchCiphertext) const
  {
      if (!fKeySet)
          return false;
  
      // max ciphertext len for a n bytes of plaintext is
      // n + AES_BLOCKSIZE bytes
      vchCiphertext.resize(vchPlaintext.size() + AES_BLOCKSIZE);
  
      AES256CBCEncrypt enc(vchKey.data(), vchIV.data(), true);
      size_t nLen = enc.Encrypt(&vchPlaintext[0], vchPlaintext.size(), vchCiphertext.data());
      if(nLen < vchPlaintext.size())
          return false;
      vchCiphertext.resize(nLen);
  
      return true;
  }
  
  bool CCrypter::Decrypt(const std::vector<unsigned char>& vchCiphertext, CKeyingMaterial& vchPlaintext) const
  {
      if (!fKeySet)
          return false;
  
      // plaintext will always be equal to or lesser than length of ciphertext
      int nLen = vchCiphertext.size();
  
      vchPlaintext.resize(nLen);
  
      AES256CBCDecrypt dec(vchKey.data(), vchIV.data(), true);
      nLen = dec.Decrypt(vchCiphertext.data(), vchCiphertext.size(), &vchPlaintext[0]);
      if(nLen == 0)
          return false;
      vchPlaintext.resize(nLen);
      return true;
  }
  
  
  static 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_IV_SIZE);
      memcpy(chIV.data(), &nIV, WALLET_CRYPTO_IV_SIZE);
      if(!cKeyCrypter.SetKey(vMasterKey, chIV))
          return false;
      return cKeyCrypter.Encrypt(*((const CKeyingMaterial*)&vchPlaintext), vchCiphertext);
  }
  
  static 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_IV_SIZE);
      memcpy(chIV.data(), &nIV, WALLET_CRYPTO_IV_SIZE);
      if(!cKeyCrypter.SetKey(vMasterKey, chIV))
          return false;
      return cKeyCrypter.Decrypt(vchCiphertext, *((CKeyingMaterial*)&vchPlaintext));
  }
  
  static bool DecryptKey(const CKeyingMaterial& vMasterKey, const std::vector<unsigned char>& vchCryptedSecret, const CPubKey& vchPubKey, CKey& key)
  {
      CKeyingMaterial vchSecret;
      if(!DecryptSecret(vMasterKey, vchCryptedSecret, vchPubKey.GetHash(), vchSecret))
          return false;
  
      if (vchSecret.size() != 32)
          return false;
  
      key.Set(vchSecret.begin(), vchSecret.end(), vchPubKey.IsCompressed());
      return key.VerifyPubKey(vchPubKey);
  }
  
  bool CCryptoKeyStore::SetCrypted()
  {
      LOCK(cs_KeyStore);
      if (fUseCrypto)
          return true;
      if (!mapKeys.empty())
          return false;
      fUseCrypto = true;
      return true;
  }
  
  bool CCryptoKeyStore::IsLocked() const
  {
      if (!IsCrypted()) {
          return false;
      }
      LOCK(cs_KeyStore);
      return vMasterKey.empty();
  }
  
  bool CCryptoKeyStore::Lock()
  {
      if (!SetCrypted())
          return false;
  
      {
          LOCK(cs_KeyStore);
          vMasterKey.clear();
      }
  
      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;
              CKey key;
              if (!DecryptKey(vMasterKeyIn, vchCryptedSecret, vchPubKey, key))
              {
                  keyFail = true;
                  break;
              }
              keyPass = true;
              if (fDecryptionThoroughlyChecked)
                  break;
          }
          if (keyPass && keyFail)
          {
              LogPrintf("The wallet is probably corrupted: Some keys decrypt but not all.\n");
              assert(false);
          }
          if (keyFail || !keyPass)
              return false;
          vMasterKey = vMasterKeyIn;
          fDecryptionThoroughlyChecked = true;
      }
      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::HaveKey(const CKeyID &address) const
  {
      LOCK(cs_KeyStore);
      if (!IsCrypted()) {
          return CBasicKeyStore::HaveKey(address);
      }
      return mapCryptedKeys.count(address) > 0;
  }
  
  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;
          return DecryptKey(vMasterKey, vchCryptedSecret, vchPubKey, keyOut);
      }
      return false;
  }
  
  bool CCryptoKeyStore::GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const
  {
      LOCK(cs_KeyStore);
      if (!IsCrypted())
          return CBasicKeyStore::GetPubKey(address, vchPubKeyOut);
  
      CryptedKeyMap::const_iterator mi = mapCryptedKeys.find(address);
      if (mi != mapCryptedKeys.end())
      {
          vchPubKeyOut = (*mi).second.first;
          return true;
      }
      // Check for watch-only pubkeys
      return CBasicKeyStore::GetPubKey(address, vchPubKeyOut);
  }
  
  std::set<CKeyID> CCryptoKeyStore::GetKeys() const
  {
      LOCK(cs_KeyStore);
      if (!IsCrypted()) {
          return CBasicKeyStore::GetKeys();
      }
      std::set<CKeyID> set_address;
      for (const auto& mi : mapCryptedKeys) {
          set_address.insert(mi.first);
      }
      return set_address;
  }
  
  bool CCryptoKeyStore::EncryptKeys(CKeyingMaterial& vMasterKeyIn)
  {
      LOCK(cs_KeyStore);
      if (!mapCryptedKeys.empty() || IsCrypted())
          return false;
  
      fUseCrypto = true;
      for (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;
  }
  