C++ (Cpp) SecureBinaryData::getHash256 Examples

Example #1

File: EncryptionUtils.cpp Project: CarltonCode/BitcoinArmory

/////////////////////////////////////////////////////////////////////////////
// Deterministically generate new public key using a chaincode
SecureBinaryData CryptoECDSA::ComputeChainedPublicKey(
                                SecureBinaryData const & binPubKey,
                                SecureBinaryData const & chainCode,
                                SecureBinaryData* multiplierOut)
{
   if(CRYPTO_DEBUG)
   {
      cout << "ComputeChainedPUBLICKey:" << endl;
      cout << "   BinPub: " << binPubKey.toHexStr() << endl;
      cout << "   BinChn: " << chainCode.toHexStr() << endl;
   }
   static SecureBinaryData SECP256K1_ORDER_BE = SecureBinaryData::CreateFromHex(
           "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141");

   // Added extra entropy to chaincode by xor'ing with hash256 of pubkey
   BinaryData chainMod  = binPubKey.getHash256();
   BinaryData chainOrig = chainCode.getRawCopy();
   BinaryData chainXor(32);
      
   for(uint8_t i=0; i<8; i++)
   {
      uint8_t offset = 4*i;
      *(uint32_t*)(chainXor.getPtr()+offset) =
                           *(uint32_t*)( chainMod.getPtr()+offset) ^ 
                           *(uint32_t*)(chainOrig.getPtr()+offset);
   }

   // Parse the chaincode as a big-endian integer
   CryptoPP::Integer mult;
   mult.Decode(chainXor.getPtr(), chainXor.getSize(), UNSIGNED);

   // "new" init as "old", to make sure it's initialized on the correct curve
   BTC_PUBKEY oldPubKey = ParsePublicKey(binPubKey); 
   BTC_PUBKEY newPubKey = ParsePublicKey(binPubKey);

   // Let Crypto++ do the EC math for us, serialize the new public key
   newPubKey.SetPublicElement( oldPubKey.ExponentiatePublicElement(mult) );

   if(multiplierOut != NULL)
      (*multiplierOut) = SecureBinaryData(chainXor);

   //LOGINFO << "Computed new chained public key using:";
   //LOGINFO << "   Public key: " << binPubKey.toHexStr().c_str();
   //LOGINFO << "   PubKeyHash: " << chainMod.toHexStr().c_str();
   //LOGINFO << "   Chaincode:  " << chainOrig.toHexStr().c_str();
   //LOGINFO << "   Multiplier: " << chainXor.toHexStr().c_str();

   return CryptoECDSA::SerializePublicKey(newPubKey);
}

Example #2

File: EncryptionUtils.cpp Project: CarltonCode/BitcoinArmory

/////////////////////////////////////////////////////////////////////////////
// Deterministically generate new private key using a chaincode
// Changed:  added using the hash of the public key to the mix
//           b/c multiplying by the chaincode alone is too "linear"
//           (there's no reason to believe it's insecure, but it doesn't
//           hurt to add some extra entropy/non-linearity to the chain
//           generation process)
SecureBinaryData CryptoECDSA::ComputeChainedPrivateKey(
                                 SecureBinaryData const & binPrivKey,
                                 SecureBinaryData const & chainCode,
                                 SecureBinaryData binPubKey,
                                 SecureBinaryData* multiplierOut)
{
   if(CRYPTO_DEBUG)
   {
      cout << "ComputeChainedPrivateKey:" << endl;
      cout << "   BinPrv: " << binPrivKey.toHexStr() << endl;
      cout << "   BinChn: " << chainCode.toHexStr() << endl;
      cout << "   BinPub: " << binPubKey.toHexStr() << endl;
   }


   if( binPubKey.getSize()==0 )
      binPubKey = ComputePublicKey(binPrivKey);

   if( binPrivKey.getSize() != 32 || chainCode.getSize() != 32)
   {
      LOGERR << "***ERROR:  Invalid private key or chaincode (both must be 32B)";
      LOGERR << "BinPrivKey: " << binPrivKey.getSize();
      LOGERR << "BinPrivKey: (not logged for security)";
      //LOGERR << "BinPrivKey: " << binPrivKey.toHexStr();
      LOGERR << "BinChain  : " << chainCode.getSize();
      LOGERR << "BinChain  : " << chainCode.toHexStr();
   }

   // Adding extra entropy to chaincode by xor'ing with hash256 of pubkey
   BinaryData chainMod  = binPubKey.getHash256();
   BinaryData chainOrig = chainCode.getRawCopy();
   BinaryData chainXor(32);
      
   for(uint8_t i=0; i<8; i++)
   {
      uint8_t offset = 4*i;
      *(uint32_t*)(chainXor.getPtr()+offset) =
                           *(uint32_t*)( chainMod.getPtr()+offset) ^ 
                           *(uint32_t*)(chainOrig.getPtr()+offset);
   }


   // Hard-code the order of the group
   static SecureBinaryData SECP256K1_ORDER_BE = SecureBinaryData().CreateFromHex(
           "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141");
   
   CryptoPP::Integer mult, origPrivExp, ecOrder;
   // A 
   mult.Decode(chainXor.getPtr(), chainXor.getSize(), UNSIGNED);
   // B 
   origPrivExp.Decode(binPrivKey.getPtr(), binPrivKey.getSize(), UNSIGNED);
   // C
   ecOrder.Decode(SECP256K1_ORDER_BE.getPtr(), SECP256K1_ORDER_BE.getSize(), UNSIGNED);

   // A*B mod C will get us a new private key exponent
   CryptoPP::Integer newPrivExponent = 
                  a_times_b_mod_c(mult, origPrivExp, ecOrder);

   // Convert new private exponent to big-endian binary string 
   SecureBinaryData newPrivData(32);
   newPrivExponent.Encode(newPrivData.getPtr(), newPrivData.getSize(), UNSIGNED);

   if(multiplierOut != NULL)
      (*multiplierOut) = SecureBinaryData(chainXor);

   //LOGINFO << "Computed new chained private key using:";
   //LOGINFO << "   Public key: " << binPubKey.toHexStr().c_str();
   //LOGINFO << "   PubKeyHash: " << chainMod.toHexStr().c_str();
   //LOGINFO << "   Chaincode:  " << chainOrig.toHexStr().c_str();
   //LOGINFO << "   Multiplier: " << chainXor.toHexStr().c_str();

   return newPrivData;
}