[PRIV] Generate Private Contract Address (#1004)

* Create a new PrivateContractAddress generation

* Remove resolveAccountFromPublicState

* Change method sign to BytesValue

Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

ethereum/core/src/main/java/tech/pegasys/pantheon/ethereum/core/Address.java

@@ -129,6 +129,28 @@ public class Address extends DelegatingBytesValue {
                 })));
   }
 
+  /**
+   * Address of the created private contract.
+   *
+   * @param senderAddress the address of the transaction sender.
+   * @param nonce the nonce of this transaction.
+   * @param privacyGroupId hash of participants list ordered from Enclave response.
+   * @return The generated address of the created private contract.
+   */
+  public static Address privateContractAddress(
+      final Address senderAddress, final long nonce, final BytesValue privacyGroupId) {
+    return Address.extract(
+        Hash.hash(
+            RLP.encode(
+                out -> {
+                  out.startList();
+                  out.writeBytesValue(senderAddress);
+                  out.writeLongScalar(nonce);
+                  out.writeBytesValue(privacyGroupId);
+                  out.endList();
+                })));
+  }
+
   @Override
   public Address copy() {
     final BytesValue copiedStorage = wrapped.copy();

ethereum/core/src/main/java/tech/pegasys/pantheon/ethereum/privacy/PrivateTransactionProcessor.java

@@ -154,7 +154,7 @@ public class PrivateTransactionProcessor {
     final MutableAccount sender =
         maybePrivateSender != null
             ? maybePrivateSender
-            : resolveAccountFromPublicState(publicWorldState, privateWorldState, senderAddress);
+            : privateWorldState.createAccount(senderAddress, 0, Wei.ZERO);
 
     final long previousNonce = sender.incrementNonce();
     LOG.trace(
@@ -166,8 +166,8 @@ public class PrivateTransactionProcessor {
     final MessageFrame initialFrame;
     final Deque<MessageFrame> messageFrameStack = new ArrayDeque<>();
     if (transaction.isContractCreation()) {
-      final Address contractAddress =
-          Address.contractAddress(senderAddress, sender.getNonce() - 1L);
+      final Address privateContractAddress =
+          Address.privateContractAddress(senderAddress, sender.getNonce() - 1L, BytesValue.EMPTY);
 
       initialFrame =
           MessageFrame.builder()
@@ -175,9 +175,9 @@ public class PrivateTransactionProcessor {
               .messageFrameStack(messageFrameStack)
               .blockchain(blockchain)
               .worldState(privateWorldState.updater())
-              .address(contractAddress)
+              .address(privateContractAddress)
               .originator(senderAddress)
-              .contract(contractAddress)
+              .contract(privateContractAddress)
               .initialGas(Gas.MAX_VALUE)
               .gasPrice(transaction.getGasPrice())
               .inputData(BytesValue.EMPTY)
@@ -239,14 +239,6 @@ public class PrivateTransactionProcessor {
     }
   }
 
-  private MutableAccount resolveAccountFromPublicState(
-      final WorldUpdater publicWorldState,
-      final WorldUpdater privateWorldState,
-      final Address senderAddress) {
-    final MutableAccount publicSender = publicWorldState.getOrCreate(senderAddress);
-    return privateWorldState.createAccount(senderAddress, publicSender.getNonce(), Wei.ZERO);
-  }
-
   private static void clearEmptyAccounts(final WorldUpdater worldState) {
     worldState.getTouchedAccounts().stream()
         .filter(Account::isEmpty)