get proof with account proof

rskj-core/src/main/java/co/rsk/core/bc/AccountInformationProvider.java

@@ -26,6 +26,7 @@
 import javax.annotation.Nullable;
 import java.math.BigInteger;
 import java.util.Iterator;
+import java.util.List;
 
 public interface AccountInformationProvider {
 
@@ -104,4 +105,17 @@ public interface AccountInformationProvider {
      * @return Keccak256(storageRoot)
      * */
     Keccak256 getStorageHash(RskAddress addr);
+
+    /**
+     * According to the EIP-1186 https://eips.ethereum.org/EIPS/eip-1186
+     *
+     * Retrieves an account proof for a given address
+     * An account proof represents all the nodes starting from the state root following the path by the given the address.
+     * Each node is RLP encoded.
+     * NOTE: the value is also included at the end of the list
+     *
+     * @param addr an address
+     * @return a list of proofs for a given account
+     * */
+    List<String> getAccountProof(RskAddress addr);
 }

rskj-core/src/main/java/co/rsk/core/bc/PendingState.java

@@ -106,6 +106,11 @@ public Keccak256 getStorageHash(RskAddress addr) {
         return postExecutionReturn(executedRepository -> executedRepository.getStorageHash(addr));
     }
 
+    @Override
+    public List<String> getAccountProof(RskAddress addr) {
+        return postExecutionReturn(executedRepository -> executedRepository.getAccountProof(addr));
+    }
+
     // sortByPriceTakingIntoAccountSenderAndNonce sorts the transactions by price, but
     // first clustering by sender and then each cluster is order by nonce.
     //

rskj-core/src/main/java/co/rsk/db/MutableTrieCache.java

@@ -119,6 +119,11 @@ public Iterator<DataWord> getStorageKeys(RskAddress addr) {
         return new StorageKeysIterator(storageKeys, accountItems, addr, trieKeyMapper);
     }
 
+    @Override
+    public List<Trie> getNodes(byte[] key) {
+        return trie.getNodes(key);
+    }
+
     // This method returns a wrapper with the same content and size expected for a account key
     // when the key is from the same size than the original wrapper, it returns the same object
     private ByteArrayWrapper getAccountWrapper(ByteArrayWrapper originalWrapper) {

rskj-core/src/main/java/co/rsk/db/MutableTrieImpl.java

@@ -106,6 +106,11 @@ public Iterator<DataWord> getStorageKeys(RskAddress addr) {
         return Collections.emptyIterator();
     }
 
+    @Override
+    public List<Trie> getNodes(byte[] key) {
+        return trie.getNodes(key);
+    }
+
     @Override
     public void deleteRecursive(byte[] key) {
         trie = trie.deleteRecursive(key);

rskj-core/src/main/java/co/rsk/rpc/modules/eth/EthModule.java

@@ -290,7 +290,8 @@ public ProofDTO getProof(String address, List<String> storageKeys, String blockO
         String codeHash = accountInformationProvider.isContract(rskAddress) ?
                 toUnformattedJsonHex(accountInformationProvider.getCode(rskAddress)) :
                 "0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470"; // todo(fedejinich) extract constant
+        List<String> accountProof = accountInformationProvider.getAccountProof(rskAddress);
 
-        return new ProofDTO(balance, codeHash, nonce, storageHash, null, null);
+        return new ProofDTO(balance, codeHash, nonce, storageHash, accountProof, null);
     }
 }

rskj-core/src/main/java/co/rsk/trie/MutableTrie.java

@@ -25,9 +25,7 @@
 import org.ethereum.vm.DataWord;
 
 import javax.annotation.Nullable;
-import java.util.Iterator;
-import java.util.Optional;
-import java.util.Set;
+import java.util.*;
 
 /**
  * Every operation of a MutableTrie mutates the parent trie top node and therefore its stateRoot.
@@ -72,4 +70,6 @@ public interface MutableTrie {
     // the key has to match exactly an account key
     // it won't work if it is used with an storage key or any other
     Iterator<DataWord> getStorageKeys(RskAddress addr);
+
+    List<Trie> getNodes(byte[] key);
 }

rskj-core/src/main/java/org/ethereum/db/MutableRepository.java

@@ -33,14 +33,16 @@
 import org.ethereum.core.Repository;
 import org.ethereum.crypto.HashUtil;
 import org.ethereum.crypto.Keccak256Helper;
+import org.ethereum.util.ByteUtil;
+import org.ethereum.util.RLP;
 import org.ethereum.vm.DataWord;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import sun.reflect.generics.reflectiveObjects.NotImplementedException;
 
 import javax.annotation.Nonnull;
 import java.math.BigInteger;
 import java.util.*;
+import java.util.stream.Collectors;
 
 public class MutableRepository implements Repository {
     private static final Logger logger = LoggerFactory.getLogger("repository");
@@ -353,6 +355,24 @@ public Keccak256 getStorageHash(RskAddress addr) {
         return new Keccak256(storageRoot);
     }
 
+    @Override
+    public List<String> getAccountProof(RskAddress addr) {
+        byte[] accountKey = trieKeyMapper.getAccountKey(addr);
+
+        List<String> accountKeys = mutableTrie
+                .getNodes(accountKey)
+                .stream()
+                .map(this::toAccountProof)
+                .collect(Collectors.toList());
+
+        return accountKeys;
+    }
+
+    private String toAccountProof(Trie trie) {
+        byte[] rlpEncodedNode = RLP.encodeElement(trie.toMessage());
+        return ByteUtil.toHexString(rlpEncodedNode);
+    }
+
     @VisibleForTesting
     public byte[] getStorageStateRoot(RskAddress addr) {
         byte[] prefix = trieKeyMapper.getAccountStoragePrefixKey(addr);

rskj-core/src/main/java/org/ethereum/vm/program/Storage.java

@@ -32,6 +32,7 @@
 
 import java.math.BigInteger;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Set;
 
 /*
@@ -184,6 +185,11 @@ public Keccak256 getStorageHash(RskAddress addr) {
         return repository.getStorageHash(addr);
     }
 
+    @Override
+    public List<String> getAccountProof(RskAddress addr) {
+        throw new UnsupportedOperationException("Shouldn't get account proof from Storage");
+    }
+
     @Override
     public Coin getBalance(RskAddress addr) {
         return repository.getBalance(addr);