IClient.java

package merkle;


import merkle.implementation.MerkleTree;

import java.io.File;
import java.util.List;
import java.util.concurrent.ThreadLocalRandom;

/**
 * This is the client
 * DO NOT UPLOAD THIS FILE
 */
public abstract class IClient {
 private IServer server;
 protected String masterHash;
 private int numberOfNodes;

 /**
 * This method simulates uploading a file to a server
 * 1 - The file is uploaded to the server
 * 2 - The merkle tree is built
 * 3- The master hash is recorded
 */
 IMerkleTree uploadFile(File file, IServer server) throws Exception {
 this.server = server;
 this.server.uploadFile(file);

 IMerkleTree merkleTree = new MerkleTree();
 this.masterHash = merkleTree.build(file);

 this.numberOfNodes = merkleTree.getNumberOfNodes();
 return merkleTree;
 }

 /**
 * This method takes the number of times verification is to be run as input
 * A randomly picked node is verified that many times
 */
 int verifyFile(int verifyCount) throws Exception {
 int result = 0;
 for (int i = 0; i < verifyCount; i++) {
 int testNode = ThreadLocalRandom.current().nextInt(2, numberOfNodes);
 List<IMerkleTree.Node> trace = this.server.generateResponse(testNode);
 boolean matched = verifyResponse(trace);
 result += matched ? 1 : 0;
 Configuration.println("Verification result for node " + testNode + " = " + matched);
 }
 return result;

 }

 /**
 * Given the path siblings this function has to verify if
 * the masterHash generated by concatenating and hashing
 * level by level is the same as <i>this.masterHash</i>
 * You can use <i>Configuration.hashFunction</i>
 */
 protected abstract boolean verifyResponse(List<IMerkleTree.Node> pathSiblings) throws Exception;
}