Merge branch 'hashsum' of flavien/Projet_JAVA_P2P_STRI2A into master

closes #15

doc/protocol.md

@@ -16,10 +16,12 @@ x bytes: [(bytes 8-?): PAYLOAD]
 - REQUESTS (msb is 0):
 	- `LIST` (0x00)
 	- `LOAD` (0x01)
+	- `HASH` (0x02)
 
 - RESPONSES (msb is 1):
 	- `LIST` (0x80)
 	- `LOAD` (0x81)
+	- `HASH` (0x82)
 	- `VERSION ERROR` (0xC0)
 	- `PROTOCOL ERROR` (0xC1)
 	- `INTERNAL ERROR` (0xC2)
@@ -63,6 +65,39 @@ Payload contains
 y bytes: [<FILENAME>]
 ```
 
+###	Hash
+#### Hash request
+Get hash of a file. Payload contains
+
+```
+4 bytes: [(bytes  8-11): FILENAME SIZE]
+y bytes: [<FILENAME>]
+z bytes: [ALGO_NAMES requested separated by \n] (ex.: SHA-256, MD5)
+```
+
+If file does not exists, a NotFound can be responded.
+
+#### Hash response
+Payload contains:
+
+
+```
+4 bytes: [(bytes  8-11): FILENAME SIZE]
+y bytes: [<FILENAME>]
+[[ multiple algo hashes bloc]]
+```
+
+A algo hash bloc contains:
+
+```
+4 bytes [ALGO_NAME size]
+? [ALGO_NAME]
+4 bytes: [HASH SIZE (bytes)] / or 0 if this hash algorithm is unsupported.
+?? [HASH]
+
+```
+
+
 ### Other response code (errors)
 #### Version error
 Response when datagram received use wrong version code.

src/clientP2P/ClientManagementTCP.java

@@ -21,12 +21,18 @@ import java.nio.file.Files;
 import java.io.File;
 import java.nio.file.Paths;
 import java.nio.file.StandardOpenOption;
+import java.util.Arrays;
 import protocolP2P.ProtocolP2PPacketTCP;
 import protocolP2P.Payload;
 import protocolP2P.RequestResponseCode;
 import protocolP2P.FileList;
 import protocolP2P.FilePart;
 import protocolP2P.LoadRequest;
+import protocolP2P.HashAlgorithm;
+import protocolP2P.HashRequest;
+import protocolP2P.HashResponse;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 
 /** Implementation of P2P-JAVA-PROJECT CLIENT
  * @author	Louis Royer
@@ -134,8 +140,30 @@ public class ClientManagementTCP implements Runnable {
 	 * @throws	EmptyFile
 	 */
 	private void download(String filename) throws EmptyFile, NotFound, InternalError, UnknownHostException, IOException, SocketClosed, TransmissionError, ProtocolError, VersionError, SizeError, InternalRemoteError, ProtocolRemoteError, VersionRemoteError {
+		byte [] hash512;
 		final long MAX_PARTIAL_SIZE = 4096;
-		ProtocolP2PPacketTCP d = new ProtocolP2PPacketTCP((Payload) new LoadRequest(filename, 0, MAX_PARTIAL_SIZE));
+		HashAlgorithm[] hashesAlgo = new HashAlgorithm[1];
+		hashesAlgo[0] = HashAlgorithm.SHA512;
+		ProtocolP2PPacketTCP d = new ProtocolP2PPacketTCP((Payload) new HashRequest(filename, hashesAlgo));
+		d.sendRequest((Object)socket);
+		try {
+			Payload pHash = d.receiveResponse().getPayload();
+			assert pHash instanceof HashResponse : "This payload must be instance of HashResponse";
+			if (!(pHash instanceof HashResponse)) {
+				throw new InternalError();
+			} else { 
+				hash512 = ((HashResponse)pHash).getHash(HashAlgorithm.SHA512);
+				if (hash512.length == 0) {
+					System.err.println("Error: server do not support sha512 hashes");
+					throw new InternalError();
+				}
+			}
+		} catch (EmptyDirectory e) {
+			System.err.println("Error: empty directory, but request was not LIST_REQUEST");
+			throw new ProtocolError();
+		}
+
+		d = new ProtocolP2PPacketTCP((Payload) new LoadRequest(filename, 0, MAX_PARTIAL_SIZE));
 		d.sendRequest((Object)socket);
 		boolean fileFullyWritten = false;
 		long offset = 0;
@@ -199,6 +227,10 @@ public class ClientManagementTCP implements Runnable {
 				throw new ProtocolError();
 			}
 		} while(!fileFullyWritten);
+		if (!Arrays.equals(hash512, computeHashsum(filename, HashAlgorithm.SHA512))) {
+			System.err.println("Error: Hashsum does not match");
+			throw new InternalError();
+		}
 		socket.close();
 	}
 
@@ -234,4 +266,20 @@ public class ClientManagementTCP implements Runnable {
 			throw new ProtocolError();
 		}
 	}
+
+	/** Compute Hashsum of a file.
+	 * @param	filename
+	 * @return	hashsum
+	 */
+	private byte[] computeHashsum(String filename, HashAlgorithm h) {
+		try {
+			MessageDigest md = MessageDigest.getInstance(HashAlgorithm.SHA512.getName());
+			return md.digest(Files.readAllBytes(Paths.get(baseDirectory + filename)));
+		} catch (NoSuchAlgorithmException e) {
+			System.out.println("Error: " + h.getName() + " not supported");
+		} catch (IOException e) {
+			System.out.println("Error: cannot read " + filename);
+		}
+		return new byte[0];
+	}
 }

src/clientP2P/ClientManagementUDP.java

@@ -20,12 +20,18 @@ import java.nio.file.Files;
 import java.io.File;
 import java.nio.file.Paths;
 import java.nio.file.StandardOpenOption;
+import java.util.Arrays;
 import protocolP2P.ProtocolP2PPacketUDP;
 import protocolP2P.Payload;
 import protocolP2P.RequestResponseCode;
 import protocolP2P.FileList;
 import protocolP2P.FilePart;
 import protocolP2P.LoadRequest;
+import protocolP2P.HashAlgorithm;
+import protocolP2P.HashRequest;
+import protocolP2P.HashResponse;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 
 /** Implementation of P2P-JAVA-PROJECT CLIENT
  * @author	Louis Royer
@@ -121,8 +127,30 @@ public class ClientManagementUDP implements Runnable {
 	 * @throws	EmptyFile
 	 */
 	private void download(String filename) throws EmptyFile, NotFound, InternalError, UnknownHostException, IOException, TransmissionError, ProtocolError, VersionError, SizeError, InternalRemoteError, ProtocolRemoteError, VersionRemoteError {
+		byte[] hash512;
 		final long MAX_PARTIAL_SIZE = 4096;
-		ProtocolP2PPacketUDP d = new ProtocolP2PPacketUDP((Payload) new LoadRequest(filename, 0, MAX_PARTIAL_SIZE));
+		HashAlgorithm[] hashesAlgo = new HashAlgorithm[1];
+		hashesAlgo[0] = HashAlgorithm.SHA512;
+		ProtocolP2PPacketUDP d = new ProtocolP2PPacketUDP((Payload) new HashRequest(filename, hashesAlgo));
+		d.sendRequest((Object)socket);
+		try {
+			Payload pHash = d.receiveResponse().getPayload();
+			assert pHash instanceof HashResponse : "This payload must be instance of HashResponse";
+			if (!(pHash instanceof HashResponse)) {
+				throw new InternalError();
+			} else { 
+				hash512 = ((HashResponse)pHash).getHash(HashAlgorithm.SHA512);
+				if (hash512.length == 0) {
+					System.err.println("Error: server do not support sha512 hashes");
+					throw new InternalError();
+				}
+			}
+		} catch (EmptyDirectory e) {
+			System.err.println("Error: empty directory, but request was not LIST_REQUEST");
+			throw new ProtocolError();
+		}
+
+		d = new ProtocolP2PPacketUDP((Payload) new LoadRequest(filename, 0, MAX_PARTIAL_SIZE));
 		d.sendRequest((Object)socket);
 		boolean fileFullyWritten = false;
 		long offset = 0;
@@ -186,6 +214,10 @@ public class ClientManagementUDP implements Runnable {
 				throw new ProtocolError();
 			}
 		} while(!fileFullyWritten);
+		if (!Arrays.equals(hash512, computeHashsum(filename, HashAlgorithm.SHA512))) {
+			System.err.println("Error: Hashsum does not match");
+			throw new InternalError();
+		}
 	}
 
 	/** list server’s directory content
@@ -219,4 +251,20 @@ public class ClientManagementUDP implements Runnable {
 			throw new ProtocolError();
 		}
 	}
+
+	/** Compute Hashsum of a file.
+	 * @param	filename
+	 * @return	hashsum
+	 */
+	private byte[] computeHashsum(String filename, HashAlgorithm h) {
+		try {
+			MessageDigest md = MessageDigest.getInstance(HashAlgorithm.SHA512.getName());
+			return md.digest(Files.readAllBytes(Paths.get(baseDirectory + filename)));
+		} catch (NoSuchAlgorithmException e) {
+			System.out.println("Error: " + h.getName() + " not supported");
+		} catch (IOException e) {
+			System.out.println("Error: cannot read " + filename);
+		}
+		return new byte[0];
+	}
 }

src/protocolP2P/HashAlgorithm.java

@@ -0,0 +1,52 @@
+package protocolP2P;
+import java.util.HashMap;
+import java.util.Map;
+import tools.BytesArrayTools;
+
+/** HashAlgorithm enum.
+ * @author	Louis Royer
+ * @author	Flavien Haas
+ * @author	JS Auge
+ * @version	1.0
+ */
+public enum HashAlgorithm {
+	SHA512("SHA-512"),
+	MD5("MD5");
+	
+	private String name;
+	/* To be able to convert name to enum */
+	private static final Map<String, HashAlgorithm> BY_NAME = new HashMap<>();
+	/* Initialization of HashMap */
+	static {
+		for (HashAlgorithm h: values()) {
+			assert !BY_NAME.containsKey(h.name) : "Duplicate in " + HashAlgorithm.class.getCanonicalName();
+			BY_NAME.put(h.name, h);
+		}
+	}
+
+	private HashAlgorithm(String name) {
+		this.name = name;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	/** Gives enum from name.
+	 * @param name	name of the hash
+	 * @return	enum element
+	 * @throws	InterlanError
+	 */
+	protected static HashAlgorithm fromName(String name) throws InternalError {
+		HashAlgorithm h = BY_NAME.get(BytesArrayTools.cleanStrings(name));
+		assert h != null : "Bad algorithm name: " + name;
+		if (h == null) {
+			throw new InternalError();
+		}
+		return h;
+		
+	}
+	
+}
+
+

src/protocolP2P/HashRequest.java

@@ -0,0 +1,165 @@
+package protocolP2P;
+import protocolP2P.Payload;
+import protocolP2P.HashAlgorithm;
+import java.io.UnsupportedEncodingException;
+import exception.TransmissionError;
+import exception.SizeError;
+import exception.ProtocolError;
+import exception.InternalError;
+import tools.BytesArrayTools;
+
+
+/** Representation of payload for hash request.
+ * @author	Louis Royer
+ * @author	Flavien Haas
+ * @author	JS Auge
+ * @version	1.0
+ */
+
+public class HashRequest extends Payload {
+	private String filename;
+	private HashAlgorithm[] algoList;
+	private static final int FILENAME_SIZE_POSITION = PAYLOAD_START_POSITION;
+	private static final int FILENAME_POSITION = FILENAME_SIZE_POSITION + 4;
+	
+	/** Constructor (typically used by the server) with a filename parameter.
+	 * @param filename	name of the file to download. Must not be empty.
+	 * @param algoList	List of hash algorithms used
+	 * @throws	InternalError
+	 * 
+	 */
+	public HashRequest(String filename, HashAlgorithm[] algoList) throws InternalError {
+		super(RequestResponseCode.HASH_REQUEST);
+		/* assert to help debugging */
+		assert filename.length() != 0 : "Size of filename in HashRequest must not be empty";
+		if (filename.length() == 0) {
+			throw new InternalError();
+		}
+		this.filename = filename;
+		assert algoList.length != 0 : "Hash algorithms list must not be empty";
+		if (algoList.length == 0) {
+			throw new InternalError();
+		}
+		this.algoList = algoList;
+	}
+
+	/** Constructor (typically used by client) with a byte[] parameter containing the Packet received.
+	 * @param packet	the full Packet received
+	 * @throws	SizeError
+	 * @throws	InternalError
+	 * @throws	ProtocolError
+	 * @throws	TransmissionError
+	 */
+	protected HashRequest(byte[] packet) throws TransmissionError, SizeError, ProtocolError, InternalError {
+		super(packet);
+		/* assert to help debugging */
+		assert requestResponseCode == RequestResponseCode.HASH_REQUEST : "HashRequest subclass is incompatible with this Packet, request/response code must be checked before using this constructor";
+		/* InternalErrorException */
+		if (requestResponseCode!= RequestResponseCode.HASH_REQUEST) {
+			throw new InternalError();
+		}
+		/* Read filename */
+		int filenameSize = BytesArrayTools.readInt(packet, FILENAME_SIZE_POSITION);
+		try {
+			filename = new String(packet, FILENAME_POSITION, filenameSize, "UTF-8");
+		} catch (UnsupportedEncodingException e) {
+			throw new InternalError();
+		}
+
+		int size = getPayloadSize(packet);
+		try {
+			String[] l = (new String(packet, FILENAME_POSITION + filenameSize, size, "UTF-8")).split("\n");
+			int i = 0;
+			algoList = new HashAlgorithm[l.length];
+			for(String algo : l) {
+				algoList[i] = HashAlgorithm.fromName(algo);
+				i++;
+			}
+		} catch (UnsupportedEncodingException e) {
+			throw new InternalError();
+		}
+	}
+
+	/** Returns a byte[] containing Packet with padding.
+	 * This Packet is still incomplete and should not be send directly.
+	 * ProtocolP2PPacket will use this method to generate the complete Packet.
+	 * @return Packet with padding
+	 * @throws	InternalError
+	 */
+	protected byte[] toPacket() throws InternalError {
+		// compute size
+		int filenameSize = filename.length();
+		int size = FILENAME_POSITION + filenameSize;
+		for (HashAlgorithm h : algoList) {
+			if (h == null) {
+				continue;
+			}
+			size += h.getName().length();
+			size += 1; // size for '\n'
+		}
+		size -=1; // remove trailing '\n'
+		byte[] packet = new byte[size + 1]; // java initialize all to zero
+		
+		// set request/response code
+		packet[RequestResponseCode.RRCODE_POSITION] = requestResponseCode.codeValue;
+		
+		// set Payload size
+		setPayloadSize(size - FILENAME_SIZE_POSITION, packet);
+
+		BytesArrayTools.write(packet, FILENAME_SIZE_POSITION, filenameSize);
+		
+		// Write filename
+		int bCount = FILENAME_POSITION;
+		try {
+			byte[] sb = filename.getBytes("UTF-8");
+			for(byte b : sb) {
+				packet[bCount] = b;
+				bCount += 1;
+			}
+		} catch (UnsupportedEncodingException e) {
+			throw new InternalError();
+		}
+		boolean firstIter = true;
+		for(HashAlgorithm h : algoList) {
+			if (h == null) {
+				continue;
+			}
+			String s = h.getName();
+			if (!firstIter) {
+				firstIter = false;
+				try {
+					packet[bCount] = "\n".getBytes("UTF-8")[0]; // separator
+				} catch (UnsupportedEncodingException e) {
+					throw new InternalError();
+				}
+				bCount += 1;
+			}
+			// Copy algoname
+			try {
+				byte[] sb = s.getBytes("UTF-8");
+				for(byte b : sb) {
+					packet[bCount] = b;
+					bCount += 1;
+				}
+			} catch (UnsupportedEncodingException e) {
+				throw new InternalError();
+			}
+			
+		}
+		return packet;
+	}
+
+	/** AlgoList getter.
+	 * @return	List of HashAlgorithms
+	 */
+	public HashAlgorithm[] getAlgoList() {
+		return algoList;
+	}
+
+	/** Filename getter.
+	 * @return	filename
+	 */
+	public String getFilename() {
+		return filename;
+	}
+}

src/protocolP2P/HashResponse.java

@@ -0,0 +1,185 @@
+package protocolP2P;
+import protocolP2P.Payload;
+import java.util.HashMap;
+import java.util.Map;
+import java.io.UnsupportedEncodingException;
+import exception.TransmissionError;
+import exception.SizeError;
+import exception.ProtocolError;
+import exception.InternalError;
+import tools.BytesArrayTools;
+
+
+/** Representation of payload for hash response.
+ * @author	Louis Royer
+ * @author	Flavien Haas
+ * @author	JS Auge
+ * @version	1.0
+ */
+
+public class HashResponse extends Payload {
+	private String filename;
+	private Map<HashAlgorithm, byte[]> hashes = new HashMap<>();
+	private static final int FILENAME_SIZE_POSITION = PAYLOAD_START_POSITION;
+	private static final int FILENAME_POSITION = FILENAME_SIZE_POSITION + 4;
+	
+	/** Constructor (typically used by the server) with a filename parameter.
+	 * @param filename	name of the file to download. Must not be empty.
+	 * @param hashes	HashMap containing hashes for file.
+	 * @throws	InternalError
+	 * 
+	 */
+	public HashResponse(String filename, Map<HashAlgorithm, byte[]> hashes) throws InternalError {
+		super(RequestResponseCode.HASH_RESPONSE);
+		/* assert to help debugging */
+		assert filename.length() != 0 : "Size of filename in HashResponse must not be empty";
+		if (filename.length() == 0) {
+			throw new InternalError();
+		}
+		this.filename = filename;
+
+		// initialize hashes
+		assert !hashes.isEmpty() : "At least 1 hash must be provided";
+		if (hashes.isEmpty())  {
+			throw new InternalError();
+		}
+		this.hashes = hashes;
+	}
+
+	/** Constructor (typically used by client) with a byte[] parameter containing the Packet received.
+	 * @param packet	the full Packet received
+	 * @throws	SizeError
+	 * @throws	InternalError
+	 * @throws	ProtocolError
+	 * @throws	TransmissionError
+	 */
+	protected HashResponse(byte[] packet) throws TransmissionError, SizeError, ProtocolError, InternalError {
+		super(packet);
+		/* assert to help debugging */
+		assert requestResponseCode == RequestResponseCode.HASH_RESPONSE : "HashResponse subclass is incompatible with this Packet, request/response code must be checked before using this constructor";
+		/* InternalErrorException */
+		if (requestResponseCode!= RequestResponseCode.HASH_RESPONSE) {
+			throw new InternalError();
+		}
+		/* Read filename */
+		int filenameSize = BytesArrayTools.readInt(packet, FILENAME_SIZE_POSITION);
+		try {
+			filename = new String(packet, FILENAME_POSITION, filenameSize, "UTF-8");
+		} catch (UnsupportedEncodingException e) {
+			throw new InternalError();
+		}
+
+		int size = getPayloadSize(packet);
+		int start = FILENAME_POSITION + filenameSize;
+		do {
+			int algoNameSize = BytesArrayTools.readInt(packet, start);
+			start +=4;
+			try {
+				String algoName = new String(packet, start, algoNameSize, "UTF-8");
+				start += algoNameSize;
+				int hashSize = BytesArrayTools.readInt(packet, start);
+				start += 4;
+				if (hashSize != 0) {
+					byte[] b = new byte[hashSize];
+					for (int i=0;i<hashSize;i++) {
+						b[i] = packet[start+i];
+					}
+					hashes.put(HashAlgorithm.fromName(algoName), b);
+				}
+				start += hashSize;
+			} catch (UnsupportedEncodingException e) {
+				throw new InternalError();
+			}
+		} while (start < size);
+			
+	}
+
+	/** Returns a byte[] containing Packet with padding.
+	 * This Packet is still incomplete and should not be send directly.
+	 * ProtocolP2PPacket will use this method to generate the complete Packet.
+	 * @return Packet with padding
+	 * @throws	InternalError
+	 */
+	protected byte[] toPacket() throws InternalError {
+		// compute size
+		int filenameSize = filename.length();
+		int size = FILENAME_POSITION + filenameSize;
+		for (HashAlgorithm h : hashes.keySet()) {
+			size += 4 + h.getName().length();
+		}
+		for (byte[] s : hashes.values()) {
+			size += 4 + s.length;
+		}
+		byte[] packet = new byte[size + 1]; // java initialize all to zero
+		
+		// set request/response code
+		packet[RequestResponseCode.RRCODE_POSITION] = requestResponseCode.codeValue;
+		
+		// set Payload size
+		setPayloadSize(size - FILENAME_SIZE_POSITION, packet);
+
+		BytesArrayTools.write(packet, FILENAME_SIZE_POSITION, filenameSize);
+		
+		// Write filename
+		int bCount = FILENAME_POSITION;
+		try {
+			byte[] sb = filename.getBytes("UTF-8");
+			for(byte b : sb) {
+				packet[bCount] = b;
+				bCount += 1;
+			}
+		} catch (UnsupportedEncodingException e) {
+			throw new InternalError();
+		}
+		for(HashAlgorithm h : hashes.keySet()) {
+			String s = h.getName();
+			BytesArrayTools.write(packet, bCount, (int)s.length());
+			bCount += 4;
+			// Copy algoname
+			try {
+				byte[] sb = s.getBytes("UTF-8");
+				for(byte b : sb) {
+					packet[bCount] = b;
+					bCount += 1;
+				}
+			} catch (UnsupportedEncodingException e) {
+				throw new InternalError();
+			}
+			byte[] hashb = hashes.get(HashAlgorithm.fromName(s));
+			if (hashb.length == 0) {
+				BytesArrayTools.write(packet, bCount, (int)0);
+				bCount += 4;
+			} else {
+				BytesArrayTools.write(packet, bCount, (int)hashb.length);
+				bCount +=4;
+				// copy hash
+				for(byte b : hashb) {
+					packet[bCount] = b;
+					bCount += 1;
+				}
+			}
+		}
+		return packet;
+	}
+
+	/** hash getter
+	 * @param hashAlgo	HashAlgorithm to return hash from
+	 * @return	hash
+	 */
+	public byte[] getHash(HashAlgorithm hashAlgo) {
+		byte[] b = hashes.get(hashAlgo);
+		if (b == null) {
+			return new byte[0];
+		} else {
+			return b;
+		}
+	}
+
+	/** filename getter.
+	 * @return	filename
+	 */
+	public String getFilename() {
+		return filename;
+	}
+
+}

src/protocolP2P/Payload.java

@@ -3,6 +3,8 @@ import protocolP2P.RequestResponseCode;
 import protocolP2P.FilePart;
 import protocolP2P.FileList;
 import protocolP2P.LoadRequest;
+import protocolP2P.HashRequest;
+import protocolP2P.HashResponse;
 import exception.ProtocolError;
 import exception.InternalError;
 import exception.TransmissionError;
@@ -28,6 +30,8 @@ public class Payload {
 		assert requestResponseCode != RequestResponseCode.LIST_RESPONSE || (this instanceof FileList) : "LIST_RESPONSE must use FilePart class";
 		assert requestResponseCode != RequestResponseCode.LOAD_RESPONSE || (this instanceof FilePart) : "LOAD_RESPONSE must use FileList class";
 		assert requestResponseCode != RequestResponseCode.LOAD_REQUEST  || (this instanceof LoadRequest) : "LOAD_REQUEST must use LoadRequest class";
+		assert requestResponseCode != RequestResponseCode.HASH_REQUEST  || (this instanceof HashRequest) : "HASH_REQUEST must use HashRequest class";
+		assert requestResponseCode != RequestResponseCode.HASH_RESPONSE  || (this instanceof HashResponse) : "HASH_RESPONSE must use HashResponse class";
 		this.requestResponseCode = requestResponseCode;
 		checkRequestResponseCode(); // this can throw InternalError
 	}

src/protocolP2P/ProtocolP2PPacketTCP.java

@@ -137,6 +137,7 @@ public class ProtocolP2PPacketTCP extends ProtocolP2PPacket {
 				case EMPTY_FILE:
 				case LOAD_RESPONSE:
 				case LIST_RESPONSE:
+				case HASH_RESPONSE:
 					// we were expecting a request, but we are receiving a response
 					throw new ProtocolError();
 				default :
@@ -281,6 +282,12 @@ public class ProtocolP2PPacketTCP extends ProtocolP2PPacket {
 			case LOAD_REQUEST:
 				payload = (Payload) new LoadRequest(packet);
 				break;
+			case HASH_REQUEST:
+				payload = (Payload) new HashRequest(packet);
+				break;
+			case HASH_RESPONSE:
+				payload = (Payload) new HashResponse(packet);
+				break;
 			default:
 				payload = new Payload(packet); // this can throw TransmissionError
 				break;

src/protocolP2P/ProtocolP2PPacketUDP.java

@@ -129,6 +129,7 @@ public class ProtocolP2PPacketUDP extends ProtocolP2PPacket {
 				case EMPTY_FILE:
 				case LOAD_RESPONSE:
 				case LIST_RESPONSE:
+				case HASH_RESPONSE:
 					// we were expecting a request, but we are receiving a response
 					throw new ProtocolError();
 				default :
@@ -277,6 +278,12 @@ public class ProtocolP2PPacketUDP extends ProtocolP2PPacket {
 			case LOAD_REQUEST:
 				payload = (Payload) new LoadRequest(packet);
 				break;
+			case HASH_REQUEST:
+				payload = (Payload) new HashRequest(packet);
+				break;
+			case HASH_RESPONSE:
+				payload = (Payload) new HashResponse(packet);
+				break;
 			default:
 				payload = new Payload(packet); // this can throw TransmissionError
 				break;

src/protocolP2P/RequestResponseCode.java

@@ -14,8 +14,10 @@ import java.lang.Byte;
 public enum RequestResponseCode {
 	LIST_REQUEST(CodeType.REQUEST, (byte)0x00),
 	LOAD_REQUEST(CodeType.REQUEST, (byte)0x01),
+	HASH_REQUEST(CodeType.REQUEST, (byte)0x02),
 	LIST_RESPONSE(CodeType.RESPONSE, (byte)0x80),
 	LOAD_RESPONSE(CodeType.RESPONSE, (byte)0x81),
+	HASH_RESPONSE(CodeType.RESPONSE, (byte)0x82),
 	VERSION_ERROR(CodeType.ERROR, (byte)0xC0),
 	PROTOCOL_ERROR(CodeType.ERROR, (byte)0xC1),
 	INTERNAL_ERROR(CodeType.ERROR, (byte)0xC2),
@@ -49,10 +51,11 @@ public enum RequestResponseCode {
 
 	/** Gives enum from Packet code.
 	 * @param code	value of the element in packet
-	 * @return enum element
+	 * @return	enum element
+	 * @throws	ProtocolError
 	 */
 	protected static RequestResponseCode fromCode(byte code) throws ProtocolError {
-		RequestResponseCode r= BY_CODE.get(Byte.valueOf(code));
+		RequestResponseCode r = BY_CODE.get(Byte.valueOf(code));
 		if (r == null) {
 			throw new ProtocolError();
 		}

src/serverP2P/ServerManagementTCP.java

@@ -6,6 +6,8 @@ import java.net.InetAddress;
 import java.net.SocketException;
 import java.nio.file.Paths;
 import java.nio.file.Files;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 import java.net.ServerSocket;
 import java.net.Socket;
 import protocolP2P.ProtocolP2PPacketTCP;
@@ -30,6 +32,11 @@ import remoteException.EmptyFile;
 import java.util.Arrays;
 import tools.Logger;
 import tools.LogLevel;
+import java.util.HashMap;
+import java.util.Map;
+import protocolP2P.HashAlgorithm;
+import protocolP2P.HashRequest;
+import protocolP2P.HashResponse;
 
 
 /** Implementation of P2P-JAVA-PROJECT VERSION 1.0 protocol for TCP.
@@ -41,6 +48,7 @@ import tools.LogLevel;
 public class ServerManagementTCP implements Runnable {
 
 	private String[] fileList;
+	private Map<String, byte[]> sha512 = new HashMap<>();
 	private String baseDirectory;
 	private int TCPPort;
 	private ServerSocket socket;
@@ -55,6 +63,7 @@ public class ServerManagementTCP implements Runnable {
 		this.baseDirectory = baseDirectory;
 		this.TCPPort = TCPPort;
 		initFileList();
+		initSha512();
 		try {
 			socket = new ServerSocket(TCPPort);
 		} catch (SocketException e) {
@@ -123,6 +132,10 @@ public class ServerManagementTCP implements Runnable {
 						logger.writeTCP(addr + "LIST_REQUEST", LogLevel.Action);
 						sendListResponse(pd);
 						break;
+					case HASH_REQUEST:
+						logger.writeTCP(addr + "HASH_REQUEST", LogLevel.Action);
+						sendHashResponse(pd);
+						break;
 					default:
 						logger.writeTCP(addr + "Received grabbage", LogLevel.Action);
 						sendInternalError(pd);
@@ -158,6 +171,22 @@ public class ServerManagementTCP implements Runnable {
 		Arrays.sort(fileList);
 	}
 
+	/** Init sha512 map.
+	 */
+	 private void initSha512() {
+		for(String f: fileList) {
+			try {
+				MessageDigest md = MessageDigest.getInstance(HashAlgorithm.SHA512.getName()); 
+				sha512.put(f, md.digest(Files.readAllBytes(Paths.get(baseDirectory + f))));
+				md.reset();
+			} catch (NoSuchAlgorithmException e) {
+				logger.writeTCP("sha512 not supported", LogLevel.Error);
+			} catch (IOException e) {
+				logger.writeTCP("cannot read " + f, LogLevel.Warning);
+			}
+		}
+	}
+
 	/** Send an internal error message.
 	 * @param pd	ProtocolP2PPacketTCP to respond
 	 */
@@ -187,6 +216,46 @@ public class ServerManagementTCP implements Runnable {
 		}
 	}
 
+	/** Send hash response to hash request
+	 * @param pd	Request received
+	 */
+	private void sendHashResponse(ProtocolP2PPacketTCP pd) {
+		Payload p = pd.getPayload();
+		assert p instanceof HashRequest : "payload must be an instance of HashRequest";
+		if (!(p instanceof HashRequest)) {
+			sendInternalError(pd);
+		} else {
+			String filename = ((HashRequest)p).getFilename();
+			if (Arrays.binarySearch(fileList, filename) >= 0) {
+				Map<HashAlgorithm, byte[]> hashes = new HashMap<>();
+				for (HashAlgorithm h : ((HashRequest)p).getAlgoList()) {
+					switch (h) {
+						case SHA512:
+							hashes.put(h, sha512.get(filename));
+							break;
+						case MD5:
+						default:
+							hashes.put(h, new byte[0]);
+							break;
+					}
+				}
+				try {
+					pd.sendResponse((ProtocolP2PPacket)new ProtocolP2PPacketTCP((Payload)(new HashResponse(filename, hashes))));
+				} catch (Exception e) {
+					logger.writeTCP(e, LogLevel.Error);
+				}
+			} else {
+				// file not found
+				try {
+					pd.sendResponse((ProtocolP2PPacket)new ProtocolP2PPacketTCP(new Payload(RequestResponseCode.NOT_FOUND)));
+				} catch (Exception e) {
+					logger.writeTCP(e, LogLevel.Error);
+				}
+			}
+		}
+	}
+			
+
 	/** Send response to load request
 	 * @param pd	Request received
 	 */

src/serverP2P/ServerManagementUDP.java

@@ -7,6 +7,8 @@ import java.net.InetAddress;
 import java.net.SocketException;
 import java.nio.file.Paths;
 import java.nio.file.Files;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 import protocolP2P.ProtocolP2PPacketUDP;
 import protocolP2P.ProtocolP2PPacket;
 import protocolP2P.RequestResponseCode;
@@ -29,7 +31,11 @@ import remoteException.EmptyFile;
 import java.util.Arrays;
 import tools.Logger;
 import tools.LogLevel;
-
+import java.util.HashMap;
+import java.util.Map;
+import protocolP2P.HashAlgorithm;
+import protocolP2P.HashRequest;
+import protocolP2P.HashResponse;
 
 /** Implementation of P2P-JAVA-PROJECT VERSION 1.0 protocol for UDP.
  * @author	Louis Royer
@@ -40,6 +46,7 @@ import tools.LogLevel;
 public class ServerManagementUDP implements Runnable {
 
 	private String[] fileList;
+	private Map<String, byte[]> sha512 = new HashMap<>();
 	private String baseDirectory;
 	private int UDPPort;
 	private DatagramSocket socket;
@@ -54,6 +61,7 @@ public class ServerManagementUDP implements Runnable {
 		this.baseDirectory = baseDirectory;
 		this.UDPPort = UDPPort;
 		initFileList();
+		initSha512();
 		try {
 			socket = new DatagramSocket(UDPPort);
 		} catch (SocketException e) {
@@ -134,6 +142,10 @@ public class ServerManagementUDP implements Runnable {
 							logger.writeUDP(e2, LogLevel.Error);
 						}
 						break;
+					case HASH_REQUEST:
+						logger.writeUDP("Received HASH_REQUEST", LogLevel.Action);
+						sendHashResponse(pd);
+						break;
 					default:
 						sendInternalError(pd);
 				}
@@ -165,7 +177,21 @@ public class ServerManagementUDP implements Runnable {
 		Arrays.sort(fileList);
 	}
 
-
+	/** Init sha512 map.
+	 */
+	 private void initSha512() {
+		for(String f: fileList) {
+			try {
+				MessageDigest md = MessageDigest.getInstance(HashAlgorithm.SHA512.getName()); 
+				sha512.put(f, md.digest(Files.readAllBytes(Paths.get(baseDirectory + f))));
+				md.reset();
+			} catch (NoSuchAlgorithmException e) {
+				logger.writeUDP("sha512 not supported", LogLevel.Error);
+			} catch (IOException e) {
+				logger.writeUDP("cannot read " + f, LogLevel.Warning);
+			}
+		}
+	}
 	
 	/** Send an internal error message.
 	 * @param pd	ProtocolP2PPacketUDP to respond
@@ -179,5 +205,44 @@ public class ServerManagementUDP implements Runnable {
 		}
 	}
 
+	/** Send hash response to hash request
+	 * @param pd	Request received
+	 */
+	private void sendHashResponse(ProtocolP2PPacketUDP pd) {
+		Payload p = pd.getPayload();
+		assert p instanceof HashRequest : "payload must be an instance of HashRequest";
+		if (!(p instanceof HashRequest)) {
+			sendInternalError(pd);
+		} else {
+			String filename = ((HashRequest)p).getFilename();
+			if (Arrays.binarySearch(fileList, filename) >= 0) {
+				Map<HashAlgorithm, byte[]> hashes = new HashMap<>();
+				for (HashAlgorithm h : ((HashRequest)p).getAlgoList()) {
+					switch (h) {
+						case SHA512:
+							hashes.put(h, sha512.get(filename));
+							break;
+						case MD5:
+						default:
+							hashes.put(h, new byte[0]);
+							break;
+					}
+				}
+				try {
+					pd.sendResponse((ProtocolP2PPacket)new ProtocolP2PPacketUDP((Payload)(new HashResponse(filename, hashes))));
+				} catch (Exception e) {
+					logger.writeUDP(e, LogLevel.Error);
+				}
+			} else {
+				// file not found
+				try {
+					pd.sendResponse((ProtocolP2PPacket)new ProtocolP2PPacketUDP(new Payload(RequestResponseCode.NOT_FOUND)));
+				} catch (Exception e) {
+					logger.writeUDP(e, LogLevel.Error);
+				}
+			}
+		}
+	}
+
 }
 

src/tools/BytesArrayTools.java

@@ -100,4 +100,20 @@ public class BytesArrayTools {
 		return size;
 	}
 
+	/** Remove trailing null bytes from string.
+	 * @param str	input string
+	 * @return	str without trailing null bytes
+	 */
+	public static String cleanStrings(String str) {
+		int i = 0;
+		int cpt = 0;
+		byte[] bArray = str.getBytes();
+		for (byte b : bArray) {
+			if (b != 0) {
+				cpt = i;
+			}
+			i++;
+		}
+		return new String(bArray, 0, cpt + 1);
+	}
 }

src/tools/LogLevel.java

@@ -1,4 +1,10 @@
 package tools;
+/** LogLevel Enum.
+ * @author	Louis Royer
+ * @author	Flavien Haas
+ * @author	JS Auge
+ * @version	1.0
+ */
 public enum LogLevel {
 	Error,
 	Info,

src/tools/Logger.java

@@ -98,6 +98,7 @@ public class Logger {
 	 */
 	public void writeTCP(Exception e, LogLevel logLevel) {
 		writeTCP(e.toString(), logLevel);
+		e.printStackTrace();
 	}
 
 	/** Appends log to filelog and print to stderr.
@@ -116,6 +117,7 @@ public class Logger {
 	 */
 	public void writeUDP(Exception e, LogLevel logLevel) {
 		writeUDP(e.toString(), logLevel);
+		e.printStackTrace();
 	}
 
 }