--- /dev/null
+
+
+
+
+/**
+ * This class provides a communication API to the webserver. It also
+ * validates the HMACs on the slots and handles encryption.
+ * @author Brian Demsky <bdemsky@uci.edu>
+ * @version 1.0
+ */
+
+
+class CloudComm {
+ private static final int SALT_SIZE = 8;
+ private static final int TIMEOUT_MILLIS = 5000; // 100
+ public static final int IV_SIZE = 16;
+
+ /** Sets the size for the HMAC. */
+ static final int HMAC_SIZE = 32;
+
+ private String baseurl;
+ private SecretKeySpec key;
+ private Mac mac;
+ private String password;
+ private SecureRandom random;
+ private char salt[];
+ private Table table;
+ private int listeningPort = -1;
+ private Thread localServerThread = NULL;
+ private bool doEnd = false;
+
+ private TimingSingleton timer = NULL;
+
+ /**
+ * Empty Constructor needed for child class.
+ */
+ CloudComm() {
+ timer = TimingSingleton.getInstance();
+ }
+
+ /**
+ * Constructor for actual use. Takes in the url and password.
+ */
+ CloudComm(Table _table, String _baseurl, String _password, int _listeningPort) {
+ timer = TimingSingleton.getInstance();
+ this.table = _table;
+ this.baseurl = _baseurl;
+ this.password = _password;
+ this.random = new SecureRandom();
+ this.listeningPort = _listeningPort;
+
+ if (this.listeningPort > 0) {
+ localServerThread = new Thread(new Runnable() {
+ public void run() {
+ localServerWorkerFunction();
+ }
+ });
+ localServerThread.start();
+ }
+ }
+
+ /**
+ * Generates Key from password.
+ */
+ private SecretKeySpec initKey() {
+ try {
+ PBEKeySpec keyspec = new PBEKeySpec(password.toCharArray(),
+ salt,
+ 65536,
+ 128);
+ SecretKey tmpkey = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256").generateSecret(keyspec);
+ return new SecretKeySpec(tmpkey.getEncoded(), "AES");
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new Error("Failed generating key.");
+ }
+ }
+
+ /**
+ * Inits all the security stuff
+ */
+ public void initSecurity() throws ServerException {
+ // try to get the salt and if one does not exist set one
+ if (!getSalt()) {
+ //Set the salt
+ setSalt();
+ }
+
+ initCrypt();
+ }
+
+ /**
+ * Inits the HMAC generator.
+ */
+ private void initCrypt() {
+
+ if (password == NULL) {
+ return;
+ }
+
+ try {
+ key = initKey();
+ password = NULL; // drop password
+ mac = Mac.getInstance("HmacSHA256");
+ mac.init(key);
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new Error("Failed To Initialize Ciphers");
+ }
+ }
+
+ /*
+ * Builds the URL for the given request.
+ */
+ private URL buildRequest(bool isput, int64_t sequencenumber, int64_t maxentries) throws IOException {
+ String reqstring = isput ? "req=putslot" : "req=getslot";
+ String urlstr = baseurl + "?" + reqstring + "&seq=" + sequencenumber;
+ if (maxentries != 0)
+ urlstr += "&max=" + maxentries;
+ return new URL(urlstr);
+ }
+
+ private void setSalt() throws ServerException {
+
+ if (salt != NULL) {
+ // Salt already sent to server so dont set it again
+ return;
+ }
+
+ try {
+ char[] saltTmp = new char[SALT_SIZE];
+ random.nextBytes(saltTmp);
+
+ for (int i = 0; i < SALT_SIZE; i++) {
+ System.out.println((int)saltTmp[i] & 255);
+ }
+
+
+ URL url = new URL(baseurl + "?req=setsalt");
+
+ timer.startTime();
+ URLConnection con = url.openConnection();
+ HttpURLConnection http = (HttpURLConnection) con;
+
+ http.setRequestMethod("POST");
+ http.setFixedLengthStreamingMode(saltTmp.length);
+ http.setDoOutput(true);
+ http.setConnectTimeout(TIMEOUT_MILLIS);
+
+
+ http.connect();
+
+ OutputStream os = http.getOutputStream();
+ os.write(saltTmp);
+ os.flush();
+
+ int responsecode = http.getResponseCode();
+ if (responsecode != HttpURLConnection.HTTP_OK) {
+ // TODO: Remove this print
+ System.out.println(responsecode);
+ throw new Error("Invalid response");
+ }
+
+ timer.endTime();
+
+ salt = saltTmp;
+ } catch (Exception e) {
+ // e.printStackTrace();
+ timer.endTime();
+ throw new ServerException("Failed setting salt", ServerException.TypeConnectTimeout);
+ }
+ }
+
+ private bool getSalt() throws ServerException {
+ URL url = NULL;
+ URLConnection con = NULL;
+ HttpURLConnection http = NULL;
+
+ try {
+ url = new URL(baseurl + "?req=getsalt");
+ } catch (Exception e) {
+ // e.printStackTrace();
+ throw new Error("getSlot failed");
+ }
+ try {
+
+ timer.startTime();
+ con = url.openConnection();
+ http = (HttpURLConnection) con;
+ http.setRequestMethod("POST");
+ http.setConnectTimeout(TIMEOUT_MILLIS);
+ http.setReadTimeout(TIMEOUT_MILLIS);
+
+
+ http.connect();
+ timer.endTime();
+ } catch (SocketTimeoutException e) {
+ timer.endTime();
+ throw new ServerException("getSalt failed", ServerException.TypeConnectTimeout);
+ } catch (Exception e) {
+ // e.printStackTrace();
+ throw new Error("getSlot failed");
+ }
+
+ try {
+
+ timer.startTime();
+
+ int responsecode = http.getResponseCode();
+ if (responsecode != HttpURLConnection.HTTP_OK) {
+ // TODO: Remove this print
+ // System.out.println(responsecode);
+ throw new Error("Invalid response");
+ }
+
+ InputStream is = http.getInputStream();
+ if (is.available() > 0) {
+ DataInputStream dis = new DataInputStream(is);
+ int salt_length = dis.readInt();
+ char [] tmp = new char[salt_length];
+ dis.readFully(tmp);
+ salt = tmp;
+ timer.endTime();
+
+ return true;
+ } else {
+ timer.endTime();
+
+ return false;
+ }
+ } catch (SocketTimeoutException e) {
+ timer.endTime();
+
+ throw new ServerException("getSalt failed", ServerException.TypeInputTimeout);
+ } catch (Exception e) {
+ // e.printStackTrace();
+ throw new Error("getSlot failed");
+ }
+ }
+
+ private char[] createIV(int64_t machineId, int64_t localSequenceNumber) {
+ ByteBuffer buffer = ByteBuffer.allocate(IV_SIZE);
+ buffer.putLong(machineId);
+ int64_t localSequenceNumberShifted = localSequenceNumber << 16;
+ buffer.putLong(localSequenceNumberShifted);
+ return buffer.array();
+
+ }
+
+ private char[] encryptSlotAndPrependIV(char[] rawData, char[] ivBytes) {
+ try {
+ IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
+ Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");
+ cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
+
+ char[] encryptedBytes = cipher.doFinal(rawData);
+
+ char[] chars = new char[encryptedBytes.length + IV_SIZE];
+ System.arraycopy(ivBytes, 0, chars, 0, ivBytes.length);
+ System.arraycopy(encryptedBytes, 0, chars, IV_SIZE, encryptedBytes.length);
+
+ return chars;
+
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new Error("Failed To Encrypt");
+ }
+ }
+
+
+ private char[] stripIVAndDecryptSlot(char[] rawData) {
+ try {
+ char[] ivBytes = new char[IV_SIZE];
+ char[] encryptedBytes = new char[rawData.length - IV_SIZE];
+ System.arraycopy(rawData, 0, ivBytes, 0, IV_SIZE);
+ System.arraycopy(rawData, IV_SIZE, encryptedBytes, 0 , encryptedBytes.length);
+
+ IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
+
+ Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");
+ cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
+ return cipher.doFinal(encryptedBytes);
+
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new Error("Failed To Decrypt");
+ }
+ }
+
+
+ /*
+ * API for putting a slot into the queue. Returns NULL on success.
+ * On failure, the server will send slots with newer sequence
+ * numbers.
+ */
+ public Slot[] putSlot(Slot slot, int max) throws ServerException {
+ URL url = NULL;
+ URLConnection con = NULL;
+ HttpURLConnection http = NULL;
+
+ try {
+ if (salt == NULL) {
+ if (!getSalt()) {
+ throw new ServerException("putSlot failed", ServerException.TypeSalt);
+ }
+ initCrypt();
+ }
+
+ int64_t sequencenumber = slot.getSequenceNumber();
+ char[] slotBytes = slot.encode(mac);
+ // slotBytes = encryptCipher.doFinal(slotBytes);
+
+ // char[] iVBytes = slot.getSlotCryptIV();
+
+ // char[] chars = new char[slotBytes.length + IV_SIZE];
+ // System.arraycopy(iVBytes, 0, chars, 0, iVBytes.length);
+ // System.arraycopy(slotBytes, 0, chars, IV_SIZE, slotBytes.length);
+
+
+ char[] chars = encryptSlotAndPrependIV(slotBytes, slot.getSlotCryptIV());
+
+ url = buildRequest(true, sequencenumber, max);
+
+ timer.startTime();
+ con = url.openConnection();
+ http = (HttpURLConnection) con;
+
+ http.setRequestMethod("POST");
+ http.setFixedLengthStreamingMode(chars.length);
+ http.setDoOutput(true);
+ http.setConnectTimeout(TIMEOUT_MILLIS);
+ http.setReadTimeout(TIMEOUT_MILLIS);
+ http.connect();
+
+ OutputStream os = http.getOutputStream();
+ os.write(chars);
+ os.flush();
+
+ timer.endTime();
+
+
+ // System.out.println("Bytes Sent: " + chars.length);
+ } catch (ServerException e) {
+ timer.endTime();
+
+ throw e;
+ } catch (SocketTimeoutException e) {
+ timer.endTime();
+
+ throw new ServerException("putSlot failed", ServerException.TypeConnectTimeout);
+ } catch (Exception e) {
+ // e.printStackTrace();
+ throw new Error("putSlot failed");
+ }
+
+
+
+ try {
+ timer.startTime();
+ InputStream is = http.getInputStream();
+ DataInputStream dis = new DataInputStream(is);
+ char[] resptype = new char[7];
+ dis.readFully(resptype);
+ timer.endTime();
+
+ if (Arrays.equals(resptype, "getslot".getBytes())) {
+ return processSlots(dis);
+ } else if (Arrays.equals(resptype, "putslot".getBytes())) {
+ return NULL;
+ } else
+ throw new Error("Bad response to putslot");
+
+ } catch (SocketTimeoutException e) {
+ timer.endTime();
+ throw new ServerException("putSlot failed", ServerException.TypeInputTimeout);
+ } catch (Exception e) {
+ // e.printStackTrace();
+ throw new Error("putSlot failed");
+ }
+ }
+
+ /**
+ * Request the server to send all slots with the given
+ * sequencenumber or newer.
+ */
+ public Slot[] getSlots(int64_t sequencenumber) throws ServerException {
+ URL url = NULL;
+ URLConnection con = NULL;
+ HttpURLConnection http = NULL;
+
+ try {
+ if (salt == NULL) {
+ if (!getSalt()) {
+ throw new ServerException("getSlots failed", ServerException.TypeSalt);
+ }
+ initCrypt();
+ }
+
+ url = buildRequest(false, sequencenumber, 0);
+ timer.startTime();
+ con = url.openConnection();
+ http = (HttpURLConnection) con;
+ http.setRequestMethod("POST");
+ http.setConnectTimeout(TIMEOUT_MILLIS);
+ http.setReadTimeout(TIMEOUT_MILLIS);
+
+
+
+ http.connect();
+ timer.endTime();
+
+ } catch (SocketTimeoutException e) {
+ timer.endTime();
+
+ throw new ServerException("getSlots failed", ServerException.TypeConnectTimeout);
+ } catch (ServerException e) {
+ timer.endTime();
+
+ throw e;
+ } catch (Exception e) {
+ // e.printStackTrace();
+ throw new Error("getSlots failed");
+ }
+
+ try {
+
+ timer.startTime();
+ InputStream is = http.getInputStream();
+ DataInputStream dis = new DataInputStream(is);
+ char[] resptype = new char[7];
+
+ dis.readFully(resptype);
+ timer.endTime();
+
+ if (!Arrays.equals(resptype, "getslot".getBytes()))
+ throw new Error("Bad Response: " + new String(resptype));
+
+ return processSlots(dis);
+ } catch (SocketTimeoutException e) {
+ timer.endTime();
+
+ throw new ServerException("getSlots failed", ServerException.TypeInputTimeout);
+ } catch (Exception e) {
+ // e.printStackTrace();
+ throw new Error("getSlots failed");
+ }
+ }
+
+ /**
+ * Method that actually handles building Slot objects from the
+ * server response. Shared by both putSlot and getSlots.
+ */
+ private Slot[] processSlots(DataInputStream dis) throws Exception {
+ int numberofslots = dis.readInt();
+ int[] sizesofslots = new int[numberofslots];
+
+ Slot[] slots = new Slot[numberofslots];
+ for (int i = 0; i < numberofslots; i++)
+ sizesofslots[i] = dis.readInt();
+
+ for (int i = 0; i < numberofslots; i++) {
+
+ char[] rawData = new char[sizesofslots[i]];
+ dis.readFully(rawData);
+
+
+ // char[] data = new char[rawData.length - IV_SIZE];
+ // System.arraycopy(rawData, IV_SIZE, data, 0, data.length);
+
+
+ char[] data = stripIVAndDecryptSlot(rawData);
+
+ // data = decryptCipher.doFinal(data);
+
+ slots[i] = Slot.decode(table, data, mac);
+ }
+ dis.close();
+ return slots;
+ }
+
+ public char[] sendLocalData(char[] sendData, int64_t localSequenceNumber, String host, int port) {
+
+ if (salt == NULL) {
+ return NULL;
+ }
+ try {
+ System.out.println("Passing Locally");
+
+ mac.update(sendData);
+ char[] genmac = mac.doFinal();
+ char[] totalData = new char[sendData.length + genmac.length];
+ System.arraycopy(sendData, 0, totalData, 0, sendData.length);
+ System.arraycopy(genmac, 0, totalData, sendData.length, genmac.length);
+
+ // Encrypt the data for sending
+ // char[] encryptedData = encryptCipher.doFinal(totalData);
+ // char[] encryptedData = encryptCipher.doFinal(totalData);
+ char[] iv = createIV(table.getMachineId(), table.getLocalSequenceNumber());
+ char[] encryptedData = encryptSlotAndPrependIV(totalData, iv);
+
+ // Open a TCP socket connection to a local device
+ Socket socket = new Socket(host, port);
+ socket.setReuseAddress(true);
+ DataOutputStream output = new DataOutputStream(socket.getOutputStream());
+ DataInputStream input = new DataInputStream(socket.getInputStream());
+
+
+ timer.startTime();
+ // Send data to output (length of data, the data)
+ output.writeInt(encryptedData.length);
+ output.write(encryptedData, 0, encryptedData.length);
+ output.flush();
+
+ int lengthOfReturnData = input.readInt();
+ char[] returnData = new char[lengthOfReturnData];
+ input.readFully(returnData);
+
+ timer.endTime();
+
+ // returnData = decryptCipher.doFinal(returnData);
+ returnData = stripIVAndDecryptSlot(returnData);
+ // returnData = decryptCipher.doFinal(returnData);
+
+ // We are done with this socket
+ socket.close();
+
+ mac.update(returnData, 0, returnData.length - HMAC_SIZE);
+ char[] realmac = mac.doFinal();
+ char[] recmac = new char[HMAC_SIZE];
+ System.arraycopy(returnData, returnData.length - realmac.length, recmac, 0, realmac.length);
+
+ if (!Arrays.equals(recmac, realmac))
+ throw new Error("Local Error: Invalid HMAC! Potential Attack!");
+
+ char[] returnData2 = new char[lengthOfReturnData - recmac.length];
+ System.arraycopy(returnData, 0, returnData2, 0, returnData2.length);
+
+ return returnData2;
+ } catch (Exception e) {
+ e.printStackTrace();
+ // throw new Error("Local comms failure...");
+
+ }
+
+ return NULL;
+ }
+
+ private void localServerWorkerFunction() {
+
+ ServerSocket inputSocket = NULL;
+
+ try {
+ // Local server socket
+ inputSocket = new ServerSocket(listeningPort);
+ inputSocket.setReuseAddress(true);
+ inputSocket.setSoTimeout(TIMEOUT_MILLIS);
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new Error("Local server setup failure...");
+ }
+
+ while (!doEnd) {
+
+ try {
+ // Accept incoming socket
+ Socket socket = inputSocket.accept();
+
+ DataInputStream input = new DataInputStream(socket.getInputStream());
+ DataOutputStream output = new DataOutputStream(socket.getOutputStream());
+
+ // Get the encrypted data from the server
+ int dataSize = input.readInt();
+ char[] readData = new char[dataSize];
+ input.readFully(readData);
+
+ timer.endTime();
+
+ // Decrypt the data
+ // readData = decryptCipher.doFinal(readData);
+ readData = stripIVAndDecryptSlot(readData);
+
+ mac.update(readData, 0, readData.length - HMAC_SIZE);
+ char[] genmac = mac.doFinal();
+ char[] recmac = new char[HMAC_SIZE];
+ System.arraycopy(readData, readData.length - recmac.length, recmac, 0, recmac.length);
+
+ if (!Arrays.equals(recmac, genmac))
+ throw new Error("Local Error: Invalid HMAC! Potential Attack!");
+
+ char[] returnData = new char[readData.length - recmac.length];
+ System.arraycopy(readData, 0, returnData, 0, returnData.length);
+
+ // Process the data
+ // char[] sendData = table.acceptDataFromLocal(readData);
+ char[] sendData = table.acceptDataFromLocal(returnData);
+
+
+ mac.update(sendData);
+ char[] realmac = mac.doFinal();
+ char[] totalData = new char[sendData.length + realmac.length];
+ System.arraycopy(sendData, 0, totalData, 0, sendData.length);
+ System.arraycopy(realmac, 0, totalData, sendData.length, realmac.length);
+
+ // Encrypt the data for sending
+ // char[] encryptedData = encryptCipher.doFinal(totalData);
+ char[] iv = createIV(table.getMachineId(), table.getLocalSequenceNumber());
+ char[] encryptedData = encryptSlotAndPrependIV(totalData, iv);
+
+
+ timer.startTime();
+ // Send data to output (length of data, the data)
+ output.writeInt(encryptedData.length);
+ output.write(encryptedData, 0, encryptedData.length);
+ output.flush();
+
+ // close the socket
+ socket.close();
+ } catch (Exception e) {
+
+ }
+ }
+
+ if (inputSocket != NULL) {
+ try {
+ inputSocket.close();
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new Error("Local server close failure...");
+ }
+ }
+ }
+
+ public void close() {
+ doEnd = true;
+
+ if (localServerThread != NULL) {
+ try {
+ localServerThread.join();
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new Error("Local Server thread join issue...");
+ }
+ }
+
+ // System.out.println("Done Closing Cloud Comm");
+ }
+
+ protected void finalize() throws Throwable {
+ try {
+ close(); // close open files
+ } finally {
+ super.finalize();
+ }
+ }
+}