version2/src/java/iotcloud/CloudComm.java

   1 package iotcloud;
   2
   3 import java.io.*;
   4 import java.net.*;
   5 import java.util.Arrays;
   6 import javax.crypto.*;
   7 import javax.crypto.spec.*;
   8 import java.security.SecureRandom;
   9
  10 /**
  11  * This class provides a communication API to the webserver.  It also
  12  * validates the HMACs on the slots and handles encryption.
  13  * @author Brian Demsky <bdemsky@uci.edu>
  14  * @version 1.0
  15  */
  16
  17
  18 class CloudComm {
  19         private static final int SALT_SIZE = 8;
  20         private static final int TIMEOUT_MILLIS = 2000; // 100
  21
  22         /** Sets the size for the HMAC. */
  23         static final int HMAC_SIZE = 32;
  24
  25         private String baseurl;
  26         private Cipher encryptCipher;
  27         private Cipher decryptCipher;
  28         private Mac mac;
  29         private String password;
  30         private SecureRandom random;
  31         private byte salt[];
  32         private Table table;
  33         private int listeningPort = -1;
  34         private Thread localServerThread = null;
  35         private boolean doEnd = false;
  36
  37         private TimingSingleton timer = null;
  38
  39         /**
  40          * Empty Constructor needed for child class.
  41          */
  42         CloudComm() {
  43                 timer = TimingSingleton.getInstance();
  44         }
  45
  46         /**
  47          * Constructor for actual use. Takes in the url and password.
  48          */
  49         CloudComm(Table _table,  String _baseurl, String _password, int _listeningPort) {
  50                 timer = TimingSingleton.getInstance();
  51                 this.table = _table;
  52                 this.baseurl = _baseurl;
  53                 this.password = _password;
  54                 this.random = new SecureRandom();
  55                 this.listeningPort = _listeningPort;
  56
  57                 if (this.listeningPort > 0) {
  58                         localServerThread = new Thread(new Runnable() {
  59                                 public void run() {
  60                                         localServerWorkerFunction();
  61                                 }
  62                         });
  63                         localServerThread.start();
  64                 }
  65         }
  66
  67         /**
  68          * Generates Key from password.
  69          */
  70         private SecretKeySpec initKey() {
  71                 try {
  72                         PBEKeySpec keyspec = new PBEKeySpec(password.toCharArray(),
  73                                                             salt,
  74                                                             65536,
  75                                                             128);
  76                         SecretKey tmpkey = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256").generateSecret(keyspec);
  77                         return new SecretKeySpec(tmpkey.getEncoded(), "AES");
  78                 } catch (Exception e) {
  79                         e.printStackTrace();
  80                         throw new Error("Failed generating key.");
  81                 }
  82         }
  83
  84         /**
  85          * Inits all the security stuff
  86          */
  87         public void initSecurity() throws ServerException {
  88                 // try to get the salt and if one does not exist set one
  89                 if (!getSalt()) {
  90                         //Set the salt
  91                         setSalt();
  92                 }
  93
  94                 initCrypt();
  95         }
  96
  97         /**
  98          * Inits the HMAC generator.
  99          */
 100         private void initCrypt() {
 101
 102                 if (password == null) {
 103                         return;
 104                 }
 105
 106                 try {
 107                         SecretKeySpec key = initKey();
 108                         password = null; // drop password
 109                         mac = Mac.getInstance("HmacSHA256");
 110                         mac.init(key);
 111                         encryptCipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
 112                         encryptCipher.init(Cipher.ENCRYPT_MODE, key);
 113                         decryptCipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
 114                         decryptCipher.init(Cipher.DECRYPT_MODE, key);
 115                 } catch (Exception e) {
 116                         e.printStackTrace();
 117                         throw new Error("Failed To Initialize Ciphers");
 118                 }
 119         }
 120
 121         /*
 122          * Builds the URL for the given request.
 123          */
 124         private URL buildRequest(boolean isput, long sequencenumber, long maxentries) throws IOException {
 125                 String reqstring = isput ? "req=putslot" : "req=getslot";
 126                 String urlstr = baseurl + "?" + reqstring + "&seq=" + sequencenumber;
 127                 if (maxentries != 0)
 128                         urlstr += "&max=" + maxentries;
 129                 return new URL(urlstr);
 130         }
 131
 132         private void setSalt() throws ServerException {
 133
 134                 if (salt != null) {
 135                         // Salt already sent to server so dont set it again
 136                         return;
 137                 }
 138
 139                 try {
 140                         byte[] saltTmp = new byte[SALT_SIZE];
 141                         random.nextBytes(saltTmp);
 142
 143                         URL url = new URL(baseurl + "?req=setsalt");
 144
 145                         timer.startTime();
 146                         URLConnection con = url.openConnection();
 147                         HttpURLConnection http = (HttpURLConnection) con;
 148
 149                         http.setRequestMethod("POST");
 150                         http.setFixedLengthStreamingMode(saltTmp.length);
 151                         http.setDoOutput(true);
 152                         http.setConnectTimeout(TIMEOUT_MILLIS);
 153
 154
 155                         http.connect();
 156
 157                         OutputStream os = http.getOutputStream();
 158                         os.write(saltTmp);
 159                         os.flush();
 160
 161                         int responsecode = http.getResponseCode();
 162                         if (responsecode != HttpURLConnection.HTTP_OK) {
 163                                 // TODO: Remove this print
 164                                 System.out.println(responsecode);
 165                                 throw new Error("Invalid response");
 166                         }
 167
 168                         timer.endTime();
 169
 170                         salt = saltTmp;
 171                 } catch (Exception e) {
 172                         // e.printStackTrace();
 173                         timer.endTime();
 174                         throw new ServerException("Failed setting salt", ServerException.TypeConnectTimeout);
 175                 }
 176         }
 177
 178         private boolean getSalt() throws ServerException {
 179                 URL url = null;
 180                 URLConnection con = null;
 181                 HttpURLConnection http = null;
 182
 183                 try {
 184                         url = new URL(baseurl + "?req=getsalt");
 185                 } catch (Exception e) {
 186                         // e.printStackTrace();
 187                         throw new Error("getSlot failed");
 188                 }
 189                 try {
 190
 191                         timer.startTime();
 192                         con = url.openConnection();
 193                         http = (HttpURLConnection) con;
 194                         http.setRequestMethod("POST");
 195                         http.setConnectTimeout(TIMEOUT_MILLIS);
 196                         http.setReadTimeout(TIMEOUT_MILLIS);
 197
 198
 199                         http.connect();
 200                         timer.endTime();
 201                 } catch (SocketTimeoutException e) {
 202                         timer.endTime();
 203                         throw new ServerException("getSalt failed", ServerException.TypeConnectTimeout);
 204                 } catch (Exception e) {
 205                         // e.printStackTrace();
 206                         throw new Error("getSlot failed");
 207                 }
 208
 209                 try {
 210
 211                         timer.startTime();
 212
 213                         int responsecode = http.getResponseCode();
 214                         if (responsecode != HttpURLConnection.HTTP_OK) {
 215                                 // TODO: Remove this print
 216                                 // System.out.println(responsecode);
 217                                 throw new Error("Invalid response");
 218                         }
 219
 220                         InputStream is = http.getInputStream();
 221                         if (is.available() > 0) {
 222                                 DataInputStream dis = new DataInputStream(is);
 223                                 int salt_length = dis.readInt();
 224                                 byte [] tmp = new byte[salt_length];
 225                                 dis.readFully(tmp);
 226                                 salt = tmp;
 227                                 timer.endTime();
 228
 229                                 return true;
 230                         } else {
 231                                 timer.endTime();
 232
 233                                 return false;
 234                         }
 235                 } catch (SocketTimeoutException e) {
 236                         timer.endTime();
 237
 238                         throw new ServerException("getSalt failed", ServerException.TypeInputTimeout);
 239                 } catch (Exception e) {
 240                         // e.printStackTrace();
 241                         throw new Error("getSlot failed");
 242                 }
 243         }
 244
 245         /*
 246          * API for putting a slot into the queue.  Returns null on success.
 247          * On failure, the server will send slots with newer sequence
 248          * numbers.
 249          */
 250         public Slot[] putSlot(Slot slot, int max) throws ServerException {
 251                 URL url = null;
 252                 URLConnection con = null;
 253                 HttpURLConnection http = null;
 254
 255                 try {
 256                         if (salt == null) {
 257                                 if (!getSalt()) {
 258                                         throw new ServerException("putSlot failed", ServerException.TypeSalt);
 259                                 }
 260                                 initCrypt();
 261                         }
 262
 263                         long sequencenumber = slot.getSequenceNumber();
 264                         byte[] bytes = slot.encode(mac);
 265                         bytes = encryptCipher.doFinal(bytes);
 266
 267
 268
 269
 270                         url = buildRequest(true, sequencenumber, max);
 271
 272                         timer.startTime();
 273                         con = url.openConnection();
 274                         http = (HttpURLConnection) con;
 275
 276                         http.setRequestMethod("POST");
 277                         http.setFixedLengthStreamingMode(bytes.length);
 278                         http.setDoOutput(true);
 279                         http.setConnectTimeout(TIMEOUT_MILLIS);
 280                         http.setReadTimeout(TIMEOUT_MILLIS);
 281                         http.connect();
 282
 283                         OutputStream os = http.getOutputStream();
 284                         os.write(bytes);
 285                         os.flush();
 286
 287                         timer.endTime();
 288
 289
 290                         // System.out.println("Bytes Sent: " + bytes.length);
 291                 } catch (ServerException e) {
 292                         timer.endTime();
 293
 294                         throw e;
 295                 } catch (SocketTimeoutException e) {
 296                         timer.endTime();
 297
 298                         throw new ServerException("putSlot failed", ServerException.TypeConnectTimeout);
 299                 } catch (Exception e) {
 300                         // e.printStackTrace();
 301                         throw new Error("putSlot failed");
 302                 }
 303
 304
 305
 306                 try {
 307                         timer.startTime();
 308                         InputStream is = http.getInputStream();
 309                         DataInputStream dis = new DataInputStream(is);
 310                         byte[] resptype = new byte[7];
 311                         dis.readFully(resptype);
 312                         timer.endTime();
 313
 314                         if (Arrays.equals(resptype, "getslot".getBytes()))
 315                         {
 316                                 return processSlots(dis);
 317                         }
 318                         else if (Arrays.equals(resptype, "putslot".getBytes()))
 319                         {
 320                                 return null;
 321                         }
 322                         else
 323                                 throw new Error("Bad response to putslot");
 324
 325                 } catch (SocketTimeoutException e) {
 326                                 timer.endTime();
 327                         throw new ServerException("putSlot failed", ServerException.TypeInputTimeout);
 328                 } catch (Exception e) {
 329                         // e.printStackTrace();
 330                         throw new Error("putSlot failed");
 331                 }
 332         }
 333
 334         /**
 335          * Request the server to send all slots with the given
 336          * sequencenumber or newer.
 337          */
 338         public Slot[] getSlots(long sequencenumber) throws ServerException {
 339                 URL url = null;
 340                 URLConnection con = null;
 341                 HttpURLConnection http = null;
 342
 343                 try {
 344                         if (salt == null) {
 345                                 if (!getSalt()) {
 346                                         throw new ServerException("getSlots failed", ServerException.TypeSalt);
 347                                 }
 348                                 initCrypt();
 349                         }
 350
 351                         url = buildRequest(false, sequencenumber, 0);
 352                         timer.startTime();
 353                         con = url.openConnection();
 354                         http = (HttpURLConnection) con;
 355                         http.setRequestMethod("POST");
 356                         http.setConnectTimeout(TIMEOUT_MILLIS);
 357                         http.setReadTimeout(TIMEOUT_MILLIS);
 358
 359
 360
 361                         http.connect();
 362                         timer.endTime();
 363
 364                 } catch (SocketTimeoutException e) {
 365                         timer.endTime();
 366
 367                         throw new ServerException("getSlots failed", ServerException.TypeConnectTimeout);
 368                 } catch (ServerException e) {
 369                         timer.endTime();
 370
 371                         throw e;
 372                 } catch (Exception e) {
 373                         // e.printStackTrace();
 374                         throw new Error("getSlots failed");
 375                 }
 376
 377                 try {
 378
 379                         timer.startTime();
 380                         InputStream is = http.getInputStream();
 381                         DataInputStream dis = new DataInputStream(is);
 382                         byte[] resptype = new byte[7];
 383
 384                         dis.readFully(resptype);
 385                         timer.endTime();
 386
 387                         if (!Arrays.equals(resptype, "getslot".getBytes()))
 388                                 throw new Error("Bad Response: " + new String(resptype));
 389
 390                         return processSlots(dis);
 391                 } catch (SocketTimeoutException e) {
 392                         timer.endTime();
 393
 394                         throw new ServerException("getSlots failed", ServerException.TypeInputTimeout);
 395                 } catch (Exception e) {
 396                         // e.printStackTrace();
 397                         throw new Error("getSlots failed");
 398                 }
 399         }
 400
 401         /**
 402          * Method that actually handles building Slot objects from the
 403          * server response.  Shared by both putSlot and getSlots.
 404          */
 405         private Slot[] processSlots(DataInputStream dis) throws Exception {
 406                 int numberofslots = dis.readInt();
 407                 int[] sizesofslots = new int[numberofslots];
 408
 409                 Slot[] slots = new Slot[numberofslots];
 410                 for (int i = 0; i < numberofslots; i++)
 411                         sizesofslots[i] = dis.readInt();
 412
 413                 for (int i = 0; i < numberofslots; i++) {
 414
 415                         byte[] data = new byte[sizesofslots[i]];
 416                         dis.readFully(data);
 417
 418                         data = decryptCipher.doFinal(data);
 419
 420                         slots[i] = Slot.decode(table, data, mac);
 421                 }
 422                 dis.close();
 423                 return slots;
 424         }
 425
 426         public byte[] sendLocalData(byte[] sendData, String host, int port) {
 427
 428                 if (salt == null) {
 429                         return null;
 430                 }
 431                 try {
 432
 433                         System.out.println("Passing Locally");
 434
 435                         mac.update(sendData);
 436                         byte[] genmac = mac.doFinal();
 437                         byte[] totalData = new byte[sendData.length + genmac.length];
 438                         System.arraycopy(sendData, 0, totalData, 0, sendData.length);
 439                         System.arraycopy(genmac, 0, totalData, sendData.length, genmac.length);
 440
 441                         // Encrypt the data for sending
 442                         // byte[] encryptedData = encryptCipher.doFinal(totalData);
 443                         byte[] encryptedData = encryptCipher.doFinal(totalData);
 444
 445                         // Open a TCP socket connection to a local device
 446                         Socket socket = new Socket(host, port);
 447                         socket.setReuseAddress(true);
 448                         DataOutputStream output = new DataOutputStream(socket.getOutputStream());
 449                         DataInputStream input = new DataInputStream(socket.getInputStream());
 450
 451
 452                         timer.startTime();
 453                         // Send data to output (length of data, the data)
 454                         output.writeInt(encryptedData.length);
 455                         output.write(encryptedData, 0, encryptedData.length);
 456                         output.flush();
 457
 458                         int lengthOfReturnData = input.readInt();
 459                         byte[] returnData = new byte[lengthOfReturnData];
 460                         input.readFully(returnData);
 461
 462                         timer.endTime();
 463
 464                         returnData = decryptCipher.doFinal(returnData);
 465
 466                         // We are done with this socket
 467                         socket.close();
 468
 469                         mac.update(returnData, 0, returnData.length - HMAC_SIZE);
 470                         byte[] realmac = mac.doFinal();
 471                         byte[] recmac = new byte[HMAC_SIZE];
 472                         System.arraycopy(returnData, returnData.length - realmac.length, recmac, 0, realmac.length);
 473
 474                         if (!Arrays.equals(recmac, realmac))
 475                                 throw new Error("Local Error: Invalid HMAC!  Potential Attack!");
 476
 477                         byte[] returnData2 = new byte[lengthOfReturnData - recmac.length];
 478                         System.arraycopy(returnData, 0, returnData2, 0, returnData2.length);
 479
 480                         return returnData2;
 481                 } catch (SocketTimeoutException e) {
 482
 483                 } catch (BadPaddingException e) {
 484
 485                 } catch (IllegalBlockSizeException e) {
 486
 487                 } catch (UnknownHostException e) {
 488
 489                 } catch (IOException e) {
 490
 491                 }
 492
 493                 return null;
 494         }
 495
 496         private void localServerWorkerFunction() {
 497
 498                 ServerSocket inputSocket = null;
 499
 500                 try {
 501                         // Local server socket
 502                         inputSocket = new ServerSocket(listeningPort);
 503                         inputSocket.setReuseAddress(true);
 504                         inputSocket.setSoTimeout(TIMEOUT_MILLIS);
 505                 } catch (Exception e) {
 506                         e.printStackTrace();
 507                         throw new Error("Local server setup failure...");
 508                 }
 509
 510                 while (!doEnd) {
 511
 512                         try {
 513                                 // Accept incoming socket
 514                                 Socket socket = inputSocket.accept();
 515
 516                                 DataInputStream input = new DataInputStream(socket.getInputStream());
 517                                 DataOutputStream output = new DataOutputStream(socket.getOutputStream());
 518
 519                                 // Get the encrypted data from the server
 520                                 int dataSize = input.readInt();
 521                                 byte[] readData = new byte[dataSize];
 522                                 input.readFully(readData);
 523
 524                                 timer.endTime();
 525
 526                                 // Decrypt the data
 527                                 readData = decryptCipher.doFinal(readData);
 528
 529                                 mac.update(readData, 0, readData.length - HMAC_SIZE);
 530                                 byte[] genmac = mac.doFinal();
 531                                 byte[] recmac = new byte[HMAC_SIZE];
 532                                 System.arraycopy(readData, readData.length - recmac.length, recmac, 0, recmac.length);
 533
 534                                 if (!Arrays.equals(recmac, genmac))
 535                                         throw new Error("Local Error: Invalid HMAC!  Potential Attack!");
 536
 537                                 byte[] returnData = new byte[readData.length - recmac.length];
 538                                 System.arraycopy(readData, 0, returnData, 0, returnData.length);
 539
 540                                 // Process the data
 541                                 // byte[] sendData = table.acceptDataFromLocal(readData);
 542                                 byte[] sendData = table.acceptDataFromLocal(returnData);
 543
 544                                 mac.update(sendData);
 545                                 byte[] realmac = mac.doFinal();
 546                                 byte[] totalData = new byte[sendData.length + realmac.length];
 547                                 System.arraycopy(sendData, 0, totalData, 0, sendData.length);
 548                                 System.arraycopy(realmac, 0, totalData, sendData.length, realmac.length);
 549
 550                                 // Encrypt the data for sending
 551                                 byte[] encryptedData = encryptCipher.doFinal(totalData);
 552
 553
 554                                 timer.startTime();
 555                                 // Send data to output (length of data, the data)
 556                                 output.writeInt(encryptedData.length);
 557                                 output.write(encryptedData, 0, encryptedData.length);
 558                                 output.flush();
 559
 560                                 // close the socket
 561                                 socket.close();
 562                         } catch (SocketTimeoutException e) {
 563
 564                         } catch (BadPaddingException e) {
 565
 566                         } catch (IllegalBlockSizeException e) {
 567
 568                         } catch (UnknownHostException e) {
 569
 570                         } catch (IOException e) {
 571
 572                         }
 573                 }
 574
 575                 if (inputSocket != null) {
 576                         try {
 577                                 inputSocket.close();
 578                         } catch (Exception e) {
 579                                 e.printStackTrace();
 580                                 throw new Error("Local server close failure...");
 581                         }
 582                 }
 583         }
 584
 585         public void close() {
 586                 doEnd = true;
 587
 588                 if (localServerThread != null) {
 589                         try {
 590                                 localServerThread.join();
 591                         } catch (Exception e) {
 592                                 e.printStackTrace();
 593                                 throw new Error("Local Server thread join issue...");
 594                         }
 595                 }
 596
 597                 // System.out.println("Done Closing Cloud Comm");
 598         }
 599
 600         protected void finalize() throws Throwable {
 601                 try {
 602                         close();        // close open files
 603                 } finally {
 604                         super.finalize();
 605                 }
 606         }
 607
 608 }