src/java/iotcloud/CloudComm.java

   1 package iotcloud;
   2 import java.io.*;
   3 import java.net.*;
   4 import java.util.Arrays;
   5 import javax.crypto.*;
   6 import javax.crypto.spec.*;
   7 import java.security.SecureRandom;
   8
   9 class CloudComm {
  10         String baseurl;
  11         Cipher encryptcipher;
  12         Cipher decryptcipher;
  13         Mac mac;
  14         byte[] salt;
  15         SecretKeySpec key;
  16         static final int SALT_SIZE = 8;
  17
  18
  19         CloudComm() {
  20         }
  21
  22         CloudComm(String _baseurl, String password) {
  23                 this.baseurl=_baseurl;
  24                 initCloud(password);
  25         }
  26
  27         private void initKey(String password) {
  28                 try {
  29                         salt=new byte[SALT_SIZE];
  30                         PBEKeySpec keyspec = new PBEKeySpec(password.toCharArray(), salt, 65536, 128);
  31                         SecretKey tmpkey = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256").generateSecret(keyspec);
  32                         this.key = new SecretKeySpec(tmpkey.getEncoded(), "AES");
  33                 } catch (Exception e) {
  34                         e.printStackTrace();
  35                         throw new Error("Failed generating key.");
  36                 }
  37         }
  38
  39         private void initCloud(String password) {
  40                 try {
  41                         initKey(password);
  42                         mac = Mac.getInstance("HmacSHA256");
  43                         mac.init(key);
  44                 } catch (Exception e) {
  45                         e.printStackTrace();
  46                         throw new Error("Failed To Initialize Ciphers");
  47                 }
  48         }
  49
  50         private URL buildRequest(boolean isput, long sequencenumber, long maxentries) throws IOException {
  51                 String reqstring=isput?"req=putslot":"req=getslot";
  52                 String urlstr=baseurl+"?"+reqstring+"&seq="+sequencenumber;
  53                 if (maxentries != 0)
  54                         urlstr += "&max="+maxentries;
  55                 return new URL(urlstr);
  56         }
  57
  58         public Slot[] putSlot(Slot slot, int max) {
  59                 try {
  60                         long sequencenumber=slot.getSequenceNumber();
  61                         byte[] bytes=slot.encode(mac);
  62
  63                         URL url=buildRequest(true, sequencenumber, max);
  64                         URLConnection con=url.openConnection();
  65                         HttpURLConnection http = (HttpURLConnection) con;
  66                         http.setRequestMethod("POST");
  67                         http.setFixedLengthStreamingMode(bytes.length);
  68                         http.setDoOutput(true);
  69                         http.connect();
  70                         OutputStream os=http.getOutputStream();
  71                         os.write(bytes);
  72                         System.out.println(http.getResponseMessage());
  73
  74                         InputStream is=http.getInputStream();
  75                         DataInputStream dis=new DataInputStream(is);
  76                         byte[] resptype=new byte[7];
  77                         dis.readFully(resptype);
  78                         if (Arrays.equals(resptype, "getslot".getBytes()))
  79                                 return processSlots(dis);
  80                         else if (Arrays.equals(resptype, "putslot".getBytes()))
  81                                 return null;
  82                         else
  83                                 throw new Error("Bad response to putslot");
  84                 } catch (Exception e) {
  85                         throw new Error("putSlot failed");
  86                 }
  87         }
  88
  89         /*
  90                         Cipher encryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
  91                         encryptCipher.init(Cipher.ENCRYPT_MODE, secret);
  92                         Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
  93                         decryptCipher.init(Cipher.DECRYPT_MODE, secret);
  94         */
  95
  96         public Slot[] getSlots(long sequencenumber) {
  97                 try {
  98                         URL url=buildRequest(false, sequencenumber, 0);
  99                         URLConnection con=url.openConnection();
 100                         HttpURLConnection http = (HttpURLConnection) con;
 101                         http.setRequestMethod("POST");
 102                         http.connect();
 103                         System.out.println(http.getResponseMessage());
 104                         InputStream is=http.getInputStream();
 105
 106                         DataInputStream dis=new DataInputStream(is);
 107                         byte[] resptype=new byte[7];
 108                         dis.readFully(resptype);
 109                         if (!Arrays.equals(resptype, "getslot".getBytes()))
 110                                 throw new Error("Bad Response: "+new String(resptype));
 111                         else
 112                                 return processSlots(dis);
 113                 } catch (Exception e) {
 114                         throw new Error("getSlots failed");
 115                 }
 116         }
 117
 118         Slot[] processSlots(DataInputStream dis) throws IOException {
 119                 int numberofslots=dis.readInt();
 120                 int[] sizesofslots=new int[numberofslots];
 121                 Slot[] slots=new Slot[numberofslots];
 122                 for(int i=0; i<numberofslots; i++)
 123                         sizesofslots[i]=dis.readInt();
 124
 125                 for(int i=0; i<numberofslots; i++) {
 126                         byte[] data=new byte[sizesofslots[i]];
 127                         dis.readFully(data);
 128                         slots[i]=Slot.decode(data, mac);
 129                 }
 130                 dis.close();
 131                 return slots;
 132         }
 133 }