package iotcloud;
+import java.util.HashMap;
+import java.util.Arrays;
+import java.util.Vector;
+import javax.crypto.spec.*;
+import javax.crypto.*;
-public class Table {
- int tablesize;
+final public class Table {
+ private int numslots;
+ private HashMap<IoTString, KeyValue> table=new HashMap<IoTString, KeyValue>();
+ private HashMap<Long, Pair<Long, Liveness> > lastmessagetable=new HashMap<Long, Pair<Long, Liveness> >();
+ private SlotBuffer buffer;
+ private CloudComm cloud;
+ private Mac hmac;
+ private long sequencenumber;
+ private long localmachineid;
+ private TableStatus lastTableStatus;
+ static final int FREE_SLOTS = 10;
+ static final int FORCED_RESIZE_INCREMENT = 20;
+
+ public Table(String baseurl, String password, long _localmachineid) {
+ localmachineid=_localmachineid;
+ buffer = new SlotBuffer();
+ numslots = buffer.capacity();
+ sequencenumber = 1;
+ initCloud(baseurl, password);
+ }
+
+ public Table(CloudComm _cloud, long _localmachineid) {
+ localmachineid=_localmachineid;
+ buffer = new SlotBuffer();
+ sequencenumber = 1;
+ cloud=_cloud;
+ }
+
+ private void initCloud(String baseurl, String password) {
+ try {
+ SecretKeySpec secret=getKey(password);
+ Cipher encryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+ encryptCipher.init(Cipher.ENCRYPT_MODE, secret);
+ Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+ decryptCipher.init(Cipher.DECRYPT_MODE, secret);
+ hmac = Mac.getInstance("HmacSHA256");
+ hmac.init(secret);
+ cloud=new CloudComm(baseurl, encryptCipher, decryptCipher, hmac);
+ } catch (Exception e) {
+ throw new Error("Failed To Initialize Ciphers");
+ }
+ }
+
+ private SecretKeySpec getKey(String password) {
+ try {
+ PBEKeySpec keyspec = new PBEKeySpec(password.toCharArray());
+ SecretKey key = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256").generateSecret(keyspec);
+ SecretKeySpec secret = new SecretKeySpec(key.getEncoded(), "AES");
+ return secret;
+ } catch (Exception e) {
+ throw new Error("Failed generating key.");
+ }
+ }
+
+ public void update() {
+ Slot[] newslots=cloud.getSlots(sequencenumber);
+ validateandupdate(newslots);
+ }
+
+ public IoTString get(IoTString key) {
+ KeyValue kv=table.get(key);
+ if (kv != null)
+ return kv.getValue();
+ else
+ return null;
+ }
+
+ public void initTable() {
+ Slot s=new Slot(1, localmachineid);
+ TableStatus status=new TableStatus(s, numslots);
+ s.addEntry(status);
+ Slot[] array=cloud.putSlot(s, numslots);
+ if (array == null) {
+ array = new Slot[] {s};
+ validateandupdate(array); // update data structure
+ } else {
+ throw new Error("Error on initialization");
+ }
+ }
+ public IoTString put(IoTString key, IoTString value) {
+ while(true) {
+ KeyValue oldvalue=table.get(key);
+ if (tryput(key, value, false)) {
+ return oldvalue.getValue();
+ }
+ }
+ }
+
+ private boolean tryput(IoTString key, IoTString value, boolean forcedresize) {
+ Slot s=new Slot(sequencenumber+1, localmachineid, buffer.getSlot(sequencenumber).getHMAC());
+ long seqn = buffer.getOldestSeqNum();
+
+ if (forcedresize) {
+ TableStatus status=new TableStatus(s, FORCED_RESIZE_INCREMENT + numslots);
+ s.addEntry(status);
+ }
+
+ if ((numslots - buffer.size()) < FREE_SLOTS) {
+ //have to check whether we have enough free slots
+ seqn = buffer.getNewestSeqNum() + 1 - numslots;
+ for(int i=0; i < FREE_SLOTS; i++, seqn++) {
+ Slot prevslot=buffer.getSlot(seqn);
+ if (!prevslot.isLive())
+ continue;
+ Vector<Entry> liveentries = prevslot.getLiveEntries();
+ for(Entry liveentry:liveentries) {
+ if (s.hasSpace(liveentry))
+ s.addEntry(liveentry);
+ else if (i==0) {
+ if (s.canFit(liveentry))
+ s.addEntry(liveentry);
+ else if (!forcedresize) {
+ return tryput(key, value, true);
+ }
+ }
+ }
+ }
+ }
+ KeyValue kv=new KeyValue(s, key, value);
+ boolean insertedkv=false;
+ if (s.hasSpace(kv)) {
+ s.addEntry(kv);
+ insertedkv=true;
+ }
+
+ long newestseqnum=buffer.getNewestSeqNum();
+ search:
+ for(;seqn<=newestseqnum;seqn++) {
+ Slot prevslot=buffer.getSlot(seqn);
+ if (!prevslot.isLive())
+ continue;
+ Vector<Entry> liveentries = prevslot.getLiveEntries();
+ for(Entry liveentry:liveentries) {
+ if (s.hasSpace(liveentry))
+ s.addEntry(liveentry);
+ else
+ break search;
+ }
+ }
+
+ int max=0;
+ if (forcedresize)
+ max = numslots + FORCED_RESIZE_INCREMENT;
+ Slot[] array=cloud.putSlot(s, max);
+ if (array == null)
+ array = new Slot[] {s};
+ else
+ insertedkv=false;
+
+ validateandupdate(array); // update data structure
+
+ return insertedkv;
+ }
+
+ private void validateandupdate(Slot[] newslots) {
+ //The cloud communication layer has checked slot HMACs already
+ //before decoding
+ if (newslots.length==0)
+ return;
+
+ long firstseqnum=newslots[0].getSequenceNumber();
+ if (firstseqnum < sequencenumber)
+ throw new Error("Server Error: Sent older slots!");
+
+ SlotIndexer indexer = new SlotIndexer(newslots, buffer);
+ checkHMACChain(indexer, newslots);
+
+ initExpectedSize();
+ for(Slot slot: newslots) {
+ updateExpectedSize();
+ processSlot(indexer, slot);
+ }
+ checkNumSlots(newslots.length);
+ commitNewMaxSize();
+
+ //commit new to slots
+ for(Slot slot:newslots) {
+ buffer.putSlot(slot);
+ }
+ }
+
+ private int expectedsize, currmaxsize;
+
+ private void checkNumSlots(int numslots) {
+ if (numslots != expectedsize)
+ throw new Error("Server Error: Server did not send all slots");
+ }
+
+ private void initExpectedSize() {
+ expectedsize = (sequencenumber < ((long) numslots)) ? (int) sequencenumber : numslots;
+ currmaxsize = numslots;
+ }
+
+ private void updateExpectedSize() {
+ expectedsize++;
+ if (expectedsize > currmaxsize)
+ expectedsize = currmaxsize;
+ }
+
+ private void updateCurrMaxSize(int newmaxsize) {
+ currmaxsize=newmaxsize;
+ }
+
+ private void commitNewMaxSize() {
+ if (numslots != currmaxsize)
+ buffer.resize(currmaxsize);
+
+ numslots=currmaxsize;
+ }
+
+ private void processEntry(KeyValue entry, SlotIndexer indexer) {
+ IoTString key=entry.getKey();
+ KeyValue oldvalue=table.get(key);
+ if (oldvalue != null) {
+ oldvalue.setDead();
+ }
+ table.put(key, entry);
+ }
+
+ private void processEntry(LastMessage entry, SlotIndexer indexer) {
+ updateLastMessage(entry.getMachineID(), entry.getSequenceNumber(), entry);
+ }
+
+ private void processEntry(RejectedMessage entry, SlotIndexer indexer) {
+ long oldseqnum=entry.getOldSeqNum();
+ long newseqnum=entry.getNewSeqNum();
+ boolean isequal=entry.getEqual();
+ long machineid=entry.getMachineID();
+ for(long seqnum=oldseqnum; seqnum<=newseqnum; seqnum++) {
+ Slot slot=indexer.getSlot(seqnum);
+ if (slot != null) {
+ long slotmachineid=slot.getMachineID();
+ if (isequal!=(slotmachineid==machineid)) {
+ throw new Error("Server Error: Trying to insert rejected message for slot "+seqnum);
+ }
+ }
+ }
+ }
+
+ private void processEntry(TableStatus entry, SlotIndexer indexer) {
+ int newnumslots=entry.getMaxSlots();
+ updateCurrMaxSize(newnumslots);
+ if (lastTableStatus != null)
+ lastTableStatus.setDead();
+ lastTableStatus = entry;
+ }
+
+ private void updateLastMessage(long machineid, long seqnum, Liveness liveness) {
+ Pair<Long, Liveness> lastmsgentry = lastmessagetable.put(machineid, new Pair<Long, Liveness>(seqnum, liveness));
+ if (lastmsgentry == null)
+ return;
+
+ long lastmsgseqnum = lastmsgentry.getFirst();
+ Liveness lastentry = lastmsgentry.getSecond();
+ if (lastentry instanceof LastMessage) {
+ ((LastMessage)lastentry).setDead();
+ } else if (lastentry instanceof Slot) {
+ ((Slot)lastentry).setDead();
+ } else {
+ throw new Error("Unrecognized type");
+ }
+
+ if (machineid == localmachineid) {
+ if (lastmsgseqnum != seqnum)
+ throw new Error("Server Error: Mismatch on local machine sequence number");
+ } else {
+ if (lastmsgseqnum > seqnum)
+ throw new Error("Server Error: Rollback on remote machine sequence number");
+ }
+ }
+
+ private void processSlot(SlotIndexer indexer, Slot slot) {
+ updateLastMessage(slot.getMachineID(), slot.getSequenceNumber(), slot);
+
+ for(Entry entry : slot.getEntries()) {
+ switch(entry.getType()) {
+ case Entry.TypeKeyValue:
+ processEntry((KeyValue)entry, indexer);
+ break;
+
+ case Entry.TypeLastMessage:
+ processEntry((LastMessage)entry, indexer);
+ break;
+
+ case Entry.TypeRejectedMessage:
+ processEntry((RejectedMessage)entry, indexer);
+ break;
+
+ case Entry.TypeTableStatus:
+ processEntry((TableStatus)entry, indexer);
+ break;
+
+ default:
+ throw new Error("Unrecognized type: "+entry.getType());
+ }
+ }
+ }
+
+ private void checkHMACChain(SlotIndexer indexer, Slot[] newslots) {
+ for(int i=0; i < newslots.length; i++) {
+ Slot currslot=newslots[i];
+ Slot prevslot=indexer.getSlot(currslot.getSequenceNumber()-1);
+ if (prevslot != null &&
+ !Arrays.equals(prevslot.getHMAC(), currslot.getPrevHMAC()))
+ throw new Error("Server Error: Invalid HMAC Chain");
+ }
+ }
}
projects / iotcloud.git / blobdiff