diff --git a/components/net/sf/briar/crypto/CryptoModule.java b/components/net/sf/briar/crypto/CryptoModule.java
index 1f6546a8cb2b91e72b899814875b2098a4f6a905..64efb11c12bb1062621dde37cd4d238f79db353d 100644
--- a/components/net/sf/briar/crypto/CryptoModule.java
+++ b/components/net/sf/briar/crypto/CryptoModule.java
@@ -1,6 +1,10 @@
package net.sf.briar.crypto;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.SecretKeySpec;
+
import net.sf.briar.api.crypto.CryptoComponent;
+import net.sf.briar.api.crypto.SecretStorageKey;
import com.google.inject.AbstractModule;
import com.google.inject.Singleton;
@@ -9,6 +13,10 @@ public class CryptoModule extends AbstractModule {
@Override
protected void configure() {
- bind(CryptoComponent.class).to(CryptoComponentImpl.class).in(Singleton.class);
+ bind(CryptoComponent.class).to(
+ CryptoComponentImpl.class).in(Singleton.class);
+ bind(SecretKey.class).annotatedWith(SecretStorageKey.class).toInstance(
+ new SecretKeySpec(new byte[32], "AES")); // FIXME
+
}
}
diff --git a/components/net/sf/briar/transport/ConnectionRecogniserImpl.java b/components/net/sf/briar/transport/ConnectionRecogniserImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..6779c6ad720da280cd15720db6dee7d55b172280
--- /dev/null
+++ b/components/net/sf/briar/transport/ConnectionRecogniserImpl.java
@@ -0,0 +1,133 @@
+package net.sf.briar.transport;
+
+import java.security.InvalidKeyException;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.SecretKey;
+
+import net.sf.briar.api.Bytes;
+import net.sf.briar.api.ContactId;
+import net.sf.briar.api.crypto.CryptoComponent;
+import net.sf.briar.api.db.DatabaseComponent;
+import net.sf.briar.api.db.DatabaseListener;
+import net.sf.briar.api.db.DbException;
+import net.sf.briar.api.db.NoSuchContactException;
+import net.sf.briar.api.transport.ConnectionRecogniser;
+import net.sf.briar.api.transport.ConnectionWindow;
+
+class ConnectionRecogniserImpl implements ConnectionRecogniser,
+DatabaseListener {
+
+ private final int transportId;
+ private final CryptoComponent crypto;
+ private final DatabaseComponent db;
+ private final Map<Bytes, ContactId> tagToContact;
+ private final Map<Bytes, Long> tagToConnectionNumber;
+ private final Map<ContactId, Map<Long, Bytes>> contactToTags;
+ private final Map<ContactId, Cipher> contactToCipher;
+ private final Map<ContactId, ConnectionWindow> contactToWindow;
+ private boolean initialised = false;
+
+ ConnectionRecogniserImpl(int transportId, CryptoComponent crypto,
+ DatabaseComponent db) {
+ this.transportId = transportId;
+ this.crypto = crypto;
+ this.db = db;
+ // FIXME: There's probably a tidier way of maintaining all this state
+ tagToContact = new HashMap<Bytes, ContactId>();
+ tagToConnectionNumber = new HashMap<Bytes, Long>();
+ contactToTags = new HashMap<ContactId, Map<Long, Bytes>>();
+ contactToCipher = new HashMap<ContactId, Cipher>();
+ contactToWindow = new HashMap<ContactId, ConnectionWindow>();
+ db.addListener(this);
+ }
+
+ private synchronized void initialise() throws DbException {
+ for(ContactId c : db.getContacts()) {
+ try {
+ // Initialise and store the contact's tag cipher
+ SecretKey tagKey = crypto.deriveTagKey(db.getSharedSecret(c));
+ Cipher cipher = crypto.getTagCipher();
+ try {
+ cipher.init(Cipher.ENCRYPT_MODE, tagKey);
+ } catch(InvalidKeyException badKey) {
+ throw new RuntimeException(badKey);
+ }
+ contactToCipher.put(c, cipher);
+ // Calculate the tags for the contact's connection window
+ ConnectionWindow w = db.getConnectionWindow(c, transportId);
+ Map<Long, Bytes> tags = new HashMap<Long, Bytes>();
+ for(Long unseen : w.getUnseenConnectionNumbers()) {
+ Bytes expectedTag = new Bytes(calculateTag(c, unseen));
+ tagToContact.put(expectedTag, c);
+ tagToConnectionNumber.put(expectedTag, unseen);
+ tags.put(unseen, expectedTag);
+ }
+ contactToTags.put(c, tags);
+ contactToWindow.put(c, w);
+ } catch(NoSuchContactException e) {
+ continue;
+ }
+ }
+ initialised = true;
+ }
+
+ private synchronized byte[] calculateTag(ContactId c,
+ long connectionNumber) {
+ byte[] tag = TagEncoder.encodeTag(transportId, connectionNumber, 0L);
+ Cipher cipher = contactToCipher.get(c);
+ assert cipher != null;
+ try {
+ return cipher.doFinal(tag);
+ } catch(BadPaddingException e) {
+ throw new RuntimeException(e);
+ } catch(IllegalBlockSizeException e) {
+ throw new RuntimeException(e);
+ }
+ }
+
+ public synchronized ContactId acceptConnection(byte[] tag)
+ throws DbException {
+ if(tag.length != 16) throw new IllegalArgumentException();
+ if(!initialised) initialise();
+ Bytes b = new Bytes(tag);
+ ContactId contactId = tagToContact.remove(b);
+ Long connectionNumber = tagToConnectionNumber.remove(b);
+ assert (contactId == null) == (connectionNumber == null);
+ if(contactId == null) return null;
+ // The tag was expected - update and save the connection window
+ ConnectionWindow w = contactToWindow.get(contactId);
+ assert w != null;
+ w.setSeen(connectionNumber);
+ db.setConnectionWindow(contactId, transportId, w);
+ // Update the set of expected tags
+ Map<Long, Bytes> oldTags = contactToTags.remove(contactId);
+ assert oldTags != null;
+ assert oldTags.containsKey(connectionNumber);
+ Map<Long, Bytes> newTags = new HashMap<Long, Bytes>();
+ for(Long unseen : w.getUnseenConnectionNumbers()) {
+ Bytes expectedTag = oldTags.get(unseen);
+ if(expectedTag == null) {
+ expectedTag = new Bytes(calculateTag(contactId, unseen));
+ tagToContact.put(expectedTag, contactId);
+ tagToConnectionNumber.put(expectedTag, connectionNumber);
+ }
+ newTags.put(unseen, expectedTag);
+ }
+ contactToTags.put(contactId, newTags);
+ return contactId;
+ }
+
+ public void eventOccurred(Event e) {
+ // When the set of contacts changes we need to re-initialise everything
+ if(e == Event.CONTACTS_UPDATED) {
+ synchronized(this) {
+ initialised = false;
+ }
+ }
+ }
+}
diff --git a/components/net/sf/briar/transport/ConnectionWindowImpl.java b/components/net/sf/briar/transport/ConnectionWindowImpl.java
index 956a5c722a072235edb610757dc22b0f0be81a48..af2c294870529366b19e3e41a1f0a761668b2090 100644
--- a/components/net/sf/briar/transport/ConnectionWindowImpl.java
+++ b/components/net/sf/briar/transport/ConnectionWindowImpl.java
@@ -7,8 +7,6 @@ import net.sf.briar.api.transport.ConnectionWindow;
class ConnectionWindowImpl implements ConnectionWindow {
- private static final long MAX_32_BIT_UNSIGNED = 4294967295L; // 2^32 - 1
-
private long centre;
private int bitmap;
@@ -33,7 +31,7 @@ class ConnectionWindowImpl implements ConnectionWindow {
private int getOffset(long connectionNumber) {
if(connectionNumber < 0L) throw new IllegalArgumentException();
- if(connectionNumber > MAX_32_BIT_UNSIGNED)
+ if(connectionNumber > Constants.MAX_32_BIT_UNSIGNED)
throw new IllegalArgumentException();
int offset = (int) (connectionNumber - centre) + 16;
if(offset < 0 || offset > 31) throw new IllegalArgumentException();
@@ -58,10 +56,11 @@ class ConnectionWindowImpl implements ConnectionWindow {
int mask = 0x80000000 >>> i;
if((bitmap & mask) == 0) {
long c = centre - 16 + i;
- if(c >= 0L && c <= MAX_32_BIT_UNSIGNED) unseen.add(c);
+ if(c >= 0L && c <= Constants.MAX_32_BIT_UNSIGNED) unseen.add(c);
}
}
- assert unseen.contains(centre) || centre == MAX_32_BIT_UNSIGNED + 1;
+ assert unseen.contains(centre)
+ || centre == Constants.MAX_32_BIT_UNSIGNED + 1;
return unseen;
}
}
diff --git a/components/net/sf/briar/transport/Constants.java b/components/net/sf/briar/transport/Constants.java
new file mode 100644
index 0000000000000000000000000000000000000000..07c96eaa065c3032cb01f007fb2a4d0d882acf80
--- /dev/null
+++ b/components/net/sf/briar/transport/Constants.java
@@ -0,0 +1,8 @@
+package net.sf.briar.transport;
+
+interface Constants {
+
+ static final int MAX_16_BIT_UNSIGNED = 65535; // 2^16 - 1
+ static final long MAX_32_BIT_UNSIGNED = 4294967295L; // 2^32 - 1
+
+}
diff --git a/components/net/sf/briar/transport/PacketWriterImpl.java b/components/net/sf/briar/transport/PacketWriterImpl.java
index c0f66d40e675e524a4c18d9d822394add76505cd..97c9626aa704a72c90abb3bc6cb6e699dfea696c 100644
--- a/components/net/sf/briar/transport/PacketWriterImpl.java
+++ b/components/net/sf/briar/transport/PacketWriterImpl.java
@@ -10,9 +10,6 @@ import net.sf.briar.api.transport.PacketWriter;
class PacketWriterImpl extends FilterOutputStream implements PacketWriter {
- private static final int MAX_16_BIT_UNSIGNED = 65535; // 2^16 - 1
- private static final long MAX_32_BIT_UNSIGNED = 4294967295L; // 2^32 - 1
-
private final PacketEncrypter encrypter;
private final Mac mac;
private final int transportIdentifier;
@@ -27,11 +24,11 @@ class PacketWriterImpl extends FilterOutputStream implements PacketWriter {
this.encrypter = encrypter;
this.mac = mac;
if(transportIdentifier < 0) throw new IllegalArgumentException();
- if(transportIdentifier > MAX_16_BIT_UNSIGNED)
+ if(transportIdentifier > Constants.MAX_16_BIT_UNSIGNED)
throw new IllegalArgumentException();
this.transportIdentifier = transportIdentifier;
if(connectionNumber < 0L) throw new IllegalArgumentException();
- if(connectionNumber > MAX_32_BIT_UNSIGNED)
+ if(connectionNumber > Constants.MAX_32_BIT_UNSIGNED)
throw new IllegalArgumentException();
this.connectionNumber = connectionNumber;
}
@@ -72,39 +69,14 @@ class PacketWriterImpl extends FilterOutputStream implements PacketWriter {
}
private void writeTag() throws IOException {
- if(packetNumber > MAX_32_BIT_UNSIGNED)
+ if(packetNumber > Constants.MAX_32_BIT_UNSIGNED)
throw new IllegalStateException();
- byte[] tag = new byte[16];
- // Encode the transport identifier as an unsigned 16-bit integer
- writeUint16(transportIdentifier, tag, 2);
- // Encode the connection number as an unsigned 32-bit integer
- writeUint32(connectionNumber, tag, 4);
- // Encode the packet number as an unsigned 32-bit integer
- writeUint32(packetNumber, tag, 8);
+ byte[] tag = TagEncoder.encodeTag(transportIdentifier, connectionNumber,
+ packetNumber);
// Write the tag to the encrypter and start calculating the MAC
encrypter.writeTag(tag);
mac.update(tag);
packetNumber++;
betweenPackets = false;
}
-
- // Package access for testing
- static void writeUint16(int i, byte[] b, int offset) {
- assert i >= 0;
- assert i <= MAX_16_BIT_UNSIGNED;
- assert b.length >= offset + 2;
- b[offset] = (byte) (i >> 8);
- b[offset + 1] = (byte) (i & 0xFF);
- }
-
- // Package access for testing
- static void writeUint32(long i, byte[] b, int offset) {
- assert i >= 0L;
- assert i <= MAX_32_BIT_UNSIGNED;
- assert b.length >= offset + 4;
- b[offset] = (byte) (i >> 24);
- b[offset + 1] = (byte) (i >> 16 & 0xFF);
- b[offset + 2] = (byte) (i >> 8 & 0xFF);
- b[offset + 3] = (byte) (i & 0xFF);
- }
}
diff --git a/components/net/sf/briar/transport/TagEncoder.java b/components/net/sf/briar/transport/TagEncoder.java
new file mode 100644
index 0000000000000000000000000000000000000000..aead6debbf2de9d251b8091ba03d4822e9c3f1f1
--- /dev/null
+++ b/components/net/sf/briar/transport/TagEncoder.java
@@ -0,0 +1,36 @@
+package net.sf.briar.transport;
+
+public class TagEncoder {
+
+ static byte[] encodeTag(int transportIdentifier, long connectionNumber,
+ long packetNumber) {
+ byte[] tag = new byte[16];
+ // Encode the transport identifier as an unsigned 16-bit integer
+ writeUint16(transportIdentifier, tag, 2);
+ // Encode the connection number as an unsigned 32-bit integer
+ writeUint32(connectionNumber, tag, 4);
+ // Encode the packet number as an unsigned 32-bit integer
+ writeUint32(packetNumber, tag, 8);
+ return tag;
+ }
+
+ // Package access for testing
+ static void writeUint16(int i, byte[] b, int offset) {
+ assert i >= 0;
+ assert i <= Constants.MAX_16_BIT_UNSIGNED;
+ assert b.length >= offset + 2;
+ b[offset] = (byte) (i >> 8);
+ b[offset + 1] = (byte) (i & 0xFF);
+ }
+
+ // Package access for testing
+ static void writeUint32(long i, byte[] b, int offset) {
+ assert i >= 0L;
+ assert i <= Constants.MAX_32_BIT_UNSIGNED;
+ assert b.length >= offset + 4;
+ b[offset] = (byte) (i >> 24);
+ b[offset + 1] = (byte) (i >> 16 & 0xFF);
+ b[offset + 2] = (byte) (i >> 8 & 0xFF);
+ b[offset + 3] = (byte) (i & 0xFF);
+ }
+}
diff --git a/test/build.xml b/test/build.xml
index f034b76f42367c161cb89c61bd5cf945672b6a6c..2791cc2a029c6e1bb278c112185650a450cd6bae 100644
--- a/test/build.xml
+++ b/test/build.xml
@@ -35,6 +35,7 @@
<test name='net.sf.briar.transport.ConnectionWindowImplTest'/>
<test name='net.sf.briar.transport.PacketEncrypterImplTest'/>
<test name='net.sf.briar.transport.PacketWriterImplTest'/>
+ <test name='net.sf.briar.transport.TagEncoderTest'/>
<test name='net.sf.briar.util.FileUtilsTest'/>
<test name='net.sf.briar.util.StringUtilsTest'/>
<test name='net.sf.briar.util.ZipUtilsTest'/>
diff --git a/test/net/sf/briar/transport/PacketWriterImplTest.java b/test/net/sf/briar/transport/PacketWriterImplTest.java
index 9bf4ee1166479c76067aa9a0fc35e8f5894a15a7..94783c7a28cd87bb7ebe2c2ef5b5ab038f568c68 100644
--- a/test/net/sf/briar/transport/PacketWriterImplTest.java
+++ b/test/net/sf/briar/transport/PacketWriterImplTest.java
@@ -140,28 +140,6 @@ public class PacketWriterImplTest extends TestCase {
assertTrue(Arrays.equals(expectedMac1, actualMac1));
}
- @Test
- public void testWriteUint16() throws Exception {
- byte[] b = new byte[3];
- PacketWriterImpl.writeUint16(0, b, 1);
- assertEquals("000000", StringUtils.toHexString(b));
- PacketWriterImpl.writeUint16(1, b, 1);
- assertEquals("000001", StringUtils.toHexString(b));
- PacketWriterImpl.writeUint16(65535, b, 1);
- assertEquals("00FFFF", StringUtils.toHexString(b));
- }
-
- @Test
- public void testWriteUint32() throws Exception {
- byte[] b = new byte[5];
- PacketWriterImpl.writeUint32(0L, b, 1);
- assertEquals("0000000000", StringUtils.toHexString(b));
- PacketWriterImpl.writeUint32(1L, b, 1);
- assertEquals("0000000001", StringUtils.toHexString(b));
- PacketWriterImpl.writeUint32(4294967295L, b, 1);
- assertEquals("00FFFFFFFF", StringUtils.toHexString(b));
- }
-
private static class NullPacketEncrypter implements PacketEncrypter {
private final OutputStream out;
diff --git a/test/net/sf/briar/transport/TagEncoderTest.java b/test/net/sf/briar/transport/TagEncoderTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..0f81d84a1a4d87b02a4047193b0920d445f76a15
--- /dev/null
+++ b/test/net/sf/briar/transport/TagEncoderTest.java
@@ -0,0 +1,32 @@
+package net.sf.briar.transport;
+
+import net.sf.briar.util.StringUtils;
+
+import org.junit.Test;
+
+import junit.framework.TestCase;
+
+public class TagEncoderTest extends TestCase {
+
+ @Test
+ public void testWriteUint16() throws Exception {
+ byte[] b = new byte[3];
+ TagEncoder.writeUint16(0, b, 1);
+ assertEquals("000000", StringUtils.toHexString(b));
+ TagEncoder.writeUint16(1, b, 1);
+ assertEquals("000001", StringUtils.toHexString(b));
+ TagEncoder.writeUint16(65535, b, 1);
+ assertEquals("00FFFF", StringUtils.toHexString(b));
+ }
+
+ @Test
+ public void testWriteUint32() throws Exception {
+ byte[] b = new byte[5];
+ TagEncoder.writeUint32(0L, b, 1);
+ assertEquals("0000000000", StringUtils.toHexString(b));
+ TagEncoder.writeUint32(1L, b, 1);
+ assertEquals("0000000001", StringUtils.toHexString(b));
+ TagEncoder.writeUint32(4294967295L, b, 1);
+ assertEquals("00FFFFFFFF", StringUtils.toHexString(b));
+ }
+}