diff --git a/components/net/sf/briar/transport/ConnectionReaderFactoryImpl.java b/components/net/sf/briar/transport/ConnectionReaderFactoryImpl.java
index 2b4288a445075284431aac79b83ec1394b3e2958..fc951da24a9ab393516db85b478e25a1bf0f9e32 100644
--- a/components/net/sf/briar/transport/ConnectionReaderFactoryImpl.java
+++ b/components/net/sf/briar/transport/ConnectionReaderFactoryImpl.java
@@ -26,15 +26,26 @@ class ConnectionReaderFactoryImpl implements ConnectionReaderFactory {
public ConnectionReader createConnectionReader(InputStream in,
byte[] secret, boolean initiator) {
- // Derive the keys and erase the secret
- ErasableKey tagKey = crypto.deriveTagKey(secret, initiator);
- ErasableKey frameKey = crypto.deriveFrameKey(secret, initiator);
- ByteUtils.erase(secret);
- // Create the reader
- Cipher tagCipher = crypto.getTagCipher();
- AuthenticatedCipher frameCipher = crypto.getFrameCipher();
- FrameReader encryption = new IncomingEncryptionLayer(in, tagCipher,
- frameCipher, tagKey, frameKey, !initiator, MAX_FRAME_LENGTH);
- return new ConnectionReaderImpl(encryption, MAX_FRAME_LENGTH);
+ if(initiator) {
+ // Derive the frame key and erase the secret
+ ErasableKey frameKey = crypto.deriveFrameKey(secret, initiator);
+ ByteUtils.erase(secret);
+ // Create a reader for the responder's side of the connection
+ AuthenticatedCipher frameCipher = crypto.getFrameCipher();
+ FrameReader encryption = new IncomingEncryptionLayer(in,
+ frameCipher, frameKey, MAX_FRAME_LENGTH);
+ return new ConnectionReaderImpl(encryption, MAX_FRAME_LENGTH);
+ } else {
+ // Derive the tag and frame keys and erase the secret
+ ErasableKey tagKey = crypto.deriveTagKey(secret, initiator);
+ ErasableKey frameKey = crypto.deriveFrameKey(secret, initiator);
+ ByteUtils.erase(secret);
+ // Create a reader for the initiator's side of the connection
+ Cipher tagCipher = crypto.getTagCipher();
+ AuthenticatedCipher frameCipher = crypto.getFrameCipher();
+ FrameReader encryption = new IncomingEncryptionLayer(in, tagCipher,
+ frameCipher, tagKey, frameKey, MAX_FRAME_LENGTH);
+ return new ConnectionReaderImpl(encryption, MAX_FRAME_LENGTH);
+ }
}
}
diff --git a/components/net/sf/briar/transport/ConnectionWriterFactoryImpl.java b/components/net/sf/briar/transport/ConnectionWriterFactoryImpl.java
index e719edd3114daa0a5e6fcb331112eae08d54d08d..415eb2fdf74ece8fa3f2be2f1cfc1309b50c854f 100644
--- a/components/net/sf/briar/transport/ConnectionWriterFactoryImpl.java
+++ b/components/net/sf/briar/transport/ConnectionWriterFactoryImpl.java
@@ -26,16 +26,26 @@ class ConnectionWriterFactoryImpl implements ConnectionWriterFactory {
public ConnectionWriter createConnectionWriter(OutputStream out,
long capacity, byte[] secret, boolean initiator) {
- // Derive the keys and erase the secret
- ErasableKey tagKey = crypto.deriveTagKey(secret, initiator);
- ErasableKey frameKey = crypto.deriveFrameKey(secret, initiator);
- ByteUtils.erase(secret);
- // Create the writer
- Cipher tagCipher = crypto.getTagCipher();
- AuthenticatedCipher frameCipher = crypto.getFrameCipher();
- FrameWriter encryption = new OutgoingEncryptionLayer(out, capacity,
- tagCipher, frameCipher, tagKey, frameKey, initiator,
- MAX_FRAME_LENGTH);
- return new ConnectionWriterImpl(encryption, MAX_FRAME_LENGTH);
+ if(initiator) {
+ // Derive the tag and frame keys and erase the secret
+ ErasableKey tagKey = crypto.deriveTagKey(secret, initiator);
+ ErasableKey frameKey = crypto.deriveFrameKey(secret, initiator);
+ ByteUtils.erase(secret);
+ // Create a writer for the initiator's side of the connection
+ Cipher tagCipher = crypto.getTagCipher();
+ AuthenticatedCipher frameCipher = crypto.getFrameCipher();
+ FrameWriter encryption = new OutgoingEncryptionLayer(out, capacity,
+ tagCipher, frameCipher, tagKey, frameKey, MAX_FRAME_LENGTH);
+ return new ConnectionWriterImpl(encryption, MAX_FRAME_LENGTH);
+ } else {
+ // Derive the frame key and erase the secret
+ ErasableKey frameKey = crypto.deriveFrameKey(secret, initiator);
+ ByteUtils.erase(secret);
+ // Create a writer for the responder's side of the connection
+ AuthenticatedCipher frameCipher = crypto.getFrameCipher();
+ FrameWriter encryption = new OutgoingEncryptionLayer(out, capacity,
+ frameCipher, frameKey, MAX_FRAME_LENGTH);
+ return new ConnectionWriterImpl(encryption, MAX_FRAME_LENGTH);
+ }
}
-}
+}
\ No newline at end of file
diff --git a/components/net/sf/briar/transport/IncomingEncryptionLayer.java b/components/net/sf/briar/transport/IncomingEncryptionLayer.java
index 084b5f5d72e8c6be7a481bfca5261786ae18f393..4e9bb09c2936d7b52485544c1c2029b70d9dcc24 100644
--- a/components/net/sf/briar/transport/IncomingEncryptionLayer.java
+++ b/components/net/sf/briar/transport/IncomingEncryptionLayer.java
@@ -25,26 +25,44 @@ class IncomingEncryptionLayer implements FrameReader {
private final AuthenticatedCipher frameCipher;
private final ErasableKey tagKey, frameKey;
private final byte[] iv, aad, ciphertext;
- private final int maxFrameLength;
+ private final int frameLength;
- private boolean readTag, lastFrame;
private long frameNumber;
+ private boolean readTag, lastFrame;
+ /** Constructor for the initiator's side of a connection. */
IncomingEncryptionLayer(InputStream in, Cipher tagCipher,
AuthenticatedCipher frameCipher, ErasableKey tagKey,
- ErasableKey frameKey, boolean readTag, int maxFrameLength) {
+ ErasableKey frameKey, int frameLength) {
this.in = in;
this.tagCipher = tagCipher;
this.frameCipher = frameCipher;
this.tagKey = tagKey;
this.frameKey = frameKey;
- this.readTag = readTag;
- this.maxFrameLength = maxFrameLength;
+ this.frameLength = frameLength;
+ iv = new byte[IV_LENGTH];
+ aad = new byte[AAD_LENGTH];
+ ciphertext = new byte[frameLength];
+ frameNumber = 0L;
+ readTag = true;
lastFrame = false;
+ }
+
+ /** Constructor for the responder's side of a connection. */
+ IncomingEncryptionLayer(InputStream in, AuthenticatedCipher frameCipher,
+ ErasableKey frameKey, int frameLength) {
+ this.in = in;
+ this.frameCipher = frameCipher;
+ this.frameKey = frameKey;
+ this.frameLength = frameLength;
+ tagCipher = null;
+ tagKey = null;
iv = new byte[IV_LENGTH];
aad = new byte[AAD_LENGTH];
- ciphertext = new byte[maxFrameLength];
+ ciphertext = new byte[frameLength];
frameNumber = 0L;
+ readTag = false;
+ lastFrame = false;
}
public int readFrame(byte[] frame) throws IOException {
@@ -70,9 +88,9 @@ class IncomingEncryptionLayer implements FrameReader {
// Read the frame
int ciphertextLength = 0;
try {
- while(ciphertextLength < maxFrameLength) {
+ while(ciphertextLength < frameLength) {
int read = in.read(ciphertext, ciphertextLength,
- maxFrameLength - ciphertextLength);
+ frameLength - ciphertextLength);
if(read == -1) break; // We'll check the length later
ciphertextLength += read;
}
@@ -96,7 +114,7 @@ class IncomingEncryptionLayer implements FrameReader {
}
// Decode and validate the header
lastFrame = FrameEncoder.isLastFrame(frame);
- if(!lastFrame && ciphertextLength < maxFrameLength)
+ if(!lastFrame && ciphertextLength < frameLength)
throw new EOFException();
int payloadLength = FrameEncoder.getPayloadLength(frame);
if(payloadLength > plaintextLength - HEADER_LENGTH)
diff --git a/components/net/sf/briar/transport/OutgoingEncryptionLayer.java b/components/net/sf/briar/transport/OutgoingEncryptionLayer.java
index f3cebfd1e9a93bed17503c3507c15e2dab2fc63a..c9080a6c5e95ec010abc51c9ed00ad83b92a843c 100644
--- a/components/net/sf/briar/transport/OutgoingEncryptionLayer.java
+++ b/components/net/sf/briar/transport/OutgoingEncryptionLayer.java
@@ -23,35 +23,54 @@ class OutgoingEncryptionLayer implements FrameWriter {
private final AuthenticatedCipher frameCipher;
private final ErasableKey tagKey, frameKey;
private final byte[] iv, aad, ciphertext;
- private final int maxFrameLength;
+ private final int frameLength;
- private boolean writeTag;
private long capacity, frameNumber;
+ private boolean writeTag;
+ /** Constructor for the initiator's side of a connection. */
OutgoingEncryptionLayer(OutputStream out, long capacity, Cipher tagCipher,
AuthenticatedCipher frameCipher, ErasableKey tagKey,
- ErasableKey frameKey, boolean writeTag, int maxFrameLength) {
+ ErasableKey frameKey, int frameLength) {
this.out = out;
- this.capacity = writeTag ? capacity - TAG_LENGTH : capacity;
+ this.capacity = capacity - TAG_LENGTH;
this.tagCipher = tagCipher;
this.frameCipher = frameCipher;
this.tagKey = tagKey;
this.frameKey = frameKey;
- this.writeTag = writeTag;
- this.maxFrameLength = maxFrameLength;
+ this.frameLength = frameLength;
+ iv = new byte[IV_LENGTH];
+ aad = new byte[AAD_LENGTH];
+ ciphertext = new byte[frameLength];
+ frameNumber = 0L;
+ writeTag = true;
+ }
+
+ /** Constructor for the responder's side of a connection. */
+ OutgoingEncryptionLayer(OutputStream out, long capacity,
+ AuthenticatedCipher frameCipher, ErasableKey frameKey,
+ int frameLength) {
+ this.out = out;
+ this.capacity = capacity;
+ this.frameCipher = frameCipher;
+ this.frameKey = frameKey;
+ this.frameLength = frameLength;
+ tagCipher = null;
+ tagKey = null;
iv = new byte[IV_LENGTH];
aad = new byte[AAD_LENGTH];
- ciphertext = new byte[maxFrameLength];
+ ciphertext = new byte[frameLength];
frameNumber = 0L;
+ writeTag = false;
}
public void writeFrame(byte[] frame, int payloadLength, int paddingLength,
boolean lastFrame) throws IOException {
int plaintextLength = HEADER_LENGTH + payloadLength + paddingLength;
int ciphertextLength = plaintextLength + MAC_LENGTH;
- if(ciphertextLength > maxFrameLength)
+ if(ciphertextLength > frameLength)
throw new IllegalArgumentException();
- if(!lastFrame && ciphertextLength < maxFrameLength)
+ if(!lastFrame && ciphertextLength < frameLength)
throw new IllegalArgumentException();
// If the initiator's side of the connection is closed without writing
// any payload or padding, don't write a tag or an empty frame
diff --git a/test/net/sf/briar/transport/FrameReadWriteTest.java b/test/net/sf/briar/transport/FrameReadWriteTest.java
index 620a63f6780045be6d7f5b5a05d068220ef6b185..a9b7361e75604551ac9257e2cc65de8c7c94bf26 100644
--- a/test/net/sf/briar/transport/FrameReadWriteTest.java
+++ b/test/net/sf/briar/transport/FrameReadWriteTest.java
@@ -75,7 +75,7 @@ public class FrameReadWriteTest extends BriarTestCase {
ByteArrayOutputStream out = new ByteArrayOutputStream();
FrameWriter encryptionOut = new OutgoingEncryptionLayer(out,
Long.MAX_VALUE, tagCipher, frameCipher, tagCopy, frameCopy,
- true, FRAME_LENGTH);
+ FRAME_LENGTH);
ConnectionWriter writer = new ConnectionWriterImpl(encryptionOut,
FRAME_LENGTH);
OutputStream out1 = writer.getOutputStream();
@@ -88,7 +88,7 @@ public class FrameReadWriteTest extends BriarTestCase {
// Read the tag and the frames back
ByteArrayInputStream in = new ByteArrayInputStream(output);
FrameReader encryptionIn = new IncomingEncryptionLayer(in, tagCipher,
- frameCipher, tagKey, frameKey, true, FRAME_LENGTH);
+ frameCipher, tagKey, frameKey, FRAME_LENGTH);
ConnectionReader reader = new ConnectionReaderImpl(encryptionIn,
FRAME_LENGTH);
InputStream in1 = reader.getInputStream();