diff --git a/api/net/sf/briar/api/FormatException.java b/api/net/sf/briar/api/FormatException.java
index b48f8ba51f08f7b38f0d229dbf01c16e4635db9d..6796df2b7fe6d86cdef4e69b4f5e771f2e78791b 100644
--- a/api/net/sf/briar/api/FormatException.java
+++ b/api/net/sf/briar/api/FormatException.java
@@ -2,8 +2,8 @@ package net.sf.briar.api;
import java.io.IOException;
+/** An exception that indicates an unrecoverable formatting error. */
public class FormatException extends IOException {
private static final long serialVersionUID = 2274966775687766337L;
-
}
diff --git a/components/net/sf/briar/transport/ConnectionReaderFactoryImpl.java b/components/net/sf/briar/transport/ConnectionReaderFactoryImpl.java
index b2f296ef74671e852e68d83538cfc72fe0952892..7ef9d7adff038cdfe0224c9cb35d5c1a976c92b0 100644
--- a/components/net/sf/briar/transport/ConnectionReaderFactoryImpl.java
+++ b/components/net/sf/briar/transport/ConnectionReaderFactoryImpl.java
@@ -49,9 +49,9 @@ class ConnectionReaderFactoryImpl implements ConnectionReaderFactory {
// No error correction
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- // Create the reader
+ // Create the reader - don't tolerate errors
Mac mac = crypto.getMac();
- return new ConnectionReaderImpl(correcter, mac, macKey);
+ return new ConnectionReaderImpl(correcter, mac, macKey, false);
}
public ConnectionReader createConnectionReader(SegmentSource in,
@@ -80,8 +80,8 @@ class ConnectionReaderFactoryImpl implements ConnectionReaderFactory {
// No error correction
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- // Create the reader
+ // Create the reader - don't tolerate errors
Mac mac = crypto.getMac();
- return new ConnectionReaderImpl(correcter, mac, macKey);
+ return new ConnectionReaderImpl(correcter, mac, macKey, false);
}
}
diff --git a/components/net/sf/briar/transport/ConnectionReaderImpl.java b/components/net/sf/briar/transport/ConnectionReaderImpl.java
index 0241369d4559a5e3c005dad9fe18657bfc0ebb33..e02905813cca46b9161fbb292940ca430ba1f252 100644
--- a/components/net/sf/briar/transport/ConnectionReaderImpl.java
+++ b/components/net/sf/briar/transport/ConnectionReaderImpl.java
@@ -20,15 +20,17 @@ class ConnectionReaderImpl extends InputStream implements ConnectionReader {
private final IncomingErrorCorrectionLayer in;
private final Mac mac;
+ private final boolean tolerateErrors;
private final Frame frame;
private long frameNumber = 0L;
private int offset = 0, length = 0;
ConnectionReaderImpl(IncomingErrorCorrectionLayer in, Mac mac,
- ErasableKey macKey) {
+ ErasableKey macKey, boolean tolerateErrors) {
this.in = in;
this.mac = mac;
+ this.tolerateErrors = tolerateErrors;
// Initialise the MAC
try {
mac.init(macKey);
@@ -47,7 +49,7 @@ class ConnectionReaderImpl extends InputStream implements ConnectionReader {
@Override
public int read() throws IOException {
- while(length == 0) if(!readFrame()) return -1;
+ while(length == 0) if(!readValidFrame()) return -1;
int b = frame.getBuffer()[offset] & 0xff;
offset++;
length--;
@@ -61,7 +63,7 @@ class ConnectionReaderImpl extends InputStream implements ConnectionReader {
@Override
public int read(byte[] b, int off, int len) throws IOException {
- while(length == 0) if(!readFrame()) return -1;
+ while(length == 0) if(!readValidFrame()) return -1;
len = Math.min(len, length);
System.arraycopy(frame.getBuffer(), offset, b, off, len);
offset += len;
@@ -69,33 +71,46 @@ class ConnectionReaderImpl extends InputStream implements ConnectionReader {
return len;
}
- private boolean readFrame() throws IOException {
+ private boolean readValidFrame() throws IOException {
+ while(true) {
+ try {
+ return readFrame();
+ } catch(InvalidDataException e) {
+ if(tolerateErrors) continue;
+ throw new FormatException();
+ }
+ }
+ }
+
+ private boolean readFrame() throws IOException, InvalidDataException {
assert length == 0;
// Don't allow more than 2^32 frames to be read
- if(frameNumber > MAX_32_BIT_UNSIGNED) throw new IllegalStateException();
+ if(frameNumber > MAX_32_BIT_UNSIGNED)
+ throw new IllegalStateException();
// Read a frame
Collection<Long> window = Collections.singleton(frameNumber);
if(!in.readFrame(frame, window)) return false;
// Check that the frame number is correct and the length is legal
byte[] buf = frame.getBuffer();
if(!HeaderEncoder.validateHeader(buf, frameNumber))
- throw new FormatException();
+ throw new InvalidDataException();
// Check that the payload and padding lengths are correct
int payload = HeaderEncoder.getPayloadLength(buf);
int padding = HeaderEncoder.getPaddingLength(buf);
if(frame.getLength() != FRAME_HEADER_LENGTH + payload + padding
- + MAC_LENGTH) throw new FormatException();
+ + MAC_LENGTH) throw new InvalidDataException();
// Check that the padding is all zeroes
int paddingStart = FRAME_HEADER_LENGTH + payload;
for(int i = paddingStart; i < paddingStart + padding; i++) {
- if(buf[i] != 0) throw new FormatException();
+ if(buf[i] != 0) throw new InvalidDataException();
}
// Check the MAC
int macStart = FRAME_HEADER_LENGTH + payload + padding;
mac.update(buf, 0, macStart);
byte[] expectedMac = mac.doFinal();
for(int i = 0; i < expectedMac.length; i++) {
- if(expectedMac[i] != buf[macStart + i]) throw new FormatException();
+ if(expectedMac[i] != buf[macStart + i])
+ throw new InvalidDataException();
}
offset = FRAME_HEADER_LENGTH;
length = payload;
diff --git a/components/net/sf/briar/transport/IncomingEncryptionLayer.java b/components/net/sf/briar/transport/IncomingEncryptionLayer.java
index 84c8776c1164a99a91f27404c4e3a741c6422616..3521ce46e6b71dd8a8b00fe9eb4ed1be8da59a0d 100644
--- a/components/net/sf/briar/transport/IncomingEncryptionLayer.java
+++ b/components/net/sf/briar/transport/IncomingEncryptionLayer.java
@@ -9,6 +9,10 @@ interface IncomingEncryptionLayer {
/**
* Reads a segment, excluding its tag, into the given buffer. Returns false
* if no more segments can be read from the connection.
+ * @throws IOException if an unrecoverable error occurs and the connection
+ * must be closed.
+ * @throws InvalidDataException if a recoverable error occurs. The caller
+ * may choose whether to retry the read or close the connection.
*/
- boolean readSegment(Segment s) throws IOException;
+ boolean readSegment(Segment s) throws IOException, InvalidDataException;
}
diff --git a/components/net/sf/briar/transport/IncomingErrorCorrectionLayer.java b/components/net/sf/briar/transport/IncomingErrorCorrectionLayer.java
index 446c7a3ef52d5f64beccf4574702f54eb36e2a7c..bd555c150cd66c33757e20d1bccf91ff4cd8adfc 100644
--- a/components/net/sf/briar/transport/IncomingErrorCorrectionLayer.java
+++ b/components/net/sf/briar/transport/IncomingErrorCorrectionLayer.java
@@ -9,6 +9,11 @@ interface IncomingErrorCorrectionLayer {
* Reads a frame into the given buffer. The frame number must be contained
* in the given window. Returns false if no more frames can be read from
* the connection.
+ * @throws IOException if an unrecoverable error occurs and the connection
+ * must be closed.
+ * @throws InvalidDataException if a recoverable error occurs. The caller
+ * may choose whether to retry the read or close the connection.
*/
- boolean readFrame(Frame f, Collection<Long> window) throws IOException;
+ boolean readFrame(Frame f, Collection<Long> window) throws IOException,
+ InvalidDataException;
}
diff --git a/components/net/sf/briar/transport/IncomingSegmentedEncryptionLayer.java b/components/net/sf/briar/transport/IncomingSegmentedEncryptionLayer.java
index 89815dc1e6f91fe687ea6fc3c730200ac442460b..f2a2ad40a3ddda8e77b7c258355f6dce51d498b9 100644
--- a/components/net/sf/briar/transport/IncomingSegmentedEncryptionLayer.java
+++ b/components/net/sf/briar/transport/IncomingSegmentedEncryptionLayer.java
@@ -11,7 +11,6 @@ import java.security.GeneralSecurityException;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
-import net.sf.briar.api.FormatException;
import net.sf.briar.api.crypto.ErasableKey;
import net.sf.briar.api.plugins.SegmentSource;
import net.sf.briar.api.transport.Segment;
@@ -32,22 +31,23 @@ class IncomingSegmentedEncryptionLayer implements IncomingEncryptionLayer {
IncomingSegmentedEncryptionLayer(SegmentSource in, Cipher tagCipher,
Cipher segCipher, ErasableKey tagKey, ErasableKey segKey,
- boolean tagEverySegment, Segment s) {
+ boolean tagEverySegment, Segment bufferedSegment) {
this.in = in;
this.tagCipher = tagCipher;
this.segCipher = segCipher;
this.tagKey = tagKey;
this.segKey = segKey;
this.tagEverySegment = tagEverySegment;
+ this.bufferedSegment = bufferedSegment;
blockSize = segCipher.getBlockSize();
if(blockSize < FRAME_HEADER_LENGTH)
throw new IllegalArgumentException();
iv = IvEncoder.encodeIv(0L, blockSize);
segment = new SegmentImpl();
- bufferedSegment = s;
}
- public boolean readSegment(Segment s) throws IOException {
+ public boolean readSegment(Segment s) throws IOException,
+ InvalidDataException {
boolean expectTag = tagEverySegment || firstSegment;
firstSegment = false;
try {
@@ -62,14 +62,14 @@ class IncomingSegmentedEncryptionLayer implements IncomingEncryptionLayer {
}
int offset = expectTag ? TAG_LENGTH : 0;
int length = segment.getLength();
- if(length > MAX_SEGMENT_LENGTH) throw new FormatException();
+ if(length > MAX_SEGMENT_LENGTH) throw new InvalidDataException();
if(length < offset + FRAME_HEADER_LENGTH + MAC_LENGTH)
- throw new FormatException();
+ throw new InvalidDataException();
byte[] ciphertext = segment.getBuffer();
// If a tag is expected then decrypt and validate it
if(expectTag) {
long seg = TagEncoder.decodeTag(ciphertext, tagCipher, tagKey);
- if(seg == -1) throw new FormatException();
+ if(seg == -1) throw new InvalidDataException();
segmentNumber = seg;
}
// Decrypt the segment
diff --git a/components/net/sf/briar/transport/InvalidDataException.java b/components/net/sf/briar/transport/InvalidDataException.java
new file mode 100644
index 0000000000000000000000000000000000000000..34580d4340feeb2239993105f8c02e8b859b02a2
--- /dev/null
+++ b/components/net/sf/briar/transport/InvalidDataException.java
@@ -0,0 +1,7 @@
+package net.sf.briar.transport;
+
+/** An exception that indicates a recoverable formatting error. */
+class InvalidDataException extends Exception {
+
+ private static final long serialVersionUID = 4455775710413826953L;
+}
diff --git a/components/net/sf/briar/transport/NullIncomingErrorCorrectionLayer.java b/components/net/sf/briar/transport/NullIncomingErrorCorrectionLayer.java
index 53898dc9f953dd40d7522082ca70e5d87c0db7fa..7d344a592909cbe11cffa291a00edcb71e1386de 100644
--- a/components/net/sf/briar/transport/NullIncomingErrorCorrectionLayer.java
+++ b/components/net/sf/briar/transport/NullIncomingErrorCorrectionLayer.java
@@ -16,7 +16,7 @@ class NullIncomingErrorCorrectionLayer implements IncomingErrorCorrectionLayer {
}
public boolean readFrame(Frame f, Collection<Long> window)
- throws IOException {
+ throws IOException, InvalidDataException {
while(true) {
if(!in.readSegment(segment)) return false;
byte[] buf = segment.getBuffer();
diff --git a/test/net/sf/briar/transport/ConnectionReaderImplTest.java b/test/net/sf/briar/transport/ConnectionReaderImplTest.java
index 344561e799c53a367719f71391c7fefdd35937f5..33358ba418960d35a2165a1f008244138fa3e037 100644
--- a/test/net/sf/briar/transport/ConnectionReaderImplTest.java
+++ b/test/net/sf/briar/transport/ConnectionReaderImplTest.java
@@ -35,7 +35,8 @@ public class ConnectionReaderImplTest extends TransportTest {
IncomingEncryptionLayer decrypter = new NullIncomingEncryptionLayer(in);
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey);
+ ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey,
+ false);
// There should be no bytes available before EOF
assertEquals(-1, r.getInputStream().read());
}
@@ -55,7 +56,8 @@ public class ConnectionReaderImplTest extends TransportTest {
IncomingEncryptionLayer decrypter = new NullIncomingEncryptionLayer(in);
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey);
+ ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey,
+ false);
// There should be one byte available before EOF
assertEquals(0, r.getInputStream().read());
assertEquals(-1, r.getInputStream().read());
@@ -83,7 +85,8 @@ public class ConnectionReaderImplTest extends TransportTest {
IncomingEncryptionLayer decrypter = new NullIncomingEncryptionLayer(in);
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey);
+ ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey,
+ false);
byte[] read = new byte[MAX_PAYLOAD_LENGTH];
TestUtils.readFully(r.getInputStream(), read);
// Try to read the second frame
@@ -119,7 +122,8 @@ public class ConnectionReaderImplTest extends TransportTest {
IncomingEncryptionLayer decrypter = new NullIncomingEncryptionLayer(in);
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey);
+ ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey,
+ false);
byte[] read = new byte[MAX_PAYLOAD_LENGTH - paddingLength];
TestUtils.readFully(r.getInputStream(), read);
// Try to read the second frame
@@ -147,7 +151,8 @@ public class ConnectionReaderImplTest extends TransportTest {
IncomingEncryptionLayer decrypter = new NullIncomingEncryptionLayer(in);
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey);
+ ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey,
+ false);
// The non-zero padding should be rejected
try {
r.getInputStream().read();
@@ -181,7 +186,8 @@ public class ConnectionReaderImplTest extends TransportTest {
IncomingEncryptionLayer decrypter = new NullIncomingEncryptionLayer(in);
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey);
+ ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey,
+ false);
byte[] read = new byte[payloadLength];
TestUtils.readFully(r.getInputStream(), read);
assertArrayEquals(new byte[payloadLength], read);
@@ -207,7 +213,8 @@ public class ConnectionReaderImplTest extends TransportTest {
IncomingEncryptionLayer decrypter = new NullIncomingEncryptionLayer(in);
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey);
+ ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey,
+ false);
try {
r.getInputStream().read();
fail();
@@ -231,7 +238,8 @@ public class ConnectionReaderImplTest extends TransportTest {
IncomingEncryptionLayer decrypter = new NullIncomingEncryptionLayer(in);
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
- ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey);
+ ConnectionReader r = new ConnectionReaderImpl(correcter, mac, macKey,
+ false);
try {
r.getInputStream().read();
fail();
diff --git a/test/net/sf/briar/transport/FrameReadWriteTest.java b/test/net/sf/briar/transport/FrameReadWriteTest.java
index 9c10894c4ad53a22b3d89ae9e41324f42ef5f653..ad25f196bb497fcfa4d21164faf069b3e30f4d43 100644
--- a/test/net/sf/briar/transport/FrameReadWriteTest.java
+++ b/test/net/sf/briar/transport/FrameReadWriteTest.java
@@ -98,7 +98,7 @@ public class FrameReadWriteTest extends BriarTestCase {
IncomingErrorCorrectionLayer correcter1 =
new NullIncomingErrorCorrectionLayer(decrypter);
ConnectionReader reader = new ConnectionReaderImpl(correcter1, mac,
- macKey);
+ macKey, false);
InputStream in1 = reader.getInputStream();
byte[] recovered = new byte[frame.length];
int offset = 0;
diff --git a/test/net/sf/briar/transport/NullIncomingEncryptionLayer.java b/test/net/sf/briar/transport/NullIncomingEncryptionLayer.java
index 6be55a3a74ec8080643d7a3a93d00083fe6e2b5f..def5509b8381ce1017533f5ecea85fdd6d527306 100644
--- a/test/net/sf/briar/transport/NullIncomingEncryptionLayer.java
+++ b/test/net/sf/briar/transport/NullIncomingEncryptionLayer.java
@@ -39,7 +39,7 @@ class NullIncomingEncryptionLayer implements IncomingEncryptionLayer {
int padding = HeaderEncoder.getPaddingLength(buf);
length = FRAME_HEADER_LENGTH + payload + padding + MAC_LENGTH;
if(length > MAX_FRAME_LENGTH) throw new FormatException();
- // Read the remainder of the frame/segment
+ // Read the remainder of the frame
while(offset < length) {
int read = in.read(buf, offset, length - offset);
if(read == -1) throw new EOFException();