Variable-length frames (untested).

This commit is contained in:
akwizgran
2015-01-05 17:35:29 +00:00
parent d3bf2d59a1
commit 1f69f0d2f6
16 changed files with 147 additions and 368 deletions

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@@ -1,185 +1,37 @@
package org.briarproject.crypto;
import static org.briarproject.api.transport.TransportConstants.AAD_LENGTH;
import static org.briarproject.api.transport.TransportConstants.HEADER_LENGTH;
import static org.briarproject.api.transport.TransportConstants.IV_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAC_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAX_FRAME_LENGTH;
import java.io.ByteArrayInputStream;
import org.briarproject.BriarTestCase;
import org.briarproject.TestLifecycleModule;
import org.briarproject.TestSystemModule;
import org.briarproject.api.FormatException;
import org.briarproject.api.crypto.AuthenticatedCipher;
import org.briarproject.api.crypto.CryptoComponent;
import org.briarproject.api.crypto.SecretKey;
import org.briarproject.util.ByteUtils;
import org.junit.Test;
import com.google.inject.Guice;
import com.google.inject.Injector;
public class StreamDecrypterImplTest extends BriarTestCase {
// FIXME: This is an integration test, not a unit test
private static final int MAX_PAYLOAD_LENGTH =
MAX_FRAME_LENGTH - HEADER_LENGTH - MAC_LENGTH;
private final CryptoComponent crypto;
private final AuthenticatedCipher frameCipher;
private final SecretKey frameKey;
public StreamDecrypterImplTest() {
Injector i = Guice.createInjector(new CryptoModule(),
new TestLifecycleModule(), new TestSystemModule());
crypto = i.getInstance(CryptoComponent.class);
frameCipher = crypto.getFrameCipher();
frameKey = crypto.generateSecretKey();
}
@Test
public void testReadValidFrames() throws Exception {
// Generate two valid frames
byte[] frame = generateFrame(0, MAX_FRAME_LENGTH, 123, false, false);
byte[] frame1 = generateFrame(1, MAX_FRAME_LENGTH, 123, false, false);
// Concatenate the frames
byte[] valid = new byte[MAX_FRAME_LENGTH * 2];
System.arraycopy(frame, 0, valid, 0, MAX_FRAME_LENGTH);
System.arraycopy(frame1, 0, valid, MAX_FRAME_LENGTH, MAX_FRAME_LENGTH);
// Read the frames
ByteArrayInputStream in = new ByteArrayInputStream(valid);
StreamDecrypterImpl i = new StreamDecrypterImpl(in, frameCipher,
frameKey);
byte[] payload = new byte[MAX_PAYLOAD_LENGTH];
assertEquals(123, i.readFrame(payload));
assertEquals(123, i.readFrame(payload));
// FIXME
}
@Test
public void testTruncatedFrameThrowsException() throws Exception {
// Generate a valid frame
byte[] frame = generateFrame(0, MAX_FRAME_LENGTH, 123, false, false);
// Chop off the last byte
byte[] truncated = new byte[MAX_FRAME_LENGTH - 1];
System.arraycopy(frame, 0, truncated, 0, MAX_FRAME_LENGTH - 1);
// Try to read the frame, which should fail due to truncation
ByteArrayInputStream in = new ByteArrayInputStream(truncated);
StreamDecrypterImpl i = new StreamDecrypterImpl(in, frameCipher,
frameKey);
try {
i.readFrame(new byte[MAX_PAYLOAD_LENGTH]);
fail();
} catch(FormatException expected) {}
// FIXME
}
@Test
public void testModifiedFrameThrowsException() throws Exception {
// Generate a valid frame
byte[] frame = generateFrame(0, MAX_FRAME_LENGTH, 123, false, false);
// Modify a randomly chosen byte of the frame
frame[(int) (Math.random() * MAX_FRAME_LENGTH)] ^= 1;
// Try to read the frame, which should fail due to modification
ByteArrayInputStream in = new ByteArrayInputStream(frame);
StreamDecrypterImpl i = new StreamDecrypterImpl(in, frameCipher,
frameKey);
try {
i.readFrame(new byte[MAX_PAYLOAD_LENGTH]);
fail();
} catch(FormatException expected) {}
}
@Test
public void testShortNonFinalFrameThrowsException() throws Exception {
// Generate a short non-final frame
byte[] frame = generateFrame(0, MAX_FRAME_LENGTH - 1, 123, false,
false);
// Try to read the frame, which should fail due to invalid length
ByteArrayInputStream in = new ByteArrayInputStream(frame);
StreamDecrypterImpl i = new StreamDecrypterImpl(in, frameCipher,
frameKey);
try {
i.readFrame(new byte[MAX_PAYLOAD_LENGTH]);
fail();
} catch(FormatException expected) {}
}
@Test
public void testShortFinalFrameDoesNotThrowException() throws Exception {
// Generate a short final frame
byte[] frame = generateFrame(0, MAX_FRAME_LENGTH - 1, 123, true, false);
// Read the frame
ByteArrayInputStream in = new ByteArrayInputStream(frame);
StreamDecrypterImpl i = new StreamDecrypterImpl(in, frameCipher,
frameKey);
int length = i.readFrame(new byte[MAX_PAYLOAD_LENGTH]);
assertEquals(123, length);
// FIXME
}
@Test
public void testInvalidPayloadLengthThrowsException() throws Exception {
// Generate a frame with an invalid payload length
byte[] frame = generateFrame(0, MAX_FRAME_LENGTH, 123, false, false);
ByteUtils.writeUint16(MAX_PAYLOAD_LENGTH + 1, frame, 0);
// Try to read the frame, which should fail due to invalid length
ByteArrayInputStream in = new ByteArrayInputStream(frame);
StreamDecrypterImpl i = new StreamDecrypterImpl(in, frameCipher,
frameKey);
try {
i.readFrame(new byte[MAX_PAYLOAD_LENGTH]);
fail();
} catch(FormatException expected) {}
// FIXME
}
@Test
public void testNonZeroPaddingThrowsException() throws Exception {
// Generate a frame with bad padding
byte[] frame = generateFrame(0, MAX_FRAME_LENGTH, 123, false, true);
// Try to read the frame, which should fail due to bad padding
ByteArrayInputStream in = new ByteArrayInputStream(frame);
StreamDecrypterImpl i = new StreamDecrypterImpl(in, frameCipher,
frameKey);
try {
i.readFrame(new byte[MAX_PAYLOAD_LENGTH]);
fail();
} catch(FormatException expected) {}
// FIXME
}
@Test
public void testCannotReadBeyondFinalFrame() throws Exception {
// Generate a valid final frame and another valid final frame after it
byte[] frame = generateFrame(0, MAX_FRAME_LENGTH, MAX_PAYLOAD_LENGTH,
true, false);
byte[] frame1 = generateFrame(1, MAX_FRAME_LENGTH, 123, true, false);
// Concatenate the frames
byte[] extraFrame = new byte[MAX_FRAME_LENGTH * 2];
System.arraycopy(frame, 0, extraFrame, 0, MAX_FRAME_LENGTH);
System.arraycopy(frame1, 0, extraFrame, MAX_FRAME_LENGTH,
MAX_FRAME_LENGTH);
// Read the final frame, which should first read the tag
ByteArrayInputStream in = new ByteArrayInputStream(extraFrame);
StreamDecrypterImpl i = new StreamDecrypterImpl(in, frameCipher,
frameKey);
byte[] payload = new byte[MAX_PAYLOAD_LENGTH];
assertEquals(MAX_PAYLOAD_LENGTH, i.readFrame(payload));
// The frame after the final frame should not be read
assertEquals(-1, i.readFrame(payload));
}
private byte[] generateFrame(long frameNumber, int frameLength,
int payloadLength, boolean finalFrame, boolean badPadding)
throws Exception {
byte[] iv = new byte[IV_LENGTH], aad = new byte[AAD_LENGTH];
byte[] plaintext = new byte[frameLength - MAC_LENGTH];
byte[] ciphertext = new byte[frameLength];
FrameEncoder.encodeIv(iv, frameNumber);
FrameEncoder.encodeAad(aad, frameNumber, plaintext.length);
frameCipher.init(true, frameKey, iv, aad);
FrameEncoder.encodeHeader(plaintext, finalFrame, payloadLength);
if(badPadding) plaintext[HEADER_LENGTH + payloadLength] = 1;
frameCipher.doFinal(plaintext, 0, plaintext.length, ciphertext, 0);
return ciphertext;
// FIXME
}
}

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@@ -1,102 +1,27 @@
package org.briarproject.crypto;
import static org.briarproject.api.transport.TransportConstants.AAD_LENGTH;
import static org.briarproject.api.transport.TransportConstants.HEADER_LENGTH;
import static org.briarproject.api.transport.TransportConstants.IV_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAC_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAX_FRAME_LENGTH;
import static org.briarproject.api.transport.TransportConstants.TAG_LENGTH;
import java.io.ByteArrayOutputStream;
import java.util.Random;
import org.briarproject.BriarTestCase;
import org.briarproject.TestLifecycleModule;
import org.briarproject.TestSystemModule;
import org.briarproject.api.crypto.AuthenticatedCipher;
import org.briarproject.api.crypto.CryptoComponent;
import org.briarproject.api.crypto.SecretKey;
import org.junit.Test;
import com.google.inject.Guice;
import com.google.inject.Injector;
public class StreamEncrypterImplTest extends BriarTestCase {
// FIXME: This is an integration test, not a unit test
private final CryptoComponent crypto;
private final AuthenticatedCipher frameCipher;
public StreamEncrypterImplTest() {
Injector i = Guice.createInjector(new CryptoModule(),
new TestLifecycleModule(), new TestSystemModule());
crypto = i.getInstance(CryptoComponent.class);
frameCipher = crypto.getFrameCipher();
}
@Test
public void testEncryptionWithoutTag() throws Exception {
int payloadLength = 123;
byte[] iv = new byte[IV_LENGTH], aad = new byte[AAD_LENGTH];
byte[] plaintext = new byte[MAX_FRAME_LENGTH - MAC_LENGTH];
byte[] ciphertext = new byte[MAX_FRAME_LENGTH];
SecretKey frameKey = crypto.generateSecretKey();
// Calculate the expected ciphertext
FrameEncoder.encodeIv(iv, 0);
FrameEncoder.encodeAad(aad, 0, plaintext.length);
frameCipher.init(true, frameKey, iv, aad);
FrameEncoder.encodeHeader(plaintext, false, payloadLength);
frameCipher.doFinal(plaintext, 0, plaintext.length, ciphertext, 0);
// Check that the actual ciphertext matches what's expected
ByteArrayOutputStream out = new ByteArrayOutputStream();
StreamEncrypterImpl o = new StreamEncrypterImpl(out, frameCipher,
frameKey, null);
o.writeFrame(new byte[payloadLength], payloadLength, false);
byte[] actual = out.toByteArray();
assertEquals(MAX_FRAME_LENGTH, actual.length);
for(int i = 0; i < MAX_FRAME_LENGTH; i++)
assertEquals(ciphertext[i], actual[i]);
// FIXME
}
@Test
public void testEncryptionWithTag() throws Exception {
byte[] tag = new byte[TAG_LENGTH];
new Random().nextBytes(tag);
int payloadLength = 123;
byte[] iv = new byte[IV_LENGTH], aad = new byte[AAD_LENGTH];
byte[] plaintext = new byte[MAX_FRAME_LENGTH - MAC_LENGTH];
byte[] ciphertext = new byte[MAX_FRAME_LENGTH];
SecretKey frameKey = crypto.generateSecretKey();
// Calculate the expected ciphertext
FrameEncoder.encodeIv(iv, 0);
FrameEncoder.encodeAad(aad, 0, plaintext.length);
frameCipher.init(true, frameKey, iv, aad);
FrameEncoder.encodeHeader(plaintext, false, payloadLength);
frameCipher.doFinal(plaintext, 0, plaintext.length, ciphertext, 0);
// Check that the actual tag and ciphertext match what's expected
ByteArrayOutputStream out = new ByteArrayOutputStream();
StreamEncrypterImpl o = new StreamEncrypterImpl(out, frameCipher,
frameKey, tag);
o.writeFrame(new byte[payloadLength], payloadLength, false);
byte[] actual = out.toByteArray();
assertEquals(TAG_LENGTH + MAX_FRAME_LENGTH, actual.length);
for(int i = 0; i < TAG_LENGTH; i++) assertEquals(tag[i], actual[i]);
for(int i = 0; i < MAX_FRAME_LENGTH; i++)
assertEquals(ciphertext[i], actual[TAG_LENGTH + i]);
// FIXME
}
@Test
public void testCloseConnectionWithoutWriting() throws Exception {
byte[] tag = new byte[TAG_LENGTH];
new Random().nextBytes(tag);
ByteArrayOutputStream out = new ByteArrayOutputStream();
// Initiator's constructor
StreamEncrypterImpl o = new StreamEncrypterImpl(out, frameCipher,
crypto.generateSecretKey(), tag);
// Write an empty final frame without having written any other frames
o.writeFrame(new byte[MAX_FRAME_LENGTH - MAC_LENGTH], 0, true);
// The tag and the empty frame should be written to the output stream
assertEquals(TAG_LENGTH + HEADER_LENGTH + MAC_LENGTH, out.size());
public void testFlushWritesTagIfNotAlreadyWritten() throws Exception {
// FIXME
}
@Test
public void testFlushDoesNotWriteTagIfAlreadyWritten() throws Exception {
// FIXME
}
}

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@@ -1,8 +1,6 @@
package org.briarproject.transport;
import static org.briarproject.api.transport.TransportConstants.HEADER_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAC_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAX_FRAME_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
import org.briarproject.BriarTestCase;
import org.briarproject.api.crypto.StreamDecrypter;
@@ -12,9 +10,6 @@ import org.junit.Test;
public class StreamReaderImplTest extends BriarTestCase {
private static final int MAX_PAYLOAD_LENGTH =
MAX_FRAME_LENGTH - HEADER_LENGTH - MAC_LENGTH;
@Test
public void testEmptyFramesAreSkipped() throws Exception {
Mockery context = new Mockery();

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@@ -1,8 +1,6 @@
package org.briarproject.transport;
import static org.briarproject.api.transport.TransportConstants.HEADER_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAC_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAX_FRAME_LENGTH;
import static org.briarproject.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
import org.briarproject.BriarTestCase;
import org.briarproject.api.crypto.StreamEncrypter;
@@ -12,9 +10,6 @@ import org.junit.Test;
public class StreamWriterImplTest extends BriarTestCase {
private static final int MAX_PAYLOAD_LENGTH =
MAX_FRAME_LENGTH - HEADER_LENGTH - MAC_LENGTH;
@Test
public void testCloseWithoutWritingWritesFinalFrame() throws Exception {
Mockery context = new Mockery();
@@ -22,7 +17,7 @@ public class StreamWriterImplTest extends BriarTestCase {
context.checking(new Expectations() {{
// Write an empty final frame
oneOf(encrypter).writeFrame(with(any(byte[].class)), with(0),
with(true));
with(0), with(true));
// Flush the stream
oneOf(encrypter).flush();
}});
@@ -40,7 +35,7 @@ public class StreamWriterImplTest extends BriarTestCase {
context.checking(new Expectations() {{
// Write a non-final frame with an empty payload
oneOf(encrypter).writeFrame(with(any(byte[].class)), with(0),
with(false));
with(0), with(false));
// Flush the stream
oneOf(encrypter).flush();
}});
@@ -51,7 +46,7 @@ public class StreamWriterImplTest extends BriarTestCase {
context.checking(new Expectations() {{
// Closing the writer writes a final frame and flushes again
oneOf(encrypter).writeFrame(with(any(byte[].class)), with(0),
with(true));
with(0), with(true));
oneOf(encrypter).flush();
}});
w.close();
@@ -67,7 +62,7 @@ public class StreamWriterImplTest extends BriarTestCase {
context.checking(new Expectations() {{
// Write a non-final frame with one payload byte
oneOf(encrypter).writeFrame(with(any(byte[].class)), with(1),
with(false));
with(0), with(false));
// Flush the stream
oneOf(encrypter).flush();
}});
@@ -79,7 +74,7 @@ public class StreamWriterImplTest extends BriarTestCase {
context.checking(new Expectations() {{
// Closing the writer writes a final frame and flushes again
oneOf(encrypter).writeFrame(with(any(byte[].class)), with(0),
with(true));
with(0), with(true));
oneOf(encrypter).flush();
}});
w.close();
@@ -94,18 +89,16 @@ public class StreamWriterImplTest extends BriarTestCase {
context.checking(new Expectations() {{
// Write a full non-final frame
oneOf(encrypter).writeFrame(with(any(byte[].class)),
with(MAX_PAYLOAD_LENGTH), with(false));
with(MAX_PAYLOAD_LENGTH), with(0), with(false));
}});
for(int i = 0; i < MAX_PAYLOAD_LENGTH; i++) {
w.write(0);
}
for(int i = 0; i < MAX_PAYLOAD_LENGTH; i++) w.write(0);
context.assertIsSatisfied();
// Clean up
context.checking(new Expectations() {{
// Closing the writer writes a final frame and flushes again
oneOf(encrypter).writeFrame(with(any(byte[].class)), with(0),
with(true));
with(0), with(true));
oneOf(encrypter).flush();
}});
w.close();
@@ -120,7 +113,7 @@ public class StreamWriterImplTest extends BriarTestCase {
context.checking(new Expectations() {{
// Write two full non-final frames
exactly(2).of(encrypter).writeFrame(with(any(byte[].class)),
with(MAX_PAYLOAD_LENGTH), with(false));
with(MAX_PAYLOAD_LENGTH), with(0), with(false));
}});
// Sanity check
assertEquals(0, MAX_PAYLOAD_LENGTH % 2);
@@ -136,7 +129,7 @@ public class StreamWriterImplTest extends BriarTestCase {
context.checking(new Expectations() {{
// Closing the writer writes a final frame and flushes again
oneOf(encrypter).writeFrame(with(any(byte[].class)), with(0),
with(true));
with(0), with(true));
oneOf(encrypter).flush();
}});
w.close();
@@ -151,10 +144,10 @@ public class StreamWriterImplTest extends BriarTestCase {
context.checking(new Expectations() {{
// Write two full non-final frames
exactly(2).of(encrypter).writeFrame(with(any(byte[].class)),
with(MAX_PAYLOAD_LENGTH), with(false));
with(MAX_PAYLOAD_LENGTH), with(0), with(false));
// Write a final frame with a one-byte payload
oneOf(encrypter).writeFrame(with(any(byte[].class)), with(1),
with(true));
with(0), with(true));
// Flush the stream
oneOf(encrypter).flush();
}});

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@@ -24,7 +24,7 @@ class TestStreamEncrypter implements StreamEncrypter {
}
public void writeFrame(byte[] payload, int payloadLength,
boolean finalFrame) throws IOException {
int paddingLength, boolean finalFrame) throws IOException {
if(writeTag) {
out.write(tag);
writeTag = false;