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Code Issues Projects Releases Wiki Activity

Include stream number in stream header nonce.

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This commit is contained in:
akwizgran
2016-09-20 15:27:01 +01:00
parent 89ab4dd04e
commit 4be1c1bb7d
8 changed files with 96 additions and 82 deletions
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17
briar-core/src/org/briarproject/crypto/StreamDecrypterFactoryImpl.java
View File

@@ -1,15 +1,15 @@
package org.briarproject.crypto;
import java.io.InputStream;
import javax.inject.Inject;
import javax.inject.Provider;
import org.briarproject.api.crypto.SecretKey;
import org.briarproject.api.crypto.StreamDecrypter;
import org.briarproject.api.crypto.StreamDecrypterFactory;
import org.briarproject.api.transport.StreamContext;
import java.io.InputStream;
import javax.inject.Inject;
import javax.inject.Provider;
class StreamDecrypterFactoryImpl implements StreamDecrypterFactory {
private final Provider<AuthenticatedCipher> cipherProvider;
@@ -19,14 +19,17 @@ class StreamDecrypterFactoryImpl implements StreamDecrypterFactory {
this.cipherProvider = cipherProvider;
}
@Override
public StreamDecrypter createStreamDecrypter(InputStream in,
StreamContext ctx) {
AuthenticatedCipher cipher = cipherProvider.get();
return new StreamDecrypterImpl(in, cipher, ctx.getHeaderKey());
return new StreamDecrypterImpl(in, cipher, ctx.getStreamNumber(),
ctx.getHeaderKey());
}
@Override
public StreamDecrypter createInvitationStreamDecrypter(InputStream in,
SecretKey headerKey) {
return new StreamDecrypterImpl(in, cipherProvider.get(), headerKey);
return new StreamDecrypterImpl(in, cipherProvider.get(), 0, headerKey);
}
}

18
briar-core/src/org/briarproject/crypto/StreamDecrypterImpl.java
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@@ -3,6 +3,7 @@ package org.briarproject.crypto;
import org.briarproject.api.FormatException;
import org.briarproject.api.crypto.SecretKey;
import org.briarproject.api.crypto.StreamDecrypter;
import org.briarproject.util.ByteUtils;
import java.io.EOFException;
import java.io.IOException;
@@ -17,11 +18,14 @@ import static org.briarproject.api.transport.TransportConstants.MAX_FRAME_LENGTH
import static org.briarproject.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
import static org.briarproject.api.transport.TransportConstants.STREAM_HEADER_IV_LENGTH;
import static org.briarproject.api.transport.TransportConstants.STREAM_HEADER_LENGTH;
import static org.briarproject.api.transport.TransportConstants.STREAM_HEADER_NONCE_LENGTH;
import static org.briarproject.util.ByteUtils.INT_64_BYTES;
class StreamDecrypterImpl implements StreamDecrypter {
private final InputStream in;
private final AuthenticatedCipher cipher;
private final long streamNumber;
private final SecretKey streamHeaderKey;
private final byte[] frameNonce, frameHeader, frameCiphertext;
@@ -30,9 +34,10 @@ class StreamDecrypterImpl implements StreamDecrypter {
private boolean finalFrame;
StreamDecrypterImpl(InputStream in, AuthenticatedCipher cipher,
SecretKey streamHeaderKey) {
long streamNumber, SecretKey streamHeaderKey) {
this.in = in;
this.cipher = cipher;
this.streamNumber = streamNumber;
this.streamHeaderKey = streamHeaderKey;
frameNonce = new byte[FRAME_NONCE_LENGTH];
frameHeader = new byte[FRAME_HEADER_PLAINTEXT_LENGTH];
@@ -42,6 +47,7 @@ class StreamDecrypterImpl implements StreamDecrypter {
finalFrame = false;
}
@Override
public int readFrame(byte[] payload) throws IOException {
// The buffer must be big enough for a full-size frame
if (payload.length < MAX_PAYLOAD_LENGTH)
@@ -103,7 +109,6 @@ class StreamDecrypterImpl implements StreamDecrypter {
}
private void readStreamHeader() throws IOException {
byte[] streamHeaderIv = new byte[STREAM_HEADER_IV_LENGTH];
byte[] streamHeaderCiphertext = new byte[STREAM_HEADER_LENGTH];
byte[] streamHeaderPlaintext = new byte[SecretKey.LENGTH];
// Read the stream header
@@ -114,11 +119,14 @@ class StreamDecrypterImpl implements StreamDecrypter {
if (read == -1) throw new EOFException();
offset += read;
}
// The nonce consists of the stream number followed by the IV
byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
ByteUtils.writeUint64(streamNumber, streamHeaderNonce, 0);
System.arraycopy(streamHeaderCiphertext, 0, streamHeaderNonce,
INT_64_BYTES, STREAM_HEADER_IV_LENGTH);
// Decrypt and authenticate the stream header
System.arraycopy(streamHeaderCiphertext, 0, streamHeaderIv, 0,
STREAM_HEADER_IV_LENGTH);
try {
cipher.init(false, streamHeaderKey, streamHeaderIv);
cipher.init(false, streamHeaderKey, streamHeaderNonce);
int decrypted = cipher.process(streamHeaderCiphertext,
STREAM_HEADER_IV_LENGTH, SecretKey.LENGTH + MAC_LENGTH,
streamHeaderPlaintext, 0);

11
briar-core/src/org/briarproject/crypto/StreamEncrypterFactoryImpl.java
View File

@@ -26,25 +26,28 @@ class StreamEncrypterFactoryImpl implements StreamEncrypterFactory {
this.cipherProvider = cipherProvider;
}
@Override
public StreamEncrypter createStreamEncrypter(OutputStream out,
StreamContext ctx) {
AuthenticatedCipher cipher = cipherProvider.get();
long streamNumber = ctx.getStreamNumber();
byte[] tag = new byte[TAG_LENGTH];
crypto.encodeTag(tag, ctx.getTagKey(), ctx.getStreamNumber());
crypto.encodeTag(tag, ctx.getTagKey(), streamNumber);
byte[] streamHeaderIv = new byte[STREAM_HEADER_IV_LENGTH];
crypto.getSecureRandom().nextBytes(streamHeaderIv);
SecretKey frameKey = crypto.generateSecretKey();
return new StreamEncrypterImpl(out, cipher, tag, streamHeaderIv,
ctx.getHeaderKey(), frameKey);
return new StreamEncrypterImpl(out, cipher, streamNumber, tag,
streamHeaderIv, ctx.getHeaderKey(), frameKey);
}
@Override
public StreamEncrypter createInvitationStreamEncrypter(OutputStream out,
SecretKey headerKey) {
AuthenticatedCipher cipher = cipherProvider.get();
byte[] streamHeaderIv = new byte[STREAM_HEADER_IV_LENGTH];
crypto.getSecureRandom().nextBytes(streamHeaderIv);
SecretKey frameKey = crypto.generateSecretKey();
return new StreamEncrypterImpl(out, cipher, null, streamHeaderIv,
return new StreamEncrypterImpl(out, cipher, 0, null, streamHeaderIv,
headerKey, frameKey);
}
}

23
briar-core/src/org/briarproject/crypto/StreamEncrypterImpl.java
View File

@@ -2,6 +2,8 @@ package org.briarproject.crypto;
import org.briarproject.api.crypto.SecretKey;
import org.briarproject.api.crypto.StreamEncrypter;
import org.briarproject.util.ByteUtils;
import org.jetbrains.annotations.Nullable;
import java.io.IOException;
import java.io.OutputStream;
@@ -15,23 +17,28 @@ import static org.briarproject.api.transport.TransportConstants.MAX_FRAME_LENGTH
import static org.briarproject.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
import static org.briarproject.api.transport.TransportConstants.STREAM_HEADER_IV_LENGTH;
import static org.briarproject.api.transport.TransportConstants.STREAM_HEADER_LENGTH;
import static org.briarproject.api.transport.TransportConstants.STREAM_HEADER_NONCE_LENGTH;
import static org.briarproject.util.ByteUtils.INT_64_BYTES;
class StreamEncrypterImpl implements StreamEncrypter {
private final OutputStream out;
private final AuthenticatedCipher cipher;
private final SecretKey streamHeaderKey, frameKey;
private final long streamNumber;
private final byte[] tag, streamHeaderIv;
private final byte[] frameNonce, frameHeader, framePlaintext, frameCiphertext;
private final byte[] frameNonce, frameHeader;
private final byte[] framePlaintext, frameCiphertext;
private long frameNumber;
private boolean writeTag, writeStreamHeader;
StreamEncrypterImpl(OutputStream out, AuthenticatedCipher cipher,
byte[] tag, byte[] streamHeaderIv, SecretKey streamHeaderKey,
SecretKey frameKey) {
long streamNumber, @Nullable byte[] tag, byte[] streamHeaderIv,
SecretKey streamHeaderKey, SecretKey frameKey) {
this.out = out;
this.cipher = cipher;
this.streamNumber = streamNumber;
this.tag = tag;
this.streamHeaderIv = streamHeaderIv;
this.streamHeaderKey = streamHeaderKey;
@@ -45,6 +52,7 @@ class StreamEncrypterImpl implements StreamEncrypter {
writeStreamHeader = true;
}
@Override
public void writeFrame(byte[] payload, int payloadLength,
int paddingLength, boolean finalFrame) throws IOException {
if (payloadLength + paddingLength > MAX_PAYLOAD_LENGTH)
@@ -91,18 +99,24 @@ class StreamEncrypterImpl implements StreamEncrypter {
}
private void writeTag() throws IOException {
if (tag == null) throw new IllegalStateException();
out.write(tag, 0, tag.length);
writeTag = false;
}
private void writeStreamHeader() throws IOException {
// The nonce consists of the stream number followed by the IV
byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
ByteUtils.writeUint64(streamNumber, streamHeaderNonce, 0);
System.arraycopy(streamHeaderIv, 0, streamHeaderNonce, INT_64_BYTES,
STREAM_HEADER_IV_LENGTH);
byte[] streamHeaderPlaintext = frameKey.getBytes();
byte[] streamHeaderCiphertext = new byte[STREAM_HEADER_LENGTH];
System.arraycopy(streamHeaderIv, 0, streamHeaderCiphertext, 0,
STREAM_HEADER_IV_LENGTH);
// Encrypt and authenticate the frame key
try {
cipher.init(true, streamHeaderKey, streamHeaderIv);
cipher.init(true, streamHeaderKey, streamHeaderNonce);
int encrypted = cipher.process(streamHeaderPlaintext, 0,
SecretKey.LENGTH, streamHeaderCiphertext,
STREAM_HEADER_IV_LENGTH);
@@ -115,6 +129,7 @@ class StreamEncrypterImpl implements StreamEncrypter {
writeStreamHeader = false;
}
@Override
public void flush() throws IOException {
// Write the tag if required
if (writeTag) writeTag();