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Replace XX/NX handshakes with IK/NK

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This commit is contained in:
Ravi Khadiwala
2024-06-24 17:20:42 -05:00
committed by ravi-signal
parent c835d85256
commit 542422b7b8
41 changed files with 1902 additions and 1611 deletions
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1
service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java
View File

@@ -933,7 +933,6 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
clientConnectionManager,
clientPublicKeysManager,
config.getNoiseWebSocketTunnelConfiguration().noiseStaticKeyPair(),
config.getNoiseWebSocketTunnelConfiguration().noiseRootPublicKeySignature(),
authenticatedGrpcServerAddress,
anonymousGrpcServerAddress,
config.getNoiseWebSocketTunnelConfiguration().recognizedProxySecret().value());

1
service/src/main/java/org/whispersystems/textsecuregcm/configuration/NoiseWebSocketTunnelConfiguration.java
View File

@@ -15,7 +15,6 @@ public record NoiseWebSocketTunnelConfiguration(@Positive int port,
@Nullable String tlsKeyStoreEntryAlias,
@Nullable SecretString tlsKeyStorePassword,
@NotNull SecretBytes noiseStaticPrivateKey,
@NotNull byte[] noiseRootPublicKeySignature,
@NotNull SecretString recognizedProxySecret) {
public ECKeyPair noiseStaticKeyPair() throws InvalidKeyException {

124
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/AbstractNoiseHandshakeHandler.java
View File

@@ -1,124 +0,0 @@
package org.whispersystems.textsecuregcm.grpc.net;
import com.southernstorm.noise.protocol.HandshakeState;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import io.netty.util.internal.EmptyArrays;
import java.security.NoSuchAlgorithmException;
import javax.crypto.BadPaddingException;
import javax.crypto.ShortBufferException;
import org.signal.libsignal.protocol.ecc.ECKeyPair;
/**
* An abstract base class for XX- and NX-patterned Noise responder handshake handlers.
*
* @see <a href="https://noiseprotocol.org/noise.html">The Noise Protocol Framework</a>
*/
abstract class AbstractNoiseHandshakeHandler extends ChannelInboundHandlerAdapter {
private final ECKeyPair ecKeyPair;
private final byte[] publicKeySignature;
private final HandshakeState handshakeState;
private static final int EXPECTED_EPHEMERAL_KEY_MESSAGE_LENGTH = 32;
/**
* Constructs a new Noise handler with the given static server keys and static public key signature. The static public
* key must be signed by a trusted root private key whose public key is known to and trusted by authenticating
* clients.
*
* @param noiseProtocolName the name of the Noise protocol implemented by this handshake handler
* @param ecKeyPair the static key pair for this server
* @param publicKeySignature an Ed25519 signature of the raw bytes of the static public key
*/
AbstractNoiseHandshakeHandler(final String noiseProtocolName,
final ECKeyPair ecKeyPair,
final byte[] publicKeySignature) {
this.ecKeyPair = ecKeyPair;
this.publicKeySignature = publicKeySignature;
try {
this.handshakeState = new HandshakeState(noiseProtocolName, HandshakeState.RESPONDER);
} catch (final NoSuchAlgorithmException e) {
throw new AssertionError("Unsupported Noise algorithm: " + noiseProtocolName, e);
}
}
protected HandshakeState getHandshakeState() {
return handshakeState;
}
/**
* Handles an initial ephemeral key message from a client, advancing the handshake state and sending the server's
* static keys to the client. Both XX and NX patterns begin with a client sending its ephemeral key to the server.
* Clients must not include an additional payload with their ephemeral key message. The server's reply contains its
* static keys along with an Ed25519 signature of its public static key by a trusted root key.
*
* @param context the channel handler context for this message
* @param frame the websocket frame containing the ephemeral key message
*
* @throws NoiseHandshakeException if the ephemeral key message from the client was not of the expected size or if a
* general Noise encryption error occurred
*/
protected void handleEphemeralKeyMessage(final ChannelHandlerContext context, final BinaryWebSocketFrame frame)
throws NoiseHandshakeException {
if (frame.content().readableBytes() != EXPECTED_EPHEMERAL_KEY_MESSAGE_LENGTH) {
throw new NoiseHandshakeException("Unexpected ephemeral key message length");
}
// Cryptographically initializing a handshake is expensive, and so we defer it until we're confident the client is
// making a good-faith effort to perform a handshake (i.e. now). Noise-java in particular will derive a public key
// from the supplied private key (and will in fact overwrite any previously-set public key when setting a private
// key), so we just set the private key here.
handshakeState.getLocalKeyPair().setPrivateKey(ecKeyPair.getPrivateKey().serialize(), 0);
handshakeState.start();
// The initial message from the client should just include a plaintext ephemeral key with no payload. The frame is
// coming off the wire and so will be in a direct buffer that doesn't have a backing array.
final byte[] ephemeralKeyMessage = ByteBufUtil.getBytes(frame.content());
frame.content().readBytes(ephemeralKeyMessage);
try {
handshakeState.readMessage(ephemeralKeyMessage, 0, ephemeralKeyMessage.length, EmptyArrays.EMPTY_BYTES, 0);
} catch (final ShortBufferException e) {
// This should never happen since we're checking the length of the frame up front
throw new NoiseHandshakeException("Unexpected client payload");
} catch (final BadPaddingException e) {
// It turns out this should basically never happen because (a) we're not using padding and (b) the "bad AEAD tag"
// subclass of a bad padding exception can only happen if we have some AD to check, which we don't for an
// ephemeral-key-only message
throw new NoiseHandshakeException("Invalid keys");
}
// Send our key material and public key signature back to the client; this buffer will include:
//
// - A 32-byte plaintext ephemeral key
// - A 32-byte encrypted static key
// - A 16-byte AEAD tag for the static key
// - The public key signature payload
// - A 16-byte AEAD tag for the payload
final byte[] keyMaterial = new byte[32 + 32 + 16 + publicKeySignature.length + 16];
try {
handshakeState.writeMessage(keyMaterial, 0, publicKeySignature, 0, publicKeySignature.length);
context.writeAndFlush(new BinaryWebSocketFrame(Unpooled.wrappedBuffer(keyMaterial)))
.addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE);
} catch (final ShortBufferException e) {
// This should never happen for messages of known length that we control
throw new AssertionError("Key material buffer was too short for message", e);
}
}
@Override
public void handlerRemoved(final ChannelHandlerContext context) {
handshakeState.destroy();
}
}

4
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/ErrorHandler.java
View File

@@ -9,6 +9,7 @@ import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
import javax.crypto.BadPaddingException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.whispersystems.textsecuregcm.util.ExceptionUtils;
/**
* An error handler serves as a general backstop for exceptions elsewhere in the pipeline. If the client has completed a
@@ -38,7 +39,7 @@ class ErrorHandler extends ChannelInboundHandlerAdapter {
@Override
public void exceptionCaught(final ChannelHandlerContext context, final Throwable cause) {
if (websocketHandshakeComplete) {
final WebSocketCloseStatus webSocketCloseStatus = switch (cause) {
final WebSocketCloseStatus webSocketCloseStatus = switch (ExceptionUtils.unwrap(cause)) {
case NoiseHandshakeException e -> ApplicationWebSocketCloseReason.NOISE_HANDSHAKE_ERROR.toWebSocketCloseStatus(e.getMessage());
case ClientAuthenticationException ignored -> ApplicationWebSocketCloseReason.CLIENT_AUTHENTICATION_ERROR.toWebSocketCloseStatus("Not authenticated");
case BadPaddingException ignored -> ApplicationWebSocketCloseReason.NOISE_ENCRYPTION_ERROR.toWebSocketCloseStatus("Noise encryption error");
@@ -51,6 +52,7 @@ class ErrorHandler extends ChannelInboundHandlerAdapter {
context.writeAndFlush(new CloseWebSocketFrame(webSocketCloseStatus))
.addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
} else {
log.debug("Error occurred before websocket handshake complete", cause);
// We haven't completed a websocket handshake, so we can't really communicate errors in a semantically-meaningful
// way; just close the connection instead.
context.close();

6
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/EstablishLocalGrpcConnectionHandler.java
View File

@@ -48,12 +48,12 @@ class EstablishLocalGrpcConnectionHandler extends ChannelInboundHandlerAdapter {
@Override
public void userEventTriggered(final ChannelHandlerContext remoteChannelContext, final Object event) {
if (event instanceof NoiseHandshakeCompleteEvent noiseHandshakeCompleteEvent) {
if (event instanceof NoiseIdentityDeterminedEvent noiseIdentityDeterminedEvent) {
// We assume that we'll only get a completed handshake event if the handshake met all authentication requirements
// for the requested service. If the handshake doesn't have an authenticated device, we assume we're trying to
// connect to the anonymous service. If it does have an authenticated device, we assume we're aiming for the
// authenticated service.
final LocalAddress grpcServerAddress = noiseHandshakeCompleteEvent.authenticatedDevice().isPresent()
final LocalAddress grpcServerAddress = noiseIdentityDeterminedEvent.authenticatedDevice().isPresent()
? authenticatedGrpcServerAddress
: anonymousGrpcServerAddress;
@@ -72,7 +72,7 @@ class EstablishLocalGrpcConnectionHandler extends ChannelInboundHandlerAdapter {
if (localChannelFuture.isSuccess()) {
clientConnectionManager.handleConnectionEstablished((LocalChannel) localChannelFuture.channel(),
remoteChannelContext.channel(),
noiseHandshakeCompleteEvent.authenticatedDevice());
noiseIdentityDeterminedEvent.authenticatedDevice());
// Close the local connection if the remote channel closes and vice versa
remoteChannelContext.channel().closeFuture().addListener(closeFuture -> localChannelFuture.channel().close());

21
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/HandshakePattern.java Normal file
View File

@@ -0,0 +1,21 @@
/*
* Copyright 2024 Signal Messenger, LLC
* SPDX-License-Identifier: AGPL-3.0-only
*/
package org.whispersystems.textsecuregcm.grpc.net;
enum HandshakePattern {
NK("Noise_NK_25519_ChaChaPoly_BLAKE2b"),
IK("Noise_IK_25519_ChaChaPoly_BLAKE2b");
private final String protocol;
public String protocol() {
return protocol;
}
HandshakePattern(String protocol) {
this.protocol = protocol;
}
}

34
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseAnonymousHandler.java Normal file
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@@ -0,0 +1,34 @@
package org.whispersystems.textsecuregcm.grpc.net;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import org.signal.libsignal.protocol.ecc.ECKeyPair;
/**
* A NoiseAnonymousHandler is a netty pipeline element that handles the responder side of an unauthenticated handshake
* and noise encryption/decryption.
* <p>
* A noise NK handshake must be used for unauthenticated connections. Optionally, the initiator can also include an
* initial request in their payload. If provided, this allows the server to begin processing the request without an
* initial message delay (fast open).
* <p>
* Once the handler receives the handshake initiator message, it will fire a {@link NoiseIdentityDeterminedEvent}
* indicating that initiator connected anonymously.
*/
class NoiseAnonymousHandler extends NoiseHandler {
public NoiseAnonymousHandler(final ECKeyPair ecKeyPair) {
super(new NoiseHandshakeHelper(HandshakePattern.NK, ecKeyPair));
}
@Override
CompletableFuture<HandshakeResult> handleHandshakePayload(final ChannelHandlerContext context,
final Optional<byte[]> initiatorPublicKey, final ByteBuf handshakePayload) {
return CompletableFuture.completedFuture(new HandshakeResult(
handshakePayload,
Optional.empty()
));
}
}

96
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseAuthenticatedHandler.java Normal file
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@@ -0,0 +1,96 @@
package org.whispersystems.textsecuregcm.grpc.net;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.util.ReferenceCountUtil;
import java.security.MessageDigest;
import java.util.Optional;
import java.util.UUID;
import java.util.concurrent.CompletableFuture;
import org.signal.libsignal.protocol.ecc.ECKeyPair;
import org.whispersystems.textsecuregcm.auth.grpc.AuthenticatedDevice;
import org.whispersystems.textsecuregcm.storage.ClientPublicKeysManager;
import org.whispersystems.textsecuregcm.util.ExceptionUtils;
/**
* A NoiseAuthenticatedHandler is a netty pipeline element that handles the responder side of an authenticated handshake
* and noise encryption/decryption. Authenticated handshakes are noise IK handshakes where the initiator's static public
* key is authenticated by the responder.
* <p>
* The authenticated handshake requires the initiator to provide a payload with their first handshake message that
* includes their account identifier and device id in network byte-order. Optionally, the initiator can also include an
* initial request in their payload. If provided, this allows the server to begin processing the request without an
* initial message delay (fast open).
* <pre>
* +-----------------+----------------+------------------------+
* | UUID (16) | deviceId (1) | request bytes (N) |
* +-----------------+----------------+------------------------+
* </pre>
* <p>
* For a successful handshake, the static key provided in the handshake message must match the server's stored public
* key for the device identified by the provided ACI and deviceId.
* <p>
* As soon as the handler authenticates the caller, it will fire a {@link NoiseIdentityDeterminedEvent}.
*/
class NoiseAuthenticatedHandler extends NoiseHandler {
private final ClientPublicKeysManager clientPublicKeysManager;
NoiseAuthenticatedHandler(final ClientPublicKeysManager clientPublicKeysManager,
final ECKeyPair ecKeyPair) {
super(new NoiseHandshakeHelper(HandshakePattern.IK, ecKeyPair));
this.clientPublicKeysManager = clientPublicKeysManager;
}
@Override
CompletableFuture<HandshakeResult> handleHandshakePayload(
final ChannelHandlerContext context,
final Optional<byte[]> initiatorPublicKey,
final ByteBuf handshakePayload) throws NoiseHandshakeException {
if (handshakePayload.readableBytes() < 17) {
throw new NoiseHandshakeException("Invalid handshake payload");
}
final byte[] publicKeyFromClient = initiatorPublicKey
.orElseThrow(() -> new IllegalStateException("No remote public key"));
// Advances the read index by 16 bytes
final UUID accountIdentifier = parseUUID(handshakePayload);
// Advances the read index by 1 byte
final byte deviceId = handshakePayload.readByte();
final ByteBuf fastOpenRequest = handshakePayload.slice();
return clientPublicKeysManager
.findPublicKey(accountIdentifier, deviceId)
.handleAsync((storedPublicKey, throwable) -> {
if (throwable != null) {
ReferenceCountUtil.release(fastOpenRequest);
throw ExceptionUtils.wrap(throwable);
}
final boolean valid = storedPublicKey
.map(spk -> MessageDigest.isEqual(publicKeyFromClient, spk.getPublicKeyBytes()))
.orElse(false);
if (!valid) {
throw ExceptionUtils.wrap(new ClientAuthenticationException());
}
return new HandshakeResult(
fastOpenRequest,
Optional.of(new AuthenticatedDevice(accountIdentifier, deviceId)));
}, context.executor());
}
/**
* Parse a {@link UUID} out of bytes, advancing the readerIdx by 16
*
* @param bytes The {@link ByteBuf} to read from
* @return The parsed UUID
* @throws NoiseHandshakeException If a UUID could not be parsed from bytes
*/
private UUID parseUUID(final ByteBuf bytes) throws NoiseHandshakeException {
if (bytes.readableBytes() < 16) {
throw new NoiseHandshakeException("Could not parse account identifier");
}
return new UUID(bytes.readLong(), bytes.readLong());
}
}

195
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseHandler.java Normal file
View File

@@ -0,0 +1,195 @@
/*
* Copyright 2024 Signal Messenger, LLC
* SPDX-License-Identifier: AGPL-3.0-only
*/
package org.whispersystems.textsecuregcm.grpc.net;
import com.southernstorm.noise.protocol.CipherState;
import com.southernstorm.noise.protocol.CipherStatePair;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketFrame;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.internal.EmptyArrays;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import javax.crypto.BadPaddingException;
import javax.crypto.ShortBufferException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.whispersystems.textsecuregcm.auth.grpc.AuthenticatedDevice;
import org.whispersystems.textsecuregcm.util.ExceptionUtils;
/**
* A bidirectional {@link io.netty.channel.ChannelHandler} that establishes a noise session with an initiator, decrypts
* inbound messages, and encrypts outbound messages
*/
abstract class NoiseHandler extends ChannelDuplexHandler {
private static final Logger log = LoggerFactory.getLogger(NoiseHandler.class);
private enum State {
// Waiting for handshake to complete
HANDSHAKE,
// Can freely exchange encrypted noise messages on an established session
TRANSPORT,
// Finished with error
ERROR
}
private final NoiseHandshakeHelper handshakeHelper;
private State state = State.HANDSHAKE;
private CipherStatePair cipherStatePair;
NoiseHandler(NoiseHandshakeHelper handshakeHelper) {
this.handshakeHelper = handshakeHelper;
}
/**
* The result of processing an initiator handshake payload
*
* @param fastOpenRequest A fast-open request included in the handshake. If none was present, this should be an
* empty ByteBuf
* @param authenticatedDevice If present, the successfully authenticated initiator identity
*/
record HandshakeResult(ByteBuf fastOpenRequest, Optional<AuthenticatedDevice> authenticatedDevice) {}
/**
* Parse and potentially authenticate the initiator handshake message
*
* @param context A {@link ChannelHandlerContext}
* @param initiatorPublicKey The initiator's static public key, if a handshake pattern that includes it was used
* @param handshakePayload The handshake payload provided in the initiator message
* @return A {@link HandshakeResult} that includes an authenticated device and a parsed fast-open request if one was
* present in the handshake payload.
* @throws NoiseHandshakeException If the handshake payload was invalid
* @throws ClientAuthenticationException If the initiatorPublicKey could not be authenticated
*/
abstract CompletableFuture<HandshakeResult> handleHandshakePayload(
final ChannelHandlerContext context,
final Optional<byte[]> initiatorPublicKey,
final ByteBuf handshakePayload) throws NoiseHandshakeException, ClientAuthenticationException;
@Override
public void channelRead(final ChannelHandlerContext context, final Object message) throws Exception {
try {
if (message instanceof BinaryWebSocketFrame frame) {
// We've read this frame off the wire, and so it's most likely a direct buffer that's not backed by an array.
// We'll need to copy it to a heap buffer.
handleInboundMessage(context, ByteBufUtil.getBytes(frame.content()));
} else {
// Anything except binary WebSocket frames should have been filtered out of the pipeline by now; treat this as an
// error
throw new IllegalArgumentException("Unexpected message in pipeline: " + message);
}
} catch (Exception e) {
fail(context, e);
} finally {
ReferenceCountUtil.release(message);
}
}
private void handleInboundMessage(final ChannelHandlerContext context, final byte[] frameBytes)
throws NoiseHandshakeException, ShortBufferException, BadPaddingException, ClientAuthenticationException {
switch (state) {
// Got an initiator handshake message
case HANDSHAKE -> {
final ByteBuf payload = handshakeHelper.read(frameBytes);
handleHandshakePayload(context, handshakeHelper.remotePublicKey(), payload).whenCompleteAsync(
(result, throwable) -> {
if (state == State.ERROR) {
return;
}
if (throwable != null) {
fail(context, ExceptionUtils.unwrap(throwable));
return;
}
context.fireUserEventTriggered(new NoiseIdentityDeterminedEvent(result.authenticatedDevice()));
// Now that we've authenticated, write the handshake response
byte[] handshakeMessage = handshakeHelper.write(EmptyArrays.EMPTY_BYTES);
context.writeAndFlush(new BinaryWebSocketFrame(Unpooled.wrappedBuffer(handshakeMessage)))
.addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE);
// The handshake is complete. We can start intercepting read/write for noise encryption/decryption
this.state = State.TRANSPORT;
this.cipherStatePair = handshakeHelper.getHandshakeState().split();
if (result.fastOpenRequest().isReadable()) {
// The handshake had a fast-open request. Forward the plaintext of the request to the server, we'll
// encrypt the response when the server writes back through us
context.fireChannelRead(result.fastOpenRequest());
} else {
ReferenceCountUtil.release(result.fastOpenRequest());
}
}, context.executor());
}
// Got a client message that should be decrypted and forwarded
case TRANSPORT -> {
final CipherState cipherState = cipherStatePair.getReceiver();
// Overwrite the ciphertext with the plaintext to avoid an extra allocation for a dedicated plaintext buffer
final int plaintextLength = cipherState.decryptWithAd(null,
frameBytes, 0,
frameBytes, 0,
frameBytes.length);
// Forward the decrypted plaintext along
context.fireChannelRead(Unpooled.wrappedBuffer(frameBytes, 0, plaintextLength));
}
// The session is already in an error state, drop the message
case ERROR -> {
}
}
}
/**
* Set the state to the error state (so subsequent messages fast-fail) and propagate the failure reason on the
* context
*/
private void fail(final ChannelHandlerContext context, final Throwable cause) {
this.state = State.ERROR;
context.fireExceptionCaught(cause);
}
@Override
public void write(final ChannelHandlerContext context, final Object message, final ChannelPromise promise)
throws Exception {
if (message instanceof ByteBuf plaintext) {
try {
// TODO Buffer/consolidate Noise writes to avoid sending a bazillion tiny (or empty) frames
final CipherState cipherState = cipherStatePair.getSender();
final int plaintextLength = plaintext.readableBytes();
// We've read these bytes from a local connection; although that likely means they're backed by a heap array, the
// buffer is read-only and won't grant us access to the underlying array. Instead, we need to copy the bytes to a
// mutable array. We also want to encrypt in place, so we allocate enough extra space for the trailing MAC.
final byte[] noiseBuffer = new byte[plaintext.readableBytes() + cipherState.getMACLength()];
plaintext.readBytes(noiseBuffer, 0, plaintext.readableBytes());
// Overwrite the plaintext with the ciphertext to avoid an extra allocation for a dedicated ciphertext buffer
cipherState.encryptWithAd(null, noiseBuffer, 0, noiseBuffer, 0, plaintextLength);
context.write(new BinaryWebSocketFrame(Unpooled.wrappedBuffer(noiseBuffer)), promise);
} finally {
ReferenceCountUtil.release(plaintext);
}
} else {
if (!(message instanceof WebSocketFrame)) {
// Downstream handlers may write WebSocket frames that don't need to be encrypted (e.g. "close" frames that
// get issued in response to exceptions)
log.warn("Unexpected object in pipeline: {}", message);
}
context.write(message, promise);
}
}
}

13
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseHandshakeCompleteEvent.java
View File

@@ -1,13 +0,0 @@
package org.whispersystems.textsecuregcm.grpc.net;
import org.whispersystems.textsecuregcm.auth.grpc.AuthenticatedDevice;
import java.util.Optional;
/**
* An event that indicates that a Noise handshake has completed, possibly authenticating a caller in the process.
*
* @param authenticatedDevice the device authenticated as part of the handshake, or empty if the handshake was not of a
* type that performs authentication
*/
record NoiseHandshakeCompleteEvent(Optional<AuthenticatedDevice> authenticatedDevice) {
}

124
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseHandshakeHelper.java Normal file
View File

@@ -0,0 +1,124 @@
/*
* Copyright 2024 Signal Messenger, LLC
* SPDX-License-Identifier: AGPL-3.0-only
*/
package org.whispersystems.textsecuregcm.grpc.net;
import com.southernstorm.noise.protocol.HandshakeState;
import com.southernstorm.noise.protocol.Noise;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import java.security.NoSuchAlgorithmException;
import java.util.Optional;
import javax.crypto.BadPaddingException;
import javax.crypto.ShortBufferException;
import org.signal.libsignal.protocol.ecc.ECKeyPair;
/**
* Helper for the responder of a 2-message handshake with a pre-shared responder static key
*/
class NoiseHandshakeHelper {
private final static int AEAD_TAG_LENGTH = 16;
private final static int KEY_LENGTH = 32;
private final HandshakePattern handshakePattern;
private final ECKeyPair serverStaticKeyPair;
private final HandshakeState handshakeState;
NoiseHandshakeHelper(HandshakePattern handshakePattern, ECKeyPair serverStaticKeyPair) {
this.handshakePattern = handshakePattern;
this.serverStaticKeyPair = serverStaticKeyPair;
try {
this.handshakeState = new HandshakeState(handshakePattern.protocol(), HandshakeState.RESPONDER);
} catch (final NoSuchAlgorithmException e) {
throw new AssertionError("Unsupported Noise algorithm: " + handshakePattern.protocol(), e);
}
}
/**
* Get the length of the initiator's keys
*
* @return length of the handshake message sent by the remote party (the initiator) not including the payload
*/
private int initiatorHandshakeMessageKeyLength() {
return switch (handshakePattern) {
// ephemeral key, static key (encrypted), AEAD tag for static key
case IK -> KEY_LENGTH + KEY_LENGTH + AEAD_TAG_LENGTH;
// ephemeral key only
case NK -> KEY_LENGTH;
};
}
HandshakeState getHandshakeState() {
return this.handshakeState;
}
ByteBuf read(byte[] remoteHandshakeMessage) throws NoiseHandshakeException {
if (handshakeState.getAction() != HandshakeState.NO_ACTION) {
throw new NoiseHandshakeException("Cannot send more data before handshake is complete");
}
// Length for an empty payload
final int minMessageLength = initiatorHandshakeMessageKeyLength() + AEAD_TAG_LENGTH;
if (remoteHandshakeMessage.length < minMessageLength || remoteHandshakeMessage.length > Noise.MAX_PACKET_LEN) {
throw new NoiseHandshakeException("Unexpected ephemeral key message length");
}
final int payloadLength = remoteHandshakeMessage.length - initiatorHandshakeMessageKeyLength() - AEAD_TAG_LENGTH;
// Cryptographically initializing a handshake is expensive, and so we defer it until we're confident the client is
// making a good-faith effort to perform a handshake (i.e. now). Noise-java in particular will derive a public key
// from the supplied private key (and will in fact overwrite any previously-set public key when setting a private
// key), so we just set the private key here.
handshakeState.getLocalKeyPair().setPrivateKey(serverStaticKeyPair.getPrivateKey().serialize(), 0);
handshakeState.start();
int payloadBytesRead;
try {
payloadBytesRead = handshakeState.readMessage(remoteHandshakeMessage, 0, remoteHandshakeMessage.length,
remoteHandshakeMessage, 0);
} catch (final ShortBufferException e) {
// This should never happen since we're checking the length of the frame up front
throw new NoiseHandshakeException("Unexpected client payload");
} catch (final BadPaddingException e) {
// We aren't using padding but may get this error if the AEAD tag does not match the encrypted client static key
// or payload
throw new NoiseHandshakeException("Invalid keys or payload");
}
if (payloadBytesRead != payloadLength) {
throw new NoiseHandshakeException(
"Unexpected payload length, required " + payloadLength + " but got " + payloadBytesRead);
}
return Unpooled.wrappedBuffer(remoteHandshakeMessage, 0, payloadBytesRead);
}
byte[] write(byte[] payload) {
if (handshakeState.getAction() != HandshakeState.WRITE_MESSAGE) {
throw new IllegalStateException("Cannot send data before handshake is complete");
}
// Currently only support handshake patterns where the server static key is known
// Send our ephemeral key and the response to the initiator with the encrypted payload
final byte[] response = new byte[KEY_LENGTH + payload.length + AEAD_TAG_LENGTH];
try {
int written = handshakeState.writeMessage(response, 0, payload, 0, payload.length);
if (written != response.length) {
throw new IllegalStateException("Unexpected handshake response length");
}
return response;
} catch (final ShortBufferException e) {
// This should never happen for messages of known length that we control
throw new IllegalStateException("Key material buffer was too short for message", e);
}
}
Optional<byte[]> remotePublicKey() {
return Optional.ofNullable(handshakeState.getRemotePublicKey()).map(dhstate -> {
final byte[] publicKeyFromClient = new byte[handshakeState.getRemotePublicKey().getPublicKeyLength()];
handshakeState.getRemotePublicKey().getPublicKey(publicKeyFromClient, 0);
return publicKeyFromClient;
});
}
}

13
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseIdentityDeterminedEvent.java Normal file
View File

@@ -0,0 +1,13 @@
package org.whispersystems.textsecuregcm.grpc.net;
import java.util.Optional;
import org.whispersystems.textsecuregcm.auth.grpc.AuthenticatedDevice;
/**
* An event that indicates that an identity of a noise handshake initiator has been determined. If the initiator is
* connecting anonymously, the identity is empty, otherwise it will be present and already authenticated.
*
* @param authenticatedDevice the device authenticated as part of the handshake, or empty if the handshake was not of a
* type that performs authentication
*/
record NoiseIdentityDeterminedEvent(Optional<AuthenticatedDevice> authenticatedDevice) {}

40
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseNXHandshakeHandler.java
View File

@@ -1,40 +0,0 @@
package org.whispersystems.textsecuregcm.grpc.net;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import java.util.Optional;
import io.netty.util.ReferenceCountUtil;
import org.signal.libsignal.protocol.ecc.ECKeyPair;
/**
* A Noise NX handler handles the responder side of a Noise NX handshake.
*/
class NoiseNXHandshakeHandler extends AbstractNoiseHandshakeHandler {
static final String NOISE_PROTOCOL_NAME = "Noise_NX_25519_ChaChaPoly_BLAKE2b";
NoiseNXHandshakeHandler(final ECKeyPair ecKeyPair, final byte[] publicKeySignature) {
super(NOISE_PROTOCOL_NAME, ecKeyPair, publicKeySignature);
}
@Override
public void channelRead(final ChannelHandlerContext context, final Object message) throws Exception {
if (message instanceof BinaryWebSocketFrame frame) {
try {
handleEphemeralKeyMessage(context, frame);
} finally {
frame.release();
}
// All we need to do is accept the client's ephemeral key and send our own static keys; after that, we can consider
// the handshake complete
context.fireUserEventTriggered(new NoiseHandshakeCompleteEvent(Optional.empty()));
context.pipeline().replace(NoiseNXHandshakeHandler.this, null, new NoiseTransportHandler(getHandshakeState().split()));
} else {
// Anything except binary WebSocket frames should have been filtered out of the pipeline by now; treat this as an
// error
ReferenceCountUtil.release(message);
throw new IllegalArgumentException("Unexpected message in pipeline: " + message);
}
}
}

95
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseTransportHandler.java
View File

@@ -1,95 +0,0 @@
package org.whispersystems.textsecuregcm.grpc.net;
import com.southernstorm.noise.protocol.CipherState;
import com.southernstorm.noise.protocol.CipherStatePair;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketFrame;
import io.netty.util.ReferenceCountUtil;
import javax.crypto.BadPaddingException;
import javax.crypto.ShortBufferException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A Noise transport handler manages a bidirectional Noise session after a handshake has completed.
*/
class NoiseTransportHandler extends ChannelDuplexHandler {
private final CipherStatePair cipherStatePair;
private static final Logger log = LoggerFactory.getLogger(NoiseTransportHandler.class);
NoiseTransportHandler(CipherStatePair cipherStatePair) {
this.cipherStatePair = cipherStatePair;
}
@Override
public void channelRead(final ChannelHandlerContext context, final Object message)
throws ShortBufferException, BadPaddingException {
if (message instanceof BinaryWebSocketFrame frame) {
try {
final CipherState cipherState = cipherStatePair.getReceiver();
// We've read this frame off the wire, and so it's most likely a direct buffer that's not backed by an array.
// We'll need to copy it to a heap buffer.
final byte[] noiseBuffer = ByteBufUtil.getBytes(frame.content());
// Overwrite the ciphertext with the plaintext to avoid an extra allocation for a dedicated plaintext buffer
final int plaintextLength = cipherState.decryptWithAd(null, noiseBuffer, 0, noiseBuffer, 0, noiseBuffer.length);
context.fireChannelRead(Unpooled.wrappedBuffer(noiseBuffer, 0, plaintextLength));
} finally {
frame.release();
}
} else {
// Anything except binary WebSocket frames should have been filtered out of the pipeline by now; treat this as an
// error
ReferenceCountUtil.release(message);
throw new IllegalArgumentException("Unexpected message in pipeline: " + message);
}
}
@Override
public void write(final ChannelHandlerContext context, final Object message, final ChannelPromise promise) throws Exception {
if (message instanceof ByteBuf plaintext) {
try {
// TODO Buffer/consolidate Noise writes to avoid sending a bazillion tiny (or empty) frames
final CipherState cipherState = cipherStatePair.getSender();
final int plaintextLength = plaintext.readableBytes();
// We've read these bytes from a local connection; although that likely means they're backed by a heap array, the
// buffer is read-only and won't grant us access to the underlying array. Instead, we need to copy the bytes to a
// mutable array. We also want to encrypt in place, so we allocate enough extra space for the trailing MAC.
final byte[] noiseBuffer = new byte[plaintext.readableBytes() + cipherState.getMACLength()];
plaintext.readBytes(noiseBuffer, 0, plaintext.readableBytes());
// Overwrite the plaintext with the ciphertext to avoid an extra allocation for a dedicated ciphertext buffer
cipherState.encryptWithAd(null, noiseBuffer, 0, noiseBuffer, 0, plaintextLength);
context.write(new BinaryWebSocketFrame(Unpooled.wrappedBuffer(noiseBuffer)), promise);
} finally {
plaintext.release();
}
} else {
if (!(message instanceof WebSocketFrame)) {
// Downstream handlers may write WebSocket frames that don't need to be encrypted (e.g. "close" frames that
// get issued in response to exceptions)
log.warn("Unexpected object in pipeline: {}", message);
}
context.write(message, promise);
}
}
@Override
public void handlerRemoved(final ChannelHandlerContext context) {
cipherStatePair.destroy();
}
}

3
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseWebSocketTunnelServer.java
View File

@@ -53,7 +53,6 @@ public class NoiseWebSocketTunnelServer implements Managed {
final ClientConnectionManager clientConnectionManager,
final ClientPublicKeysManager clientPublicKeysManager,
final ECKeyPair ecKeyPair,
final byte[] publicKeySignature,
final LocalAddress authenticatedGrpcServerAddress,
final LocalAddress anonymousGrpcServerAddress,
final String recognizedProxySecret) throws SSLException {
@@ -107,7 +106,7 @@ public class NoiseWebSocketTunnelServer implements Managed {
.addLast(new RejectUnsupportedMessagesHandler())
// The WebSocket handshake complete listener will replace itself with an appropriate Noise handshake handler once
// a WebSocket handshake has been completed
.addLast(new WebsocketHandshakeCompleteHandler(clientPublicKeysManager, ecKeyPair, publicKeySignature, recognizedProxySecret))
.addLast(new WebsocketHandshakeCompleteHandler(clientPublicKeysManager, ecKeyPair, recognizedProxySecret))
// This handler will open a local connection to the appropriate gRPC server and install a ProxyHandler
// once the Noise handshake has completed
.addLast(new EstablishLocalGrpcConnectionHandler(clientConnectionManager, authenticatedGrpcServerAddress, anonymousGrpcServerAddress))

178
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/NoiseXXHandshakeHandler.java
View File

@@ -1,178 +0,0 @@
package org.whispersystems.textsecuregcm.grpc.net;
import com.southernstorm.noise.protocol.HandshakeState;
import io.netty.buffer.ByteBufUtil;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame;
import io.netty.util.ReferenceCountUtil;
import java.security.MessageDigest;
import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.UUID;
import javax.crypto.BadPaddingException;
import javax.crypto.ShortBufferException;
import org.signal.libsignal.protocol.ecc.ECKeyPair;
import org.whispersystems.textsecuregcm.auth.grpc.AuthenticatedDevice;
import org.whispersystems.textsecuregcm.storage.ClientPublicKeysManager;
import org.whispersystems.textsecuregcm.util.UUIDUtil;
/**
* A Noise XX handler handles the responder side of a Noise XX handshake. This implementation expects clients to send
* identifying information (an account identifier and device ID) as an additional payload when sending its static key
* material. It compares the static public key against the stored public key for the identified device asynchronously,
* buffering traffic from the client until the authentication check completes.
*/
class NoiseXXHandshakeHandler extends AbstractNoiseHandshakeHandler {
private final ClientPublicKeysManager clientPublicKeysManager;
private AuthenticationState authenticationState = AuthenticationState.GET_EPHEMERAL_KEY;
private final List<BinaryWebSocketFrame> pendingInboundFrames = new ArrayList<>();
static final String NOISE_PROTOCOL_NAME = "Noise_XX_25519_ChaChaPoly_BLAKE2b";
// When the client sends its static key message, we expect:
//
// - A 32-byte encrypted static public key
// - A 16-byte AEAD tag for the static key
// - 17 bytes of identity data in the message payload (a UUID and a one-byte device ID)
// - A 16-byte AEAD tag for the identity payload
private static final int EXPECTED_CLIENT_STATIC_KEY_MESSAGE_LENGTH = 81;
private enum AuthenticationState {
GET_EPHEMERAL_KEY,
GET_STATIC_KEY,
CHECK_PUBLIC_KEY,
ERROR
}
public NoiseXXHandshakeHandler(final ClientPublicKeysManager clientPublicKeysManager,
final ECKeyPair ecKeyPair,
final byte[] publicKeySignature) {
super(NOISE_PROTOCOL_NAME, ecKeyPair, publicKeySignature);
this.clientPublicKeysManager = clientPublicKeysManager;
}
@Override
public void channelRead(final ChannelHandlerContext context, final Object message) throws Exception {
if (message instanceof BinaryWebSocketFrame frame) {
try {
switch (authenticationState) {
case GET_EPHEMERAL_KEY -> {
try {
handleEphemeralKeyMessage(context, frame);
authenticationState = AuthenticationState.GET_STATIC_KEY;
} finally {
frame.release();
}
}
case GET_STATIC_KEY -> {
try {
handleStaticKey(context, frame);
authenticationState = AuthenticationState.CHECK_PUBLIC_KEY;
} finally {
frame.release();
}
}
case CHECK_PUBLIC_KEY -> {
// Buffer any inbound traffic until we've finished checking the client's public key
pendingInboundFrames.add(frame);
}
case ERROR -> {
// If authentication has failed for any reason, just discard inbound traffic until the channel closes
frame.release();
}
}
} catch (final ShortBufferException e) {
authenticationState = AuthenticationState.ERROR;
throw new NoiseHandshakeException("Unexpected payload length");
} catch (final BadPaddingException e) {
authenticationState = AuthenticationState.ERROR;
throw new ClientAuthenticationException();
}
} else {
// Anything except binary WebSocket frames should have been filtered out of the pipeline by now; treat this as an
// error
ReferenceCountUtil.release(message);
throw new IllegalArgumentException("Unexpected message in pipeline: " + message);
}
}
private void handleStaticKey(final ChannelHandlerContext context, final BinaryWebSocketFrame frame)
throws NoiseHandshakeException, ShortBufferException, BadPaddingException {
if (frame.content().readableBytes() != EXPECTED_CLIENT_STATIC_KEY_MESSAGE_LENGTH) {
throw new NoiseHandshakeException("Unexpected client static key message length");
}
final HandshakeState handshakeState = getHandshakeState();
// The websocket frame will have come right off the wire, and so needs to be copied from a non-array-backed direct
// buffer into a heap buffer.
final byte[] staticKeyAndClientIdentityMessage = ByteBufUtil.getBytes(frame.content());
// The payload from the client should be a UUID (16 bytes) followed by a device ID (1 byte)
final byte[] payload = new byte[17];
final UUID accountIdentifier;
final byte deviceId;
final int payloadBytesRead = handshakeState.readMessage(staticKeyAndClientIdentityMessage,
0, staticKeyAndClientIdentityMessage.length, payload, 0);
if (payloadBytesRead != 17) {
throw new NoiseHandshakeException("Unexpected identity payload length");
}
try {
accountIdentifier = UUIDUtil.fromBytes(payload, 0);
} catch (final IllegalArgumentException e) {
throw new NoiseHandshakeException("Could not parse account identifier");
}
deviceId = payload[16];
// Verify the identity of the caller by comparing the submitted static public key against the stored public key for
// the identified device
clientPublicKeysManager.findPublicKey(accountIdentifier, deviceId)
.whenCompleteAsync((maybePublicKey, throwable) -> maybePublicKey.ifPresentOrElse(storedPublicKey -> {
final byte[] publicKeyFromClient = new byte[handshakeState.getRemotePublicKey().getPublicKeyLength()];
handshakeState.getRemotePublicKey().getPublicKey(publicKeyFromClient, 0);
if (MessageDigest.isEqual(publicKeyFromClient, storedPublicKey.getPublicKeyBytes())) {
context.fireUserEventTriggered(new NoiseHandshakeCompleteEvent(
Optional.of(new AuthenticatedDevice(accountIdentifier, deviceId))));
context.pipeline().addAfter(context.name(), null, new NoiseTransportHandler(handshakeState.split()));
// Flush any buffered reads
pendingInboundFrames.forEach(context::fireChannelRead);
pendingInboundFrames.clear();
context.pipeline().remove(NoiseXXHandshakeHandler.this);
} else {
// We found a key, but it doesn't match what the caller submitted
context.fireExceptionCaught(new ClientAuthenticationException());
authenticationState = AuthenticationState.ERROR;
}
},
() -> {
// We couldn't find a key for the identified account/device
context.fireExceptionCaught(new ClientAuthenticationException());
authenticationState = AuthenticationState.ERROR;
}),
context.executor());
}
@Override
public void handlerRemoved(final ChannelHandlerContext context) {
super.handlerRemoved(context);
pendingInboundFrames.forEach(BinaryWebSocketFrame::release);
pendingInboundFrames.clear();
}
}

7
service/src/main/java/org/whispersystems/textsecuregcm/grpc/net/WebsocketHandshakeCompleteHandler.java
View File

@@ -31,7 +31,6 @@ class WebsocketHandshakeCompleteHandler extends ChannelInboundHandlerAdapter {
private final ClientPublicKeysManager clientPublicKeysManager;
private final ECKeyPair ecKeyPair;
private final byte[] publicKeySignature;
private final byte[] recognizedProxySecret;
@@ -45,12 +44,10 @@ class WebsocketHandshakeCompleteHandler extends ChannelInboundHandlerAdapter {
WebsocketHandshakeCompleteHandler(final ClientPublicKeysManager clientPublicKeysManager,
final ECKeyPair ecKeyPair,
final byte[] publicKeySignature,
final String recognizedProxySecret) {
this.clientPublicKeysManager = clientPublicKeysManager;
this.ecKeyPair = ecKeyPair;
this.publicKeySignature = publicKeySignature;
// The recognized proxy secret is an arbitrary string, and not an encoded byte sequence (i.e. a base64- or hex-
// encoded value). We convert it into a byte array here for easier constant-time comparisons via
@@ -84,10 +81,10 @@ class WebsocketHandshakeCompleteHandler extends ChannelInboundHandlerAdapter {
final ChannelHandler noiseHandshakeHandler = switch (handshakeCompleteEvent.requestUri()) {
case NoiseWebSocketTunnelServer.AUTHENTICATED_SERVICE_PATH ->
new NoiseXXHandshakeHandler(clientPublicKeysManager, ecKeyPair, publicKeySignature);
new NoiseAuthenticatedHandler(clientPublicKeysManager, ecKeyPair);
case NoiseWebSocketTunnelServer.ANONYMOUS_SERVICE_PATH ->
new NoiseNXHandshakeHandler(ecKeyPair, publicKeySignature);
new NoiseAnonymousHandler(ecKeyPair);
default -> {
// The WebSocketOpeningHandshakeHandler should have caught all of these cases already; we'll consider it an