Simon Wicky
546 lines
20 KiB
Rust
546 lines
20 KiB
Rust
// Copyright 2021 - Nym Technologies SA <contact@nymtech.net>
|
|
// SPDX-License-Identifier: GPL-3.0-only
|
|
|
|
use futures::{
|
|
future::{FusedFuture, OptionFuture},
|
|
FutureExt, StreamExt,
|
|
};
|
|
use log::*;
|
|
use nym_gateway_requests::{
|
|
iv::{IVConversionError, IV},
|
|
types::{BinaryRequest, ServerResponse},
|
|
ClientControlRequest, GatewayRequestsError,
|
|
};
|
|
use nym_sphinx::forwarding::packet::MixPacket;
|
|
use nym_task::TaskClient;
|
|
use nym_validator_client::coconut::CoconutApiError;
|
|
use rand::{CryptoRng, Rng};
|
|
use thiserror::Error;
|
|
use tokio::io::{AsyncRead, AsyncWrite};
|
|
use tokio_tungstenite::tungstenite::{protocol::Message, Error as WsError};
|
|
|
|
use std::{convert::TryFrom, process, time::Duration};
|
|
|
|
use crate::node::{
|
|
client_handling::{
|
|
websocket::{
|
|
connection_handler::{ClientDetails, FreshHandler},
|
|
message_receiver::{
|
|
IsActive, IsActiveRequestReceiver, IsActiveResultSender, MixMessageReceiver,
|
|
},
|
|
},
|
|
FREE_TESTNET_BANDWIDTH_VALUE,
|
|
},
|
|
storage::{error::StorageError, Storage},
|
|
};
|
|
|
|
#[derive(Debug, Error)]
|
|
pub(crate) enum RequestHandlingError {
|
|
#[error("Internal gateway storage error")]
|
|
StorageError(#[from] StorageError),
|
|
|
|
#[error("Provided bandwidth IV is malformed - {0}")]
|
|
MalformedIV(#[from] IVConversionError),
|
|
|
|
#[error("Provided binary request was malformed - {0}")]
|
|
InvalidBinaryRequest(#[from] GatewayRequestsError),
|
|
|
|
#[error("Provided binary request was malformed - {0}")]
|
|
InvalidTextRequest(<ClientControlRequest as TryFrom<String>>::Error),
|
|
|
|
#[error("The received request is not valid in the current context")]
|
|
IllegalRequest,
|
|
|
|
#[error("Provided bandwidth credential did not verify correctly on {0}")]
|
|
InvalidBandwidthCredential(String),
|
|
|
|
#[error("This gateway is only accepting coconut credentials for bandwidth")]
|
|
OnlyCoconutCredentials,
|
|
|
|
#[error("Nyxd Error - {0}")]
|
|
NyxdError(#[from] nym_validator_client::nyxd::error::NyxdError),
|
|
|
|
#[error("Validator API error - {0}")]
|
|
APIError(#[from] nym_validator_client::ValidatorClientError),
|
|
|
|
#[error("Not enough nym API endpoints provided. Needed {needed}, received {received}")]
|
|
NotEnoughNymAPIs { received: usize, needed: usize },
|
|
|
|
#[error("There was a problem with the proposal id: {reason}")]
|
|
ProposalIdError { reason: String },
|
|
|
|
#[error("Compact ecash error - {0}")]
|
|
CompactEcashError(#[from] nym_compact_ecash::error::CompactEcashError),
|
|
|
|
#[error("Coconut interface error - {0}")]
|
|
CoconutInterfaceError(#[from] nym_coconut_interface::error::CoconutInterfaceError),
|
|
|
|
#[error("coconut api query failure: {0}")]
|
|
CoconutApiError(#[from] CoconutApiError),
|
|
|
|
#[error("Credential error - {0}")]
|
|
CredentialError(#[from] nym_credentials::error::Error),
|
|
|
|
#[error("Internal error")]
|
|
InternalError,
|
|
}
|
|
|
|
impl RequestHandlingError {
|
|
fn into_error_message(self) -> Message {
|
|
ServerResponse::new_error(self.to_string()).into()
|
|
}
|
|
}
|
|
|
|
/// Helper trait that allows converting result of handling client request into a websocket message
|
|
// Note: I couldn't have implemented a normal "From" trait as both `Message` and `Result` are foreign types
|
|
trait IntoWSMessage {
|
|
fn into_ws_message(self) -> Message;
|
|
}
|
|
|
|
impl IntoWSMessage for Result<ServerResponse, RequestHandlingError> {
|
|
fn into_ws_message(self) -> Message {
|
|
match self {
|
|
Ok(response) => response.into(),
|
|
Err(err) => err.into_error_message(),
|
|
}
|
|
}
|
|
}
|
|
|
|
pub(crate) struct AuthenticatedHandler<R, S, St> {
|
|
inner: FreshHandler<R, S, St>,
|
|
client: ClientDetails,
|
|
mix_receiver: MixMessageReceiver,
|
|
// Occasionally the handler is requested to ping the connected client for confirm that it's
|
|
// active, such as when a duplicate connection is detected. This hashmap stores the oneshot
|
|
// senders that are used to return the result of the ping to the handler requesting the ping.
|
|
is_active_request_receiver: IsActiveRequestReceiver,
|
|
is_active_ping_pending_reply: Option<(u64, IsActiveResultSender)>,
|
|
}
|
|
|
|
// explicitly remove handle from the global store upon being dropped
|
|
impl<R, S, St> Drop for AuthenticatedHandler<R, S, St> {
|
|
fn drop(&mut self) {
|
|
self.inner
|
|
.active_clients_store
|
|
.disconnect(self.client.address)
|
|
}
|
|
}
|
|
|
|
impl<R, S, St> AuthenticatedHandler<R, S, St>
|
|
where
|
|
// TODO: those trait bounds here don't really make sense....
|
|
R: Rng + CryptoRng,
|
|
St: Storage,
|
|
{
|
|
/// Upgrades `FreshHandler` into the Authenticated variant implying the client is now authenticated
|
|
/// and thus allowed to perform more actions with the gateway, such as redeeming bandwidth or
|
|
/// sending sphinx packets.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// * `fresh`: fresh, unauthenticated, connection handler.
|
|
/// * `client`: details (i.e. address and shared keys) of the registered client
|
|
/// * `mix_receiver`: channel used for receiving messages from the mixnet destined for this client.
|
|
pub(crate) fn upgrade(
|
|
fresh: FreshHandler<R, S, St>,
|
|
client: ClientDetails,
|
|
mix_receiver: MixMessageReceiver,
|
|
is_active_request_receiver: IsActiveRequestReceiver,
|
|
) -> Self {
|
|
AuthenticatedHandler {
|
|
inner: fresh,
|
|
client,
|
|
mix_receiver,
|
|
is_active_request_receiver,
|
|
is_active_ping_pending_reply: None,
|
|
}
|
|
}
|
|
|
|
/// Explicitly removes handle from the global store.
|
|
fn disconnect(self) {
|
|
self.inner
|
|
.active_clients_store
|
|
.disconnect(self.client.address)
|
|
}
|
|
|
|
/// Checks the amount of bandwidth available for the connected client.
|
|
async fn get_available_bandwidth(&self) -> Result<i64, RequestHandlingError> {
|
|
let bandwidth = self
|
|
.inner
|
|
.storage
|
|
.get_available_bandwidth(self.client.address)
|
|
.await?
|
|
.unwrap_or_default();
|
|
Ok(bandwidth)
|
|
}
|
|
|
|
/// Increases the amount of available bandwidth of the connected client by the specified value.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// * `amount`: amount to increase the available bandwidth by.
|
|
async fn increase_bandwidth(&self, amount: i64) -> Result<(), RequestHandlingError> {
|
|
self.inner
|
|
.storage
|
|
.increase_bandwidth(self.client.address, amount)
|
|
.await?;
|
|
Ok(())
|
|
}
|
|
|
|
/// Decreases the amount of available bandwidth of the connected client by the specified value.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// * `amount`: amount to decrease the available bandwidth by.
|
|
async fn consume_bandwidth(&self, amount: i64) -> Result<(), RequestHandlingError> {
|
|
self.inner
|
|
.storage
|
|
.consume_bandwidth(self.client.address, amount)
|
|
.await?;
|
|
Ok(())
|
|
}
|
|
|
|
/// Forwards the received mix packet from the client into the mix network.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// * `mix_packet`: packet received from the client that should get forwarded into the network.
|
|
fn forward_packet(&self, mix_packet: MixPacket) {
|
|
if let Err(err) = self.inner.outbound_mix_sender.unbounded_send(mix_packet) {
|
|
error!("We failed to forward requested mix packet - {err}. Presumably our mix forwarder has crashed. We cannot continue.");
|
|
process::exit(1);
|
|
}
|
|
}
|
|
|
|
/// Tries to handle the received bandwidth request by checking correctness of the received data
|
|
/// and if successful, increases client's bandwidth by an appropriate amount.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// * `enc_credential`: raw encrypted credential to verify.
|
|
/// * `iv`: fresh iv used for the credential.
|
|
async fn handle_bandwidth(
|
|
&mut self,
|
|
enc_credential: Vec<u8>,
|
|
iv: Vec<u8>,
|
|
) -> Result<ServerResponse, RequestHandlingError> {
|
|
let iv = IV::try_from_bytes(&iv)?;
|
|
let credential = ClientControlRequest::try_from_enc_ecash_credential(
|
|
enc_credential,
|
|
&self.client.shared_keys,
|
|
iv,
|
|
)?;
|
|
|
|
// Get the latest coconut signers and their VK
|
|
let credential_api_clients = self
|
|
.inner
|
|
.ecash_verifier
|
|
.all_ecash_api_clients(*credential.epoch_id())
|
|
.await?;
|
|
let current_api_clients = self
|
|
.inner
|
|
.ecash_verifier
|
|
.all_current_ecash_api_clients()
|
|
.await?;
|
|
if credential_api_clients.is_empty() || current_api_clients.is_empty() {
|
|
return Err(RequestHandlingError::NotEnoughNymAPIs {
|
|
received: 0,
|
|
needed: 1,
|
|
});
|
|
}
|
|
|
|
let aggregated_verification_key =
|
|
nym_credentials::obtain_aggregate_verification_key(&credential_api_clients).await?;
|
|
|
|
self.inner
|
|
.ecash_verifier
|
|
.check_payment(&credential, &aggregated_verification_key)
|
|
.await?;
|
|
|
|
if self.inner.offline_credential_verification {
|
|
self.inner
|
|
.ecash_verifier
|
|
.post_credential(current_api_clients, credential.clone())?;
|
|
|
|
self.inner.storage.insert_credential(credential).await?;
|
|
} else {
|
|
self.inner
|
|
.ecash_verifier
|
|
.release_funds(current_api_clients, &credential)
|
|
.await?;
|
|
}
|
|
|
|
let bandwidth_value = 100000000; //SW MAKE A GLOBAL PARAMETER
|
|
|
|
self.increase_bandwidth(bandwidth_value).await?;
|
|
let available_total = self.get_available_bandwidth().await?;
|
|
|
|
Ok(ServerResponse::Bandwidth { available_total })
|
|
}
|
|
|
|
async fn handle_claim_testnet_bandwidth(
|
|
&mut self,
|
|
) -> Result<ServerResponse, RequestHandlingError> {
|
|
if self.inner.only_coconut_credentials {
|
|
return Err(RequestHandlingError::OnlyCoconutCredentials);
|
|
}
|
|
|
|
self.increase_bandwidth(FREE_TESTNET_BANDWIDTH_VALUE)
|
|
.await?;
|
|
let available_total = self.get_available_bandwidth().await?;
|
|
|
|
Ok(ServerResponse::Bandwidth { available_total })
|
|
}
|
|
|
|
/// Tries to handle request to forward sphinx packet into the network. The request can only succeed
|
|
/// if the client has enough available bandwidth.
|
|
///
|
|
/// Upon forwarding, client's bandwidth is decreased by the size of the forwarded packet.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// * `mix_packet`: packet received from the client that should get forwarded into the network.
|
|
async fn handle_forward_sphinx(
|
|
&self,
|
|
mix_packet: MixPacket,
|
|
) -> Result<ServerResponse, RequestHandlingError> {
|
|
let consumed_bandwidth = mix_packet.packet().len() as i64;
|
|
|
|
let available_bandwidth = self.get_available_bandwidth().await?;
|
|
|
|
if available_bandwidth < consumed_bandwidth {
|
|
return Ok(ServerResponse::new_error(
|
|
"Insufficient bandwidth available",
|
|
));
|
|
}
|
|
|
|
self.consume_bandwidth(consumed_bandwidth).await?;
|
|
self.forward_packet(mix_packet);
|
|
|
|
Ok(ServerResponse::Send {
|
|
remaining_bandwidth: available_bandwidth - consumed_bandwidth,
|
|
})
|
|
}
|
|
|
|
/// Attempts to handle a binary data frame websocket message.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// * `bin_msg`: raw message to handle.
|
|
async fn handle_binary(&self, bin_msg: Vec<u8>) -> Message {
|
|
// this function decrypts the request and checks the MAC
|
|
match BinaryRequest::try_from_encrypted_tagged_bytes(bin_msg, &self.client.shared_keys) {
|
|
Err(e) => {
|
|
error!("{e}");
|
|
RequestHandlingError::InvalidBinaryRequest(e).into_error_message()
|
|
}
|
|
Ok(request) => match request {
|
|
// currently only a single type exists
|
|
BinaryRequest::ForwardSphinx(mix_packet) => self
|
|
.handle_forward_sphinx(mix_packet)
|
|
.await
|
|
.into_ws_message(),
|
|
},
|
|
}
|
|
}
|
|
|
|
/// Attempts to handle a text data frame websocket message.
|
|
///
|
|
/// Currently the bandwidth credential request is the only one we can receive after authentication.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// * `raw_request`: raw message to handle.
|
|
async fn handle_text(&mut self, raw_request: String) -> Message {
|
|
match ClientControlRequest::try_from(raw_request) {
|
|
Err(e) => RequestHandlingError::InvalidTextRequest(e).into_error_message(),
|
|
Ok(request) => match request {
|
|
ClientControlRequest::EcashCredential { enc_credential, iv } => self
|
|
.handle_bandwidth(enc_credential, iv)
|
|
.await
|
|
.into_ws_message(),
|
|
ClientControlRequest::ClaimFreeTestnetBandwidth => self
|
|
.handle_claim_testnet_bandwidth()
|
|
.await
|
|
.into_ws_message(),
|
|
_ => RequestHandlingError::IllegalRequest.into_error_message(),
|
|
},
|
|
}
|
|
}
|
|
|
|
/// Handles pong message received from the client.
|
|
/// If the client is still active, the handler that requested the ping will receive a reply.
|
|
async fn handle_pong(&mut self, msg: Vec<u8>) {
|
|
if let Ok(msg) = msg.try_into() {
|
|
let msg = u64::from_be_bytes(msg);
|
|
trace!("Received pong from client: {msg}");
|
|
if let Some((tag, _)) = &self.is_active_ping_pending_reply {
|
|
if tag == &msg {
|
|
debug!("Reporting back to the handler that the client is still active");
|
|
// safety:
|
|
// the unwrap here is fine as we can only enter this if branch if `self.is_active_ping_pending_reply`
|
|
// was a `Some`
|
|
#[allow(clippy::unwrap_used)]
|
|
let tx = self.is_active_ping_pending_reply.take().unwrap().1;
|
|
if let Err(err) = tx.send(IsActive::Active) {
|
|
warn!("Failed to send pong reply back to the requesting handler: {err:?}");
|
|
}
|
|
} else {
|
|
warn!("Received pong reply from the client with unexpected tag: {msg}",);
|
|
}
|
|
}
|
|
} else {
|
|
warn!("the received pong message was not a valid u64")
|
|
}
|
|
}
|
|
|
|
/// Attempts to handle websocket message received from the connected client.
|
|
///
|
|
/// # Arguments
|
|
///
|
|
/// * `raw_request`: raw received websocket message.
|
|
async fn handle_request(&mut self, raw_request: Message) -> Option<Message> {
|
|
// apparently tungstenite auto-handles ping/pong/close messages so for now let's ignore
|
|
// them and let's test that claim. If that's not the case, just copy code from
|
|
// desktop nym-client websocket as I've manually handled everything there
|
|
match raw_request {
|
|
Message::Binary(bin_msg) => Some(self.handle_binary(bin_msg).await),
|
|
Message::Text(text_msg) => Some(self.handle_text(text_msg).await),
|
|
Message::Pong(msg) => {
|
|
self.handle_pong(msg).await;
|
|
None
|
|
}
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
/// Send a ping to the connected client and return a tag identifying the ping.
|
|
async fn send_ping(&mut self) -> Result<u64, WsError>
|
|
where
|
|
S: AsyncRead + AsyncWrite + Unpin,
|
|
{
|
|
let tag: u64 = rand::thread_rng().gen();
|
|
debug!("Got request to ping our connection: {}", tag);
|
|
self.inner
|
|
.send_websocket_message(Message::Ping(tag.to_be_bytes().to_vec()))
|
|
.await?;
|
|
Ok(tag)
|
|
}
|
|
|
|
/// Handles the ping timeout by responding back to the handler that requested the ping.
|
|
async fn handle_ping_timeout(&mut self) {
|
|
debug!("Ping timeout expired!");
|
|
if let Some((_tag, reply_tx)) = self.is_active_ping_pending_reply.take() {
|
|
if let Err(err) = reply_tx.send(IsActive::NotActive) {
|
|
warn!("Failed to respond back to the handler requesting the ping: {err:?}");
|
|
}
|
|
}
|
|
}
|
|
|
|
async fn handle_is_active_request(
|
|
&mut self,
|
|
reply_tx: IsActiveResultSender,
|
|
) -> Result<(), WsError>
|
|
where
|
|
S: AsyncRead + AsyncWrite + Unpin,
|
|
{
|
|
if self.is_active_ping_pending_reply.is_some() {
|
|
warn!("Received request to ping the client, but a ping is already in progress!");
|
|
if let Err(err) = reply_tx.send(IsActive::BusyPinging) {
|
|
warn!("Failed to respond back to the handler requesting the ping: {err:?}");
|
|
}
|
|
return Ok(());
|
|
}
|
|
|
|
match self.send_ping().await {
|
|
Ok(tag) => {
|
|
self.is_active_ping_pending_reply = Some((tag, reply_tx));
|
|
Ok(())
|
|
}
|
|
Err(err) => {
|
|
warn!("Failed to send ping to client: {err}. Assuming the connection is dead.");
|
|
Err(err)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Simultaneously listens for incoming client requests, which realistically should only be
|
|
/// binary requests to forward sphinx packets or increase bandwidth
|
|
/// and for sphinx packets received from the mix network that should be sent back to the client.
|
|
pub(crate) async fn listen_for_requests(mut self, mut shutdown: TaskClient)
|
|
where
|
|
S: AsyncRead + AsyncWrite + Unpin,
|
|
St: Storage,
|
|
{
|
|
trace!("Started listening for ALL incoming requests...");
|
|
|
|
// Ping timeout future used to check if the client responded to our ping request
|
|
let mut ping_timeout: OptionFuture<_> = None.into();
|
|
|
|
while !shutdown.is_shutdown() {
|
|
tokio::select! {
|
|
_ = shutdown.recv() => {
|
|
log::trace!("client_handling::AuthenticatedHandler: received shutdown");
|
|
},
|
|
// Received a request to ping the client to check if it's still active
|
|
tx = self.is_active_request_receiver.next() => {
|
|
match tx {
|
|
None => break,
|
|
Some(reply_tx) => {
|
|
if self.handle_is_active_request(reply_tx).await.is_err() {
|
|
break;
|
|
}
|
|
// NOTE: fuse here due to .is_terminated() check below
|
|
ping_timeout = Some(Box::pin(tokio::time::sleep(Duration::from_millis(1000)).fuse())).into();
|
|
}
|
|
};
|
|
},
|
|
// The ping timeout expired, meaning the client didn't respond to our ping request
|
|
_ = &mut ping_timeout, if !ping_timeout.is_terminated() => {
|
|
ping_timeout = None.into();
|
|
self.handle_ping_timeout().await;
|
|
},
|
|
socket_msg = self.inner.read_websocket_message() => {
|
|
let socket_msg = match socket_msg {
|
|
None => break,
|
|
Some(Ok(socket_msg)) => socket_msg,
|
|
Some(Err(err)) => {
|
|
error!("failed to obtain message from websocket stream! stopping connection handler: {err}");
|
|
break;
|
|
}
|
|
};
|
|
|
|
if socket_msg.is_close() {
|
|
break;
|
|
}
|
|
|
|
if let Some(response) = self.handle_request(socket_msg).await {
|
|
if let Err(err) = self.inner.send_websocket_message(response).await {
|
|
warn!(
|
|
"Failed to send message over websocket: {err}. Assuming the connection is dead.",
|
|
);
|
|
break;
|
|
}
|
|
}
|
|
},
|
|
mix_messages = self.mix_receiver.next() => {
|
|
let mix_messages = match mix_messages {
|
|
None => {
|
|
warn!("mix receiver was closed! Assuming the connection is dead.");
|
|
break;
|
|
}
|
|
Some(mix_messages) => mix_messages,
|
|
};
|
|
if let Err(err) = self.inner.push_packets_to_client(&self.client.shared_keys, mix_messages).await {
|
|
warn!("failed to send the unwrapped sphinx packets back to the client - {err}, assuming the connection is dead");
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
self.disconnect();
|
|
trace!("The stream was closed!");
|
|
}
|
|
}
|