[WIP] Security work While on holiday

This commit is contained in:
Alex 2026-08-12 22:45:28 +02:00
commit 7f0231e3f1
Signed by: alex
SSH key fingerprint: SHA256:D1+Ub8o0v4K5y1JNivW8IxEOelqLSvPmUzBbDIoZkRQ
109 changed files with 19694 additions and 5210 deletions

View file

@ -67,7 +67,10 @@ pub(crate) async fn run_driver(
let host_config = host_config.clone();
let auth_semaphore = auth_semaphore.clone();
connection_tasks.spawn(async move {
let _permit = permit;
// The permit normally lives for this HTTP/3 connection.
// For an MTP session it is moved into the resulting
// connection so the limit covers the session lifetime.
let mut connection_permit = Some(permit);
let connect_start = std::time::Instant::now();
let connection = match incoming.await {
Ok(connection) => connection,
@ -149,27 +152,41 @@ pub(crate) async fn run_driver(
remote_addr,
));
let mtp_tx = mtp_tx.clone();
let mtp_queue_permit = match mtp_tx.clone().try_reserve_owned() {
Ok(permit) => permit,
Err(_) => {
tracing::debug!(
"rejecting MTP session because the application queue is full"
);
connection.close(
quinn::VarInt::from_u32(0),
b"mtp application queue is full",
);
return;
}
};
let auth_semaphore = auth_semaphore.clone();
let host_config = host_config.clone();
let connection_guard = connection_permit.take();
let connection = connection.clone();
let close_connection = connection.clone();
tokio::spawn(async move {
let result =
accept_web_connection(session, mtp_path, connection, send_pongs, policy, host_config, auth_semaphore)
.await;
match mtp_tx.try_send(result) {
Ok(()) => {}
Err(tokio::sync::mpsc::error::TrySendError::Full(result)) => {
tracing::warn!("MTP connection backlog is full; dropping connection");
if let Ok(connection) = result {
connection.sender.close();
}
}
Err(tokio::sync::mpsc::error::TrySendError::Closed(result)) => {
if let Ok(connection) = result {
connection.sender.close();
}
}
let result = accept_web_connection(
session,
mtp_path,
connection,
send_pongs,
policy,
host_config,
auth_semaphore,
connection_guard,
)
.await;
if result.is_err() {
close_connection
.close(quinn::VarInt::from_u32(0), b"mtp handshake failed");
}
mtp_queue_permit.send(result);
});
return;
}

View file

@ -1,8 +1,5 @@
use bytes::Bytes;
use mtp_codec::{
DataType, DataValue, Version,
registry::{Registry, VersionedCodec},
};
use mtp_codec::registry::Registry;
use mtp_common::CommunicationError;
use mtp_host::AcceptError;
use mtp_host::HostConfig;
@ -11,14 +8,9 @@ use mtp_transport::{
TransportSendStream,
};
use std::sync::Arc;
#[cfg(feature = "crypto")]
use std::time::Instant;
use tokio::io::{AsyncReadExt, AsyncWriteExt};
use tracing::error;
#[cfg(feature = "crypto")]
const GUEST_ID_MAX_RETRIES: u32 = 100;
type Session = h3_webtransport::server::WebTransportSession<h3_quinn::Connection, Bytes>;
type H3SendStream = h3_webtransport::stream::SendStream<h3_quinn::SendStream<Bytes>, Bytes>;
type H3RecvStream = h3_webtransport::stream::RecvStream<h3_quinn::RecvStream, Bytes>;
@ -228,38 +220,6 @@ pub type WebMtpReceiver = GenericReceiver<H3TransportConnection>;
pub type WebMTPConnection =
mtp_host::MTPConnection<WebMtpSender, WebMtpReceiver, H3TransportReceiver>;
#[cfg(feature = "crypto")]
impl H3TransportConnection {
/// Assign a unique guest ID, using the configured generator if present.
async fn assign_guest_id(host_config: &HostConfig) -> Result<u64, AcceptError> {
if let Some(ref generator) = host_config.guest_id_generator {
let id = generator().await.ok_or_else(|| {
AcceptError::AuthenticationFailed(
"guest id generator rejected the connection".into(),
)
})?;
if id > mtp_codec::MAX_WIRE_ID {
return Err(AcceptError::AuthenticationFailed(
"guest id exceeds wire limit".into(),
));
}
if (host_config.get_existing_client)(id, None).await.is_none() {
return Ok(id);
}
}
// Fall back to random ID with collision check
for _ in 0..GUEST_ID_MAX_RETRIES {
let id = rand::random::<u64>() & mtp_codec::MAX_WIRE_ID;
if (host_config.get_existing_client)(id, None).await.is_none() {
return Ok(id);
}
}
Err(AcceptError::AuthenticationFailed(
"failed to allocate a unique guest id after retries".into(),
))
}
}
pub(crate) async fn accept_web_connection(
session: Arc<Session>,
path: String,
@ -267,25 +227,45 @@ pub(crate) async fn accept_web_connection(
send_pongs: bool,
policy: Policy,
host_config: Arc<HostConfig>,
_auth_semaphore: Arc<tokio::sync::Semaphore>,
#[allow(unused_variables)] auth_semaphore: Arc<tokio::sync::Semaphore>,
connection_guard: Option<tokio::sync::OwnedSemaphorePermit>,
) -> Result<WebMTPConnection, AcceptError> {
#[cfg(feature = "crypto")]
{
let permit = _auth_semaphore.clone().acquire_owned().await.map_err(|_| {
AcceptError::AuthenticationFailed("authentication service stopped".into())
})?;
let result = tokio::time::timeout(
host_config.auth_timeout,
accept_web_connection_inner(session, path, quinn, send_pongs, policy, host_config),
let deadline = tokio::time::Instant::now() + host_config.auth_timeout;
let permit = tokio::time::timeout_at(deadline, auth_semaphore.clone().acquire_owned())
.await
.map_err(|_| AcceptError::AuthenticationTimedOut)?
.map_err(|_| {
AcceptError::AuthenticationFailed("authentication service stopped".into())
})?;
let result = accept_web_connection_inner(
session,
path,
quinn,
send_pongs,
policy,
host_config,
Some(deadline),
connection_guard,
)
.await
.unwrap_or(Err(AcceptError::AuthenticationTimedOut));
.await;
drop(permit);
result
}
#[cfg(not(feature = "crypto"))]
accept_web_connection_inner(session, path, quinn, send_pongs, policy, host_config).await
accept_web_connection_inner(
session,
path,
quinn,
send_pongs,
policy,
host_config,
None,
connection_guard,
)
.await
}
async fn accept_web_connection_inner(
@ -294,434 +274,74 @@ async fn accept_web_connection_inner(
quinn: quinn::Connection,
send_pongs: bool,
policy: Policy,
_host_config: Arc<HostConfig>,
host_config: Arc<HostConfig>,
#[allow(unused_variables)] deadline: Option<tokio::time::Instant>,
connection_guard: Option<tokio::sync::OwnedSemaphorePermit>,
) -> Result<WebMTPConnection, AcceptError> {
#[cfg(feature = "crypto")]
let auth_handshake_started = Instant::now();
let max_message_size = policy.max_message_size;
let transport = H3TransportConnection::new(session, quinn);
let remote_addr = transport.remote_addr();
let policy = Arc::new(policy);
let receiver = WebMtpReceiver::new(transport.clone(), policy.clone());
let sender = WebMtpSender::new(transport.clone(), policy.clone());
let receiver = WebMtpReceiver::new(transport, policy.clone());
let first = receiver.receive().await.map_err(AcceptError::Receive)?;
let version = match first.get_data(DataType::Version) {
DataValue::Str(value) => Version::parse(value).ok_or(AcceptError::MissingVersion)?,
_ => return Err(AcceptError::MissingVersion),
};
let registry = Registry::builtin();
let negotiated = registry
.negotiate(std::slice::from_ref(&version))
.ok_or_else(|| AcceptError::UnsupportedVersion(version.clone()))?;
let codec = VersionedCodec::for_version(registry, negotiated.clone())
.ok_or_else(|| AcceptError::UnsupportedVersion(negotiated.clone()))?;
let description = match first.get_data(DataType::Description) {
DataValue::Str(value) => Some(value.clone()),
_ => None,
};
let sender = WebMtpSender::new(transport, policy.clone());
if send_pongs {
receiver.respond_to_pings(sender.clone()).await;
}
let engine = mtp_host::HandshakeEngine::new(Registry::builtin(), host_config);
#[cfg(feature = "crypto")]
let result = engine
.accept_until(
&sender,
&receiver,
deadline.expect("crypto WebTransport handshakes have a deadline"),
)
.await?;
#[cfg(not(feature = "crypto"))]
let result = engine.accept(&sender, &receiver).await?;
let version = result.negotiated_version.clone();
let codec = result.codec.clone();
let description = result.description.clone();
#[cfg(feature = "pipes")]
let connection: WebMTPConnection = mtp_host::MTPConnection::from_transport_parts_with_policy(
negotiated,
version,
codec,
sender,
receiver,
path,
description.clone(),
description,
Some(remote_addr),
policy,
);
#[cfg(not(feature = "pipes"))]
let connection: WebMTPConnection =
mtp_host::MTPConnection::from_transport_parts_with_remote_addr(
negotiated,
version,
codec,
sender,
receiver,
path,
description.clone(),
description,
Some(remote_addr),
);
#[cfg(not(feature = "crypto"))]
{
connection.receiver.set_max_message_size(max_message_size);
Ok(connection)
}
#[cfg(feature = "crypto")]
let mut connection = connection;
#[cfg(feature = "crypto")]
{
use mtp_codec::{CommunicationType, DataType, DataValue};
use mtp_crypto::{
Ed25519Signer, MlDsaSigner, PublicKeyBundle, SignatureScheme, auth, verify_ed25519,
};
let tm = mtp_codec::TypeMap::latest();
let is_allow_auth = matches!(
_host_config.authentication_policy,
mtp_host::AuthenticationPolicy::AllowAuthentication
);
let is_force_auth = matches!(
_host_config.authentication_policy,
mtp_host::AuthenticationPolicy::ForceAuthentication
);
// Unauthenticated: send accepted response with guest ID (or ID 0)
if !is_allow_auth && !is_force_auth {
let response =
mtp_codec::CommunicationValue::new(CommunicationType::IdentificationResponse)
.add_typed_default(DataType::Connected, DataValue::BoolTrue)
.add_typed_default(
DataType::Version,
DataValue::Str(connection.version.to_string()),
)
.add_typed_default(DataType::Id, DataValue::UnsignedNumber(0));
connection
.sender
.send(&response)
.await
.map_err(AcceptError::Send)?;
connection
.sender
.finish_stream()
.await
.map_err(AcceptError::Send)?;
connection.receiver.set_max_message_size(max_message_size);
return Ok(connection);
}
// AllowAuthentication / ForceAuthentication: perform authentication
let client_lookup_started = Instant::now();
let first_type = first.get_type();
let id_type = CommunicationType::Identification.try_to_id(&tm);
let reg_type = CommunicationType::Register.try_to_id(&tm);
let first_type_opt = Some(first_type);
let (client_id, client_bundle, response_type, is_guest) = if is_allow_auth
&& first_type_opt == id_type
{
// AllowAuthentication Identification: try lookup, fall back to guest
let id = match first.get_data(DataType::Id) {
DataValue::UnsignedNumber(value) => *value as u64,
_ => 0,
};
if id > 0 {
if let Some(bundle) =
(_host_config.get_existing_client)(id, description.clone()).await
{
(
id,
Some(bundle),
CommunicationType::IdentificationResponse,
false,
)
} else {
// Unknown client: fall back to guest
let guest_id = H3TransportConnection::assign_guest_id(&_host_config).await?;
(
guest_id,
None,
CommunicationType::IdentificationResponse,
true,
)
}
} else {
// ID zero or missing: fall back to guest
let guest_id = H3TransportConnection::assign_guest_id(&_host_config).await?;
(
guest_id,
None,
CommunicationType::IdentificationResponse,
true,
)
}
} else if first_type_opt == reg_type {
// Registration: always authenticate (both AllowAuth and ForceAuth)
let bundle = match first.get_data(DataType::PublicKeys) {
DataValue::Bytes(bytes) => PublicKeyBundle::from_bytes(bytes).map_err(|_| {
AcceptError::AuthenticationFailed("invalid public key bundle".into())
})?,
_ => {
return Err(AcceptError::AuthenticationFailed(
"missing public keys".into(),
));
}
};
(0, Some(bundle), CommunicationType::RegisterResponse, false)
} else if first_type_opt == id_type {
// ForceAuthentication Identification: require lookup
let id = match first.get_data(DataType::Id) {
DataValue::UnsignedNumber(value) => *value as u64,
_ => {
return Err(AcceptError::AuthenticationFailed(
"missing client id".into(),
));
}
};
let bundle = (_host_config.get_existing_client)(id, description.clone())
.await
.ok_or_else(|| AcceptError::AuthenticationFailed("unknown client id".into()))?;
(
id,
Some(bundle),
CommunicationType::IdentificationResponse,
false,
)
} else {
return Err(AcceptError::AuthenticationFailed(
"unexpected authentication message".into(),
));
};
tracing::debug!(elapsed = ?client_lookup_started.elapsed(), is_guest, "web authentication handshake: identify client");
// Guest path: skip challenge/response, send accepted with guest ID
if is_guest {
let guest_id = client_id;
let response =
mtp_codec::CommunicationValue::new(CommunicationType::IdentificationResponse)
.add_typed_default(DataType::Connected, DataValue::BoolTrue)
.add_typed_default(
DataType::Version,
DataValue::Str(connection.version.to_string()),
)
.add_typed_default(DataType::Id, DataValue::UnsignedNumber(guest_id as u128));
connection
.sender
.send(&response)
.await
.map_err(AcceptError::Send)?;
connection
.sender
.finish_stream()
.await
.map_err(AcceptError::Send)?;
connection.receiver.set_max_message_size(max_message_size);
connection.auth_state = mtp_host::AuthState::Unauthenticated;
connection.client_id = guest_id;
return Ok(connection);
}
let client_bundle = client_bundle.unwrap();
// PQ preflight: if host requires PQ, it must have a PQ key
let pq_enabled = !_host_config
.host_keyring
.sig_pq_secret_key
.as_bytes()
.is_empty();
if _host_config.require_pq
&& (!pq_enabled
|| _host_config
.host_keyring
.sig_pq_public_key
.as_bytes()
.is_empty())
{
return Err(AcceptError::AuthenticationFailed(
"host requires PQ authentication but has no PQ signing key".into(),
));
}
let signer_init_started = Instant::now();
let host_pq_signer = if pq_enabled {
Some(Arc::new(
MlDsaSigner::new(
&_host_config.host_keyring.sig_pq_secret_key,
&_host_config.host_keyring.sig_pq_public_key,
)
.map_err(|e| AcceptError::AuthenticationFailed(e.to_string()))?,
))
} else {
None
};
tracing::debug!(elapsed = ?signer_init_started.elapsed(), "web authentication handshake: signer initialization");
let server_challenge: u128 = rand::random();
let host_sign = |payload: Vec<u8>| {
let host_config = _host_config.clone();
let pq_signer = host_pq_signer.clone();
async move {
let signer = Ed25519Signer::new(&host_config.host_keyring.sig_cl_secret_key)
.map_err(|e| AcceptError::AuthenticationFailed(e.to_string()))?;
if let Some(pq_signer) = pq_signer {
mtp_crypto::sign_parallel::sign_dual_parallel_shared_pq(
signer, pq_signer, payload,
)
.await
.map_err(|e| AcceptError::AuthenticationFailed(e.to_string()))
} else {
let sig = signer
.sign(&payload)
.map_err(|e| AcceptError::AuthenticationFailed(e.to_string()))?;
Ok((sig, Vec::new()))
}
}
};
let sign_challenge_started = Instant::now();
let (sig, pq_sig) = host_sign(auth::challenge_payload(client_id, server_challenge)).await?;
tracing::debug!(elapsed = ?sign_challenge_started.elapsed(), "web authentication handshake: sign challenge");
let mut challenge = mtp_codec::CommunicationValue::new(CommunicationType::Challenge)
.add_typed_default(
DataType::ServerNonce,
DataValue::UnsignedNumber(server_challenge),
)
.add_typed_default(DataType::Signature, DataValue::Bytes(sig))
.add_typed_default(
DataType::RequirePq,
if _host_config.require_pq {
DataValue::BoolTrue
} else {
DataValue::BoolFalse
},
);
if pq_enabled {
challenge =
challenge.add_typed_default(DataType::PqSignature, DataValue::Bytes(pq_sig));
}
let send_challenge_started = Instant::now();
connection
.sender
.send(&challenge)
.await
.map_err(AcceptError::Send)?;
tracing::debug!(elapsed = ?send_challenge_started.elapsed(), "web authentication handshake: send challenge");
let receive_proof_started = Instant::now();
let proof = {
#[cfg(feature = "pipes")]
{
connection.receive().await.map_err(AcceptError::Receive)?
}
#[cfg(not(feature = "pipes"))]
{
let mut proof = connection
.receiver
.receive()
.await
.map_err(AcceptError::Receive)?;
proof.set_type_map(connection.codec.type_map());
proof
}
};
tracing::debug!(elapsed = ?receive_proof_started.elapsed(), "web authentication handshake: receive client proof");
if Some(proof.get_type()) != CommunicationType::ChallengeResponse.try_to_id(&tm) {
return Err(AcceptError::AuthenticationFailed(
"missing challenge response".into(),
));
}
let nonce = match proof.get_data(DataType::ClientNonce) {
DataValue::UnsignedNumber(n) => n.to_owned(),
_ => {
return Err(AcceptError::AuthenticationFailed(
"missing client nonce".into(),
));
}
};
let signature = match proof.get_data(DataType::Signature) {
DataValue::Bytes(bytes) => bytes,
_ => {
return Err(AcceptError::AuthenticationFailed(
"missing challenge signature".into(),
));
}
};
let pq_signature = match proof.get_data(DataType::PqSignature) {
DataValue::Bytes(bytes) => bytes.as_slice(),
_ => &[],
};
let payload = if first.get_type() == CommunicationType::Register.try_to_id(&tm).unwrap() {
auth::register_proof_payload(
&version.to_string(),
&client_bundle.as_bytes(),
server_challenge,
nonce,
)
} else {
auth::login_proof_payload(&version.to_string(), client_id, server_challenge, nonce)
};
// Verify client proof: classical is always required; PQ is verified
// when supplied (even if not required), matching native behavior.
let has_client_pq_key = !client_bundle.sig_pq_public_key.as_bytes().is_empty();
let verify_proof_started = Instant::now();
let proof_ok = if pq_signature.is_empty() {
!_host_config.require_pq
&& verify_ed25519(&client_bundle.sig_cl_public_key, &payload, signature).is_ok()
} else if has_client_pq_key {
mtp_crypto::sign_parallel::verify_dual_parallel(
client_bundle.sig_cl_public_key.clone(),
client_bundle.sig_pq_public_key.clone(),
payload,
signature.to_vec(),
pq_signature.to_vec(),
)
.await
.is_ok()
} else {
false
};
tracing::debug!(elapsed = ?verify_proof_started.elapsed(), "web authentication handshake: verify client proof");
if !proof_ok {
let rejection =
mtp_codec::CommunicationValue::new(CommunicationType::IdentificationResponse)
.add_typed_default(DataType::Connected, DataValue::BoolFalse)
.add_typed_default(
DataType::ErrorMessage,
DataValue::Str("client proof signature invalid".into()),
);
let _ = connection.sender.send(&rejection).await;
connection.sender.close();
return Err(AcceptError::AuthenticationFailed(
"client proof signature invalid".into(),
));
}
let register_started = Instant::now();
let assigned_id = if response_type == CommunicationType::RegisterResponse {
(_host_config.complete_register)(client_bundle.clone(), description.clone()).await
} else {
client_id
};
tracing::debug!(elapsed = ?register_started.elapsed(), "web authentication handshake: registration callback");
let sign_final_started = Instant::now();
let (final_sig, final_pq) = host_sign(auth::host_final_payload(
assigned_id,
nonce,
server_challenge,
))
.await?;
tracing::debug!(elapsed = ?sign_final_started.elapsed(), "web authentication handshake: sign final response");
let mut response = mtp_codec::CommunicationValue::new(response_type)
.add_typed_default(DataType::Connected, DataValue::BoolTrue)
.add_typed_default(DataType::Id, DataValue::UnsignedNumber(assigned_id as u128))
.add_typed_default(DataType::ClientNonce, DataValue::UnsignedNumber(nonce))
.add_typed_default(DataType::Signature, DataValue::Bytes(final_sig))
.add_typed_default(DataType::Version, DataValue::Str(version.to_string()));
if pq_enabled {
response =
response.add_typed_default(DataType::PqSignature, DataValue::Bytes(final_pq));
}
let send_final_started = Instant::now();
connection
.sender
.send(&response)
.await
.map_err(AcceptError::Send)?;
connection
.sender
.finish_stream()
.await
.map_err(AcceptError::Send)?;
tracing::debug!(elapsed = ?send_final_started.elapsed(), "web authentication handshake: send final response");
tracing::debug!(elapsed = ?auth_handshake_started.elapsed(), "web authentication handshake: complete");
connection.receiver.set_max_message_size(max_message_size);
connection.auth_state = mtp_host::AuthState::Authenticated;
connection.client_id = assigned_id;
connection.client_public_key = Some(client_bundle);
Ok(connection)
connection.auth_state = result.auth_state;
connection.client_id = result.client_id;
connection.client_public_key = result.client_public_key;
connection.set_guest_id_lease(result.guest_id_lease);
}
if let Some(connection_guard) = connection_guard {
connection.set_connection_guard(connection_guard);
}
if send_pongs {
connection
.receiver
.respond_to_pings(connection.sender.clone())
.await;
}
connection.receiver.set_max_message_size(max_message_size);
Ok(connection)
}