quic: stateless reset generate strategy

Generate stateless reset token cryptographically

Fixes: #62

Author: jasnell

doc/api/errors.md

@@ -1671,6 +1671,10 @@ TBD
 
 TBD
 
+<a id="ERR_QUICSOCKET_INVALID_STATELESS_RESET_SECRET_LENGTH"></a>
+### ERR_QUICSOCKET_INVALID_STATELESS_RESET_SECRET_LENGTH
+TBD
+
 <a id="ERR_QUICSOCKET_LISTENING"></a>
 ### ERR_QUICSOCKET_LISTENING
 

doc/api/quic.md

@@ -1596,6 +1596,15 @@ Changing TTL values is typically done for network probes or when multicasting.
 The argument to `socket.setTTL()` is a number of hops between `1` and `255`.
 The default on most systems is `64` but can vary.
 
+#### quicsocket.statelessResetCount
+<!-- YAML
+added: REPLACEME
+-->
+
+* Type: {BigInt}
+
+A `BigInt` that represents the number of stateless resets that have been sent.
+
 #### quicsocket.unref();
 <!-- YAML
 added: REPLACEME

lib/internal/errors.js

@@ -1128,6 +1128,9 @@ E('ERR_QUICSOCKET_CLOSING',
   'Cannot call %s while a QuicSocket is closing', Error);
 E('ERR_QUICSOCKET_DESTROYED',
   'Cannot call %s after a QuicSocket has been destroyed', Error);
+E('ERR_QUICSOCKET_INVALID_STATELESS_RESET_SECRET_LENGTH',
+  'The stateResetToken must be exactly 16-bytes in length',
+  Error);
 E('ERR_QUICSOCKET_LISTENING',
   'This QuicSocket is already listening', Error);
 E('ERR_QUICSOCKET_UNBOUND',

lib/internal/quic/core.js

@@ -168,6 +168,7 @@ const {
     IDX_QUIC_SOCKET_STATS_PACKETS_SENT,
     IDX_QUIC_SOCKET_STATS_SERVER_SESSIONS,
     IDX_QUIC_SOCKET_STATS_CLIENT_SESSIONS,
+    IDX_QUIC_SOCKET_STATS_STATELESS_RESET_COUNT,
     ERR_INVALID_REMOTE_TRANSPORT_PARAMS,
     ERR_INVALID_TLS_SESSION_TICKET,
     NGTCP2_PATH_VALIDATION_RESULT_FAILURE,
@@ -809,6 +810,9 @@ class QuicSocket extends EventEmitter {
 
       // Whether qlog should be enabled for sessions
       qlog,
+
+      // Stateless reset token secret (16 byte buffer)
+      statelessResetSecret
     } = validateQuicSocketOptions(options);
     super();
     const socketOptions =
@@ -827,7 +831,8 @@ class QuicSocket extends EventEmitter {
         socketOptions,
         retryTokenTimeout,
         maxConnectionsPerHost,
-        qlog);
+        qlog,
+        statelessResetSecret);
     udpHandle.quicSocket = handle;
     handle[owner_symbol] = this;
     this[async_id_symbol] = handle.getAsyncId();
@@ -1397,6 +1402,11 @@ class QuicSocket extends EventEmitter {
     return stats[IDX_QUIC_SOCKET_STATS_CLIENT_SESSIONS];
   }
 
+  get statelessResetCount() {
+    const stats = this.#stats || this[kHandle].stats;
+    return stats[IDX_QUIC_SOCKET_STATS_STATELESS_RESET_COUNT];
+  }
+
   setDiagnosticPacketLoss(options) {
     if (this.#state === kSocketDestroyed)
       throw new ERR_QUICSOCKET_DESTROYED('setDiagnosticPacketLoss');

lib/internal/quic/util.js

@@ -6,6 +6,7 @@ const {
     ERR_INVALID_ARG_VALUE,
     ERR_OUT_OF_RANGE,
     ERR_QUICSESSION_INVALID_DCID,
+    ERR_QUICSOCKET_INVALID_STATELESS_RESET_SECRET_LENGTH,
   },
 } = require('internal/errors');
 
@@ -369,6 +370,7 @@ function validateQuicSocketOptions(options) {
     validateAddressLRU = false,
     retryTokenTimeout = DEFAULT_RETRYTOKEN_EXPIRATION,
     qlog = false,
+    statelessResetSecret,
   } = { ...options };
   validateBindOptions(port, address);
   if (typeof type !== 'string')
@@ -411,6 +413,17 @@ function validateQuicSocketOptions(options) {
     throw new ERR_INVALID_ARG_TYPE('options.qlog', 'boolean', qlog);
   }
 
+  if (statelessResetSecret !== undefined) {
+    if (!isArrayBufferView(statelessResetSecret)) {
+      throw new ERR_INVALID_ARG_TYPE(
+        'options.statelessResetSecret',
+        ['string', 'Buffer', 'TypedArray', 'DataView'],
+        statelessResetSecret);
+    }
+    if (statelessResetSecret.length !== 16)
+      throw new ERR_QUICSOCKET_INVALID_STATELESS_RESET_SECRET_LENGTH();
+  }
+
   return {
     address,
     autoClose,
@@ -426,6 +439,7 @@ function validateQuicSocketOptions(options) {
     validateAddress: validateAddress || validateAddressLRU,
     validateAddressLRU,
     qlog,
+    statelessResetSecret,
   };
 }
 

src/node_quic.cc

@@ -233,6 +233,7 @@ void Initialize(Local<Object> target,
   NODE_DEFINE_CONSTANT(constants, IDX_QUIC_SOCKET_STATS_PACKETS_SENT);
   NODE_DEFINE_CONSTANT(constants, IDX_QUIC_SOCKET_STATS_SERVER_SESSIONS);
   NODE_DEFINE_CONSTANT(constants, IDX_QUIC_SOCKET_STATS_CLIENT_SESSIONS);
+  NODE_DEFINE_CONSTANT(constants, IDX_QUIC_SOCKET_STATS_STATELESS_RESET_COUNT);
 
   NODE_DEFINE_CONSTANT(constants, IDX_HTTP3_QPACK_MAX_TABLE_CAPACITY);
   NODE_DEFINE_CONSTANT(constants, IDX_HTTP3_QPACK_BLOCKED_STREAMS);

src/node_quic_crypto.cc

@@ -125,6 +125,23 @@ bool GenerateRandData(uint8_t* buf, size_t len) {
   return true;
 }
 
+bool GenerateResetToken(
+    uint8_t* token,
+    uint8_t* secret,
+    size_t secretlen,
+    const ngtcp2_cid* cid) {
+  ngtcp2_crypto_ctx ctx;
+  ngtcp2_crypto_ctx_initial(&ctx);
+  return NGTCP2_OK(ngtcp2_crypto_hkdf_expand(
+      token,
+      NGTCP2_STATELESS_RESET_TOKENLEN,
+      &ctx.md,
+      secret,
+      secretlen,
+      cid->data,
+      cid->datalen));
+}
+
 // The Retry Token is an encrypted token that is sent to the client
 // by the server as part of the path validation flow. The plaintext
 // format within the token is opaque and only meaningful the server.

src/node_quic_crypto.h

@@ -63,6 +63,12 @@ bool UpdateKey(
     std::vector<uint8_t>* current_rx_secret,
     std::vector<uint8_t>* current_tx_secret);
 
+bool GenerateResetToken(
+    uint8_t* token,
+    uint8_t* secret,
+    size_t secretlen,
+    const ngtcp2_cid* cid);
+
 bool GenerateRetryToken(
     uint8_t* token,
     size_t* tokenlen,

src/node_quic_session.cc

@@ -678,20 +678,37 @@ void JSQuicSessionListener::OnQLog(const uint8_t* data, size_t len) {
       &str);
 }
 
-// Generates and associates a new connection ID for this QuicSession.
+// Generates a new connection ID for this QuicSession.
 // ngtcp2 will call this multiple times at the start of a new connection
 // in order to build a pool of available CIDs.
 void RandomConnectionIDStrategy::GetNewConnectionID(
     QuicSession* session,
     ngtcp2_cid* cid,
-    uint8_t* token,
     size_t cidlen) {
   cid->datalen = cidlen;
   // cidlen shouldn't ever be zero here but just in case that
   // behavior changes in ngtcp2 in the future...
   if (cidlen > 0)
     EntropySource(cid->data, cidlen);
-  EntropySource(token, NGTCP2_STATELESS_RESET_TOKENLEN);
+}
+
+// Generates a new stateless reset token randomly
+void RandomStatelessResetTokenStrategy::GetNewStatelessToken(
+    QuicSession* session,
+    ngtcp2_cid* cid,
+    uint8_t* token,
+    size_t tokenlen) {
+  EntropySource(token, tokenlen);
+}
+
+void CryptoStatelessResetTokenStrategy::GetNewStatelessToken(
+    QuicSession* session,
+    ngtcp2_cid* cid,
+    uint8_t* token,
+    size_t tokenlen) {
+  std::array<uint8_t, NGTCP2_STATELESS_RESET_TOKENLEN>* secret =
+      session->Socket()->GetSessionResetSecret();
+  CHECK(GenerateResetToken(token, secret->data(), secret->size(), cid));
 }
 
 // Check required capabilities were not excluded from the OpenSSL build:
@@ -1260,6 +1277,7 @@ QuicSession::QuicSession(
         reinterpret_cast<double*>(&recovery_stats_)) {
   PushListener(&default_listener_);
   SetConnectionIDStrategory(&default_connection_id_strategy_);
+  SetStatelessResetTokenStrategy(&default_stateless_reset_strategy_);
   crypto_context_.reset(new QuicCryptoContext(this, ctx, side, options));
   application_.reset(SelectApplication(this));
   if (rcid != nullptr)
@@ -1634,6 +1652,12 @@ void QuicSession::SetConnectionIDStrategory(ConnectionIDStrategy* strategy) {
   connection_id_strategy_ = strategy;
 }
 
+void QuicSession::SetStatelessResetTokenStrategy(
+    StatelessResetTokenStrategy* strategy) {
+  CHECK_NOT_NULL(strategy);
+  stateless_reset_strategy_ = strategy;
+}
+
 // Generates and associates a new connection ID for this QuicSession.
 // ngtcp2 will call this multiple times at the start of a new connection
 // in order to build a pool of available CIDs.
@@ -1643,7 +1667,16 @@ int QuicSession::GetNewConnectionID(
     size_t cidlen) {
   DCHECK(!IsFlagSet(QUICSESSION_FLAG_DESTROYED));
   CHECK_NOT_NULL(connection_id_strategy_);
-  connection_id_strategy_->GetNewConnectionID(this, cid, token, cidlen);
+  connection_id_strategy_->GetNewConnectionID(
+      this,
+      cid,
+      cidlen);
+  stateless_reset_strategy_->GetNewStatelessToken(
+      this,
+      cid,
+      token,
+      NGTCP2_STATELESS_RESET_TOKENLEN);
+
   AssociateCID(cid);
   return 0;
 }

src/node_quic_session.h

@@ -292,7 +292,6 @@ class ConnectionIDStrategy {
   virtual void GetNewConnectionID(
       QuicSession* session,
       ngtcp2_cid* cid,
-      uint8_t* token,
       size_t cidlen) = 0;
 };
 
@@ -301,10 +300,27 @@ class RandomConnectionIDStrategy : public ConnectionIDStrategy {
   void GetNewConnectionID(
       QuicSession* session,
       ngtcp2_cid* cid,
-      uint8_t* token,
       size_t cidlen) override;
 };
 
+class StatelessResetTokenStrategy {
+ public:
+  virtual void GetNewStatelessToken(
+      QuicSession* session,
+      ngtcp2_cid* cid,
+      uint8_t* token,
+      size_t tokenlen) = 0;
+};
+
+class CryptoStatelessResetTokenStrategy : public StatelessResetTokenStrategy {
+ public:
+  void GetNewStatelessToken(
+      QuicSession* session,
+      ngtcp2_cid* cid,
+      uint8_t* token,
+      size_t tokenlen) override;
+};
+
 // The QuicCryptoContext class encapsulates all of the crypto/TLS
 // handshake details on behalf of a QuicSession.
 class QuicCryptoContext : public MemoryRetainer {
@@ -933,6 +949,7 @@ class QuicSession : public AsyncWrap,
   void RemoveListener(QuicSessionListener* listener);
 
   void SetConnectionIDStrategory(ConnectionIDStrategy* strategy);
+  void SetStatelessResetTokenStrategy(StatelessResetTokenStrategy* strategy);
 
   // Report that the stream data is flow control blocked
   void StreamDataBlocked(int64_t stream_id);
@@ -1296,6 +1313,9 @@ class QuicSession : public AsyncWrap,
   ConnectionIDStrategy* connection_id_strategy_ = nullptr;
   RandomConnectionIDStrategy default_connection_id_strategy_;
 
+  StatelessResetTokenStrategy* stateless_reset_strategy_ = nullptr;
+  CryptoStatelessResetTokenStrategy default_stateless_reset_strategy_;
+
   QuicSessionListener* listener_ = nullptr;
   JSQuicSessionListener default_listener_;