text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef NET_QUIC_QUIC_CRYPTO_SERVER_STREAM_H_
  #define NET_QUIC_QUIC_CRYPTO_SERVER_STREAM_H_
  
  #include <stdint.h>
  
  #include <string>
  
  #include "base/macros.h"
  #include "net/quic/crypto/crypto_handshake.h"
  #include "net/quic/crypto/quic_compressed_certs_cache.h"
  #include "net/quic/crypto/quic_crypto_server_config.h"
  #include "net/quic/proto/source_address_token.pb.h"
  #include "net/quic/quic_config.h"
  #include "net/quic/quic_crypto_stream.h"
  
  namespace net {
  
  class CachedNetworkParameters;
  class CryptoHandshakeMessage;
  class QuicCryptoServerConfig;
  class QuicCryptoServerStreamBase;
  class QuicSession;
  
  namespace test {
  class CryptoTestUtils;
  class QuicCryptoServerStreamPeer;
  }  // namespace test
  
  // Receives a notification when the server hello (SHLO) has been ACKed by the
  // peer. At this point we disable HANDSHAKE_MODE in the sent packet manager.
  class NET_EXPORT_PRIVATE ServerHelloNotifier : public QuicAckListenerInterface {
   public:
    explicit ServerHelloNotifier(QuicCryptoServerStreamBase* stream)
        : server_stream_(stream) {}
  
    void OnPacketAcked(int acked_bytes, QuicTime::Delta ack_delay_time) override;
  
    void OnPacketRetransmitted(int retransmitted_bytes) override;
  
   private:
    ~ServerHelloNotifier() override {}
  
    QuicCryptoServerStreamBase* server_stream_;
  
    DISALLOW_COPY_AND_ASSIGN(ServerHelloNotifier);
  };
  
  // TODO(alyssar) see what can be moved out of QuicCryptoServerStream with
  // various code and test refactoring.
  class NET_EXPORT_PRIVATE QuicCryptoServerStreamBase : public QuicCryptoStream {
   public:
    explicit QuicCryptoServerStreamBase(QuicSession* session)
        : QuicCryptoStream(session) {}
    ~QuicCryptoServerStreamBase() override {}
  
    // Cancel any outstanding callbacks, such as asynchronous validation of client
    // hello.
    virtual void CancelOutstandingCallbacks() = 0;
  
    // GetBase64SHA256ClientChannelID sets |*output| to the base64 encoded,
    // SHA-256 hash of the client's ChannelID key and returns true, if the client
    // presented a ChannelID. Otherwise it returns false.
    virtual bool GetBase64SHA256ClientChannelID(std::string* output) const = 0;
  
    virtual int NumServerConfigUpdateMessagesSent() const = 0;
  
    // Sends the latest server config and source-address token to the client.
    virtual void SendServerConfigUpdate(
        const CachedNetworkParameters* cached_network_params) = 0;
  
    // Called by the ServerHello AckNotifier once the SHLO has been ACKed by the
    // client.
    virtual void OnServerHelloAcked() = 0;
  
    // These are all accessors and setters to their respective counters.
    virtual uint8_t NumHandshakeMessages() const = 0;
    virtual uint8_t NumHandshakeMessagesWithServerNonces() const = 0;
    virtual bool UseStatelessRejectsIfPeerSupported() const = 0;
    virtual bool PeerSupportsStatelessRejects() const = 0;
    virtual void SetPeerSupportsStatelessRejects(bool set) = 0;
    virtual const CachedNetworkParameters* PreviousCachedNetworkParams()
        const = 0;
    virtual void SetPreviousCachedNetworkParams(
        CachedNetworkParameters cached_network_params) = 0;
  };
  
  class NET_EXPORT_PRIVATE QuicCryptoServerStream
      : public QuicCryptoServerStreamBase {
   public:
    // |crypto_config| must outlive the stream.
    QuicCryptoServerStream(const QuicCryptoServerConfig* crypto_config,
                           QuicCompressedCertsCache* compressed_certs_cache,
                           bool use_stateless_rejects_if_peer_supported,
                           QuicSession* session);
    ~QuicCryptoServerStream() override;
  
    // From QuicCryptoServerStreamBase
    void CancelOutstandingCallbacks() override;
    void OnHandshakeMessage(const CryptoHandshakeMessage& message) override;
    bool GetBase64SHA256ClientChannelID(std::string* output) const override;
    void SendServerConfigUpdate(
        const CachedNetworkParameters* cached_network_params) override;
    void OnServerHelloAcked() override;
    uint8_t NumHandshakeMessages() const override;
    uint8_t NumHandshakeMessagesWithServerNonces() const override;
    int NumServerConfigUpdateMessagesSent() const override;
    const CachedNetworkParameters* PreviousCachedNetworkParams() const override;
    bool UseStatelessRejectsIfPeerSupported() const override;
    bool PeerSupportsStatelessRejects() const override;
    void SetPeerSupportsStatelessRejects(
        bool peer_supports_stateless_rejects) override;
    void SetPreviousCachedNetworkParams(
        CachedNetworkParameters cached_network_params) override;
  
   protected:
    virtual QuicErrorCode ProcessClientHello(
        const CryptoHandshakeMessage& message,
        const ValidateClientHelloResultCallback::Result& result,
        CryptoHandshakeMessage* reply,
        std::string* error_details);
  
    // Hook that allows the server to set QuicConfig defaults just
    // before going through the parameter negotiation step.
    virtual void OverrideQuicConfigDefaults(QuicConfig* config);
  
    // Given the current connection_id, generates a new ConnectionId to
    // be returned with a stateless reject.
    virtual QuicConnectionId GenerateConnectionIdForReject(
        QuicConnectionId connection_id);
  
   private:
    friend class test::CryptoTestUtils;
    friend class test::QuicCryptoServerStreamPeer;
  
    class ValidateCallback : public ValidateClientHelloResultCallback {
     public:
      explicit ValidateCallback(QuicCryptoServerStream* parent);
      // To allow the parent to detach itself from the callback before deletion.
      void Cancel();
  
      // From ValidateClientHelloResultCallback
      void RunImpl(const CryptoHandshakeMessage& client_hello,
                   const Result& result) override;
  
     private:
      QuicCryptoServerStream* parent_;
  
      DISALLOW_COPY_AND_ASSIGN(ValidateCallback);
    };
  
    // Invoked by ValidateCallback::RunImpl once initial validation of
    // the client hello is complete.  Finishes processing of the client
    // hello message and handles handshake success/failure.
    void FinishProcessingHandshakeMessage(
        const CryptoHandshakeMessage& message,
        const ValidateClientHelloResultCallback::Result& result);
  
    // Checks the options on the handshake-message to see whether the
    // peer supports stateless-rejects.
    static bool DoesPeerSupportStatelessRejects(
        const CryptoHandshakeMessage& message);
  
    // crypto_config_ contains crypto parameters for the handshake.
    const QuicCryptoServerConfig* crypto_config_;
  
    // compressed_certs_cache_ contains a set of most recently compressed certs.
    // Owned by QuicDispatcher.
    QuicCompressedCertsCache* compressed_certs_cache_;
  
    // Server's certificate chain and signature of the server config, as provided
    // by ProofSource::GetProof.
    QuicCryptoProof crypto_proof_;
  
    // Pointer to the active callback that will receive the result of
    // the client hello validation request and forward it to
    // FinishProcessingHandshakeMessage for processing.  nullptr if no
    // handshake message is being validated.
    ValidateCallback* validate_client_hello_cb_;
  
    // Number of handshake messages received by this stream.
    uint8_t num_handshake_messages_;
  
    // Number of handshake messages received by this stream that contain
    // server nonces (indicating that this is a non-zero-RTT handshake
    // attempt).
    uint8_t num_handshake_messages_with_server_nonces_;
  
    // Number of server config update (SCUP) messages sent by this stream.
    int num_server_config_update_messages_sent_;
  
    // If the client provides CachedNetworkParameters in the STK in the CHLO, then
    // store here, and send back in future STKs if we have no better bandwidth
    // estimate to send.
    scoped_ptr<CachedNetworkParameters> previous_cached_network_params_;
  
    // Contains any source address tokens which were present in the CHLO.
    SourceAddressTokens previous_source_address_tokens_;
  
    // If true, the server should use stateless rejects, so long as the
    // client supports them, as indicated by
    // peer_supports_stateless_rejects_.
    bool use_stateless_rejects_if_peer_supported_;
  
    // Set to true, once the server has received information from the
    // client that it supports stateless reject.
    //  TODO(jokulik): Remove once client stateless reject support
    // becomes the default.
    bool peer_supports_stateless_rejects_;
  
    DISALLOW_COPY_AND_ASSIGN(QuicCryptoServerStream);
  };
  
  }  // namespace net
  
  #endif  // NET_QUIC_QUIC_CRYPTO_SERVER_STREAM_H_
  