/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef tls_agent_h_
#define tls_agent_h_

#include "prio.h"
#include "ssl.h"

#include <iostream>
#include <functional>

#include "test_io.h"

#define GTEST_HAS_RTTI 0
#include "gtest/gtest.h"

namespace nss_test {

#define LOG(msg) std::cerr << name_ << ": " << msg << std::endl

enum SessionResumptionMode {
  RESUME_NONE = 0,
  RESUME_SESSIONID = 1,
  RESUME_TICKET = 2,
  RESUME_BOTH = RESUME_SESSIONID | RESUME_TICKET
};

class TlsAgent;

typedef
  std::function<SECStatus(TlsAgent& agent, PRBool checksig, PRBool isServer)>
  AuthCertificateCallbackFunction;

typedef
  std::function<void(TlsAgent& agent)>
  HandshakeCallbackFunction;

class TlsAgent : public PollTarget {
 public:
  enum Role { CLIENT, SERVER };
  enum State { STATE_INIT, STATE_CONNECTING, STATE_CONNECTED, STATE_ERROR };

  TlsAgent(const std::string& name, Role role, Mode mode, SSLKEAType kea);
  virtual ~TlsAgent();

  bool Init() {
    pr_fd_ = DummyPrSocket::CreateFD(name_, mode_);
    if (!pr_fd_) return false;

    adapter_ = DummyPrSocket::GetAdapter(pr_fd_);
    if (!adapter_) return false;

    return true;
  }

  void SetPeer(TlsAgent* peer) { adapter_->SetPeer(peer->adapter_); }

  void SetPacketFilter(PacketFilter* filter) {
    adapter_->SetPacketFilter(filter);
  }


  void StartConnect();
  void CheckKEAType(SSLKEAType type) const;
  void CheckAuthType(SSLAuthType type) const;

  void Handshake();
  // Marks the internal state as CONNECTING in anticipation of renegotiation.
  void PrepareForRenegotiate();
  // Prepares for renegotiation, then actually triggers it.
  void StartRenegotiate();
  void DisableCiphersByKeyExchange(SSLKEAType kea);
  bool EnsureTlsSetup();

  void SetupClientAuth();
  void RequestClientAuth(bool requireAuth);
  bool GetClientAuthCredentials(CERTCertificate** cert,
                                SECKEYPrivateKey** priv) const;

  void ConfigureSessionCache(SessionResumptionMode mode);
  void SetSessionTicketsEnabled(bool en);
  void SetSessionCacheEnabled(bool en);
  void SetVersionRange(uint16_t minver, uint16_t maxver);
  void GetVersionRange(uint16_t* minver, uint16_t* maxver);
  void CheckPreliminaryInfo();
  void SetExpectedVersion(uint16_t version);
  void SetServerKeyBits(uint16_t bits);
  void SetExpectedReadError(bool err);
  void EnableFalseStart();
  void ExpectResumption();
  void SetSignatureAlgorithms(const SSLSignatureAndHashAlg* algorithms,
                              size_t count);
  void EnableAlpn(const uint8_t* val, size_t len);
  void CheckAlpn(SSLNextProtoState expected_state,
                 const std::string& expected) const;
  void EnableSrtp();
  void CheckSrtp() const;
  void CheckErrorCode(int32_t expected) const;
  // Send data on the socket, encrypting it.
  void SendData(size_t bytes, size_t blocksize = 1024);
  // Send data directly to the underlying socket, skipping the TLS layer.
  void SendDirect(const DataBuffer& buf);
  void ReadBytes();
  void ResetSentBytes(); // Hack to test drops.
  void EnableExtendedMasterSecret();
  void CheckExtendedMasterSecret(bool expected);
  void DisableRollbackDetection();
  void EnableCompression();
  void SetDowngradeCheckVersion(uint16_t version);

  Role role() const { return role_; }

  State state() const { return state_; }

  SSLKEAType kea() const { return kea_; }

  const char* state_str() const { return state_str(state()); }

  const char* state_str(State state) const { return states[state]; }

  PRFileDesc* ssl_fd() { return ssl_fd_; }
  DummyPrSocket* adapter() { return adapter_; }

  bool is_compressed() const {
    return info_.compressionMethod != ssl_compression_null;
  }
  uint16_t server_key_bits() const { return server_key_bits_; }
  uint16_t min_version() const { return vrange_.min; }
  uint16_t max_version() const { return vrange_.max; }
  uint16_t version() const {
    EXPECT_EQ(STATE_CONNECTED, state_);
    return info_.protocolVersion;
  }

  bool cipher_suite(int16_t* cipher_suite) const {
    if (state_ != STATE_CONNECTED) return false;

    *cipher_suite = info_.cipherSuite;
    return true;
  }

  std::string cipher_suite_name() const {
    if (state_ != STATE_CONNECTED) return "UNKNOWN";

    return csinfo_.cipherSuiteName;
  }

  std::vector<uint8_t> session_id() const {
    return std::vector<uint8_t>(info_.sessionID,
                                info_.sessionID + info_.sessionIDLength);
  }

  size_t received_bytes() const { return recv_ctr_; }
  int32_t error_code() const { return error_code_; }

  bool can_falsestart_hook_called() const { return can_falsestart_hook_called_; }

  void SetHandshakeCallback(HandshakeCallbackFunction handshake_callback) {
    handshake_callback_ = handshake_callback;
  }

  void SetAuthCertificateCallback(
      AuthCertificateCallbackFunction auth_certificate_callback) {
    auth_certificate_callback_ = auth_certificate_callback;
  }

 private:
  const static char* states[];

  void SetState(State state) {
    if (state_ == state) return;

    LOG("Changing state from " << state_str(state_) << " to "
                               << state_str(state));
    state_ = state;
  }

  // Dummy auth certificate hook.
  static SECStatus AuthCertificateHook(void* arg, PRFileDesc* fd,
                                       PRBool checksig, PRBool isServer) {
    TlsAgent* agent = reinterpret_cast<TlsAgent*>(arg);
    agent->CheckPreliminaryInfo();
    agent->auth_certificate_hook_called_ = true;
    if (agent->auth_certificate_callback_) {
      return agent->auth_certificate_callback_(*agent, checksig, isServer);
    }
    return SECSuccess;
  }

  // Client auth certificate hook.
  static SECStatus ClientAuthenticated(void* arg, PRFileDesc* fd,
                                       PRBool checksig, PRBool isServer) {
    TlsAgent* agent = reinterpret_cast<TlsAgent*>(arg);
    EXPECT_TRUE(agent->expect_client_auth_);
    EXPECT_TRUE(isServer);
    if (agent->auth_certificate_callback_) {
      agent->auth_certificate_callback_(*agent, checksig, isServer);
    }
    return SECSuccess;
  }

  static SECStatus GetClientAuthDataHook(void* self, PRFileDesc* fd,
                                         CERTDistNames* caNames,
                                         CERTCertificate** cert,
                                         SECKEYPrivateKey** privKey);

  static void ReadableCallback(PollTarget* self, Event event) {
    TlsAgent* agent = static_cast<TlsAgent*>(self);
    agent->ReadableCallback_int();
  }


  void ReadableCallback_int() {
    LOG("Readable");
    switch (state_) {
      case STATE_CONNECTING:
        Handshake();
        break;
      case STATE_CONNECTED:
        ReadBytes();
        break;
      default:
        break;
    }
  }

  static PRInt32 SniHook(PRFileDesc *fd, const SECItem *srvNameArr,
                         PRUint32 srvNameArrSize,
                         void *arg) {
    TlsAgent* agent = reinterpret_cast<TlsAgent*>(arg);
    agent->CheckPreliminaryInfo();
    agent->sni_hook_called_ = true;
    return SSL_SNI_CURRENT_CONFIG_IS_USED;
  }

  static SECStatus CanFalseStartCallback(PRFileDesc *fd, void *arg,
                                         PRBool *canFalseStart) {
    TlsAgent* agent = reinterpret_cast<TlsAgent*>(arg);
    agent->CheckPreliminaryInfo();
    EXPECT_TRUE(agent->falsestart_enabled_);
    EXPECT_FALSE(agent->can_falsestart_hook_called_);
    agent->can_falsestart_hook_called_ = true;
    *canFalseStart = true;
    return SECSuccess;
  }

  static void HandshakeCallback(PRFileDesc *fd, void *arg) {
    TlsAgent* agent = reinterpret_cast<TlsAgent*>(arg);
    agent->CheckPreliminaryInfo();
    agent->handshake_callback_called_ = true;
    if (agent->handshake_callback_) {
      agent->handshake_callback_(*agent);
    }
  }

  void CheckCallbacks() const;
  void Connected();

  const std::string name_;
  Mode mode_;
  SSLKEAType kea_;
  uint16_t server_key_bits_;
  PRFileDesc* pr_fd_;
  DummyPrSocket* adapter_;
  PRFileDesc* ssl_fd_;
  Role role_;
  State state_;
  bool falsestart_enabled_;
  uint16_t expected_version_;
  uint16_t expected_cipher_suite_;
  bool expect_resumption_;
  bool expect_client_auth_;
  bool can_falsestart_hook_called_;
  bool sni_hook_called_;
  bool auth_certificate_hook_called_;
  bool handshake_callback_called_;
  SSLChannelInfo info_;
  SSLCipherSuiteInfo csinfo_;
  SSLVersionRange vrange_;
  int32_t error_code_;
  size_t send_ctr_;
  size_t recv_ctr_;
  bool expected_read_error_;
  HandshakeCallbackFunction handshake_callback_;
  AuthCertificateCallbackFunction auth_certificate_callback_;
};

class TlsAgentTestBase : public ::testing::Test {
 public:
  static ::testing::internal::ParamGenerator<std::string> kTlsRolesAll;

  TlsAgentTestBase(TlsAgent::Role role,
                   Mode mode) : agent_(nullptr),
                                       fd_(nullptr),
                                       role_(role),
                                       mode_(mode),
                                       kea_(ssl_kea_rsa) {}
  ~TlsAgentTestBase() {
    delete agent_;
    if (fd_) {
      PR_Close(fd_);
    }
  }

  static inline TlsAgent::Role ToRole(const std::string& str) {
    return str == "CLIENT" ? TlsAgent::CLIENT : TlsAgent::SERVER;
  }

  static inline Mode ToMode(const std::string& str) {
    return str == "TLS" ? STREAM : DGRAM;
  }

  void Init();

 protected:
  void EnsureInit();
  void ProcessMessage(const DataBuffer& buffer,
                      TlsAgent::State expected_state,
                      int32_t error_code = 0);


  TlsAgent* agent_;
  PRFileDesc* fd_;
  TlsAgent::Role role_;
  Mode mode_;
  SSLKEAType kea_;
};

class TlsAgentTest :
      public TlsAgentTestBase,
      public ::testing::WithParamInterface
      <std::tuple<std::string,std::string>> {
 public:
  TlsAgentTest() :
      TlsAgentTestBase(ToRole(std::get<0>(GetParam())),
                       ToMode(std::get<1>(GetParam()))) {}
};

}  // namespace nss_test

#endif