net/socket/ssl_client_socket.h

// 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_SOCKET_SSL_CLIENT_SOCKET_H_
#define NET_SOCKET_SSL_CLIENT_SOCKET_H_

#include <stdint.h>

#include <string>

#include "base/gtest_prod_util.h"
#include "base/strings/string_piece.h"
#include "net/base/completion_callback.h"
#include "net/base/load_flags.h"
#include "net/base/net_errors.h"
#include "net/socket/ssl_socket.h"
#include "net/socket/stream_socket.h"

namespace base {
class FilePath;
class SequencedTaskRunner;
}

namespace crypto {
class ECPrivateKey;
}

namespace net {

class CTPolicyEnforcer;
class CertVerifier;
class ChannelIDService;
class CTVerifier;
class SSLCertRequestInfo;
struct SSLConfig;
class SSLInfo;
class TransportSecurityState;
class X509Certificate;

// This struct groups together several fields which are used by various
// classes related to SSLClientSocket.
struct SSLClientSocketContext {
  SSLClientSocketContext() = default;
  SSLClientSocketContext(CertVerifier* cert_verifier_arg,
                         ChannelIDService* channel_id_service_arg,
                         TransportSecurityState* transport_security_state_arg,
                         CTVerifier* cert_transparency_verifier_arg,
                         CTPolicyEnforcer* ct_policy_enforcer_arg,
                         const std::string& ssl_session_cache_shard_arg)
      : cert_verifier(cert_verifier_arg),
        channel_id_service(channel_id_service_arg),
        transport_security_state(transport_security_state_arg),
        cert_transparency_verifier(cert_transparency_verifier_arg),
        ct_policy_enforcer(ct_policy_enforcer_arg),
        ssl_session_cache_shard(ssl_session_cache_shard_arg) {}

  CertVerifier* cert_verifier = nullptr;
  ChannelIDService* channel_id_service = nullptr;
  TransportSecurityState* transport_security_state = nullptr;
  CTVerifier* cert_transparency_verifier = nullptr;
  CTPolicyEnforcer* ct_policy_enforcer = nullptr;
  // ssl_session_cache_shard is an opaque string that identifies a shard of the
  // SSL session cache. SSL sockets with the same ssl_session_cache_shard may
  // resume each other's SSL sessions but we'll never sessions between shards.
  const std::string ssl_session_cache_shard;
};

// A client socket that uses SSL as the transport layer.
//
// NOTE: The SSL handshake occurs within the Connect method after a TCP
// connection is established.  If a SSL error occurs during the handshake,
// Connect will fail.
//
class NET_EXPORT SSLClientSocket : public SSLSocket {
 public:
  SSLClientSocket();

  // Next Protocol Negotiation (NPN) allows a TLS client and server to come to
  // an agreement about the application level protocol to speak over a
  // connection.
  enum NextProtoStatus {
    // WARNING: These values are serialized to disk. Don't change them.

    kNextProtoUnsupported = 0,  // The server doesn't support NPN.
    kNextProtoNegotiated = 1,   // We agreed on a protocol.
    kNextProtoNoOverlap = 2,    // No protocols in common. We requested
                                // the first protocol in our list.
  };

  // TLS extension used to negotiate protocol.
  enum SSLNegotiationExtension {
    kExtensionUnknown,
    kExtensionALPN,
    kExtensionNPN,
  };

  // Gets the SSL CertificateRequest info of the socket after Connect failed
  // with ERR_SSL_CLIENT_AUTH_CERT_NEEDED.
  virtual void GetSSLCertRequestInfo(
      SSLCertRequestInfo* cert_request_info) = 0;

  static NextProto NextProtoFromString(base::StringPiece proto_string);

  static const char* NextProtoToString(NextProto next_proto);

  static const char* NextProtoStatusToString(const NextProtoStatus status);

  // Log SSL key material to |path| on |task_runner|. Must be called before any
  // SSLClientSockets are created.
  //
  // TODO(davidben): Switch this to a parameter on the SSLClientSocketContext
  // once https://crbug.com/458365 is resolved. This will require splitting
  // SSLKeyLogger into an interface, built with OS_NACL and a non-NaCl
  // SSLKeyLoggerImpl.
  static void SetSSLKeyLogFile(
      const base::FilePath& path,
      const scoped_refptr<base::SequencedTaskRunner>& task_runner);

  // Returns true if |error| is OK or |load_flags| ignores certificate errors
  // and |error| is a certificate error.
  static bool IgnoreCertError(int error, int load_flags);

  // ClearSessionCache clears the SSL session cache, used to resume SSL
  // sessions.
  static void ClearSessionCache();

  // Returns the ChannelIDService used by this socket, or NULL if
  // channel ids are not supported.
  virtual ChannelIDService* GetChannelIDService() const = 0;

  // Signs the EKM value for Token Binding with |*key| and puts it in |*out|.
  // Returns a net error code.
  virtual Error GetSignedEKMForTokenBinding(crypto::ECPrivateKey* key,
                                            std::vector<uint8_t>* out) = 0;

  // This method is only for debugging crbug.com/548423 and will be removed when
  // that bug is closed. This returns the channel ID key that was used when
  // establishing the connection (or NULL if no channel ID was used).
  virtual crypto::ECPrivateKey* GetChannelIDKey() const = 0;

  // Returns true if the CECPQ1 (experimental post-quantum) experiment is
  // enabled.  This should be removed after the experiment is ended, around
  // 2017-18.
  static bool IsPostQuantumExperimentEnabled();

 protected:
  void set_signed_cert_timestamps_received(
      bool signed_cert_timestamps_received) {
    signed_cert_timestamps_received_ = signed_cert_timestamps_received;
  }

  void set_stapled_ocsp_response_received(bool stapled_ocsp_response_received) {
    stapled_ocsp_response_received_ = stapled_ocsp_response_received;
  }

  // Serialize |next_protos| in the wire format for ALPN and NPN: protocols are
  // listed in order, each prefixed by a one-byte length.
  static std::vector<uint8_t> SerializeNextProtos(
      const NextProtoVector& next_protos);

 private:
  FRIEND_TEST_ALL_PREFIXES(SSLClientSocket, SerializeNextProtos);
  // For signed_cert_timestamps_received_ and stapled_ocsp_response_received_.
  FRIEND_TEST_ALL_PREFIXES(SSLClientSocketTest,
                           ConnectSignedCertTimestampsEnabledTLSExtension);
  FRIEND_TEST_ALL_PREFIXES(SSLClientSocketTest,
                           ConnectSignedCertTimestampsEnabledOCSP);
  FRIEND_TEST_ALL_PREFIXES(SSLClientSocketTest,
                           ConnectSignedCertTimestampsDisabled);
  FRIEND_TEST_ALL_PREFIXES(SSLClientSocketTest,
                           VerifyServerChainProperlyOrdered);

  // True if SCTs were received via a TLS extension.
  bool signed_cert_timestamps_received_;
  // True if a stapled OCSP response was received.
  bool stapled_ocsp_response_received_;
};

}  // namespace net

#endif  // NET_SOCKET_SSL_CLIENT_SOCKET_H_