// Copyright Joyent, Inc. and other Node contributors.

//

// Permission is hereby granted, free of charge, to any person obtaining a

// copy of this software and associated documentation files (the

// "Software"), to deal in the Software without restriction, including

// without limitation the rights to use, copy, modify, merge, publish,

// distribute, sublicense, and/or sell copies of the Software, and to permit

// persons to whom the Software is furnished to do so, subject to the

// following conditions:

//

// The above copyright notice and this permission notice shall be included

// in all copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN

// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,

// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE

// USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef SRC_NODE_CRYPTO_CLIENTHELLO_H_

#define SRC_NODE_CRYPTO_CLIENTHELLO_H_

#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#include <cstddef> // size_t

#include <cstdint>

namespace node {

namespace crypto {

// Parse the client hello so we can do async session resumption. OpenSSL's

// session resumption uses synchronous callbacks, see SSL_CTX_sess_set_get_cb

// and get_session_cb.

//

// TLS1.3 handshakes masquerade as TLS1.2 session resumption, and to do this,

// they always include a session_id in the ClientHello, making up a bogus value

// if necessary. The parser can't know if its a bogus id, and will cause a

// 'newSession' event to be emitted. This should do no harm, the id won't be

// found, and the handshake will continue.

class ClientHelloParser {

public:

inline ClientHelloParser();

class ClientHello {

public:

inline uint8_t session_size() const { return session_size_; }

inline const uint8_t* session_id() const { return session_id_; }

inline bool has_ticket() const { return has_ticket_; }

inline uint8_t servername_size() const { return servername_size_; }

inline const uint8_t* servername() const { return servername_; }

private:

uint8_t session_size_;

const uint8_t* session_id_;

bool has_ticket_;

uint8_t servername_size_;

const uint8_t* servername_;

friend class ClientHelloParser;

};

typedef void (*OnHelloCb)(void* arg, const ClientHello& hello);

typedef void (*OnEndCb)(void* arg);

void Parse(const uint8_t* data, size_t avail);

inline void Reset();

inline void Start(OnHelloCb onhello_cb, OnEndCb onend_cb, void* onend_arg);

inline void End();

inline bool IsPaused() const;

inline bool IsEnded() const;

private:

static const size_t kMaxTLSFrameLen = 16 * 1024 + 5;

static const size_t kMaxSSLExFrameLen = 32 * 1024;

static const uint8_t kServernameHostname = 0;

static const size_t kMinStatusRequestSize = 5;

enum ParseState {

kWaiting,

kTLSHeader,

kPaused,

kEnded

};

enum FrameType {

kChangeCipherSpec = 20,

kAlert = 21,

kHandshake = 22,

kApplicationData = 23,

kOther = 255

};

enum HandshakeType {

kClientHello = 1

};

enum ExtensionType {

kServerName = 0,

kTLSSessionTicket = 35

};

bool ParseRecordHeader(const uint8_t* data, size_t avail);

void ParseHeader(const uint8_t* data, size_t avail);

void ParseExtension(const uint16_t type,

const uint8_t* data,

size_t len);

bool ParseTLSClientHello(const uint8_t* data, size_t avail);

ParseState state_;

OnHelloCb onhello_cb_;

OnEndCb onend_cb_;

void* cb_arg_;

size_t frame_len_ = 0;

size_t body_offset_ = 0;

size_t extension_offset_ = 0;

uint8_t session_size_ = 0;

const uint8_t* session_id_ = nullptr;

uint16_t servername_size_ = 0;

const uint8_t* servername_ = nullptr;

uint16_t tls_ticket_size_ = -1;

const uint8_t* tls_ticket_ = nullptr;

};

} // namespace crypto

} // namespace node

#endif // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS

#endif // SRC_NODE_CRYPTO_CLIENTHELLO_H_