Class: TTTLS13::Client

Inherits:
Object
  • Object
show all
Includes:
Logging
Defined in:
lib/tttls1.3/client.rb

Overview

rubocop: disable Metrics/ClassLength

Constant Summary collapse

HpkeSymmetricCipherSuit = 
ECHConfig::ECHConfigContents::HpkeKeyConfig::HpkeSymmetricCipherSuite

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Logging

#logger, logger

Constructor Details

#initialize(socket, hostname, **settings) ⇒ Client

Returns a new instance of Client.

Parameters:

  • socket (Socket)
  • hostname (String)
  • settings (Hash)

Raises:



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# File 'lib/tttls1.3/client.rb', line 101

def initialize(socket, hostname, **settings)
  @connection = Connection.new(socket, :client)
  @hostname = hostname
  @settings = DEFAULT_CLIENT_SETTINGS.merge(settings)
  logger.level = @settings[:loglevel]

  @early_data = ''
  @succeed_early_data = false
  @retry_configs = []
  @rejected_ech = false
  raise Error::ConfigError unless valid_settings?
end

Instance Attribute Details

#transcript ⇒ Object (readonly)

Returns the value of attribute transcript.



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# File 'lib/tttls1.3/client.rb', line 96

def transcript
  @transcript
end

Class Method Details

.softfail_check_certificate_status(res, cert, chain) ⇒ Boolean

Examples:

m = Client.method(:softfail_check_certificate_status)
Client.new(
  socket,
  hostname,
  check_certificate_status: true,
  process_certificate_status: m
)

Parameters:

  • res (OpenSSL::OCSP::Response)
  • cert (OpenSSL::X509::Certificate)
  • chain (Array of OpenSSL::X509::Certificate, nil)

Returns:

  • (Boolean) 


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# File 'lib/tttls1.3/client.rb', line 621

def self.softfail_check_certificate_status(res, cert, chain)
  ocsp_response = res
  cid = OpenSSL::OCSP::CertificateId.new(cert, chain.first)

  # When NOT received OCSPResponse in TLS handshake, this method will
  # send OCSPRequest. If ocsp_uri is NOT presented in Certificate, return
  # true. Also, if it sends OCSPRequest and does NOT receive a HTTPresponse
  # within 2 seconds, return true.
  if ocsp_response.nil?
    uri = cert.ocsp_uris&.find { |u| URI::DEFAULT_PARSER.make_regexp =~ u }
    return true if uri.nil?

    begin
      # send OCSP::Request
      ocsp_request = gen_ocsp_request(cid)
      Timeout.timeout(2) do
        ocsp_response = send_ocsp_request(ocsp_request, uri)
      end

      # check nonce of OCSP::Response
      check_nonce = ocsp_request.check_nonce(ocsp_response.basic)
      return true unless [-1, 1].include?(check_nonce)
    rescue StandardError
      return true
    end
  end
  return true \
    if ocsp_response.status != OpenSSL::OCSP::RESPONSE_STATUS_SUCCESSFUL

  status = ocsp_response.basic.status.find { |s| s.first.cmp(cid) }
  status[1] != OpenSSL::OCSP::V_CERTSTATUS_REVOKED
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/tttls1.3/client.rb', line 545

def close
  @connection.close
end

#connect ⇒ Object

START <—-+

          Send ClientHello |        | Recv HelloRetryRequest
     [K_send = early data] |        |
                           v        |
      /                 WAIT_SH ----+
      |                    | Recv ServerHello
      |                    | K_recv = handshake
  Can |                    V
 send |                 WAIT_EE
early |                    | Recv EncryptedExtensions
 data |           +--------+--------+
      |     Using |                 | Using certificate
      |       PSK |                 v
      |           |            WAIT_CERT_CR
      |           |        Recv |       | Recv CertificateRequest
      |           | Certificate |       v
      |           |             |    WAIT_CERT
      |           |             |       | Recv Certificate
      |           |             v       v
      |           |              WAIT_CV
      |           |                 | Recv CertificateVerify
      |           +> WAIT_FINISHED <+
      |                  | Recv Finished
      \                  | [Send EndOfEarlyData]
                         | K_send = handshake
                         | [Send Certificate [+ CertificateVerify]]

Can send | Send Finished app data –> | K_send = K_recv = application after here v

CONNECTED

datatracker.ietf.org/doc/html/rfc8446#appendix-A.1

rubocop: disable Metrics/AbcSize rubocop: disable Metrics/BlockLength rubocop: disable Metrics/CyclomaticComplexity rubocop: disable Metrics/MethodLength rubocop: disable Metrics/PerceivedComplexity



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# File 'lib/tttls1.3/client.rb', line 152

def connect
  @transcript = Transcript.new
  key_schedule = nil # TTTLS13::KeySchedule
  psk = nil
  if use_psk?
    psk = gen_psk_from_nst(
      @settings[:resumption_secret],
      @settings[:ticket_nonce],
      CipherSuite.digest(@settings[:psk_cipher_suite])
    )
    key_schedule = KeySchedule.new(
      psk:,
      shared_secret: nil,
      cipher_suite: @settings[:psk_cipher_suite],
      transcript: @transcript
    )
  end

  shared_secret = nil # TTTLS13::SharedSecret
  hs_wcipher = nil # TTTLS13::Cryptograph::$Object
  hs_rcipher = nil # TTTLS13::Cryptograph::$Object
  e_wcipher = nil # TTTLS13::Cryptograph::$Object
  sslkeylogfile = nil # TTTLS13::SslKeyLogFile::Writer
  ch1_outer = nil # TTTLS13::Message::ClientHello for rejected ECH
  ch_outer = nil # TTTLS13::Message::ClientHello for rejected ECH
  ech_state = nil # TTTLS13::EchState for ECH with HRR
  unless @settings[:sslkeylogfile].nil?
    begin
      sslkeylogfile = SslKeyLogFile::Writer.new(@settings[:sslkeylogfile])
    rescue SystemCallError => e
      msg = "\"#{@settings[:sslkeylogfile]}\" file can NOT open: #{e}"
      logger.warn(msg)
    end
  end

  @connection.state = ClientState::START
  loop do
    case @connection.state
    when ClientState::START
      logger.debug('ClientState::START')

      extensions, shared_secret = gen_ch_extensions
      binder_key = (use_psk? ? key_schedule.binder_key_res : nil)
      ch, inner, ech_state, ech_secret = send_client_hello(extensions, binder_key)
      unless ech_secret.nil?
        sslkeylogfile&.write_ech_secret(ch.random, ech_secret)
        sslkeylogfile&.write_ech_config(ch.random, @settings[:ech_config].encode)
      end

      ch_outer = ch
      # use ClientHelloInner messages for the transcript hash
      ch = inner.nil? ? ch : inner
      @transcript[CH] = [ch, ch.serialize]
      @connection.send_ccs if @settings[:compatibility_mode]
      if use_early_data?
        e_wcipher = Endpoint.gen_cipher(
          @settings[:psk_cipher_suite],
          key_schedule.early_data_write_key,
          key_schedule.early_data_write_iv
        )
        sslkeylogfile&.write_client_early_traffic_secret(
          @transcript[CH].first.random,
          key_schedule.client_early_traffic_secret
        )
        send_early_data(e_wcipher)
      end

      @connection.state = ClientState::WAIT_SH
    when ClientState::WAIT_SH
      logger.debug('ClientState::WAIT_SH')

      sh, = @transcript[SH] = recv_server_hello

      # downgrade protection
      if !sh.negotiated_tls_1_3? && sh.downgraded?
        @connection.terminate(:illegal_parameter)
      # support only TLS 1.3
      elsif !sh.negotiated_tls_1_3?
        @connection.terminate(:protocol_version)
      end

      # validate parameters
      @connection.terminate(:illegal_parameter) \
        unless sh.appearable_extensions?
      @connection.terminate(:illegal_parameter) \
        unless sh.legacy_compression_method == "\x00"

      # validate sh using ch
      ch, = @transcript[CH]
      @connection.terminate(:illegal_parameter) \
        unless sh.legacy_version == ch.legacy_version
      @connection.terminate(:illegal_parameter) \
        unless sh.legacy_session_id_echo == ch.legacy_session_id
      @connection.terminate(:illegal_parameter) \
        unless ch.cipher_suites.include?(sh.cipher_suite)
      @connection.terminate(:unsupported_extension) \
        unless (sh.extensions.keys - ch.extensions.keys).empty?

      # validate sh using hrr
      if @transcript.include?(HRR)
        hrr, = @transcript[HRR]
        @connection.terminate(:illegal_parameter) \
          unless sh.cipher_suite == hrr.cipher_suite

        sh_sv = sh.extensions[Message::ExtensionType::SUPPORTED_VERSIONS]
        hrr_sv = hrr.extensions[Message::ExtensionType::SUPPORTED_VERSIONS]
        @connection.terminate(:illegal_parameter) \
          unless sh_sv.versions == hrr_sv.versions
      end

      # handling HRR
      if sh.hrr?
        @connection.terminate(:unexpected_message) \
          if @transcript.include?(HRR)

        ch1, = @transcript[CH1] = @transcript.delete(CH)
        hrr, = @transcript[HRR] = @transcript.delete(SH)
        ch1_outer = ch_outer
        ch_outer = nil

        # validate cookie
        diff_sets = sh.extensions.keys - ch1.extensions.keys
        @connection.terminate(:unsupported_extension) \
          unless (diff_sets - [Message::ExtensionType::COOKIE]).empty?

        # validate key_share
        # TODO: validate pre_shared_key
        ngl = ch1.extensions[Message::ExtensionType::SUPPORTED_GROUPS]
                 .named_group_list
        kse = ch1.extensions[Message::ExtensionType::KEY_SHARE]
                 .key_share_entry
        group = hrr.extensions[Message::ExtensionType::KEY_SHARE]
                   .key_share_entry.first.group
        @connection.terminate(:illegal_parameter) \
          unless ngl.include?(group) && !kse.map(&:group).include?(group)

        # send new client_hello
        extensions, shared_secret = gen_newch_extensions(ch1, hrr)
        binder_key = (use_psk? ? key_schedule.binder_key_res : nil)
        ch, inner = send_new_client_hello(
          ch1,
          hrr,
          extensions,
          binder_key,
          ech_state
        )
        # use ClientHelloInner messages for the transcript hash
        ch_outer = ch
        ch = inner.nil? ? ch : inner
        @transcript[CH] = [ch, ch.serialize]

        @connection.state = ClientState::WAIT_SH
        next
      end

      # generate shared secret
      if sh.extensions.include?(Message::ExtensionType::PRE_SHARED_KEY)
      # TODO: validate pre_shared_key
      else
        psk = nil
      end
      ch_ks = ch.extensions[Message::ExtensionType::KEY_SHARE]
                .key_share_entry.map(&:group)
      sh_ks = sh.extensions[Message::ExtensionType::KEY_SHARE]
                .key_share_entry.first.group
      @connection.terminate(:illegal_parameter) unless ch_ks.include?(sh_ks)

      kse = sh.extensions[Message::ExtensionType::KEY_SHARE]
              .key_share_entry
              .first
      ke = kse.key_exchange
      @named_group = kse.group
      @cipher_suite = sh.cipher_suite
      key_schedule = KeySchedule.new(
        psk:,
        shared_secret: shared_secret.build(@named_group, ke),
        cipher_suite: @cipher_suite,
        transcript: @transcript
      )

      # rejected ECH
      # It can compute (hrr_)accept_ech until client selects the
      # cipher_suite.
      if !sh.hrr? && use_ech?
        if !@transcript.include?(HRR) && !key_schedule.accept_ech?
          # 1sh SH
          @transcript[CH] = [ch_outer, ch_outer.serialize]
          @rejected_ech = true
        elsif @transcript.include?(HRR) &&
              key_schedule.hrr_accept_ech? != key_schedule.accept_ech?
          # 2nd SH
          @connection.terminate(:illegal_parameter)
        elsif @transcript.include?(HRR) && !key_schedule.hrr_accept_ech?
          # 2nd SH
          @transcript[CH1] = [ch1_outer, ch1_outer.serialize]
          @transcript[CH] = [ch_outer, ch_outer.serialize]
          @rejected_ech = true
        end
      end

      @connection.alert_wcipher = hs_wcipher = Endpoint.gen_cipher(
        @cipher_suite,
        key_schedule.client_handshake_write_key,
        key_schedule.client_handshake_write_iv
      )
      sslkeylogfile&.write_client_handshake_traffic_secret(
        @transcript[CH].first.random,
        key_schedule.client_handshake_traffic_secret
      )
      hs_rcipher = Endpoint.gen_cipher(
        @cipher_suite,
        key_schedule.server_handshake_write_key,
        key_schedule.server_handshake_write_iv
      )
      sslkeylogfile&.write_server_handshake_traffic_secret(
        @transcript[CH].first.random,
        key_schedule.server_handshake_traffic_secret
      )
      @connection.state = ClientState::WAIT_EE
    when ClientState::WAIT_EE
      logger.debug('ClientState::WAIT_EE')

      ee, = @transcript[EE] = recv_encrypted_extensions(hs_rcipher)
      @connection.terminate(:illegal_parameter) \
        unless ee.appearable_extensions?

      ch, = @transcript[CH]
      @connection.terminate(:unsupported_extension) \
        unless (ee.extensions.keys - ch.extensions.keys).empty?

      rsl = ee.extensions[Message::ExtensionType::RECORD_SIZE_LIMIT]
      @recv_record_size = rsl.record_size_limit unless rsl.nil?
      @succeed_early_data = true \
        if ee.extensions.include?(Message::ExtensionType::EARLY_DATA)
      @alpn = ee.extensions[
        Message::ExtensionType::APPLICATION_LAYER_PROTOCOL_NEGOTIATION
      ]&.protocol_name_list&.first
      @retry_configs = ee.extensions[
        Message::ExtensionType::ENCRYPTED_CLIENT_HELLO
      ]&.retry_configs
      @connection.terminate(:unsupported_extension) \
        if !rejected_ech? && !@retry_configs.nil?

      @connection.state = ClientState::WAIT_CERT_CR
      @connection.state = ClientState::WAIT_FINISHED unless psk.nil?
    when ClientState::WAIT_CERT_CR
      logger.debug('ClientState::WAIT_CERT_CR')

      message, orig_msg = @connection.recv_message(
        receivable_ccs: true,
        cipher: hs_rcipher
      )
      case message.msg_type
      when Message::HandshakeType::CERTIFICATE,
           Message::HandshakeType::COMPRESSED_CERTIFICATE
        ct, = @transcript[CT] = [message, orig_msg]
        @connection.terminate(:bad_certificate) \
          if ct.is_a?(Message::CompressedCertificate) &&
             !@settings[:compress_certificate_algorithms]
             .include?(ct.algorithm)

        ct = ct.certificate_message \
          if ct.is_a?(Message::CompressedCertificate)
        alert = check_invalid_certificate(ct, @transcript[CH].first)
        @connection.terminate(alert) unless alert.nil?

        @connection.state = ClientState::WAIT_CV
      when Message::HandshakeType::CERTIFICATE_REQUEST
        @transcript[CR] = [message, orig_msg]
        # TODO: client authentication
        @connection.state = ClientState::WAIT_CERT
      else
        @connection.terminate(:unexpected_message)
      end
    when ClientState::WAIT_CERT
      logger.debug('ClientState::WAIT_CERT')

      ct, = @transcript[CT] = recv_certificate(hs_rcipher)
      if ct.is_a?(Message::CompressedCertificate) &&
         !@settings[:compress_certificate_algorithms].include?(ct.algorithm)
        @connection.terminate(:bad_certificate)
      elsif ct.is_a?(Message::CompressedCertificate)
        ct = ct.certificate_message
      end

      alert = check_invalid_certificate(ct, @transcript[CH].first)
      @connection.terminate(alert) unless alert.nil?

      @connection.state = ClientState::WAIT_CV
    when ClientState::WAIT_CV
      logger.debug('ClientState::WAIT_CV')

      cv, = @transcript[CV] = recv_certificate_verify(hs_rcipher)
      digest = CipherSuite.digest(@cipher_suite)
      hash = @transcript.hash(digest, CT)
      ct, = @transcript[CT]
      ct = ct.certificate_message \
        if ct.is_a?(Message::CompressedCertificate)
      @connection.terminate(:decrypt_error) \
        unless verified_certificate_verify?(ct, cv, hash)

      @signature_scheme = cv.signature_scheme
      @connection.state = ClientState::WAIT_FINISHED
    when ClientState::WAIT_FINISHED
      logger.debug('ClientState::WAIT_FINISHED')

      sf, = @transcript[SF] = recv_finished(hs_rcipher)
      digest = CipherSuite.digest(@cipher_suite)
      @connection.terminate(:decrypt_error) \
        unless Endpoint.verified_finished?(
          finished: sf,
          digest:,
          finished_key: key_schedule.server_finished_key,
          hash: @transcript.hash(digest, CV)
        )

      if use_early_data? && succeed_early_data?
        eoed = send_eoed(e_wcipher)
        @transcript[EOED] = [eoed, eoed.serialize]
      end
      # TODO: Send Certificate [+ CertificateVerify]
      signature = Endpoint.sign_finished(
        digest:,
        finished_key: key_schedule.client_finished_key,
        hash: @transcript.hash(digest, EOED)
      )
      cf = send_finished(signature, hs_wcipher)
      @transcript[CF] = [cf, cf.serialize]
      @connection.ap_wcipher = Endpoint.gen_cipher(
        @cipher_suite,
        key_schedule.client_application_write_key,
        key_schedule.client_application_write_iv
      )
      @connection.alert_wcipher = @connection.ap_wcipher
      sslkeylogfile&.write_client_traffic_secret_0(
        @transcript[CH].first.random,
        key_schedule.client_application_traffic_secret
      )
      @connection.ap_rcipher = Endpoint.gen_cipher(
        @cipher_suite,
        key_schedule.server_application_write_key,
        key_schedule.server_application_write_iv
      )
      sslkeylogfile&.write_server_traffic_secret_0(
        @transcript[CH].first.random,
        key_schedule.server_application_traffic_secret
      )
      @exporter_secret = key_schedule.exporter_secret
      @resumption_secret = key_schedule.resumption_secret
      @connection.state = ClientState::CONNECTED
    when ClientState::CONNECTED
      logger.debug('ClientState::CONNECTED')

      @connection.send_alert(:ech_required) \
        if use_ech? && (!@retry_configs.nil? && !@retry_configs.empty?)
      break
    end
  end
  sslkeylogfile&.close
end

#early_data(binary) ⇒ Object

Parameters:

  • binary (String)

Raises:



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# File 'lib/tttls1.3/client.rb', line 584

def early_data(binary)
  raise Error::ConfigError unless @connection.state == INITIAL && use_psk?

  @early_data = binary
end

#eof? ⇒ Boolean

return [Boolean]

Returns:

  • (Boolean) 


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# File 'lib/tttls1.3/client.rb', line 541

def eof?
  @connection.eof?
end

#exporter(label, context, key_length) ⇒ String?

Parameters:

  • label (String)
  • context (String)
  • key_length (Integer)

Returns:

  • (String, nil) 


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# File 'lib/tttls1.3/client.rb', line 574

def exporter(label, context, key_length)
  return nil if @exporter_secret.nil? || @cipher_suite.nil?

  digest = CipherSuite.digest(@cipher_suite)
  Endpoint.exporter(@exporter_secret, digest, label, context, key_length)
end

#negotiated_alpn ⇒ String

Returns:

  • (String) 


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# File 'lib/tttls1.3/client.rb', line 565

def negotiated_alpn
  @alpn
end

#negotiated_cipher_suite ⇒ TTTLS13::CipherSuite?

Returns:



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# File 'lib/tttls1.3/client.rb', line 550

def negotiated_cipher_suite
  @cipher_suite
end

#negotiated_named_group ⇒ TTTLS13::NamedGroup?

Returns:



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# File 'lib/tttls1.3/client.rb', line 555

def negotiated_named_group
  @named_group
end

#negotiated_signature_scheme ⇒ TTTLS13::SignatureScheme?

Returns:



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# File 'lib/tttls1.3/client.rb', line 560

def negotiated_signature_scheme
  @signature_scheme
end

#read ⇒ String

Returns:

  • (String)

Raises:



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# File 'lib/tttls1.3/client.rb', line 521

def read
  nst_process = method(:process_new_session_ticket)
  @connection.read(nst_process)
end

#rejected_ech? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tttls1.3/client.rb', line 603

def rejected_ech?
  @rejected_ech
end

#retry_configs ⇒ Array of ECHConfig

Returns:

  • (Array of ECHConfig) 


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# File 'lib/tttls1.3/client.rb', line 591

def retry_configs
  @retry_configs.filter do |c|
    SUPPORTED_ECHCONFIG_VERSIONS.include?(c.version)
  end
end

#succeed_early_data? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tttls1.3/client.rb', line 598

def succeed_early_data?
  @succeed_early_data
end

#write(binary) ⇒ Object

Parameters:

  • binary (String) 


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# File 'lib/tttls1.3/client.rb', line 527

def write(binary)
  # the client can regard ECH as securely disabled by the server, and it
  # SHOULD retry the handshake with a new transport connection and ECH
  # disabled.
  if !@retry_configs.nil? && !@retry_configs.empty?
    msg = 'SHOULD retry the handshake with a new transport connection'
    logger.warn(msg)
    return
  end

  @connection.write(binary)
end