Class: TTTLS13::Message::ServerHello

Inherits:
Object
  • Object
show all
Defined in:
lib/tttls1.3/message/server_hello.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(legacy_version: ProtocolVersion::TLS_1_2, random: OpenSSL::Random.random_bytes(32), legacy_session_id_echo:, cipher_suite:, legacy_compression_method: "\x00", extensions: Extensions.new) ⇒ ServerHello

rubocop: disable Metrics/ParameterLists

Parameters:

  • legacy_version (String) (defaults to: ProtocolVersion::TLS_1_2)
  • random (String) (defaults to: OpenSSL::Random.random_bytes(32))
  • legacy_session_id_echo (String)
  • cipher_suite (TTTLS13::CipherSuite)
  • legacy_compression_method (String) (defaults to: "\x00")
  • extensions (TTTLS13::Message::Extensions) (defaults to: Extensions.new) 


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# File 'lib/tttls1.3/message/server_hello.rb', line 51

def initialize(legacy_version: ProtocolVersion::TLS_1_2,
               random: OpenSSL::Random.random_bytes(32),
               legacy_session_id_echo:,
               cipher_suite:,
               legacy_compression_method: "\x00",
               extensions: Extensions.new)
  @msg_type = HandshakeType::SERVER_HELLO
  @legacy_version = legacy_version
  @random = random
  @legacy_session_id_echo = legacy_session_id_echo
  @cipher_suite = cipher_suite
  @legacy_compression_method = legacy_compression_method
  @extensions = extensions
  @hrr = (random == HRR_RANDOM)
end

Instance Attribute Details

#cipher_suite ⇒ Object (readonly)

Returns the value of attribute cipher_suite.



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# File 'lib/tttls1.3/message/server_hello.rb', line 40

def cipher_suite
  @cipher_suite
end

#extensions ⇒ Object (readonly)

Returns the value of attribute extensions.



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# File 'lib/tttls1.3/message/server_hello.rb', line 42

def extensions
  @extensions
end

#legacy_compression_method ⇒ Object (readonly)

Returns the value of attribute legacy_compression_method.



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# File 'lib/tttls1.3/message/server_hello.rb', line 41

def legacy_compression_method
  @legacy_compression_method
end

#legacy_session_id_echo ⇒ Object (readonly)

Returns the value of attribute legacy_session_id_echo.



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# File 'lib/tttls1.3/message/server_hello.rb', line 39

def legacy_session_id_echo
  @legacy_session_id_echo
end

#legacy_version ⇒ Object (readonly)

Returns the value of attribute legacy_version.



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# File 'lib/tttls1.3/message/server_hello.rb', line 37

def legacy_version
  @legacy_version
end

#msg_type ⇒ Object (readonly)

Returns the value of attribute msg_type.



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# File 'lib/tttls1.3/message/server_hello.rb', line 36

def msg_type
  @msg_type
end

#random ⇒ Object (readonly)

Returns the value of attribute random.



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# File 'lib/tttls1.3/message/server_hello.rb', line 38

def random
  @random
end

Class Method Details

.deserialize(binary) ⇒ TTTLS13::Message::ServerHello

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

Parameters:

  • binary (String)

Returns:

Raises:



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# File 'lib/tttls1.3/message/server_hello.rb', line 90

def self.deserialize(binary)
  raise Error::ErrorAlerts, :internal_error if binary.nil?
  raise Error::ErrorAlerts, :decode_error if binary.length < 39
  raise Error::ErrorAlerts, :internal_error \
    unless binary[0] == HandshakeType::SERVER_HELLO

  msg_len = Convert.bin2i(binary.slice(1, 3))
  legacy_version = binary.slice(4, 2)
  random = binary.slice(6, 32)
  lsid_len = Convert.bin2i(binary[38])
  legacy_session_id_echo = binary.slice(39, lsid_len)
  i = 39 + lsid_len
  cipher_suite = binary.slice(i, 2)
  i += 2
  legacy_compression_method = binary[i]
  i += 1
  exs_len = Convert.bin2i(binary.slice(i, 2))
  i += 2
  exs_bin = binary.slice(i, exs_len)
  if random == HRR_RANDOM
    msg_type = HandshakeType::HELLO_RETRY_REQUEST
    @hrr = true
  else
    msg_type = HandshakeType::SERVER_HELLO
    @hrr = false
  end
  extensions = Extensions.deserialize(exs_bin, msg_type)
  i += exs_len
  raise Error::ErrorAlerts, :decode_error unless i == msg_len + 4 &&
                                                 i == binary.length

  ServerHello.new(legacy_version: legacy_version,
                  random: random,
                  legacy_session_id_echo: legacy_session_id_echo,
                  cipher_suite: cipher_suite,
                  legacy_compression_method: legacy_compression_method,
                  extensions: extensions)
end

Instance Method Details

#appearable_extensions? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tttls1.3/message/server_hello.rb', line 139

def appearable_extensions?
  exs = @extensions.keys - APPEARABLE_SH_EXTENSIONS
  exs = @extensions.keys - APPEARABLE_HRR_EXTENSIONS if hrr?
  return true if exs.empty?

  !(exs - DEFINED_EXTENSIONS).empty?
end

#downgraded? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tttls1.3/message/server_hello.rb', line 156

def downgraded?
  [DOWNGRADE_PROTECTION_TLS_1_2,
   DOWNGRADE_PROTECTION_TLS_1_1].include?(@random[-8..])
end

#hrr? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tttls1.3/message/server_hello.rb', line 134

def hrr?
  @hrr
end

#negotiated_tls_1_3? ⇒ Booelan

Returns:

  • (Booelan) 


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# File 'lib/tttls1.3/message/server_hello.rb', line 148

def negotiated_tls_1_3?
  sv = @extensions[Message::ExtensionType::SUPPORTED_VERSIONS]

  @legacy_version == Message::ProtocolVersion::TLS_1_2 &&
    (sv&.versions || []).first == Message::ProtocolVersion::TLS_1_3
end

#serialize ⇒ String

Returns:

  • (String) 


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# File 'lib/tttls1.3/message/server_hello.rb', line 69

def serialize
  binary = ''
  binary += @legacy_version
  binary += @random
  binary += @legacy_session_id_echo.prefix_uint8_length
  binary += @cipher_suite
  binary += @legacy_compression_method
  binary += @extensions.serialize

  @msg_type + binary.prefix_uint24_length
end