This page hosts a formal specification of tls_client_hello using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Ruby generated by Kaitai Struct depends on the Ruby runtime library. You have to install it before you can parse data.
The Ruby runtime library can be installed from RubyGems:
gem install kaitai-structParse a local file and get structure in memory:
data = TlsClientHello.from_file("path/to/local/file.bin")
Or parse structure from a string of bytes:
bytes = "\x00\x01\x02..."
data = TlsClientHello.new(Kaitai::Struct::Stream.new(bytes))
After that, one can get various attributes from the structure by invoking getter methods like:
data.version # => get version
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
require 'kaitai/struct/struct'
unless Gem::Version.new(Kaitai::Struct::VERSION) >= Gem::Version.new('0.9')
raise "Incompatible Kaitai Struct Ruby API: 0.9 or later is required, but you have #{Kaitai::Struct::VERSION}"
end
class TlsClientHello < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@version = Version.new(@_io, self, @_root)
@random = Random.new(@_io, self, @_root)
@session_id = SessionId.new(@_io, self, @_root)
@cipher_suites = CipherSuites.new(@_io, self, @_root)
@compression_methods = CompressionMethods.new(@_io, self, @_root)
if _io.eof? == false
@extensions = Extensions.new(@_io, self, @_root)
end
self
end
class ServerName < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@name_type = @_io.read_u1
@length = @_io.read_u2be
@host_name = @_io.read_bytes(length)
self
end
attr_reader :name_type
attr_reader :length
attr_reader :host_name
end
class Random < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@gmt_unix_time = @_io.read_u4be
@random = @_io.read_bytes(28)
self
end
attr_reader :gmt_unix_time
attr_reader :random
end
class SessionId < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@len = @_io.read_u1
@sid = @_io.read_bytes(len)
self
end
attr_reader :len
attr_reader :sid
end
class Sni < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@list_length = @_io.read_u2be
@server_names = []
i = 0
while not @_io.eof?
@server_names << ServerName.new(@_io, self, @_root)
i += 1
end
self
end
attr_reader :list_length
attr_reader :server_names
end
class CipherSuites < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@len = @_io.read_u2be
@cipher_suites = []
((len / 2)).times { |i|
@cipher_suites << @_io.read_u2be
}
self
end
attr_reader :len
attr_reader :cipher_suites
end
class CompressionMethods < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@len = @_io.read_u1
@compression_methods = @_io.read_bytes(len)
self
end
attr_reader :len
attr_reader :compression_methods
end
class Alpn < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@ext_len = @_io.read_u2be
@alpn_protocols = []
i = 0
while not @_io.eof?
@alpn_protocols << Protocol.new(@_io, self, @_root)
i += 1
end
self
end
attr_reader :ext_len
attr_reader :alpn_protocols
end
class Extensions < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@len = @_io.read_u2be
@extensions = []
i = 0
while not @_io.eof?
@extensions << Extension.new(@_io, self, @_root)
i += 1
end
self
end
attr_reader :len
attr_reader :extensions
end
class Version < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@major = @_io.read_u1
@minor = @_io.read_u1
self
end
attr_reader :major
attr_reader :minor
end
class Protocol < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@strlen = @_io.read_u1
@name = @_io.read_bytes(strlen)
self
end
attr_reader :strlen
attr_reader :name
end
class Extension < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@type = @_io.read_u2be
@len = @_io.read_u2be
case type
when 0
@_raw_body = @_io.read_bytes(len)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = Sni.new(_io__raw_body, self, @_root)
when 16
@_raw_body = @_io.read_bytes(len)
_io__raw_body = Kaitai::Struct::Stream.new(@_raw_body)
@body = Alpn.new(_io__raw_body, self, @_root)
else
@body = @_io.read_bytes(len)
end
self
end
attr_reader :type
attr_reader :len
attr_reader :body
attr_reader :_raw_body
end
attr_reader :version
attr_reader :random
attr_reader :session_id
attr_reader :cipher_suites
attr_reader :compression_methods
attr_reader :extensions
end