module HrrRbSsh::Transport::KexAlgorithm::DiffieHellman

Public Class Methods

new(logger: nil) click to toggle source
# File lib/hrr_rb_ssh/transport/kex_algorithm/diffie_hellman.rb, line 16
def initialize logger: nil
  self.logger = logger
  @dh = OpenSSL::PKey::DH.new
  if @dh.respond_to?(:set_pqg)
    @dh.set_pqg OpenSSL::BN.new(self.class::P, 16), nil, OpenSSL::BN.new(self.class::G)
  else
    @dh.p = OpenSSL::BN.new(self.class::P, 16)
    @dh.g = OpenSSL::BN.new(self.class::G)
  end
  @dh.generate_key!
  @public_key = @dh.pub_key.to_i
end

Public Instance Methods

hash(transport) click to toggle source
# File lib/hrr_rb_ssh/transport/kex_algorithm/diffie_hellman.rb, line 52
def hash transport
  h0_payload = {
    :'V_C' => transport.v_c,
    :'V_S' => transport.v_s,
    :'I_C' => transport.i_c,
    :'I_S' => transport.i_s,
    :'K_S' => @k_s,
    :'e'   => @e,
    :'f'   => @f,
    :'k'   => @shared_secret,
  }
  h0 = H0.new(logger: logger).encode h0_payload
  h  = OpenSSL::Digest.digest self.class::DIGEST, h0
end
receive_kexdh_init(payload) click to toggle source
# File lib/hrr_rb_ssh/transport/kex_algorithm/diffie_hellman.rb, line 72
def receive_kexdh_init payload
  Message::SSH_MSG_KEXDH_INIT.new(logger: logger).decode payload
end
receive_kexdh_reply(payload) click to toggle source
# File lib/hrr_rb_ssh/transport/kex_algorithm/diffie_hellman.rb, line 96
def receive_kexdh_reply payload
  Message::SSH_MSG_KEXDH_REPLY.new(logger: logger).decode payload
end
send_kexdh_init(transport) click to toggle source
# File lib/hrr_rb_ssh/transport/kex_algorithm/diffie_hellman.rb, line 87
def send_kexdh_init transport
  message = {
    :'message number' => Message::SSH_MSG_KEXDH_INIT::VALUE,
    :'e'              => @e,
  }
  payload = Message::SSH_MSG_KEXDH_INIT.new(logger: logger).encode message
  transport.send payload
end
send_kexdh_reply(transport) click to toggle source
# File lib/hrr_rb_ssh/transport/kex_algorithm/diffie_hellman.rb, line 76
def send_kexdh_reply transport
  message = {
    :'message number'                                => Message::SSH_MSG_KEXDH_REPLY::VALUE,
    :'server public host key and certificates (K_S)' => @k_s,
    :'f'                                             => @f,
    :'signature of H'                                => sign(transport),
  }
  payload = Message::SSH_MSG_KEXDH_REPLY.new(logger: logger).encode message
  transport.send payload
end
shared_secret() click to toggle source
# File lib/hrr_rb_ssh/transport/kex_algorithm/diffie_hellman.rb, line 48
def shared_secret
  @shared_secret
end
sign(transport) click to toggle source
# File lib/hrr_rb_ssh/transport/kex_algorithm/diffie_hellman.rb, line 67
def sign transport
  h = hash transport
  s = transport.server_host_key_algorithm.sign h
end
start(transport) click to toggle source
# File lib/hrr_rb_ssh/transport/kex_algorithm/diffie_hellman.rb, line 29
def start transport
  case transport.mode
  when Mode::SERVER
    @k_s = transport.server_host_key_algorithm.server_public_host_key
    @f   = @public_key
    message = receive_kexdh_init transport.receive
    @e = message[:'e']
    @shared_secret = OpenSSL::BN.new(@dh.compute_key(OpenSSL::BN.new(@e)), 2).to_i
    send_kexdh_reply transport
  when Mode::CLIENT
    @e   = @public_key
    send_kexdh_init transport
    message = receive_kexdh_reply transport.receive
    @k_s = message[:'server public host key and certificates (K_S)']
    @f   = message[:'f']
    @shared_secret = OpenSSL::BN.new(@dh.compute_key(OpenSSL::BN.new(@f)), 2).to_i
  end
end