Class: MTProto::AuthKeyGenerator

Inherits:
Object
  • Object
show all
Defined in:
lib/mtproto/auth_key_generator.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(connection, public_key, dc_number = nil, test_mode: false, timeout: 10) ⇒ AuthKeyGenerator

Returns a new instance of AuthKeyGenerator.

Raises:

  • (ArgumentError) 


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# File 'lib/mtproto/auth_key_generator.rb', line 19

def initialize(connection, public_key, dc_number = nil, test_mode: false, timeout: 10)
  raise ArgumentError, 'public_key is required' if public_key.nil? || public_key.empty?
  raise ArgumentError, 'dc_number must be positive. Use test_mode: true for test DCs' if dc_number && dc_number < 0

  @connection = connection
  @public_key = public_key
  @dc_number = dc_number
  @test_mode = test_mode
  @timeout = timeout
  @auth_key = nil
  @server_salt = nil
  @time_offset = 0
end

Instance Attribute Details

#auth_key ⇒ Object (readonly)

Returns the value of attribute auth_key.



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# File 'lib/mtproto/auth_key_generator.rb', line 17

def auth_key
  @auth_key
end

#connection ⇒ Object (readonly)

Returns the value of attribute connection.



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# File 'lib/mtproto/auth_key_generator.rb', line 17

def connection
  @connection
end

#server_salt ⇒ Object (readonly)

Returns the value of attribute server_salt.



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# File 'lib/mtproto/auth_key_generator.rb', line 17

def server_salt
  @server_salt
end

#time_offset ⇒ Object (readonly)

Returns the value of attribute time_offset.



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# File 'lib/mtproto/auth_key_generator.rb', line 17

def time_offset
  @time_offset
end

#timeout ⇒ Object (readonly)

Returns the value of attribute timeout.



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# File 'lib/mtproto/auth_key_generator.rb', line 17

def timeout
  @timeout
end

Instance Method Details

#generate ⇒ Object 



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# File 'lib/mtproto/auth_key_generator.rb', line 33

def generate
  res_pq = send_and_receive(TL::ReqPqMulti.new(SecureRandom.random_bytes(16)), TL::ResPq)

  server_key = Crypto::RSAKey.find_by_fingerprint(res_pq.fingerprints, @public_key)
  raise 'No matching RSA key found!' unless server_key

  p, q = Crypto::Factorization.factorize_pq(res_pq.pq)
  new_nonce = SecureRandom.random_bytes(32)

  server_dh_params = send_req_dh_params(res_pq, p, q, server_key, new_nonce)
  server_dh_inner_data = decrypt_server_dh_params(res_pq, new_nonce, server_dh_params)

  Crypto::DHValidator.validate_dh_params(
    server_dh_inner_data.g,
    server_dh_inner_data.dh_prime,
    server_dh_inner_data.g_a
  )

  client_dh_params = Crypto::DHKeyExchange.generate_client_dh_params(
    server_dh_inner_data.g,
    server_dh_inner_data.dh_prime
  )

  auth_key = Crypto::DHKeyExchange.compute_auth_key(
    server_dh_inner_data.g_a,
    client_dh_params[:b],
    server_dh_inner_data.dh_prime
  )

  tmp_aes_key = Crypto::AuthKeyHelper.derive_tmp_aes_key(new_nonce, res_pq.server_nonce)
  tmp_aes_iv = Crypto::AuthKeyHelper.derive_tmp_aes_iv(new_nonce, res_pq.server_nonce)

  dh_gen_response = send_client_dh_params(
    res_pq,
    new_nonce,
    client_dh_params,
    tmp_aes_key,
    tmp_aes_iv
  )

  verify_dh_gen_response(dh_gen_response, new_nonce, auth_key)

  @auth_key = auth_key
  @server_salt = compute_server_salt(new_nonce, res_pq.server_nonce)
  @time_offset = server_dh_inner_data.server_time - Time.now.to_i

  {
    auth_key: @auth_key,
    server_salt: @server_salt,
    time_offset: @time_offset
  }
end