Class: Signer

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

Defined Under Namespace

Modules: Key

Instance Method Summary collapse

Constructor Details

#initialize(wmid, password, key) ⇒ Signer

Returns a new instance of Signer.

Raises:

  • (ArgumentError) 


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# File 'lib/signer.rb', line 82

def initialize(wmid, password, key)
  raise ArgumentError, "nil wmid" if wmid.nil?
  raise ArgumentError, "Incorrect WMID" unless is_wmid wmid
  raise ArgumentError, "nil password" if password.nil?
  raise ArgumentError, "nil key" if key.nil?

  key = Base64.decode64 key
  raise ArgumentError, "Illegal size for keydata" if key.length != 164

  io = StringIO.open key.force_encoding('BINARY'), 'rb'
  @key = Key.read io, wmid, password
end

Instance Method Details

#sign(data) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/signer.rb', line 95

def sign(data)
  raise ArgumentError, "nil data" if data.nil?

  digest = OpenSSL::Digest::MD4.new
  digest.update data
  data = digest.digest.unpack("V*")

  10.times do
    data << SecureRandom.random_number(1 << 32)
  end

  data = data.pack("V*")

  data = ([ data.length ].pack("v") + data).ljust( @key[:n].num_bytes, 0.chr).reverse

  data_bignum = OpenSSL::BN.new data, 2

  signature = data_bignum.mod_exp(@key[:e], @key[:n])

  signature.to_s(2).rjust(@key[:n].num_bytes, 0.chr).unpack('n*').reverse.map { |w| sprintf '%04x', w }.join
end