Module: DCI::KeyGenerator

Defined in:
lib/dci/protocol.rb

Class Method Summary collapse

Class Method Details

.encodeChar(c) ⇒ Object

encode the special characters to that delightful DCN notation



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# File 'lib/dci/protocol.rb', line 235

def self.encodeChar(c)
  if [0,5,36,96,124,126].include? c
    return sprintf("/%%DCN%03d\%%/",c)
  end
  return c.chr
end

.generate_key(challenge) ⇒ Object

Convert a lock to a key. See <wza.digitalbrains.com/DC/doc/Appendix_A.html>. create a key for a lock given as challenge



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# File 'lib/dci/protocol.rb', line 211

def self.generate_key (challenge)
  clen = challenge.length
  k = ""
  #Convert string to integer array
  b = []
  challenge.each_byte{|byte| b.push byte}
  #First byte
  u = b[0]
  l = b[clen-1]
  o = b[clen-2]
  u = u^l^o^5;
  v = (((u<<8)|u)>>4) & 255
  k += encodeChar(v)
  1.upto(clen-1){|i|
    u = b[i]
    l = b[i-1]
    u = u^l
    v = (((u<<8)|u)>>4) & 255
    k += encodeChar(v)
  }       
  return k
end