# File lib/openid/util.rb, line 71
    def Util.num_to_str(n)
      # taken from openid-ruby 0.0.1
      bits = n.to_s(2)
      prepend = (8 - bits.length % 8) || (bits.index(/^1/) ? 8 : 0)
      bits = ('0' * prepend) + bits if prepend
      [bits].pack('B*')
    end