to_ssh (OpenSSL::BN)

        # File lib/net/ssh/transport/openssl.rb, line 13
    13:     def to_ssh
    14:       if zero?
    15:         return [0].pack("N")
    16:       else
    17:         buf = to_s(2)
    18:         if buf.getbyte(0)[7] == 1
    19:           return [buf.length+1, 0, buf].pack("NCA*")
    20:         else
    21:           return [buf.length, buf].pack("NA*")
    22:         end
    23:       end
    24:     end