# File lib/net/ssh/transport/openssl.rb, line 219
        def ssh_do_sign(data)
          digest = digester.digest(data)
          sig = dsa_sign_asn1(digest)
          a1sig = OpenSSL::ASN1.decode( sig )

          sig_r = a1sig.value[0].value
          sig_s = a1sig.value[1].value

          return Net::SSH::Buffer.from(:bignum, sig_r, :bignum, sig_s).to_s
        end