ssh_do_sign (OpenSSL::PKey::DSA)

    # File lib/net/ssh/util/openssl.rb, line 126
          def ssh_do_sign( data )
            sig = sign( OpenSSL::Digest::DSS1.new, data)
            a1sig = OpenSSL::ASN1.decode( sig )

            sig_r = a1sig.value[0].value.to_s(2)
            sig_s = a1sig.value[1].value.to_s(2)

            if sig_r.length > 20 || sig_s.length > 20
              raise OpenSSL::PKey::DSAError, "bad sig size"
            end

            sig_r = "\0" * ( 20 - sig_r.length ) + sig_r if sig_r.length < 20
            sig_s = "\0" * ( 20 - sig_s.length ) + sig_s if sig_s.length < 20

            return sig_r + sig_s
          end