# File lib/net/ntlm/client/session.rb, line 70
      def verify_signature(signature, message)
        seq = signature[-4..-1]
        sig = OpenSSL::HMAC.digest(OpenSSL::Digest::MD5.new, server_sign_key, "#{seq}#{message}")[0..7]
        if negotiate_key_exchange?
          sig = server_cipher.update sig
          sig << server_cipher.final
        end
        "#{VERSION_MAGIC}#{sig}#{seq}" == signature
      end