code: func (c *ServerContext) EncryptMessage(msg []byte, qop, seqno uint32) ([]byte, error) {
  	return encryptMessage(c.sctxt, msg, qop, seqno)
  }
docs: // EncryptMessage uses the established server context to encrypt a message
  // using the provided quality of protection flags and sequence number.
  // It returns the signature token in addition to any error.
  // IMPORTANT: the input msg parameter is updated in place by the low-level windows api
  // so must be copied if the initial content should not be modified.