code: func endpointThumbprint(endpoint *types.LookupServiceRegistrationEndpoint) string {
  	if len(endpoint.SslTrust) == 0 {
  		return ""
  	}
  	enc := endpoint.SslTrust[0]
  
  	b, err := base64.StdEncoding.DecodeString(enc)
  	if err != nil {
  		log.Printf("base64.Decode(%q): %s", enc, err)
  		return ""
  	}
  
  	cert, err := x509.ParseCertificate(b)
  	if err != nil {
  		log.Printf("x509.ParseCertificate(%q): %s", enc, err)
  		return ""
  	}
  
  	return soap.ThumbprintSHA1(cert)
  }
docs: // endpointThumbprint converts the base64 encoded endpoint certificate to a SHA1 thumbprint.