Fix domain validation for subdomains (#19)

Don't run the advisor over scans from the CLI if an error occurred

Author: wolveix

cmd/dss/main.go

@@ -23,7 +23,7 @@ var (
 		Use:     "dss",
 		Short:   "Scan a domain's DNS records.",
 		Long:    "Scan a domain's DNS records.\nhttps://github.com/GlobalCyberAlliance/domain-security-scanner",
-		Version: "2.4.6",
+		Version: "2.4.7",
 		PersistentPreRun: func(cmd *cobra.Command, args []string) {
 			if debug {
 				log = zerolog.New(zerolog.ConsoleWriter{Out: os.Stdout, TimeFormat: time.RFC3339}).With().Timestamp().Logger().Level(zerolog.DebugLevel)

cmd/dss/scan.go

@@ -60,7 +60,7 @@ var cmdScan = &cobra.Command{
 				ScanResult: result,
 			}
 
-			if advise {
+			if result.Error == "" && advise {
 				resultWithAdvice.Advice = domainAdvisor.CheckAll(result.BIMI, result.DKIM, result.DMARC, result.Domain, result.MX, result.SPF, checkTls)
 			}
 

pkg/scanner/scanner.go

@@ -272,9 +272,13 @@ func (s *Scanner) Scan(domain string) *ScanResult {
 	// check that the domain name is valid
 	records, err := s.getDNSAnswers(domain, dns.TypeNS)
 	if err != nil || len(records) == 0 {
-		return &ScanResult{
-			Domain: domain,
-			Error:  "invalid domain name",
+		// check if TXT records exist, as the nameserver check won't work for subdomains
+		records, err = s.getDNSAnswers(domain, dns.TypeTXT)
+		if err != nil || len(records) == 0 {
+			return &ScanResult{
+				Domain: domain,
+				Error:  "invalid domain name",
+			}
 		}
 	}