refactor: improve and align ftp tls error msg

modules/ftp/scanner.go

@@ -216,14 +216,14 @@ func (ftp *Connection) GetFTPSCertificates() error {
 	ftpsReady, err := ftp.SetupFTPS()
 
 	if err != nil {
-		return err
+		return fmt.Errorf("error setting up FTPS: %w", err)
 	}
 	if !ftpsReady {
 		return nil
 	}
 	var conn *zgrab2.TLSConnection
 	if conn, err = ftp.config.TLSFlags.GetTLSConnection(ftp.conn); err != nil {
-		return err
+		return fmt.Errorf("error setting up TLS connection: %w", err)
 	}
 	ftp.results.TLSLog = conn.GetLog()
 
@@ -232,25 +232,25 @@ func (ftp *Connection) GetFTPSCertificates() error {
 		// AUTH TLS succeeds, but the handshake fails, dumping
 		// "error:1408A0C1:SSL routines:ssl3_get_client_hello:no shared cipher"
 		// to the socket.
-		return err
+		return fmt.Errorf("TLS handshake failed: %w", err)
 	}
 	ftp.conn = conn
 	return nil
 }
 
 // Scan performs the configured scan on the FTP server, as follows:
-// * Read the banner into results.Banner (if it is not a 2XX response, bail)
-// * If the FTPAuthTLS flag is not set, finish.
-// * Send the AUTH TLS command to the server. If the response is not 2XX, then
-//   send the AUTH SSL command. If the response is not 2XX, then finish.
-// * Perform ths TLS handshake / any configured TLS scans, populating
-//   results.TLSLog.
-// * Return SCAN_SUCCESS, &results, nil
+//   - Read the banner into results.Banner (if it is not a 2XX response, bail)
+//   - If the FTPAuthTLS flag is not set, finish.
+//   - Send the AUTH TLS command to the server. If the response is not 2XX, then
+//     send the AUTH SSL command. If the response is not 2XX, then finish.
+//   - Perform ths TLS handshake / any configured TLS scans, populating
+//     results.TLSLog.
+//   - Return SCAN_SUCCESS, &results, nil
 func (s *Scanner) Scan(t zgrab2.ScanTarget) (status zgrab2.ScanStatus, result interface{}, thrown error) {
 	var err error
 	conn, err := t.Open(&s.config.BaseFlags)
 	if err != nil {
-		return zgrab2.TryGetScanStatus(err), nil, err
+		return zgrab2.TryGetScanStatus(err), nil, fmt.Errorf("error opening connection: %w", err)
 	}
 	cn := conn
 	defer func() {
@@ -261,25 +261,25 @@ func (s *Scanner) Scan(t zgrab2.ScanTarget) (status zgrab2.ScanStatus, result in
 	if s.config.ImplicitTLS {
 		tlsConn, err := s.config.TLSFlags.GetTLSConnection(conn)
 		if err != nil {
-			return zgrab2.TryGetScanStatus(err), nil, err
+			return zgrab2.TryGetScanStatus(err), nil, fmt.Errorf("error setting up TLS connection: %w", err)
 		}
 		results.ImplicitTLS = true
 		results.TLSLog = tlsConn.GetLog()
 		err = tlsConn.Handshake()
 		if err != nil {
-			return zgrab2.TryGetScanStatus(err), nil, err
+			return zgrab2.TryGetScanStatus(err), nil, fmt.Errorf("TLS handshake failed: %w", err)
 		}
 		cn = tlsConn
 	}
 
 	ftp := Connection{conn: cn, config: s.config, results: results}
 	is200Banner, err := ftp.GetFTPBanner()
 	if err != nil {
-		return zgrab2.TryGetScanStatus(err), &ftp.results, err
+		return zgrab2.TryGetScanStatus(err), &ftp.results, fmt.Errorf("error reading FTP banner: %w", err)
 	}
 	if s.config.FTPAuthTLS && is200Banner {
 		if err := ftp.GetFTPSCertificates(); err != nil {
-			return zgrab2.SCAN_APPLICATION_ERROR, &ftp.results, err
+			return zgrab2.TryGetScanStatus(err), &ftp.results, fmt.Errorf("error getting FTPS certificates: %w", err)
 		}
 	}
 	return zgrab2.SCAN_SUCCESS, &ftp.results, nil