Add exclude-hostname-length flag

cli/vhost/vhost.go

@@ -31,6 +31,7 @@ func getFlags() []cli.Flag {
 		&cli.StringFlag{Name: "exclude-status", Aliases: []string{"xs"}, Usage: "exclude the following status codes. Can also handle ranges like 200,300-400,404.", Value: ""},
 		&cli.StringFlag{Name: "domain", Aliases: []string{"do"}, Usage: "the domain to append when using an IP address as URL. If left empty and you specify a domain based URL the hostname from the URL is extracted"},
 		&cli.BoolFlag{Name: "force", Value: false, Usage: "Force execution even when result is not guaranteed."},
+		&cli.BoolFlag{Name: "exclude-hostname-length", Aliases: []string{"xh"}, Value: false, Usage: "Automatically adjust exclude-length based on dynamic hostname length in responses"},
 	}...)
 
 	return flags
@@ -47,6 +48,7 @@ func run(c *cli.Context) error {
 
 	pluginOpts.AppendDomain = c.Bool("append-domain")
 	pluginOpts.ExcludeLength = c.String("exclude-length")
+	pluginOpts.ExcludeHostnameLength = c.Bool("exclude-hostname-length")
 	ret, err := libgobuster.ParseCommaSeparatedInt(pluginOpts.ExcludeLength)
 	if err != nil {
 		return fmt.Errorf("invalid value for exclude-length: %w", err)

gobustervhost/gobustervhost.go

@@ -127,12 +127,18 @@ func (v *GobusterVhost) PreRun(ctx context.Context, _ *libgobuster.Progress) err
 // ProcessWord is the process implementation of gobusterdir
 func (v *GobusterVhost) ProcessWord(ctx context.Context, word string, progress *libgobuster.Progress) (libgobuster.Result, error) {
 	var subdomain string
+	var wordLength int
 	if v.options.AppendDomain {
 		subdomain = fmt.Sprintf("%s.%s", word, v.domain)
 	} else {
 		// wordlist needs to include full domains
 		subdomain = word
 	}
+	if v.options.ExcludeHostnameLength {
+		wordLength = len(word)
+	} else {
+		wordLength = 0
+	}
 
 	// warn people when there is no . detected so they might want to use the other options
 	v.once.Do(func() {
@@ -194,7 +200,7 @@ func (v *GobusterVhost) ProcessWord(ctx context.Context, word string, progress *
 	// subdomain must not match default vhost and non existent vhost
 	// or verbose mode is enabled
 	found := body != nil && !bytes.Equal(body, v.normalBody) && !bytes.Equal(body, v.abnormalBody)
-	if found && !v.options.ExcludeLengthParsed.Contains(int(size)) && !v.options.ExcludeStatusParsed.Contains(statusCode) {
+	if found && !v.options.ExcludeLengthParsed.Contains(int(size)-wordLength) && !v.options.ExcludeStatusParsed.Contains(statusCode) {
 		r := Result{
 			Vhost:      subdomain,
 			StatusCode: statusCode,
@@ -300,6 +306,10 @@ func (v *GobusterVhost) GetConfigString() (string, error) {
 		}
 	}
 
+	if _, err := fmt.Fprintf(tw, "[+] Exclude Hostname Length:\t%t\n", v.options.ExcludeHostnameLength); err != nil {
+		return "", err
+	}
+
 	if err := tw.Flush(); err != nil {
 		return "", fmt.Errorf("error on tostring: %w", err)
 	}

gobustervhost/options.go

@@ -7,12 +7,13 @@ import (
 // OptionsVhost is the struct to hold all options for this plugin
 type OptionsVhost struct {
 	libgobuster.HTTPOptions
-	AppendDomain        bool
-	ExcludeLength       string
-	ExcludeLengthParsed libgobuster.Set[int]
+	AppendDomain          bool
+	ExcludeLength         string
+	ExcludeLengthParsed   libgobuster.Set[int]
 	ExcludeStatus       string
 	ExcludeStatusParsed libgobuster.Set[int]
-	Domain              string
+	Domain                string
+	ExcludeHostnameLength bool
 }
 
 // NewOptions returns a new initialized OptionsVhost