main.go

package main

import (
	"bufio"
	"fmt"
	"net"
	"os"
	"sync"
)

func resolveSubdomain(subdomain string, domain string, results chan string, wg *sync.WaitGroup) {
	defer wg.Done()
	fullDomain := subdomain + "." + domain
	_, err := net.LookupHost(fullDomain)
	if err == nil {
		// fmt.Println("[+] Found:", fullDomain)
		fmt.Println(fullDomain)
		results <- fullDomain
	}
}

func worker(domain string, wordlist chan string, results chan string, wg *sync.WaitGroup) {
	for subdomain := range wordlist {
		wg.Add(1)
		resolveSubdomain(subdomain, domain, results, wg)
	}
}

func loadWordlist(wordlistPath string) ([]string, error) {
	file, err := os.Open(wordlistPath)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	var wordlist []string
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		wordlist = append(wordlist, scanner.Text())
	}
	if err := scanner.Err(); err != nil {
		return nil, err
	}
	return wordlist, nil
}

func printBanner() {
	banner := `
    ██████   ██████  ██████  ████████ ███    ██ ███████ ██████  
   ██       ██    ██ ██   ██    ██    ████   ██ ██      ██   ██ 
   ██   ███ ██    ██ ██████     ██    ██ ██  ██ █████   ██████  
   ██    ██ ██    ██ ██   ██    ██    ██  ██ ██ ██      ██   ██ 
    ██████   ██████  ██████     ██    ██   ████ ███████ ██   ██ 
	`
	author := "Author: Amit Agarwal"
	fmt.Fprintln(os.Stderr, banner) // Print banner to stderr
	fmt.Fprintln(os.Stderr, author) // Print author name to stderr
}

func main() {
	// Print the banner to stderr
	printBanner()

	if len(os.Args) != 4 {
		fmt.Println("Usage: go run main.go <domain> <wordlist> <threads>")
		os.Exit(1)
	}

	domain := os.Args[1]
	wordlistPath := os.Args[2]
	threadCount := 0

	// Parse thread count
	_, err := fmt.Sscanf(os.Args[3], "%d", &threadCount)
	if err != nil || threadCount <= 1 {
		fmt.Println("Invalid number of threads. Provide a positive integer greater than 1.")
		os.Exit(1)
	}

	// Load the wordlist
	wordlist, err := loadWordlist(wordlistPath)
	if err != nil {
		fmt.Println("Error loading wordlist:", err)
		os.Exit(1)
	}

	// Channels for wordlist distribution and result collection
	wordlistChan := make(chan string, len(wordlist))
	resultsChan := make(chan string)
	var wg sync.WaitGroup

	// Start workers
	for i := 0; i < threadCount; i++ {
		go worker(domain, wordlistChan, resultsChan, &wg)
	}

	// Feed wordlist into the channel
	for _, word := range wordlist {
		wordlistChan <- word
	}
	close(wordlistChan)

	// Wait for all goroutines to finish
	go func() {
		wg.Wait()
		close(resultsChan)
	}()

	// Collect results
	found := make([]string, 0)
	for result := range resultsChan {
		found = append(found, result)
	}

	// fmt.Println("\nValid Subdomains Found:")
	// for _, subdomain := range found {
	// fmt.Println(subdomain)
	// }
}