├── go.mod
├── README.md
├── .gitignore
└── hakfindinternaldomains.go


/go.mod:
--------------------------------------------------------------------------------
1 | module github.com/hakluke/hakfindinternaldomains
2 | 
3 | go 1.16
4 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # hakfindinternaldomains
 2 | Feed it a list of subdomains, it will resolve them and tell you which ones are internal
 3 | 
 4 | # Installation
 5 | 
 6 | ```
 7 | go install github.com/hakluke/hakfindinternaldomains
 8 | ```
 9 | 
10 | # Usage
11 | 
12 | ```
13 | cat subdomains.txt | hakfindinternaldomains -t 50
14 | ```
15 | 


--------------------------------------------------------------------------------
/.gitignore:
--------------------------------------------------------------------------------
 1 | # Binaries for programs and plugins
 2 | *.exe
 3 | *.exe~
 4 | *.dll
 5 | *.so
 6 | *.dylib
 7 | 
 8 | # Test binary, built with `go test -c`
 9 | *.test
10 | 
11 | # Output of the go coverage tool, specifically when used with LiteIDE
12 | *.out
13 | 
14 | # Dependency directories (remove the comment below to include it)
15 | # vendor/
16 | 


--------------------------------------------------------------------------------
/hakfindinternaldomains.go:
--------------------------------------------------------------------------------
 1 | package main
 2 | 
 3 | import (
 4 | 	"bufio"
 5 | 	"flag"
 6 | 	"fmt"
 7 | 	"log"
 8 | 	"net"
 9 | 	"os"
10 | 	"sync"
11 | )
12 | 
13 | func main() {
14 | 	concurrencyPtr := flag.Int("t", 8, "Number of threads to utilise. Default is 8.")
15 | 	flag.Parse()
16 | 	// Taken from https://datatracker.ietf.org/doc/html/rfc5735
17 | 	cidr_strings := []string{
18 | 		"0.0.0.0/8",          // "This" Network RFC 1122, Section 3.2.1.3
19 | 		"10.0.0.0/8",         // Private-Use Networks RFC 1918
20 | 		"127.0.0.0/8",        // Loopback RFC 1122, Section 3.2.1.3
21 | 		"169.254.0.0/16",     // Link Local RFC 3927
22 | 		"172.16.0.0/12",      // Private-Use Networks RFC 1918
23 | 		"192.0.0.0/24",       // IETF Protocol Assignments RFC 5736
24 | 		"192.0.2.0/24",       // TEST-NET-1 RFC 5737
25 | 		"192.88.99.0/24",     // 6to4 Relay Anycast RFC 3068
26 | 		"192.168.0.0/16",     // Private-Use Networks RFC 1918
27 | 		"198.18.0.0/15",      // Network Interconnect
28 | 		"198.51.100.0/24",    // TEST-NET-2 RFC 5737
29 | 		"203.0.113.0/24",     // TEST-NET-3 RFC 5737
30 | 		"224.0.0.0/4",        // Multicast RFC 3171
31 | 		"240.0.0.0/4",        // Reserved for Future Use RFC 1112, Section 4
32 | 		"255.255.255.255/32", // Limited Broadcast RFC 919, Section 7
33 | 	}
34 | 	cidrs := make([]net.IPNet, 15)
35 | 	for _, cidr_str := range cidr_strings {
36 | 		_, cidr, _ := net.ParseCIDR(cidr_str)
37 | 		cidrs = append(cidrs, *cidr)
38 | 	}
39 | 
40 | 	work := make(chan string)
41 | 	go func() {
42 | 		s := bufio.NewScanner(os.Stdin)
43 | 		for s.Scan() {
44 | 			work <- s.Text()
45 | 		}
46 | 		close(work)
47 | 	}()
48 | 
49 | 	wg := &sync.WaitGroup{}
50 | 
51 | 	for i := 0; i < *concurrencyPtr; i++ {
52 | 		wg.Add(1)
53 | 
54 | 		go doWork(work, wg, cidrs)
55 | 	}
56 | 	wg.Wait()
57 | }
58 | 
59 | func doWork(work chan string, wg *sync.WaitGroup, cidrs []net.IPNet) {
60 | 	defer wg.Done()
61 | 	for text := range work {
62 | 		ip, err := net.LookupIP(text)
63 | 		if err != nil {
64 | 			log.Println("DNS resolve failed:", err)
65 | 		}
66 | 		for _, cidr := range cidrs {
67 | 			if len(ip) == 0 {
68 | 				continue
69 | 			}
70 | 			if cidr.Contains(ip[0]) {
71 | 				fmt.Println(text, ip)
72 | 			}
73 | 		}
74 | 	}
75 | }
76 | 


--------------------------------------------------------------------------------