Add HTTP proxy support

v2/pkg/passive/passive.go

@@ -11,11 +11,11 @@ import (
 )
 
 // EnumerateSubdomains enumerates all the subdomains for a given domain
-func (a *Agent) EnumerateSubdomains(domain string, keys *subscraping.Keys, timeout int, maxEnumTime time.Duration) chan subscraping.Result {
+func (a *Agent) EnumerateSubdomains(domain string, keys *subscraping.Keys, proxy string, timeout int, maxEnumTime time.Duration) chan subscraping.Result {
 	results := make(chan subscraping.Result)
 
 	go func() {
-		session, err := subscraping.NewSession(domain, keys, timeout)
+		session, err := subscraping.NewSession(domain, keys, proxy, timeout)
 		if err != nil {
 			results <- subscraping.Result{Type: subscraping.Error, Error: fmt.Errorf("could not init passive session for %s: %s", domain, err)}
 		}

v2/pkg/runner/enumerate.go

@@ -37,7 +37,7 @@ func (r *Runner) EnumerateSingleDomain(ctx context.Context, domain string, outpu
 
 	// Run the passive subdomain enumeration
 	now := time.Now()
-	passiveResults := r.passiveAgent.EnumerateSubdomains(domain, &keys, r.options.Timeout, time.Duration(r.options.MaxEnumerationTime)*time.Minute)
+	passiveResults := r.passiveAgent.EnumerateSubdomains(domain, &keys, r.options.Proxy, r.options.Timeout, time.Duration(r.options.MaxEnumerationTime)*time.Minute)
 
 	wg := &sync.WaitGroup{}
 	wg.Add(1)

v2/pkg/runner/options.go

@@ -39,7 +39,7 @@ type Options struct {
 	Resolvers          string // Resolvers is the comma-separated resolvers to use for enumeration
 	ResolverList       string // ResolverList is a text file containing list of resolvers to use for enumeration
 	ConfigFile         string // ConfigFile contains the location of the config file
-
+    Proxy              string // HTTP proxy
 	YAMLConfig ConfigFile // YAMLConfig contains the unmarshalled yaml config file
 }
 
@@ -76,6 +76,7 @@ func ParseOptions() *Options {
 	flag.StringVar(&options.ResolverList, "rL", "", "Text file containing list of resolvers to use")
 	flag.BoolVar(&options.RemoveWildcard, "nW", false, "Remove Wildcard & Dead Subdomains from output")
 	flag.StringVar(&options.ConfigFile, "config", path.Join(config, "config.yaml"), "Configuration file for API Keys, etc")
+	flag.StringVar(&options.Proxy, "proxy", "", "HTTP proxy")
 	flag.BoolVar(&options.Version, "version", false, "Show version of subfinder")
 	flag.Parse()
 

v2/pkg/subscraping/agent.go

@@ -14,15 +14,28 @@ import (
 )
 
 // NewSession creates a new session object for a domain
-func NewSession(domain string, keys *Keys, timeout int) (*Session, error) {
+func NewSession(domain string, keys *Keys, proxy string, timeout int) (*Session, error) {
-	client := &http.Client{
+	Transport := &http.Transport{
-		Transport: &http.Transport{
         MaxIdleConns:        100,
         MaxIdleConnsPerHost: 100,
         TLSClientConfig: &tls.Config{
             InsecureSkipVerify: true,
         },
-		},
+    }
+
+    // Add proxy
+    if proxy != "" {
+        proxyUrl, _ := url.Parse(proxy)
+        if proxyUrl == nil {
+            // Log warning but continue anyways
+            gologger.Warning().Msgf("Invalid proxy '%s' provided", proxy)
+        } else {
+            Transport.Proxy = http.ProxyURL(proxyUrl)
+        }
+    }
+
+	client := &http.Client{
+		Transport: Transport,
 		Timeout: time.Duration(timeout) * time.Second,
 	}