improve ua modifier with client side spoofing

proxychain/requestmodifers/spoof_referrer.go

@@ -1,20 +1,29 @@
 package requestmodifers
 
 import (
+	"fmt"
 	"ladder/proxychain"
+	tx "ladder/proxychain/responsemodifers"
 )
 
-// SpoofReferrer modifies the referrer header
-// useful if the page can be accessed from a search engine
-// or social media site, but not by browsing the website itself
-// if url is "", then the referrer header is removed
+// SpoofReferrer modifies the referrer header.
+// It is useful if the page can be accessed from a search engine
+// or social media site, but not by browsing the website itself.
+// if url is "", then the referrer header is removed.
 func SpoofReferrer(url string) proxychain.RequestModification {
-	return func(px *proxychain.ProxyChain) error {
+	return func(chain *proxychain.ProxyChain) error {
+
+		// change refer on client side js
+		script := fmt.Sprintf(`document.referrer = "%s"`, url)
+		chain.AddOnceResponseModifications(
+			tx.InjectScriptBeforeDOMContentLoaded(script),
+		)
+
 		if url == "" {
-			px.Request.Header.Del("referrer")
+			chain.Request.Header.Del("referrer")
 			return nil
 		}
-		px.Request.Header.Set("referrer", url)
+		chain.Request.Header.Set("referrer", url)
 		return nil
 	}
 }