Universal Android SSL Pinning Bypass with Frida

/*
   Android SSL Re-pinning frida script v0.2 030417-pier

   $ adb push burpca-cert-der.crt /data/local/tmp/cert-der.crt
   $ frida -U -f it.app.mobile -l frida-android-repinning.js --no-pause

   https://techblog.mediaservice.net/2017/07/universal-android-ssl-pinning-bypass-with-frida/

   UPDATE 20191605: Fixed undeclared var. Thanks to @oleavr and @ehsanpc9999 !
*/

setTimeout(function(){
    Java.perform(function (){
        console.log("");
        console.log("[.] Cert Pinning Bypass/Re-Pinning");

        var CertificateFactory = Java.use("java.security.cert.CertificateFactory");
        var FileInputStream = Java.use("java.io.FileInputStream");
        var BufferedInputStream = Java.use("java.io.BufferedInputStream");
        var X509Certificate = Java.use("java.security.cert.X509Certificate");
        var KeyStore = Java.use("java.security.KeyStore");
        var TrustManagerFactory = Java.use("javax.net.ssl.TrustManagerFactory");
        var SSLContext = Java.use("javax.net.ssl.SSLContext");

        // Load CAs from an InputStream
        console.log("[+] Loading our CA...")
        var cf = CertificateFactory.getInstance("X.509");

        try {
            var fileInputStream = FileInputStream.$new("/data/local/tmp/cert-der.crt");
        }
        catch(err) {
            console.log("[o] " + err);
        }

        var bufferedInputStream = BufferedInputStream.$new(fileInputStream);
        var ca = cf.generateCertificate(bufferedInputStream);
        bufferedInputStream.close();

        var certInfo = Java.cast(ca, X509Certificate);
        console.log("[o] Our CA Info: " + certInfo.getSubjectDN());

        // Create a KeyStore containing our trusted CAs
        console.log("[+] Creating a KeyStore for our CA...");
        var keyStoreType = KeyStore.getDefaultType();
        var keyStore = KeyStore.getInstance(keyStoreType);
        keyStore.load(null, null);
        keyStore.setCertificateEntry("ca", ca);

        // Create a TrustManager that trusts the CAs in our KeyStore
        console.log("[+] Creating a TrustManager that trusts the CA in our KeyStore...");
        var tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
        var tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
        tmf.init(keyStore);
        console.log("[+] Our TrustManager is ready...");

        console.log("[+] Hijacking SSLContext methods now...")
        console.log("[-] Waiting for the app to invoke SSLContext.init()...")

        SSLContext.init.overload("[Ljavax.net.ssl.KeyManager;", "[Ljavax.net.ssl.TrustManager;", "java.security.SecureRandom").implementation = function(a,b,c) {
            console.log("[o] App invoked javax.net.ssl.SSLContext.init...");
            SSLContext.init.overload("[Ljavax.net.ssl.KeyManager;", "[Ljavax.net.ssl.TrustManager;", "java.security.SecureRandom").call(this, a, tmf.getTrustManagers(), c);
            console.log("[+] SSLContext initialized with our custom TrustManager!");
        }
    });
},0);