# Frida Tutorial

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## Installazione

Installa **frida tools**:
```bash
pip install frida-tools
pip install frida
```
**Scarica e installa** nel android il **frida server** ([Scarica l'ultima versione](https://github.com/frida/frida/releases)).\
Comando per riavviare adb in modalità root, connettersi ad esso, caricare frida-server, dare permessi di esecuzione e eseguirlo in background:
```bash
adb root; adb connect localhost:6000; sleep 1; adb push frida-server /data/local/tmp/; adb shell "chmod 755 /data/local/tmp/frida-server"; adb shell "/data/local/tmp/frida-server &"
```
**Controlla** se sta **funzionando**:
```bash
frida-ps -U #List packages and processes
frida-ps -U | grep -i <part_of_the_package_name> #Get all the package name
```
## Tutorial

### [Tutorial 1](frida-tutorial-1.md)

**Da**: [https://medium.com/infosec-adventures/introduction-to-frida-5a3f51595ca1](https://medium.com/infosec-adventures/introduction-to-frida-5a3f51595ca1)\
**APK**: [https://github.com/t0thkr1s/frida-demo/releases](https://github.com/t0thkr1s/frida-demo/releases)\
**Codice sorgente**: [https://github.com/t0thkr1s/frida-demo](https://github.com/t0thkr1s/frida-demo)

**Segui il [link per leggerlo](frida-tutorial-1.md).**

### [Tutorial 2](frida-tutorial-2.md)

**Da**: [https://11x256.github.io/Frida-hooking-android-part-2/](https://11x256.github.io/Frida-hooking-android-part-2/) (Parti 2, 3 & 4)\
**APK e codice sorgente**: [https://github.com/11x256/frida-android-examples](https://github.com/11x256/frida-android-examples)

**Segui il [link per leggerlo.](frida-tutorial-2.md)**

### [Tutorial 3](owaspuncrackable-1.md)

**Da**: [https://joshspicer.com/android-frida-1](https://joshspicer.com/android-frida-1)\
**APK**: [https://github.com/OWASP/owasp-mstg/blob/master/Crackmes/Android/Level_01/UnCrackable-Level1.apk](https://github.com/OWASP/owasp-mstg/blob/master/Crackmes/Android/Level_01/UnCrackable-Level1.apk)

**Segui il [link per leggerlo](owaspuncrackable-1.md).**

**Puoi trovare altri fantastici script Frida qui:** [**https://codeshare.frida.re/**](https://codeshare.frida.re)

## Esempi rapidi

### Chiamare Frida dalla riga di comando
```bash
frida-ps -U

#Basic frida hooking
frida -l disableRoot.js -f owasp.mstg.uncrackable1

#Hooking before starting the app
frida -U --no-pause -l disableRoot.js -f owasp.mstg.uncrackable1
#The --no-pause and -f options allow the app to be spawned automatically,
#frozen so that the instrumentation can occur, and the automatically
#continue execution with our modified code.
```
### Script Python di Base
```python
import frida, sys

jscode = open(sys.argv[0]).read()
process = frida.get_usb_device().attach('infosecadventures.fridademo')
script = process.create_script(jscode)
print('[ * ] Running Frida Demo application')
script.load()
sys.stdin.read()
```
### Hooking functions without parameters

Collegare la funzione `a()` della classe `sg.vantagepoint.a.c`
```javascript
Java.perform(function () {
;  rootcheck1.a.overload().implementation = function() {
rootcheck1.a.overload().implementation = function() {
send("sg.vantagepoint.a.c.a()Z   Root check 1 HIT!  su.exists()");
return false;
};
});
```
Collegare java `exit()`
```javascript
var sysexit = Java.use("java.lang.System")
sysexit.exit.overload("int").implementation = function (var_0) {
send("java.lang.System.exit(I)V  // We avoid exiting the application  :)")
}
```
Collegare MainActivity `.onStart()` e `.onCreate()`
```javascript
var mainactivity = Java.use("sg.vantagepoint.uncrackable1.MainActivity")
mainactivity.onStart.overload().implementation = function () {
send("MainActivity.onStart() HIT!!!")
var ret = this.onStart.overload().call(this)
}
mainactivity.onCreate.overload("android.os.Bundle").implementation = function (
var_0
) {
send("MainActivity.onCreate() HIT!!!")
var ret = this.onCreate.overload("android.os.Bundle").call(this, var_0)
}
```
Collegare android `.onCreate()`
```javascript
var activity = Java.use("android.app.Activity")
activity.onCreate.overload("android.os.Bundle").implementation = function (
var_0
) {
send("Activity HIT!!!")
var ret = this.onCreate.overload("android.os.Bundle").call(this, var_0)
}
```
### Hooking functions with parameters and retrieving the value

Hooking una funzione di decrittazione. Stampa l'input, chiama la funzione originale per decrittare l'input e infine, stampa i dati in chiaro:
```javascript
function getString(data) {
var ret = ""
for (var i = 0; i < data.length; i++) {
ret += data[i].toString()
}
return ret
}
var aes_decrypt = Java.use("sg.vantagepoint.a.a")
aes_decrypt.a.overload("[B", "[B").implementation = function (var_0, var_1) {
send("sg.vantagepoint.a.a.a([B[B)[B   doFinal(enc)  // AES/ECB/PKCS7Padding")
send("Key       : " + getString(var_0))
send("Encrypted : " + getString(var_1))
var ret = this.a.overload("[B", "[B").call(this, var_0, var_1)
send("Decrypted : " + ret)

var flag = ""
for (var i = 0; i < ret.length; i++) {
flag += String.fromCharCode(ret[i])
}
send("Decrypted flag: " + flag)
return ret //[B
}
```
### Hooking functions and calling them with our input

Collegare una funzione che riceve una stringa e chiamarla con un'altra stringa (da [qui](https://11x256.github.io/Frida-hooking-android-part-2/))
```javascript
var string_class = Java.use("java.lang.String") // get a JS wrapper for java's String class

my_class.fun.overload("java.lang.String").implementation = function (x) {
//hooking the new function
var my_string = string_class.$new("My TeSt String#####") //creating a new String by using `new` operator
console.log("Original arg: " + x)
var ret = this.fun(my_string) // calling the original function with the new String, and putting its return value in ret variable
console.log("Return value: " + ret)
return ret
}
```
### Ottenere un oggetto già creato di una classe

Se vuoi estrarre un attributo di un oggetto creato, puoi usare questo.

In questo esempio vedrai come ottenere l'oggetto della classe my_activity e come chiamare la funzione .secret() che stamperà un attributo privato dell'oggetto:
```javascript
Java.choose("com.example.a11x256.frida_test.my_activity", {
onMatch: function (instance) {
//This function will be called for every instance found by frida
console.log("Found instance: " + instance)
console.log("Result of secret func: " + instance.secret())
},
onComplete: function () {},
})
```
## Altri tutorial su Frida

- [https://github.com/DERE-ad2001/Frida-Labs](https://github.com/DERE-ad2001/Frida-Labs)
- [Parte 1 della serie di blog sull'uso avanzato di Frida: Librerie di crittografia IOS](https://8ksec.io/advanced-frida-usage-part-1-ios-encryption-libraries-8ksec-blogs/)


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