hacktricks/src/mobile-pentesting/android-app-pentesting/frida-tutorial/frida-tutorial-1.md

# Frida Tutorial 1

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**Hii ni muhtasari wa chapisho**: [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)\
**Msimbo wa Chanzo**: [https://github.com/t0thkr1s/frida-demo](https://github.com/t0thkr1s/frida-demo)

## Python

Frida inakuwezesha **kuingiza msimbo wa JavaScript** ndani ya kazi za programu inayotembea. Lakini unaweza kutumia **python** **kuita** viungio na hata **kuingiliana** na **viungio**.

Hii ni skripti rahisi ya python ambayo unaweza kutumia na mifano yote iliyopendekezwa katika tutorial hii:
```python
#hooking.py
import frida, sys

with open(sys.argv[1], 'r') as f:
jscode = f.read()
process = frida.get_usb_device().attach('infosecadventures.fridademo')
script = process.create_script(jscode)
print('[ * ] Running Frida Demo application')
script.load()
sys.stdin.read()
```
Call the script:
```bash
python hooking.py <hookN.js>
```
Ni muhimu kujua jinsi ya kutumia python na frida, lakini kwa mifano hii unaweza pia kuita moja kwa moja Frida ukitumia zana za amri za frida:
```bash
frida -U --no-pause -l hookN.js -f infosecadventures.fridademo
```
## Hook 1 - Boolean Bypass

Hapa unaweza kuona jinsi ya **hook** njia ya **boolean** (_checkPin_) kutoka darasa: _infosecadventures.fridademo.utils.PinUtil_
```javascript
//hook1.js
Java.perform(function () {
console.log("[ * ] Starting implementation override...")
var MainActivity = Java.use("infosecadventures.fridademo.utils.PinUtil")
MainActivity.checkPin.implementation = function (pin) {
console.log("[ + ] PIN check successfully bypassed!")
return true
}
})
```

```
python hooking.py hook1.js
```
Tazama: Kazi inapata kama parameter String, je, si lazima overload?

## Hook 2 - Function Bruteforce

### Kazi Isiyo ya Kawaida

Ikiwa unataka kuita kazi isiyo ya kawaida ya darasa, **kwanza unahitaji mfano** wa darasa hilo. Kisha, unaweza kutumia mfano huo kuita kazi hiyo.\
Ili kufanya hivyo, unaweza **kupata mfano uliopo** na kuutumia:
```javascript
Java.perform(function () {
console.log("[ * ] Starting PIN Brute-force, please wait...")
Java.choose("infosecadventures.fridademo.utils.PinUtil", {
onMatch: function (instance) {
console.log("[ * ] Instance found in memory: " + instance)
for (var i = 1000; i < 9999; i++) {
if (instance.checkPin(i + "") == true) {
console.log("[ + ] Found correct PIN: " + i)
break
}
}
},
onComplete: function () {},
})
})
```
Katika kesi hii hii haifanyi kazi kwani hakuna mfano wowote na kazi ni Static

### Static Function

Ikiwa kazi ni static, unaweza kuikalia tu:
```javascript
//hook2.js
Java.perform(function () {
console.log("[ * ] Starting PIN Brute-force, please wait...")
var PinUtil = Java.use("infosecadventures.fridademo.utils.PinUtil")

for (var i = 1000; i < 9999; i++) {
if (PinUtil.checkPin(i + "") == true) {
console.log("[ + ] Found correct PIN: " + i)
}
}
})
```
## Hook 3 - Kupata hoja na thamani ya kurudi

Unaweza kuunganisha kazi na kufanya iwe **chapishe** thamani ya **hoja zilizopitishwa** na thamani ya **kurudi:**
```javascript
//hook3.js
Java.perform(function () {
console.log("[ * ] Starting implementation override...")

var EncryptionUtil = Java.use(
"infosecadventures.fridademo.utils.EncryptionUtil"
)
EncryptionUtil.encrypt.implementation = function (key, value) {
console.log("Key: " + key)
console.log("Value: " + value)
var encrypted_ret = this.encrypt(key, value) //Call the original function
console.log("Encrypted value: " + encrypted_ret)
return encrypted_ret
}
})
```
## Muhimu

Katika tutorial hii umeshikilia mbinu ukitumia jina la mbinu na _.implementation_. Lakini kama kuna **mbinu zaidi ya moja** zenye jina sawa, utahitaji **kueleza mbinu** unayotaka kushikilia **ukionyesha aina ya hoja**.

Unaweza kuona hilo katika [tutorial inayofuata](frida-tutorial-2.md).


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