Support downloading Viber stickers

[princo1415]

Hello Mr laggy killer.Does this app now support viber stickers exportation and if not ,what's the reason,is it because it's end to end encrypted

Best regards,

[laggykiller]

v2.8.5 adds support for Viber sticker download and compressing files to Viber-compliant 490x490 png files, but not exporting.

I have attempted to reverse engineer Viber Android app. To export Viber stickers, we need to get member_id and udid, which should be the same for each user but not sure where they could be obtained. Even worse, we need to get m_token, which is changed everytime when app is restarted, and I have no idea how I can automatically get it.

This is best attempt for exporting Viber sticker, which obviously won't work:

import requests
import time

viber_version = "22.4.3.0"
user_agent = f"Mozilla/5.0 (Linux; Android 11; Android SDK built for x86 Build/RSR1.210210.001.A1; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/83.0.4103.106 Mobile Safari/537.36 Viber/{viber_version}"

# Zip file containing 490x490 png images to upload (00.png, 01.png, ...)
with open("upload.zip", "rb") as f: 
    result = requests.post(
        "https://market.api.viber.com/2/users/custom-sticker-packs/create",
        files={
            "file": ("upload.zip", f)
        },
        data={
            "member_id": "REDACTED",  # Same for each user
            "m_token": "REDACTED",  # Changed when app is restarted
            "m_ts": str(int(time.time() * 1000)),
            "title": "my-custom-pack",
            "description": "My custom viber sticker pack",
            "shareable": "1",
            "udid": "REDACTED",  # Same for each user
            "phone_country": "US",
            "mcc": "000",  # Mobile Country Codes, see https://mcc-mnc.com/
            "mnc": "000",  # Mobile Network Codes, see https://mcc-mnc.com/
            "vv": viber_version,
            "sid": "1",
            "lang": "en",
            "privacy_flags": "7",
        },
        headers={
            "User-Agent": user_agent
        }
    )

    print(result.text)  # status should be 1 if success

If anyone want to reverse the Android app, I recommend using PCAPdroid on rooted Android emulator with mitm addon, with MagiskTrustUserCerts. Jadx decompilation might also be useful.

We can also analyze Windows version of Viber, but I am not familiar with it. What makes matter worse, Viber Windows start to store database with encrypted SQLCipher (Russian forum, use Google translate: https://4pda.to/forum/index.php?showtopic=714685&view=findpost&p=125818765), which means things like udid might be locked behind a database that is decrypted with unknown way.

Anyway, I don't think this is high prority and I probably won't continue investigating, as:

• Few people use Viber
• Viber automatically converts image to compliant format, which means it is already easy to create stickers using official Viber app.

If someone has solution, please comment / submit PR, thank you.

[princo1415]

Thank you for the thorough explanation. I meant to download to png format files not exporting. so that should work fine in the v2.8.5 version right? I need them to png files so I can import them to Signal app.

Kind regards,

[laggykiller]

You are correct, you can download Viber stickers in v2.8.5+, but not able to upload. Please try.

[laggykiller]

I am closing this, issue of adding support for exporting Viber stickers is moved to #146