[DRMLab Project ] Extracting Widevine L1 from an eMMC Dump (MSTAR Devices)

[DRM]

What You Need
• An eMMC dump (usually the largest file)
• Windows, Linux or macOS
• Hex editor or tools like strings, grep
• Provisioning Script ( can be used and VT )
• Basic understanding of DRM flows

2️⃣ Identifying the Correct eMMC Dump

✔ File Size
• Usually 4–8 GB
• Sometimes 15 GB+ (TV models)

➡️ Always pick the largest dump file

✔ Detecting MSTAR Devices looking for on userdata

Open the dump and check the beginning:

MBOOT

If it starts with MBOOT, the device uses an MSTAR SoC
(common for TVs and set-top boxes).

3️⃣ Locating the Widevine Keybox

❌ What is NOT the keybox
• Files like:
• bgroupcert.dat
• zgpriv.dat
• Dumps containing many MSTAR_SECURE blocks
→ most of them are garbage

✅ How to Spot the Real Widevine Keybox

Search inside the dump for:

MSTAR_SECURE

�� Key insight: the LENGTH matters

A real Widevine keybox usually contains:
• Around 6 lines of HEX data immediately after MSTAR_SECURE

Examples:
• 3–4 lines → ❌ not a keybox
• Very large data → ❌ not a keybox
• ~6 lines → ✅ likely the keybox

This is how experienced people recognize it instantly.

build.prop — Why It’s Needed?

build.prop is used to generate:

�� device_client_id_blob

Search in the dump for:

ro.build.fingerprint=

�� Required Properties Mapping

device_client_id field
build.prop property
company_name
ro.product.manufacturer
model_name
ro.product.model
architecture_name
ro.product.cpu.abi
device_name
ro.product.device
product_name
ro.product.name
build_info
ro.build.fingerprint

⚠️ If build.prop is missing:
• L1 can still work
• Metadata will just be generic
• Lifetime remains the same (5 hours)

MSTAR AES KEY

0007FF4154534D92FC55AA0FFF0110E0

Questions, Suggestions, Discussing, hints, fix, issue use DRMLab Discord Server

https://discord.gg/bexEz5KypW

Tools & Scripts

https://git.drmlab.io

[notaghost]

Disclaimer if you use any public provisional script it’ll kill working keyboard in 1-2 days

[DRM]

Yes if he dont use new API but you aways can provision it manually and will not have issue you also can provision it with VT public provision script will work if use right build.prop for now after I do manual 9 days and still are isnt revoked, on leak of widevine partners can found a right way to provision it

[sleepinfinity]

I have tried that with two keyboxes from two different dumps, but i always get this error from the google provision api :
{'error': {'code': 400, 'message': 'Invalid Value', 'errors': [{'message': 'Invalid Value', 'domain': 'global', 'reason': 'invalid'}]}}

Am i doing something wrong ?

[DRM]

I have tried that with two keyboxes from two different dumps, but i always get this error from the google provision api :
{'error': {'code': 400, 'message': 'Invalid Value', 'errors': [{'message': 'Invalid Value', 'domain': 'global', 'reason': 'invalid'}]}}

Am i doing something wrong ?

REVOKED it’s hard to found good and not revoked cert from public dumps

[sleepinfinity]

I have tried that with two keyboxes from two different dumps, but i always get this error from the google provision api :
{'error': {'code': 400, 'message': 'Invalid Value', 'errors': [{'message': 'Invalid Value', 'domain': 'global', 'reason': 'invalid'}]}}

Am i doing something wrong ?

REVOKED it’s hard to found good and not revoked cert from public dumps

Thanks for your reply
Can you suggest me a device model i can buy today and dump it ?

[DRM]

I have tried that with two keyboxes from two different dumps, but i always get this error from the google provision api :
{'error': {'code': 400, 'message': 'Invalid Value', 'errors': [{'message': 'Invalid Value', 'domain': 'global', 'reason': 'invalid'}]}}

Am i doing something wrong ?

REVOKED it’s hard to found good and not revoked cert from public dumps

Thanks for your reply
Can you suggest me a device model i can buy today and dump it ?

Nobody can answer you on that question nobody know which dump will be already revoked or not you can download manual everyone and try or need to dump by yourself from your own device