abbuaus / reprogram-tee-on-qualcomm-devices

Guide to reprogram the TEE on Qualcomm devices to fix lost attestation keys

Reprogram TEE on Qualcomm devices

Guide to reprogram the TEE on Qualcomm devices to fix lost attestation keys.

Why?

If you are here it is because your phone has lost the TEE attestation keys, possibly due to flashing the persist partition of your phone.

If opening Key Attestation Demo does not give you any error, do NOT follow this guide.

If you want to pass the Strong verdict from Play Integrity you could, but that is not the purpose of this guide and I will NOT provide instructions for that.

WARNINGS:

• Your data will be lost, so backup your phone data first.
• The original keys that your phone may include in the TEE will be lost.
• I am not responsible for any other problems that may arise, these instructions are made on a POCO X3 Pro (vayu) and work perfectly, they may not work as they should on other phones.

You will need:

• A working brain.
• A working computer.
• An unlocked bootloader.
• A valid keybox.xml file, you can use this one in the repo.
• The engineering ROM for your device.

Instructions:

1. Flash engineering ROM.
2. Phone must be connected to PC, then execute this commands IN ORDER:

adb root

adb disable-verity

adb reboot

adb root

adb remount

adb shell mkdir –p /data/nativetest64/qti_keymaster_tests/

adb push keybox.xml /data/nativetest64/qti_keymaster_tests/

adb shell

cd /data/nativetest64/qti_keymaster_tests/

LD_LIBRARY_PATH=/vendor/lib64/hw KmInstallKeybox {KEYBOX FILE} {KEYBOX DEVICE ID} {ATTEST PROPS?}

{KEYBOX FILE}: Should be "keybox.xml"

{KEYBOX DEVICE ID}: Open keybox file and search for "DeviceID", repo keybox uses "X705F100000000"

{ATTEST PROPS?}: Boolean, should be true/false, I recommend setting it as false always, not all TEE support this.

So, for the keybox in the repo you must run:

LD_LIBRARY_PATH=/vendor/lib64/hw KmInstallKeybox keybox.xml X705F100000000 false