From e5fb27c8f9cc06beb80e4817eff41d9c212201fd Mon Sep 17 00:00:00 2001
From: Enginex0 <enginex0@users.noreply.github.com>
Date: Mon, 9 Mar 2026 20:00:14 +0100
Subject: [PATCH] fix(attestation): null out all-zero verifiedBootHash from TEE
 cache

Matches the existing verifiedBootKey null-zero guard. When the TEE
returns a zeroed hash, fall through to the system property or random
fallback instead of embedding a detectable all-zero value.
---
 .../TEESimulator/attestation/DeviceAttestationService.kt      | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/app/src/main/java/org/matrix/TEESimulator/attestation/DeviceAttestationService.kt b/app/src/main/java/org/matrix/TEESimulator/attestation/DeviceAttestationService.kt
index f6451bc..114ad3d 100644
--- a/app/src/main/java/org/matrix/TEESimulator/attestation/DeviceAttestationService.kt
+++ b/app/src/main/java/org/matrix/TEESimulator/attestation/DeviceAttestationService.kt
@@ -249,6 +249,10 @@ object DeviceAttestationService {
                 verifiedBootKey = null
             }
 
+            if (verifiedBootHash?.all { it == 0.toByte() } == true) {
+                verifiedBootHash = null
+            }
+
             SystemLogger.info(
                 "Successfully extracted attestation data: version=$attestVersion, osVersion=$osVersion, osPatch=$osPatchLevel, vendorPatch=$vendorPatchLevel, bootPatch=$bootPatchLevel, moduleHash=${moduleHash?.toHex()}, bootKey=${verifiedBootKey?.toHex()}, bootHash=${verifiedBootHash?.toHex()}"
             )