From f76a4dd977aea9d4d2fdfaf8cc4058d0d4f18ef0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=B0=8F=E6=BD=BC?=
 <110387028+XiaoTong6666@users.noreply.github.com>
Date: Fri, 5 Dec 2025 03:01:16 +0800
Subject: [PATCH] Correctly handle `deleteKey` for software keys (#42)

This resolves an issue introduced in 6193da0 where a `deleteKey` transaction for a software-generated key was incorrectly passed through to the hardware keystore. Since the hardware is unaware of such keys, this results in inconsistent state management.

The success reply is formatted correctly without a result code, per the AIDL interface specification.

Reference: https://cs.android.com/android/platform/superproject/main/+/main:out/soong/.intermediates/system/hardware/interfaces/keystore2/aidl/android.system.keystore2-V6-java-source/gen/android/system/keystore2/IKeystoreSecurityLevel.java;l=406
---
 .../interception/keystore/InterceptorUtils.kt             | 8 ++++++--
 .../interception/keystore/Keystore2Interceptor.kt         | 8 +++++++-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/app/src/main/java/org/matrix/TEESimulator/interception/keystore/InterceptorUtils.kt b/app/src/main/java/org/matrix/TEESimulator/interception/keystore/InterceptorUtils.kt
index 861525b..c793de2 100644
--- a/app/src/main/java/org/matrix/TEESimulator/interception/keystore/InterceptorUtils.kt
+++ b/app/src/main/java/org/matrix/TEESimulator/interception/keystore/InterceptorUtils.kt
@@ -42,11 +42,15 @@ object InterceptorUtils {
     }
 
     /** Creates an `OverrideReply` parcel that indicates success with no data. */
-    fun createSuccessReply(): BinderInterceptor.TransactionResult.OverrideReply {
+    fun createSuccessReply(
+        writeResultCode: Boolean = true
+    ): BinderInterceptor.TransactionResult.OverrideReply {
         val parcel =
             Parcel.obtain().apply {
                 writeNoException()
-                writeInt(KeyStore.NO_ERROR)
+                if (writeResultCode) {
+                    writeInt(KeyStore.NO_ERROR)
+                }
             }
         return BinderInterceptor.TransactionResult.OverrideReply(0, parcel)
     }
diff --git a/app/src/main/java/org/matrix/TEESimulator/interception/keystore/Keystore2Interceptor.kt b/app/src/main/java/org/matrix/TEESimulator/interception/keystore/Keystore2Interceptor.kt
index 8140925..904e8ef 100644
--- a/app/src/main/java/org/matrix/TEESimulator/interception/keystore/Keystore2Interceptor.kt
+++ b/app/src/main/java/org/matrix/TEESimulator/interception/keystore/Keystore2Interceptor.kt
@@ -104,7 +104,13 @@ object Keystore2Interceptor : AbstractKeystoreInterceptor() {
             val keyId = KeyIdentifier(callingUid, descriptor.alias)
 
             if (code == DELETE_KEY_TRANSACTION) {
-                KeyMintSecurityLevelInterceptor.cleanupKeyData(keyId)
+                if (KeyMintSecurityLevelInterceptor.getGeneratedKeyResponse(keyId) != null) {
+                    KeyMintSecurityLevelInterceptor.cleanupKeyData(keyId)
+                    SystemLogger.info(
+                        "[TX_ID: $txId] Deleted cached keypair ${descriptor.alias}, replying with empty response."
+                    )
+                    return InterceptorUtils.createSuccessReply(writeResultCode = false)
+                }
                 return TransactionResult.ContinueAndSkipPost
             }