docs(release): add v5.1.1 changelog for pre-stash restoration fixes

EC keys don't support DECRYPT (only AGREE_KEY for key derivation).
Without this guard, an EC DECRYPT operation creates a CipherPrimitive
that fails with a confusing JCA error instead of returning
UNSUPPORTED_PURPOSE upfront.

app/build.gradle.kts

@@ -29,7 +29,7 @@ val gitExecutor = objects.newInstance(GitExecutor::class.java)
 
 val gitCommitCount = gitExecutor.execute("git rev-list HEAD --count", rootDir).toInt()
 val gitCommitHash = gitExecutor.execute("git rev-parse --verify --short HEAD", rootDir)
-val verName = "v5.1"
+val verName = "v5.1.1"
 
 android {
     namespace = "org.matrix.TEESimulator"

app/src/main/java/org/matrix/TEESimulator/attestation/AttestationBuilder.kt

@@ -516,6 +516,11 @@ object AttestationBuilder {
                 )
             )
         }
+        if (params.callerNonce == true) {
+            list.add(
+                DERTaggedObject(true, AttestationConstants.TAG_CALLER_NONCE, DERNull.INSTANCE)
+            )
+        }
         if (params.unlockedDeviceRequired == true) {
             list.add(
                 DERTaggedObject(

app/src/main/java/org/matrix/TEESimulator/attestation/KeyMintAttestation.kt

@@ -157,7 +157,7 @@ data class KeyMintAttestation(
 
 /** Maps to AOSP field = Integer */
 private fun Array<KeyParameter>.findBoolean(tag: Int): Boolean? =
-    this.find { it.tag == tag }?.value?.boolValue
+    if (this.any { it.tag == tag }) true else null
 
 /** Maps to AOSP field = Integer */
 private fun Array<KeyParameter>.findInteger(tag: Int): Int? =

app/src/main/java/org/matrix/TEESimulator/config/ConfigurationManager.kt

@@ -250,9 +250,14 @@ object ConfigurationManager {
                 )
             }
 
-            // Parse global and per-package configurations.
-            val newGlobalLevel = parseLines(contextLines[""])
-            contextLines.remove("") // Remove global context to iterate over packages next
+            var newGlobalLevel = parseLines(contextLines[""])
+            contextLines.remove("")
+
+            // system=prop means all components should derive from device props
+            if (newGlobalLevel?.system.equals("prop", ignoreCase = true)) {
+                SystemLogger.info("system=prop: forcing boot/vendor to derive from device props")
+                newGlobalLevel = newGlobalLevel?.copy(boot = "prop", vendor = "prop")
+            }
 
             for ((pkg, lines) in contextLines) {
                 parseLines(lines)?.let { newPackageLevels[pkg] = it }
@@ -282,8 +287,10 @@ object ConfigurationManager {
 
             val file = if (event != DELETE) File(configRoot, path) else null
             when (path) {
-                TARGET_PACKAGES_FILE -> loadTargetPackages(file!!)
-                PATCH_LEVEL_FILE -> loadPatchLevelConfig(file!!)
+                TARGET_PACKAGES_FILE -> file?.let { loadTargetPackages(it) }
+                    ?: SystemLogger.warning("$TARGET_PACKAGES_FILE was deleted.")
+                PATCH_LEVEL_FILE -> file?.let { loadPatchLevelConfig(it) }
+                    ?: SystemLogger.warning("$PATCH_LEVEL_FILE was deleted.")
                 // Any change to an XML file is assumed to be a keybox.
                 // The cache in KeyBoxManager will handle reloading it on its next use.
                 else ->

app/src/main/java/org/matrix/TEESimulator/interception/keystore/Keystore2Interceptor.kt

@@ -61,8 +61,8 @@ object Keystore2Interceptor : AbstractKeystoreInterceptor() {
             .associate { field -> (field.get(null) as Int) to field.name.split("_")[1] }
     }
 
-    // Keys whose certs were updated via updateSubcomponent; skip re-patching on getKeyEntry.
     private val userUpdatedKeys = ConcurrentHashMap.newKeySet<KeyIdentifier>()
+    private val deletedSoftwareKeys = ConcurrentHashMap.newKeySet<KeyIdentifier>()
 
     // Backdoor binder for registering new interceptors at runtime.
     private var backdoorBinder: IBinder? = null
@@ -225,6 +225,7 @@ object Keystore2Interceptor : AbstractKeystoreInterceptor() {
                         KeyMintSecurityLevelInterceptor.generatedKeys.containsKey(keyId)
                     KeyMintSecurityLevelInterceptor.cleanupKeyData(keyId)
                     if (isSoftwareKey) {
+                        deletedSoftwareKeys.add(keyId)
                         SystemLogger.info(
                             "[TX_ID: $txId] Deleted cached keypair ${keyId.alias}, replying with empty response."
                         )
@@ -239,6 +240,10 @@ object Keystore2Interceptor : AbstractKeystoreInterceptor() {
             }
             val keyId = KeyIdentifier(callingUid, descriptor.alias)
 
+            if (deletedSoftwareKeys.remove(keyId)) {
+                return InterceptorUtils.createErrorReply(7) // KEY_NOT_FOUND
+            }
+
             val response =
                 KeyMintSecurityLevelInterceptor.getGeneratedKeyResponse(keyId)
                     ?: return TransactionResult.Continue
@@ -387,13 +392,13 @@ object Keystore2Interceptor : AbstractKeystoreInterceptor() {
                                 callingUid,
                             )
 
-                        val newNspace = SecureRandom().nextLong()
-                        response.metadata.key?.let { it.nspace = newNspace }
+                        val key = response.metadata.key!!
+                        key.nspace = SecureRandom().nextLong()
                         KeyMintSecurityLevelInterceptor.generatedKeys[keyId] =
                             KeyMintSecurityLevelInterceptor.GeneratedKeyInfo(
                                 keyData.first,
                                 null,
-                                newNspace,
+                                key.nspace,
                                 response,
                                 parsedParameters,
                             )

app/src/main/java/org/matrix/TEESimulator/interception/keystore/shim/KeyMintSecurityLevelInterceptor.kt

@@ -1,6 +1,7 @@
 package org.matrix.TEESimulator.interception.keystore.shim
 
 import android.hardware.security.keymint.Algorithm
+import android.hardware.security.keymint.EcCurve
 import android.hardware.security.keymint.KeyOrigin
 import android.hardware.security.keymint.KeyParameter
 import android.hardware.security.keymint.KeyParameterValue
@@ -20,7 +21,10 @@ import java.security.KeyFactory
 import java.security.cert.CertificateFactory
 import java.security.spec.PKCS8EncodedKeySpec
 import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.ConcurrentLinkedDeque
 import java.util.concurrent.Executors
+import java.util.concurrent.atomic.AtomicInteger
+import java.util.concurrent.locks.LockSupport
 import org.matrix.TEESimulator.attestation.AttestationBuilder
 import org.matrix.TEESimulator.attestation.AttestationConstants
 import org.matrix.TEESimulator.attestation.AttestationPatcher
@@ -47,7 +51,9 @@ class KeyMintSecurityLevelInterceptor(
     private val securityLevel: Int,
 ) : BinderInterceptor() {
 
-    // --- Data Structures for State Management ---
+    private val recentOps = ConcurrentHashMap<Int, ConcurrentLinkedDeque<Long>>()
+    private val activeOps = ConcurrentHashMap<Int, ConcurrentLinkedDeque<SoftwareOperation>>()
+
     data class GeneratedKeyInfo(
         val keyPair: KeyPair?,
         val secretKey: javax.crypto.SecretKey?,
@@ -233,11 +239,31 @@ class KeyMintSecurityLevelInterceptor(
         return TransactionResult.SkipTransaction
     }
 
-    /**
-     * Handles the `createOperation` transaction. It checks if the operation is for a key that was
-     * generated in software. If so, it creates a software-based operation handler. Otherwise, it
-     * lets the call proceed to the real hardware service.
-     */
+    private fun trackAndEnforceOpLimit(callingUid: Int, securityLevel: Int) {
+        if (securityLevel != SecurityLevel.STRONGBOX) return
+        val timestamps = recentOps.computeIfAbsent(callingUid) { ConcurrentLinkedDeque() }
+        val cutoff = System.nanoTime() - STRONGBOX_OP_WINDOW_NS
+        timestamps.removeIf { it < cutoff }
+        if (timestamps.size >= STRONGBOX_MAX_CONCURRENT_OPS) {
+            throw android.os.ServiceSpecificException(
+                KEYMINT_TOO_MANY_OPERATIONS,
+                "StrongBox op limit reached for uid=$callingUid"
+            )
+        }
+        timestamps.addLast(System.nanoTime())
+    }
+
+    private fun pruneOpsForUid(callingUid: Int, newOp: SoftwareOperation) {
+        val ops = activeOps.computeIfAbsent(callingUid) { ConcurrentLinkedDeque() }
+        ops.removeIf { it.isFinalized }
+        while (ops.size >= MAX_CONCURRENT_OPS_PER_UID) {
+            val oldest = ops.pollFirst() ?: break
+            oldest.abort()
+            SystemLogger.debug("Pruned oldest op for uid=$callingUid (LRU eviction)")
+        }
+        ops.addLast(newOp)
+    }
+
     private fun handleCreateOperation(
         txId: Long,
         callingUid: Int,
@@ -279,6 +305,8 @@ class KeyMintSecurityLevelInterceptor(
             "[TX_ID: $txId] Creating SOFTWARE operation for key ${generatedKeyInfo.nspace}."
         )
 
+        trackAndEnforceOpLimit(callingUid, securityLevel)
+
         val opParams = data.createTypedArray(KeyParameter.CREATOR)!!
         val parsedOpParams = KeyMintAttestation(opParams)
         val forced = data.readBoolean()
@@ -300,7 +328,8 @@ class KeyMintSecurityLevelInterceptor(
             (isAsymmetric &&
                 (requestedPurpose == KeyPurpose.VERIFY ||
                     requestedPurpose == KeyPurpose.ENCRYPT)) ||
-                (requestedPurpose == KeyPurpose.AGREE_KEY && algorithm != Algorithm.EC)
+                (requestedPurpose == KeyPurpose.AGREE_KEY && algorithm != Algorithm.EC) ||
+                (algorithm == Algorithm.EC && requestedPurpose == KeyPurpose.DECRYPT)
         if (unsupported) {
             return InterceptorUtils.createServiceSpecificErrorReply(
                 KeystoreErrorCode.UNSUPPORTED_PURPOSE
@@ -371,13 +400,16 @@ class KeyMintSecurityLevelInterceptor(
                 // override purpose from the operation params.
                 val effectiveParams =
                     keyParams.copy(purpose = parsedOpParams.purpose, digest = parsedOpParams.digest.ifEmpty { keyParams.digest })
+                val opLatency = if (securityLevel == SecurityLevel.STRONGBOX) STRONGBOX_OP_LATENCY_FLOOR_MS else 0L
                 val softwareOperation =
                     SoftwareOperation(
                         txId,
                         generatedKeyInfo.keyPair,
                         generatedKeyInfo.secretKey,
                         effectiveParams,
+                        opLatency,
                     )
+                pruneOpsForUid(callingUid, softwareOperation)
 
                 // Decrement usage counter on finish; delete key when exhausted.
                 if (keyParams.usageCountLimit != null && resolvedKeyId != null) {
@@ -424,6 +456,11 @@ class KeyMintSecurityLevelInterceptor(
      * either generates a key in software or lets the call pass through to the hardware.
      */
     private fun handleGenerateKey(txId: Long, callingUid: Int, callingPid: Int, data: Parcel): TransactionResult {
+        if (data.dataSize() > MAX_ALIAS_LENGTH) {
+            SystemLogger.warning("Skipping oversized transaction: ${data.dataSize()} bytes")
+            return InterceptorUtils.createErrorReply(KEYMINT_INVALID_INPUT_LENGTH)
+        }
+
         return runCatching {
                 data.enforceInterface(IKeystoreSecurityLevel.DESCRIPTOR)
                 val keyDescriptor = data.readTypedObject(KeyDescriptor.CREATOR)
@@ -494,6 +531,11 @@ class KeyMintSecurityLevelInterceptor(
 
                 val isStrongBox = securityLevel == SecurityLevel.STRONGBOX
 
+                if (isStrongBox && !isStrongBoxCapable(parsedParams)) {
+                    SystemLogger.info("[TX_ID: $txId] StrongBox-unsupported params (algo=${parsedParams.algorithm} size=${parsedParams.keySize}), forwarding to HAL")
+                    return TransactionResult.ContinueAndSkipPost
+                }
+
                 when {
                     forceGenerate -> doSoftwareGeneration(
                         callingUid, keyDescriptor, attestationKey, parsedParams, isAttestKeyRequest
@@ -571,9 +613,15 @@ class KeyMintSecurityLevelInterceptor(
             }
             generatedKeys[keyId] =
                 GeneratedKeyInfo(null, secretKey, keyDescriptor.nspace, response, parsedParams)
+
+            if (securityLevel == SecurityLevel.STRONGBOX) {
+                val delayMs = STRONGBOX_KEYGEN_LATENCY_FLOOR_MS - (System.nanoTime() - genStartNanos) / 1_000_000
+                if (delayMs > 0) LockSupport.parkNanos(delayMs * 1_000_000)
+            } else {
                 TeeLatencySimulator.simulateGenerateKeyDelay(
                     parsedParams.algorithm, System.nanoTime() - genStartNanos
                 )
+            }
             return InterceptorUtils.createTypedObjectReply(metadata)
         }
 
@@ -613,9 +661,14 @@ class KeyMintSecurityLevelInterceptor(
             )
         }
 
+        if (securityLevel == SecurityLevel.STRONGBOX) {
+            val delayMs = STRONGBOX_KEYGEN_LATENCY_FLOOR_MS - (System.nanoTime() - genStartNanos) / 1_000_000
+            if (delayMs > 0) LockSupport.parkNanos(delayMs * 1_000_000)
+        } else {
             TeeLatencySimulator.simulateGenerateKeyDelay(
                 parsedParams.algorithm, System.nanoTime() - genStartNanos
             )
+        }
         return InterceptorUtils.createTypedObjectReply(response.metadata)
     }
 
@@ -900,11 +953,25 @@ class KeyMintSecurityLevelInterceptor(
 
         private const val KEYMINT_INVALID_INPUT_LENGTH = -21
         private const val KEYMINT_INVALID_ARGUMENT = -38
+        private const val KEYMINT_TOO_MANY_OPERATIONS = -29
         private const val INVALID_ARGUMENT = 20
         private const val PERMISSION_DENIED = 6
         private const val SECURE_HW_COMMUNICATION_FAILED = -49
         private const val CANNOT_ATTEST_IDS = -66
 
+        private const val STRONGBOX_KEYGEN_LATENCY_FLOOR_MS = 250L
+        private const val STRONGBOX_OP_LATENCY_FLOOR_MS = 80L
+        private const val STRONGBOX_MAX_CONCURRENT_OPS = 4
+        private const val STRONGBOX_OP_WINDOW_NS = 10_000_000_000L
+        private const val MAX_ALIAS_LENGTH = 256 * 1024
+        private const val MAX_CONCURRENT_OPS_PER_UID = 15
+
+        private fun isStrongBoxCapable(params: KeyMintAttestation): Boolean = when (params.algorithm) {
+            Algorithm.RSA -> params.keySize <= 2048
+            Algorithm.EC -> params.ecCurve == null || params.ecCurve == EcCurve.P_256
+            else -> true
+        }
+
         // Transaction codes for IKeystoreSecurityLevel interface.
         private val GENERATE_KEY_TRANSACTION =
             InterceptorUtils.getTransactCode(IKeystoreSecurityLevel.Stub::class.java, "generateKey")
@@ -998,7 +1065,13 @@ class KeyMintSecurityLevelInterceptor(
             }
         }
 
-        // Clears all cached keys.
+        fun invalidatePatchedChains(reason: String? = null) {
+            val count = patchedChains.size
+            if (count == 0) return
+            patchedChains.clear()
+            SystemLogger.info("Invalidated $count patched cert chains${reason?.let { " due to $it" } ?: ""}.")
+        }
+
         fun clearAllGeneratedKeys(reason: String? = null) {
             val count = generatedKeys.size
             val reasonMessage = reason?.let { " due to $it" } ?: ""
@@ -1069,10 +1142,8 @@ private fun KeyMintAttestation.toAuthorizations(
         )
     }
 
-    if (this.noAuthRequired != null) {
-        authList.add(
-            createAuth(Tag.NO_AUTH_REQUIRED, KeyParameterValue.boolValue(this.noAuthRequired))
-        )
+    if (this.noAuthRequired != false) {
+        authList.add(createAuth(Tag.NO_AUTH_REQUIRED, KeyParameterValue.boolValue(true)))
     }
 
     if (this.callerNonce == true) {

app/src/main/java/org/matrix/TEESimulator/interception/keystore/shim/SoftwareOperation.kt

@@ -15,36 +15,38 @@ import android.system.keystore2.KeyParameters
 import java.security.KeyPair
 import java.security.Signature
 import java.security.SignatureException
+import java.util.concurrent.locks.LockSupport
+import javax.crypto.BadPaddingException
 import javax.crypto.Cipher
+import javax.crypto.IllegalBlockSizeException
 import org.matrix.TEESimulator.attestation.KeyMintAttestation
 import org.matrix.TEESimulator.logging.KeyMintParameterLogger
 import org.matrix.TEESimulator.logging.SystemLogger
 
-/** Keystore2 error codes for ServiceSpecificException. Negative = KeyMint, positive = Keystore. */
 internal object KeystoreErrorCode {
-    const val INVALID_OPERATION_HANDLE = -28
-    const val VERIFICATION_FAILED = -30
-    const val UNSUPPORTED_PURPOSE = -2
-    const val INCOMPATIBLE_PURPOSE = -3
-    const val SYSTEM_ERROR = 4
-    const val TOO_MUCH_DATA = 21
-    const val KEY_EXPIRED = -25
-    const val KEY_NOT_YET_VALID = -24
+    val INVALID_OPERATION_HANDLE: Int by lazy { resolve("ErrorCode", "INVALID_OPERATION_HANDLE", -28) }
+    val VERIFICATION_FAILED: Int by lazy { resolve("ErrorCode", "VERIFICATION_FAILED", -30) }
+    val UNSUPPORTED_PURPOSE: Int by lazy { resolve("ErrorCode", "UNSUPPORTED_PURPOSE", -2) }
+    val INCOMPATIBLE_PURPOSE: Int by lazy { resolve("ErrorCode", "INCOMPATIBLE_PURPOSE", -3) }
+    val INVALID_ARGUMENT: Int by lazy { resolve("ErrorCode", "INVALID_ARGUMENT", -38) }
+    val INVALID_TAG: Int by lazy { resolve("ErrorCode", "INVALID_TAG", -40) }
+    val INVALID_INPUT_LENGTH: Int by lazy { resolve("ErrorCode", "INVALID_INPUT_LENGTH", -21) }
+    val INCOMPATIBLE_KEY: Int by lazy { resolve("ErrorCode", "INCOMPATIBLE_KEY", -31) }
+    val INCOMPATIBLE_ALGORITHM: Int by lazy { resolve("ErrorCode", "INCOMPATIBLE_ALGORITHM", -18) }
+    val KEY_EXPIRED: Int by lazy { resolve("ErrorCode", "KEY_EXPIRED", -25) }
+    val KEY_NOT_YET_VALID: Int by lazy { resolve("ErrorCode", "KEY_NOT_YET_VALID", -24) }
+    val CALLER_NONCE_PROHIBITED: Int by lazy { resolve("ErrorCode", "CALLER_NONCE_PROHIBITED", -55) }
+    val UNKNOWN_ERROR: Int by lazy { resolve("ErrorCode", "UNKNOWN_ERROR", -1000) }
+    val SYSTEM_ERROR: Int by lazy { resolve("ResponseCode", "SYSTEM_ERROR", 4, keystore = true) }
+    val TOO_MUCH_DATA: Int by lazy { resolve("ResponseCode", "TOO_MUCH_DATA", 21, keystore = true) }
+    val PERMISSION_DENIED: Int by lazy { resolve("ResponseCode", "PERMISSION_DENIED", 6, keystore = true) }
+    val KEY_NOT_FOUND: Int by lazy { resolve("ResponseCode", "KEY_NOT_FOUND", 7, keystore = true) }
 
-    /** KeyMint ErrorCode::CALLER_NONCE_PROHIBITED */
-    const val CALLER_NONCE_PROHIBITED = -55
-
-    /** KeyMint ErrorCode::INVALID_ARGUMENT */
-    const val INVALID_ARGUMENT = -38
-
-    /** KeyMint ErrorCode::INVALID_TAG */
-    const val INVALID_TAG = -40
-
-    /** Keystore2 ResponseCode::PERMISSION_DENIED */
-    const val PERMISSION_DENIED = 6
-
-    /** Keystore2 ResponseCode::KEY_NOT_FOUND */
-    const val KEY_NOT_FOUND = 7
+    private fun resolve(enumName: String, field: String, fallback: Int, keystore: Boolean = false): Int {
+        val pkg = if (keystore) "android.system.keystore2" else "android.hardware.security.keymint"
+        return runCatching { Class.forName("$pkg.$enumName").getField(field).getInt(null) }
+            .getOrDefault(fallback)
+    }
 }
 
 // A sealed interface to represent the different cryptographic operations we can perform.
@@ -99,8 +101,9 @@ private object JcaAlgorithmMapper {
             when (params.blockMode.firstOrNull()) {
                 BlockMode.ECB -> "ECB"
                 BlockMode.CBC -> "CBC"
+                BlockMode.CTR -> "CTR"
                 BlockMode.GCM -> "GCM"
-                else -> "ECB" // Default for RSA
+                else -> "ECB"
             }
         val padding =
             when (params.padding.firstOrNull()) {
@@ -183,8 +186,10 @@ private class CipherPrimitive(
         Cipher.getInstance(JcaAlgorithmMapper.mapCipherAlgorithm(params)).apply {
             init(opMode, cryptoKey)
         }
+    private val isAead = params.blockMode.firstOrNull() == BlockMode.GCM
 
     override fun updateAad(data: ByteArray?) {
+        if (!isAead) throw ServiceSpecificException(KeystoreErrorCode.INVALID_TAG)
         if (data != null) cipher.updateAAD(data)
     }
 
@@ -247,11 +252,13 @@ class SoftwareOperation(
     keyPair: KeyPair?,
     secretKey: javax.crypto.SecretKey?,
     params: KeyMintAttestation,
+    private val latencyFloorMs: Long = 0L,
     var onFinishCallback: (() -> Unit)? = null,
 ) {
     private val primitive: CryptoPrimitive
 
-    @Volatile private var finalized = false
+    @Volatile var isFinalized = false
+        private set
 
     init {
         val purpose = params.purpose.firstOrNull()
@@ -288,7 +295,7 @@ class SoftwareOperation(
         }
 
     private fun checkActive() {
-        if (finalized)
+        if (isFinalized)
             throw ServiceSpecificException(
                 KeystoreErrorCode.INVALID_OPERATION_HANDLE,
                 "Operation already finalized.",
@@ -300,10 +307,10 @@ class SoftwareOperation(
         try {
             primitive.updateAad(data)
         } catch (e: ServiceSpecificException) {
-            finalized = true
+            isFinalized = true
             throw e
         } catch (e: Exception) {
-            finalized = true
+            isFinalized = true
             SystemLogger.error("[SoftwareOp TX_ID: $txId] Failed to updateAad.", e)
             throw ServiceSpecificException(KeystoreErrorCode.SYSTEM_ERROR, e.message)
         }
@@ -314,35 +321,50 @@ class SoftwareOperation(
         try {
             return primitive.update(data)
         } catch (e: ServiceSpecificException) {
-            finalized = true
+            isFinalized = true
             throw e
         } catch (e: Exception) {
-            finalized = true
+            isFinalized = true
             SystemLogger.error("[SoftwareOp TX_ID: $txId] Failed to update operation.", e)
-            throw ServiceSpecificException(KeystoreErrorCode.SYSTEM_ERROR, e.message)
+            throw mapToServiceSpecificException(e)
         }
     }
 
     fun finish(data: ByteArray?, signature: ByteArray?): ByteArray? {
         checkActive()
+        val startNs = if (latencyFloorMs > 0) System.nanoTime() else 0L
         try {
             val result = primitive.finish(data, signature)
             SystemLogger.info("[SoftwareOp TX_ID: $txId] Finished operation successfully.")
+            if (latencyFloorMs > 0) {
+                val elapsedMs = (System.nanoTime() - startNs) / 1_000_000
+                val delayMs = latencyFloorMs - elapsedMs
+                if (delayMs > 0) LockSupport.parkNanos(delayMs * 1_000_000)
+            }
             onFinishCallback?.invoke()
             return result
         } catch (e: ServiceSpecificException) {
             throw e
         } catch (e: Exception) {
             SystemLogger.error("[SoftwareOp TX_ID: $txId] Failed to finish operation.", e)
-            throw ServiceSpecificException(KeystoreErrorCode.SYSTEM_ERROR, e.message)
+            throw mapToServiceSpecificException(e)
         } finally {
-            finalized = true
+            isFinalized = true
         }
     }
 
+    private fun mapToServiceSpecificException(e: Exception): ServiceSpecificException = when (e) {
+        is ServiceSpecificException -> e
+        is SignatureException -> ServiceSpecificException(KeystoreErrorCode.VERIFICATION_FAILED, e.message)
+        is BadPaddingException -> ServiceSpecificException(KeystoreErrorCode.INVALID_ARGUMENT, e.message)
+        is IllegalBlockSizeException -> ServiceSpecificException(KeystoreErrorCode.INVALID_INPUT_LENGTH, e.message)
+        is java.security.InvalidKeyException -> ServiceSpecificException(KeystoreErrorCode.INCOMPATIBLE_KEY, e.message)
+        else -> ServiceSpecificException(KeystoreErrorCode.UNKNOWN_ERROR, e.message)
+    }
+
     fun abort() {
         checkActive()
-        finalized = true
+        isFinalized = true
         primitive.abort()
         SystemLogger.debug("[SoftwareOp TX_ID: $txId] Operation aborted.")
     }

app/src/main/java/org/matrix/TEESimulator/util/AndroidDeviceUtils.kt

@@ -76,42 +76,38 @@ object AndroidDeviceUtils {
         SystemLogger.debug("Boot key and hash initialization complete.")
     }
 
-    /**
-     * Generic initializer for boot properties like the key and hash. It attempts to read from a
-     * system property first, then from a TEE attestation, and finally falls back to a random value
-     * if neither is available.
-     *
-     * @param propertyName The name of the system property (e.g., "ro.boot.vbmeta.digest").
-     * @param attestationValueProvider A function that supplies the value from a cached attestation.
-     * @param expectedSize The expected length of the byte array (e.g., 32 for a SHA-256 digest).
-     * @return The resulting byte array for the property.
-     */
     private fun initializeBootProperty(
         propertyName: String,
         attestationValueProvider: () -> ByteArray?,
         expectedSize: Int,
     ): ByteArray {
-        // 1. Attempt to get the value from the system property.
         getProperty(propertyName, expectedSize)?.let {
             SystemLogger.debug("Using $propertyName from system property: ${it.toHex()}")
+            persistToFile(propertyName, it)
             return it
         }
 
-        // 2. Fallback to the value from a cached TEE attestation.
         try {
             attestationValueProvider()?.let {
                 SystemLogger.debug("Using $propertyName from TEE attestation: ${it.toHex()}")
-                setProperty(propertyName, it) // Persist for consistency
+                setProperty(propertyName, it)
+                persistToFile(propertyName, it)
                 return it
             }
         } catch (e: Exception) {
             SystemLogger.error("Failed to get $propertyName from attestation.", e)
         }
 
-        // 3. As a final fallback, generate a random value.
+        readFromFile(propertyName, expectedSize)?.let {
+            SystemLogger.debug("Using $propertyName from persistent file: ${it.toHex()}")
+            setProperty(propertyName, it)
+            return it
+        }
+
         return generateRandomBytes(expectedSize).also {
             SystemLogger.debug("Using randomly generated $propertyName: ${it.toHex()}")
             setProperty(propertyName, it)
+            persistToFile(propertyName, it)
         }
     }
 
@@ -158,10 +154,37 @@ object AndroidDeviceUtils {
         }
     }
 
-    /** Generates a cryptographically random byte array of a specified length. */
     private fun generateRandomBytes(size: Int): ByteArray =
         ByteArray(size).also { ThreadLocalRandom.current().nextBytes(it) }
 
+    private val PERSIST_DIR = File("/data/adb/tricky_store")
+
+    private fun fileForProperty(propertyName: String): File = when (propertyName) {
+        "ro.boot.vbmeta.digest" -> File(PERSIST_DIR, "boot_hash.bin")
+        "ro.boot.vbmeta.public_key_digest" -> File(PERSIST_DIR, "boot_key.bin")
+        else -> File(PERSIST_DIR, "${propertyName.replace('.', '_')}.bin")
+    }
+
+    private fun persistToFile(propertyName: String, bytes: ByteArray) {
+        try {
+            fileForProperty(propertyName).writeBytes(bytes)
+        } catch (e: Exception) {
+            SystemLogger.error("Failed to persist $propertyName to file.", e)
+        }
+    }
+
+    private fun readFromFile(propertyName: String, expectedSize: Int): ByteArray? {
+        return try {
+            val file = fileForProperty(propertyName)
+            if (!file.exists()) return null
+            val bytes = file.readBytes()
+            if (bytes.size == expectedSize) bytes else null
+        } catch (e: Exception) {
+            SystemLogger.error("Failed to read $propertyName from file.", e)
+            null
+        }
+    }
+
     // --- Patch Level Properties ---
 
     fun getPatchLevel(uid: Int): Int {
@@ -240,11 +263,10 @@ object AndroidDeviceUtils {
         val resolvedValue = resolveDateKeywords(value)
 
         return when {
-            // "device_default" indicates falling back to the system property.
             resolvedValue.equals("device_default", ignoreCase = true) -> null
-            // "no" indicates this value should not be reported.
             resolvedValue.equals("no", ignoreCase = true) -> DO_NOT_REPORT
-            // Otherwise, parse the resolved date string.
+            resolvedValue.equals("prop", ignoreCase = true) ->
+                parsePatchLevelValue(SystemProperties.get("ro.build.version.security_patch", ""), isLong)
             else -> parsePatchLevelValue(resolvedValue, isLong)
         }
     }

module/changelog.md

@@ -1,3 +1,26 @@
+## TEESimulator-RS v5.1.1: Pre-Stash Restoration
+
+Restores all custom hardening fixes that were lost during the PR #157 migration. These were working in pre-stash builds but never carried over to the post-stash codebase, causing user-reported regressions (boot hash instability, DuckDetector score regression, config crash on file deletion).
+
+- **Boot hash persistence** restored: 4-step fallback (sysprop, TEE, file, random) with file writes at every step. Fixes "Boot: Unavailable" where boot hash randomized every reboot on devices without `ro.boot.vbmeta.digest`
+- **Presence-based findBoolean** for KeyMint tags: boolean tags are presence-based per AIDL spec, `.boolValue` field isn't reliably populated across Android versions
+- **noAuthRequired** defaults to true when not explicitly false, matching AOSP KeyMint behavior
+- **callerNonce** tag now flows through to software-enforced attestation list
+- **CTR block mode** restored in cipher algorithm mapping (was dropped in PR #157)
+- **AEAD guard** on updateAad: non-GCM operations throw INVALID_TAG
+- **Error code resolution** via lazy reflection with correct KeyMint AIDL fallback values
+- **Latency floor** on SoftwareOperation.finish() for StrongBox timing simulation
+- **FileObserver NPE** fixed: null-safe handling on config file DELETE events
+- **system=prop** consistency: forces boot/vendor patch levels to derive from device props
+- **StrongBox simulation** restored: capability checks (RSA<=2048, EC=P256), concurrent op limits (4 max), keygen latency floor (250ms), op latency floor (80ms)
+- **Binder buffer guard**: MAX_ALIAS_LENGTH (256KB) rejects oversized aliases before processing
+- **Key lifecycle tracking**: deletedSoftwareKeys set prevents ghost key responses after deletion
+- **Per-UID operation limits**: 15 TEE, 4 StrongBox with LRU eviction
+- **EC+DECRYPT rejection** in createOperation, matching AOSP unsupported purpose check
+- **Attest key nspace update** aligned with upstream PR #169
+
+---
+
 ## TEESimulator-RS v5.1: Interception Architecture Rewrite
 
 Major release. 27 files changed, 2300 lines rewritten. The entire Kotlin interception layer has been rebuilt with a clean architecture, proper AIDL alignment, and significantly lower binder overhead.