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6 Commits
Author SHA1 Message Date
Enginex0 90ff59e0aa fix(interception): check generatedKeys before deletedSoftwareKeys on getKeyEntry
The deletion guard must not shadow re-generated keys. If an app
deletes a key then re-creates it, getKeyEntry was still returning
KEY_NOT_FOUND because deletedSoftwareKeys was checked first.
2026-03-16 22:36:02 +01:00
Enginex0 8bdf0d59fa docs(release): bump to v4.5 with detection hardening changelog 2026-03-16 22:07:56 +01:00
Enginex0 6ab09f4889 fix(interception): prevent ghost key responses after software key deletion
After deleting a software-generated key, getKeyEntry was falling
through to the real keystore2 service which could return a stale
hardware key with the same alias. The post-transact live-patch
fallback would then resurrect the key with a patched chain —
detectors flag this as binder inconsistency.

Track deleted software key aliases and return KEY_NOT_FOUND (7) for
subsequent getKeyEntry calls. Also always invoke cleanupKeyData on
delete to clear stale patchedChains entries for hardware keys.
2026-03-16 22:06:53 +01:00
Enginex0 f4559bcd19 perf(keygen): normalize software generateKey RTT to match TEE latency
Software-generated keys complete in ~4ms, real TEE averages 55-65ms
with a floor around 15ms. Detectors measure this RTT to distinguish
software from hardware paths. Gaussian delay sampling (mean=55ms,
σ=12ms, floor=15ms) brings total RTT into the expected range.
2026-03-16 22:06:38 +01:00
Enginex0 3b5043a1bb docs(release): bump to v4.4 with AOSP conformance changelog 2026-03-16 13:26:34 +01:00
Enginex0 8001a8678a fix(interception): absorb upstream correctness fixes and patch error reply format
Cherry-pick three upstream fixes: Parcel position reset in hasException()
so the method doesn't consume reply data (7804743), list_past_alias
enumeration filter inversion (2aac65c), and KeyMetadata alignment with
AOSP semantics — modificationTimeMs, Tag.ORIGIN, KeyDescriptor
normalization (86db5bf).

Additionally, createErrorReply() was missing the empty remote stack
trace header int between the exception message and error code, per
AOSP Status.cpp:196. Binder readers expecting the standard
EX_SERVICE_SPECIFIC wire format would misparse our error replies.
2026-03-16 13:23:36 +01:00
8 changed files with 74 additions and 13 deletions
+1 -1
View File
@@ -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 = "v4.3"
val verName = "v4.5"
android {
namespace = "org.matrix.TEESimulator"
@@ -89,5 +89,5 @@ object AttestationConstants {
// --- Other Constants ---
// https://cs.android.com/android/platform/superproject/main/+/main:system/keymaster/km_openssl/attestation_record.cpp
const val CHALLENGE_LENGTH_LIMIT = 128 // kMaximumAttestationChallengeLength
const val CHALLENGE_LENGTH_LIMIT = 128
}
@@ -18,6 +18,7 @@ object InterceptorUtils {
val parcel = Parcel.obtain().apply {
writeInt(EX_SERVICE_SPECIFIC)
writeString(null)
writeInt(0) // empty remote stack trace header (AOSP Status.cpp:196)
writeInt(errorCode)
}
return BinderInterceptor.TransactionResult.OverrideReply(parcel)
@@ -119,6 +120,8 @@ object InterceptorUtils {
/** Checks if a reply parcel contains an exception without consuming it. */
fun hasException(reply: Parcel): Boolean {
return runCatching { reply.readException() }.exceptionOrNull() != null
val exception = runCatching { reply.readException() }.exceptionOrNull()
if (exception != null) reply.setDataPosition(0)
return exception != null
}
}
@@ -10,6 +10,7 @@ import android.system.keystore2.KeyDescriptor
import android.system.keystore2.KeyEntryResponse
import java.security.SecureRandom
import java.security.cert.Certificate
import java.util.concurrent.ConcurrentHashMap
import org.matrix.TEESimulator.attestation.AttestationPatcher
import org.matrix.TEESimulator.attestation.KeyMintAttestation
import org.matrix.TEESimulator.config.ConfigurationManager
@@ -54,6 +55,9 @@ object Keystore2Interceptor : AbstractKeystoreInterceptor() {
.associate { field -> (field.get(null) as Int) to field.name.split("_")[1] }
}
private const val RESPONSE_KEY_NOT_FOUND = 7
private val deletedSoftwareKeys: MutableSet<KeyIdentifier> = ConcurrentHashMap.newKeySet()
override val serviceName = "android.system.keystore2.IKeystoreService/default"
override val processName = "keystore2"
override val injectionCommand = "exec ./inject `pidof keystore2` libTEESimulator.so entry"
@@ -156,8 +160,10 @@ object Keystore2Interceptor : AbstractKeystoreInterceptor() {
val keyId = KeyIdentifier(callingUid, descriptor.alias)
if (code == DELETE_KEY_TRANSACTION) {
if (KeyMintSecurityLevelInterceptor.getGeneratedKeyResponse(keyId) != null) {
KeyMintSecurityLevelInterceptor.cleanupKeyData(keyId)
val wasSoftwareKey = KeyMintSecurityLevelInterceptor.getGeneratedKeyResponse(keyId) != null
KeyMintSecurityLevelInterceptor.cleanupKeyData(keyId)
if (wasSoftwareKey) {
deletedSoftwareKeys.add(keyId)
SystemLogger.info(
"[TX_ID: $txId] Deleted cached keypair ${descriptor.alias}, replying with empty response."
)
@@ -166,9 +172,14 @@ object Keystore2Interceptor : AbstractKeystoreInterceptor() {
return TransactionResult.ContinueAndSkipPost
}
val response =
KeyMintSecurityLevelInterceptor.getGeneratedKeyResponse(keyId)
?: return TransactionResult.Continue
val response = KeyMintSecurityLevelInterceptor.getGeneratedKeyResponse(keyId)
if (response == null) {
if (deletedSoftwareKeys.remove(keyId)) {
SystemLogger.info("[TX_ID: $txId] Returning KEY_NOT_FOUND for deleted key ${descriptor.alias}")
return InterceptorUtils.createErrorReply(RESPONSE_KEY_NOT_FOUND)
}
return TransactionResult.Continue
}
if (KeyMintSecurityLevelInterceptor.isAttestationKey(keyId))
SystemLogger.info("${descriptor.alias} was an attestation key")
@@ -129,7 +129,7 @@ object ListEntriesHandler {
startPastAlias: String?,
): List<KeyDescriptor> {
return KeyMintSecurityLevelInterceptor.generatedKeys.keys
.filter { it.uid == uid && (startPastAlias == null || it.alias < startPastAlias) }
.filter { it.uid == uid && (startPastAlias == null || it.alias > startPastAlias) }
.map { keyId ->
KeyDescriptor().apply {
this.domain = Domain.APP
@@ -3,6 +3,7 @@ package org.matrix.TEESimulator.interception.keystore.shim
import android.hardware.security.keymint.Algorithm
import android.hardware.security.keymint.KeyParameter
import android.hardware.security.keymint.KeyParameterValue
import android.hardware.security.keymint.KeyOrigin
import android.hardware.security.keymint.Tag
import android.os.IBinder
import android.os.Parcel
@@ -316,6 +317,7 @@ class KeyMintSecurityLevelInterceptor(
keyId: KeyIdentifier,
isAttestKeyRequest: Boolean,
): TransactionResult {
val startNs = System.nanoTime()
keyDescriptor.nspace = secureRandom.nextLong()
SystemLogger.info("Generating software key for ${keyDescriptor.alias}[${keyDescriptor.nspace}].")
@@ -349,6 +351,10 @@ class KeyMintSecurityLevelInterceptor(
isAttestationKey = isAttestKeyRequest,
)
val elapsedMs = (System.nanoTime() - startNs) / 1_000_000
val delayMs = sampleTeeLatencyMs() - elapsedMs
if (delayMs > 0) Thread.sleep(delayMs)
return InterceptorUtils.createTypedObjectReply(response.metadata)
}
@@ -425,12 +431,20 @@ class KeyMintSecurityLevelInterceptor(
params: KeyMintAttestation,
descriptor: KeyDescriptor,
): KeyEntryResponse {
val normalizedKeyDescriptor =
KeyDescriptor().apply {
domain = Domain.KEY_ID
nspace = descriptor.nspace
alias = null
blob = null
}
val metadata =
KeyMetadata().apply {
keySecurityLevel = securityLevel
key = descriptor
key = normalizedKeyDescriptor
CertificateHelper.updateCertificateChain(this, chain.toTypedArray()).getOrThrow()
authorizations = params.toAuthorizations(securityLevel)
modificationTimeMs = System.currentTimeMillis()
}
return KeyEntryResponse().apply {
this.metadata = metadata
@@ -533,6 +547,9 @@ class KeyMintSecurityLevelInterceptor(
// Sliding window: max hardware keygen permits per UID within the burst window
private const val MAX_HW_KEYGEN_PER_WINDOW = 2
private const val BURST_WINDOW_MS = 30_000L
private const val TEE_LATENCY_MEAN_MS = 55.0
private const val TEE_LATENCY_STDDEV_MS = 12.0
private const val TEE_LATENCY_FLOOR_MS = 15L
private val uidHardwareKeygenCount = ConcurrentHashMap<Int, AtomicInteger>()
private val hardwareKeygenTxIds = ConcurrentHashMap.newKeySet<Long>()
@@ -561,6 +578,11 @@ class KeyMintSecurityLevelInterceptor(
}
}
private fun sampleTeeLatencyMs(): Long {
val sample = TEE_LATENCY_MEAN_MS + secureRandom.nextGaussian() * TEE_LATENCY_STDDEV_MS
return sample.toLong().coerceAtLeast(TEE_LATENCY_FLOOR_MS)
}
private val GENERATE_KEY_TRANSACTION =
InterceptorUtils.getTransactCode(IKeystoreSecurityLevel.Stub::class.java, "generateKey")
private val IMPORT_KEY_TRANSACTION =
@@ -665,6 +687,12 @@ private fun KeyMintAttestation.toAuthorizations(securityLevel: Int): Array<Autho
authList.add(createAuth(Tag.ALGORITHM, KeyParameterValue.algorithm(this.algorithm)))
authList.add(createAuth(Tag.KEY_SIZE, KeyParameterValue.integer(this.keySize)))
authList.add(createAuth(Tag.EC_CURVE, KeyParameterValue.ecCurve(this.ecCurve)))
authList.add(
createAuth(
Tag.ORIGIN,
KeyParameterValue.origin(this.origin ?: KeyOrigin.GENERATED),
)
)
authList.add(createAuth(Tag.NO_AUTH_REQUIRED, KeyParameterValue.boolValue(true)))
return authList.toTypedArray()
+19
View File
@@ -1,3 +1,22 @@
## TEESimulator v4.5: Detection Hardening
Tested against [KeyDetector](https://github.com/XiaoTong6666/KeyDetector) (23-check attestation validator). All keystore-level checks now pass.
- **Key deletion consistency** — After deleting a software-generated key, `getKeyEntry` now correctly returns `KEY_NOT_FOUND` instead of falling through to a stale live-patch fallback. Fixes binder consistency checks that detect ghost key responses.
- **generateKey timing normalization** — Software key generation RTT now matches real TEE latency profile (Gaussian distribution, mean=55ms, floor=15ms). Previously completed in ~4ms, which is an immediate timing side-channel.
- **Delete cleanup scope** — `deleteKey` now clears all cached state (patched chains, attestation keys) regardless of whether the key was software or hardware-generated.
---
## TEESimulator v4.4: AOSP Conformance
- **Binder error reply format** — Aligned EX_SERVICE_SPECIFIC wire layout with AOSP Status.cpp, including the remote stack trace header field.
- **Key enumeration** — Corrected list_past_alias pagination order to match AOSP database.rs semantics.
- **KeyMetadata fields** — Generated key responses now include modificationTimeMs, Tag.ORIGIN, and normalized KeyDescriptor fields per AOSP Keystore2.
- **Parcel handling** — hasException() preserves reply position for downstream consumers.
---
## TEESimulator v4.3: Performance & Reliability
- **Debug log gating** — `SystemLogger.debug()` now skipped entirely in release builds, eliminating unnecessary logcat syscalls on every intercepted transaction.
+3 -3
View File
@@ -1,6 +1,6 @@
{
"version": "v4.3",
"versionCode": 107,
"zipUrl": "https://github.com/Enginex0/TEESimulator/releases/download/v4.3/TEESimulator-v4.3-Release.zip",
"version": "v4.5",
"versionCode": 111,
"zipUrl": "https://github.com/Enginex0/TEESimulator/releases/download/v4.5/TEESimulator-v4.5-Release.zip",
"changelog": "https://raw.githubusercontent.com/Enginex0/TEESimulator/main/module/changelog.md"
}