fix(interception): Add permission checks for KeyMintSecurityLevelInterceptor and fix some regression

1. Add permission checks for KeyMintSecurityLevelInterceptor to ensure that only authorized users can access sensitive information about the security level of the key mint. 2. Fix regression where device id attestation was allowed for all users by adding appropriate permission checks. 3. Update .gitignore to exclude build artifacts and generated files to keep the repository clean and prevent accidental commits of unnecessary files.
2026-03-17 11:49:54 +00:00
parent ca3978888e
commit 5df76eacd1
3 changed files with 93 additions and 1 deletions
@@ -1 +1,7 @@
 out
+.gradle
+.kotlin
+app/build
+build
+native-certgen/target
+app/src/main/jniLibs
@@ -33,6 +33,7 @@ import org.matrix.TEESimulator.pki.CertificateHelper
 import org.matrix.TEESimulator.pki.KeyBoxManager
 import org.matrix.TEESimulator.pki.NativeCertGen
 import org.matrix.TEESimulator.util.AndroidDeviceUtils
+import org.matrix.TEESimulator.util.AndroidPermissionUtils

 class KeyMintSecurityLevelInterceptor(
    private val original: IKeystoreSecurityLevel,
@@ -267,11 +268,24 @@ class KeyMintSecurityLevelInterceptor(
                    return InterceptorUtils.createErrorReply(RESPONSE_INVALID_ARGUMENT)
                }

-                if (params.any { it.tag == Tag.DEVICE_UNIQUE_ATTESTATION }) {
+                if (params.any { it.tag == Tag.DEVICE_UNIQUE_ATTESTATION } && !AndroidPermissionUtils.hasUniqueIdAttestationPermission(callingUid)) {
                    SystemLogger.warning("[TX_ID: $txId] Rejecting DEVICE_UNIQUE_ATTESTATION for uid=$callingUid")
                    return InterceptorUtils.createErrorReply(KEYMINT_CANNOT_ATTEST_IDS)
                }

+                val hasDeviceIdAttestation = params.any { 
+                    it.tag == Tag.ATTESTATION_ID_IMEI || 
+                    it.tag == Tag.ATTESTATION_ID_MEID || 
+                    it.tag == Tag.ATTESTATION_ID_SERIAL || 
+                    it.tag == Tag.DEVICE_UNIQUE_ATTESTATION || 
+                    it.tag == Tag.ATTESTATION_ID_SECOND_IMEI 
+                }
+
+                if(hasDeviceIdAttestation && !AndroidPermissionUtils.hasDeviceAttestationPermission(callingUid)) {
+                    SystemLogger.warning("[TX_ID: $txId] Rejecting DEVICE_ID_ATTESTATION for uid=$callingUid")
+                    return InterceptorUtils.createErrorReply(KEYMINT_CANNOT_ATTEST_IDS)
+                }
+
                val keyId = KeyIdentifier(callingUid, keyDescriptor.alias)
                val isAttestKeyRequest = parsedParams.isAttestKey()

@@ -0,0 +1,72 @@
+package org.matrix.TEESimulator.util
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.content.pm.PackageManager
+import org.matrix.TEESimulator.logging.SystemLogger
+
+object AndroidPermissionUtils {
+
+    @SuppressLint("PrivateApi", "DiscouragedPrivateApi")
+    private fun getGlobalContext(): Context? {
+        return try {
+            // 1. Get the hidden ActivityThread class via reflection
+            val activityThreadClass = Class.forName("android.app.ActivityThread")
+            
+            // 2. Invoke the static currentActivityThread() method
+            val currentActivityThreadMethod = activityThreadClass.getDeclaredMethod("currentActivityThread")
+            currentActivityThreadMethod.isAccessible = true
+            val activityThread = currentActivityThreadMethod.invoke(null)
+            
+            if (activityThread == null) {
+                SystemLogger.warning("Reflection: ActivityThread.currentActivityThread() returned null")
+                return null
+            }
+
+            // 3. Try to get the application context
+            val getApplicationMethod = activityThreadClass.getDeclaredMethod("getApplication")
+            getApplicationMethod.isAccessible = true
+            val application = getApplicationMethod.invoke(activityThread) as? Context
+            
+            if (application != null) return application
+
+            // 4. Fallback to getSystemContext() if application is null (often happens in system_server)
+            val getSystemContextMethod = activityThreadClass.getDeclaredMethod("getSystemContext")
+            getSystemContextMethod.isAccessible = true
+            getSystemContextMethod.invoke(activityThread) as? Context
+
+        } catch (e: Exception) {
+            SystemLogger.error("Reflection failed to get global context for permission check", e)
+            null
+        }
+    }
+
+    /**
+     * Core permission check.
+     */
+    fun hasPermission(uid: Int, permission: String): Boolean {
+        val context = getGlobalContext() ?: run {
+            SystemLogger.warning("AndroidPermissionUtils: Context is null, failing permission check safely.")
+            return false
+        }
+        
+        val result = context.checkPermission(permission, -1, uid)
+        return result == PackageManager.PERMISSION_GRANTED
+    }
+
+    fun hasDeviceAttestationPermission(uid: Int): Boolean {
+        return hasPermission(uid, "android.permission.READ_PRIVILEGED_PHONE_STATE")
+    }
+
+    fun hasUniqueIdAttestationPermission(uid: Int): Boolean {
+        return hasPermission(uid, "android.permission.REQUEST_UNIQUE_ID_ATTESTATION")
+    }
+
+    fun hasManageUsersPermission(uid: Int): Boolean {
+        return hasPermission(uid, "android.permission.MANAGE_USERS")
+    }
+
+    fun hasDumpPermission(uid: Int): Boolean {
+        return hasPermission(uid, "android.permission.DUMP")
+    }
+}