Fix race condition (2303f98d) · Commits · e / os / cert4android

src/main/java/at/bitfire/cert4android/CustomCertManager.kt

+21 −14

Original line number	Diff line number	Diff line
		@@ -13,7 +13,7 @@ import android.content.Context
		import android.content.Intent
		import android.content.ServiceConnection
		import android.os.*
		import android.util.SparseArray
		import android.util.SparseBooleanArray
		import java.io.Closeable
		import java.security.cert.CertificateException
		import java.security.cert.X509Certificate
		@@ -39,7 +39,8 @@ class CustomCertManager: X509TrustManager, Closeable {
		var SERVICE_TIMEOUT: Long = 5601000

		val nextDecisionID = AtomicInteger()
		val decisions = SparseArray<Boolean?>()

		val decisions = SparseBooleanArray()
		val decisionLock = Object()

		/** thread to receive replies from {@link CustomCertService} */
		@@ -51,15 +52,12 @@ class CustomCertManager: X509TrustManager, Closeable {
		/** messenger to receive replies from {@link CustomCertService} */
		val messenger = Messenger(Handler(messengerThread.looper, MessageHandler()))

		@JvmField
		val MSG_CERTIFICATE_DECISION = 0

		// Messenger for receiving replies from CustomCertificateService
		private class MessageHandler: Handler.Callback {
		override fun handleMessage(msg: Message): Boolean {
		Constants.log.fine("Received reply from CustomCertificateService: " + msg)
		return when (msg.what) {
		MSG_CERTIFICATE_DECISION ->
		CustomCertService.MSG_CERTIFICATE_DECISION ->
		synchronized(decisionLock) {
		decisions.put(msg.arg1, msg.arg2 != 0)
		decisionLock.notifyAll()
		@@ -127,7 +125,7 @@ class CustomCertManager: X509TrustManager, Closeable {
		constructor(context: Context, trustSystemCerts: Boolean): this(context, trustSystemCerts, null)

		override fun close() {
		serviceConnection?.let(context::unbindService)
		serviceConnection?.let { context.unbindService(it) }
		}


		@@ -164,13 +162,14 @@ class CustomCertManager: X509TrustManager, Closeable {
		}

		internal fun checkCustomTrusted(cert: X509Certificate) {
		Constants.log.fine("Querying custom certificate trustworthiness")
		val decisionID = nextDecisionID.getAndIncrement()
		Constants.log.fine("Querying custom certificate trustworthiness (expecting decision $decisionID)")

		val service : Messenger = this.service ?: throw CertificateException("Custom certificate service not available")

		var msg = Message.obtain()
		msg.what = CustomCertService.MSG_CHECK_TRUSTED
		msg.arg1 = nextDecisionID.getAndIncrement()
		msg.arg1 = decisionID
		val id = msg.arg1
		msg.replyTo = messenger

		@@ -185,15 +184,23 @@ class CustomCertManager: X509TrustManager, Closeable {
		throw CertificateException("Couldn't query custom certificate trustworthiness", e)
		}

		// wait for a reply
		val startTime = System.currentTimeMillis()
		synchronized(decisionLock) {
		while (System.currentTimeMillis() < startTime + SERVICE_TIMEOUT) {
		var idx = decisions.indexOfKey(id)

		// wait for a reply for up to SERVICE_TIMEOUT milliseconds, if necessary
		val startTime = System.currentTimeMillis()
		while (idx < 0 && System.currentTimeMillis() < startTime + SERVICE_TIMEOUT) {
		Constants.log.finer("Waiting for reply from service (decision $id)")
		try {
		decisionLock.wait(SERVICE_TIMEOUT)
		} catch(e: InterruptedException) {
		}
		decisions.get(id)?.let { decision ->
		idx = decisions.indexOfKey(id)
		}

		if (idx >= 0) {
		Constants.log.finer("Decision $id received from service")
		decisions.valueAt(idx).let { decision ->
		decisions.delete(id)
		if (decision)
		// certificate trusted
		@@ -204,7 +211,7 @@ class CustomCertManager: X509TrustManager, Closeable {
		}
		}

		// timeout occurred, send cancellation
		Constants.log.finer("Timeout for decision $id, sending cancellation to service")
		msg = Message.obtain()
		msg.what = CustomCertService.MSG_CHECK_TRUSTED_ABORT
		msg.arg1 = id

src/main/java/at/bitfire/cert4android/CustomCertService.kt

+17 −7

Original line number	Diff line number	Diff line
		@@ -12,7 +12,10 @@ import android.app.PendingIntent
		import android.app.Service
		import android.content.Context
		import android.content.Intent
		import android.os.*
		import android.os.Handler
		import android.os.Message
		import android.os.Messenger
		import android.os.RemoteException
		import android.support.v4.app.NotificationManagerCompat
		import android.support.v7.app.NotificationCompat
		import android.widget.Toast
		@@ -44,12 +47,15 @@ class CustomCertService: Service() {


		// bound service; Messenger for IPC

		val MSG_CHECK_TRUSTED = 1
		val MSG_DATA_CERTIFICATE = "certificate"
		val MSG_DATA_APP_IN_FOREGROUND ="appInForeground"

		val MSG_CHECK_TRUSTED_ABORT = 2

		// reply messages sent by service
		val MSG_CERTIFICATE_DECISION = 0

		}

		var keyStoreFile: File? = null
		@@ -69,7 +75,7 @@ class CustomCertService: Service() {
		try {
		FileInputStream(keyStoreFile).use { trustedKeyStore.load(it, null) }
		} catch(e: Exception) {
		Constants.log.log(Level.INFO, "No persisent key store (yet), creating in-memory key store", e)
		Constants.log.log(Level.INFO, "No persistent key store (yet), creating in-memory key store", e)
		try {
		trustedKeyStore.load(null, null)
		} catch(e: Exception) {
		@@ -138,10 +144,11 @@ class CustomCertService: Service() {
		pendingDecisions[cert]?.let { receivers ->
		for ((messenger, id) in receivers) {
		val message = Message.obtain()
		message.what = CustomCertManager.MSG_CERTIFICATE_DECISION
		message.what = MSG_CERTIFICATE_DECISION
		message.arg1 = id
		message.arg2 = if (trusted) 1 else 0
		try {
		Constants.log.finer("Sending user decision $id (trusted: $trusted) to manager")
		messenger.send(message)
		} catch(e: RemoteException) {
		Constants.log.log(Level.WARNING, "Couldn't forward decision to CustomCertManager", e)
		@@ -200,9 +207,9 @@ class CustomCertService: Service() {
		*/
		when {
		service.untrustedCerts.contains(cert) -> {
		Constants.log.fine("Certificate is cached as untrusted")
		Constants.log.fine("Certificate is cached as untrusted, rejecting decision $id")
		try {
		msg.replyTo.send(obtainMessage(CustomCertManager.MSG_CERTIFICATE_DECISION, id, 0))
		msg.replyTo.send(obtainMessage(MSG_CERTIFICATE_DECISION, id, 0))
		} catch(e: RemoteException) {
		Constants.log.log(Level.WARNING, "Couldn't send distrust information to CustomCertManager", e)
		}
		@@ -210,12 +217,15 @@ class CustomCertService: Service() {
		}
		service.inTrustStore(cert) -> {
		try {
		msg.replyTo.send(obtainMessage(CustomCertManager.MSG_CERTIFICATE_DECISION, id, 1))
		Constants.log.fine("Certificate is cached as trusted, accepting decision $id")
		msg.replyTo.send(obtainMessage(MSG_CERTIFICATE_DECISION, id, 1))
		} catch(e: RemoteException) {
		Constants.log.log(Level.WARNING, "Couldn't send trust information to CustomCertManager", e)
		}
		}
		else -> {
		Constants.log.fine("Certificate is not known, user decision required $id")

		val receivers = LinkedList<ReplyInfo>()
		receivers += replyInfo
		service.pendingDecisions.put(cert, receivers)