Android Keystore?.getKey returns 在某些设备上为空

Question

我正在我的应用程序中实施指纹验证。我遇到了在某些设备上无法正常工作并且我的应用程序崩溃的问题。尽管如此，它也适用于某些设备。问题出在这一行

val key = keyStore?.getKey(Constants.FINGERPRINT_KEY_NAME, null) as SecretKey

LogCat 说：

 11-02 14:27:42.825 E: FATAL EXCEPTION: main
                  Process: kyivenergo.ua.kyivenegro, PID: 2298
                  java.lang.RuntimeException: Unable to start activity ComponentInfo{kyivenergo.ua.kyivenegro/ua.dtec.appOk.ui.screens.splash.SplashScreenActivity}: kotlin.TypeCastException: null cannot be cast to non-null type javax.crypto.SecretKey
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
                      at android.app.ActivityThread.-wrap12(ActivityThread.java)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:154)
                      at android.app.ActivityThread.main(ActivityThread.java:6077)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
                   Caused by: kotlin.TypeCastException: null cannot be cast to non-null type javax.crypto.SecretKey
                      at ua.dtec.appOk.ui.dialog.FingerprintDialog.initCipher(FingerprintDialog.kt:222)
                      at ua.dtec.appOk.ui.dialog.FingerprintDialog.doCheck(FingerprintDialog.kt:147)
                      at ua.dtec.appOk.ui.dialog.FingerprintDialog.show(FingerprintDialog.kt:65)
                      at ua.dtec.appOk.ui.screens.splash.SplashScreenActivity.showFingerprintDialog(SplashScreenActivity.kt:55)
                      at ua.dtec.appOk.ui.screens.splash.SplashScreenActivity.onStart(SplashScreenActivity.kt:33)
                      at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1248)
                      at android.app.Activity.performStart(Activity.java:6679)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2609)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 
                      at android.app.ActivityThread.-wrap12(ActivityThread.java) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:154) 
                      at android.app.ActivityThread.main(ActivityThread.java:6077) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)

这是我的完整代码：

private fun doCheck() {

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

        keyguardManager =
                c.getSystemService(KEYGUARD_SERVICE) as KeyguardManager
        fingerprintManager =
                c.getSystemService(FINGERPRINT_SERVICE) as FingerprintManager

        if (!fingerprintManager!!.isHardwareDetected()) {

            Toast.makeText(c, R.string.dialog_fingerprint_no_hardware_toast, Toast.LENGTH_SHORT).show()

        }

        if (ActivityCompat.checkSelfPermission(c, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) {

            Toast.makeText(c, R.string.dialog_fingerprint_enable_fingerprint_permission, Toast.LENGTH_SHORT).show()
        }

        if (!fingerprintManager!!.hasEnrolledFingerprints()) {

            Toast.makeText(c, R.string.dialog_fingerprint_no_fingerprints, Toast.LENGTH_SHORT).show()
        }

        if (!keyguardManager?.isKeyguardSecure()!!) {
            Toast.makeText(c, R.string.dialog_fingerprint_no_lock_screen, Toast.LENGTH_SHORT).show()
        } else {

            generateKey()

        }

        if (initCipher()) {
            cryptoObject = FingerprintManager.CryptoObject(cipher)

            helper = FingerPrintHelper(dialog!!)
            helper?.FingerprintHandler(c)
            helper?.startAuth(fingerprintManager!!, cryptoObject!!)
        }

    }
}

private fun generateKey() {

    try {

        keyStore = KeyStore.getInstance("AndroidKeyStore")

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

            keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore")
            keyStore?.load(null)
            keyGenerator!!.init(

                    KeyGenParameterSpec.Builder(Constants.FINGERPRINT_KEY_NAME,
                            KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT)
                            .setBlockModes(KeyProperties.BLOCK_MODE_CBC)
                            .setUserAuthenticationRequired(true)
                            .setEncryptionPaddings(
                                    KeyProperties.ENCRYPTION_PADDING_PKCS7)
                            .build())
        }

        keyGenerator?.generateKey()

    } catch (exc: KeyStoreException) {
        exc.printStackTrace()
        throw FingerprintException(exc)
    } catch (exc: NoSuchAlgorithmException) {
        exc.printStackTrace()
        throw FingerprintException(exc)
    } catch (exc: NoSuchProviderException) {
        exc.printStackTrace()
        throw FingerprintException(exc)
    } catch (exc: InvalidAlgorithmParameterException) {
        exc.printStackTrace()
        throw FingerprintException(exc)
    } catch (exc: CertificateException) {
        exc.printStackTrace()
        throw FingerprintException(exc)
    } catch (exc: IOException) {
        exc.printStackTrace()
        throw FingerprintException(exc)
    }

}

@RequiresApi(Build.VERSION_CODES.M)
fun initCipher(): Boolean {
    try {

        cipher = Cipher.getInstance(
                KeyProperties.KEY_ALGORITHM_AES + "/"
                        + KeyProperties.BLOCK_MODE_CBC + "/"
                        + KeyProperties.ENCRYPTION_PADDING_PKCS7)
    } catch (e: NoSuchAlgorithmException) {
        throw RuntimeException("Failed to get Cipher", e)
    } catch (e: NoSuchPaddingException) {
        throw RuntimeException("Failed to get Cipher", e)
    }

    try {
        keyStore?.load(
                null)
        val key = keyStore?.getKey(Constants.FINGERPRINT_KEY_NAME, null) as SecretKey

        cipher?.init(Cipher.ENCRYPT_MODE, key)
        return true
    } catch (e: KeyPermanentlyInvalidatedException) {

        return false
    } catch (e: KeyStoreException) {
        throw RuntimeException("Failed to init Cipher", e)
    } catch (e: CertificateException) {
        throw RuntimeException("Failed to init Cipher", e)
    } catch (e: UnrecoverableKeyException) {
        throw RuntimeException("Failed to init Cipher", e)
    } catch (e: IOException) {
        throw RuntimeException("Failed to init Cipher", e)
    } catch (e: NoSuchAlgorithmException) {
        throw RuntimeException("Failed to init Cipher", e)
    } catch (e: InvalidKeyException) {
        throw RuntimeException("Failed to init Cipher", e)
    }

}

Answer 1

构建版本应大于或等于 marshmallow。如果您尝试少于 M 那么它可能会引发错误..

Answer 2

您将 null 转换为不可为 null 的 SecretKey

val key = keyStore?.getKey(Constants.FINGERPRINT_KEY_NAME, null) as SecretKey

当 keyStore 为空或 getKey() returns 为空时（如果给定的别名不存在或未标识与键相关的条目），您可以获得空值。

所以在那里得到 null 是完全没问题的。因为你在向上转型，你甚至可能运行变成 ClassCastException。为防止这种情况，只需使用类型安全的转换运算符 as? 即可。

val key: SecretKey? = keyStore?.getKey(Constants.FINGERPRINT_KEY_NAME, null) as? SecretKey

Android Keystore?.getKey returns 在某些设备上为空

Android Keystore?.getKey returns null on some devices

android

kotlin

android-security

android-fingerprint-api