mKeyStore？.getKey( "default_key" ， null) 在 Kotlin 中变为空

Question

我尝试了Android中的指纹身份验证器。最初它在工作，那是在Java。我现在将代码移植到Kotlin。这次对我不起作用。

try {
        mKeyStore = KeyStore.getInstance("AndroidKeyStore");
    } catch (KeyStoreException e) {
        throw new RuntimeException("Failed to get an instance of KeyStore", e);
    }
    try {
        mKeyGenerator = KeyGenerator
                .getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");
    } catch (NoSuchAlgorithmException | NoSuchProviderException e) {
        throw new RuntimeException("Failed to get an instance of KeyGenerator", e);
    }    
mKeyStore.load(null);
SecretKey key = (SecretKey) mKeyStore.getKey("default_key", null);

上面的书面代码在Java中，我将键作为非零值。

但是，当Kotlin用相同的代码写入相同的代码时，密钥将获得零值。

try {
    mKeyStore = KeyStore.getInstance("AndroidKeyStore")
} catch (e: KeyStoreException) {
    throw RuntimeException("Failed to get an instance of KeyStore", e)
}
try {
    mKeyGenerator = KeyGenerator
        .getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore")
} catch (e: NoSuchAlgorithmException) {
    throw RuntimeException("Failed to get an instance of KeyGenerator", e)
} catch (e: NoSuchProviderException) {
    throw RuntimeException("Failed to get an instance of KeyGenerator", e)
}
mKeyStore?.load(null)
val key = mKeyStore?.getKey("default_key", null) as? SecretKey

为什么我得到这个？澄清我是否缺少任何东西。

谢谢您的宝贵时间。

Answer 1

初始化键机，然后提取SecretKey。

 mKeyGenerator.init(
        KeyGenParameterSpec.Builder("default_key", KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT)
            .setBlockModes(KeyProperties.BLOCK_MODE_CBC)
            .setUserAuthenticationRequired(true)
            .setEncryptionPaddings(
                KeyProperties.ENCRYPTION_PADDING_PKCS7
            )
            .build()
    )
    mKeyGenerator.generateKey()