android - 如何解决谷歌安全警报 - 不太安全的加密模式

Question

下面是我的代码，它的加密不太安全，来自 google playstore 的警报。指向 encrypter.kt 文件中的加密方法。任何人都可以帮助摆脱这个警报。我对加密技术的了解很少。

**Encryptor.kt**

内部类加密器{

private var iv: ByteArray? = null

@Throws(UnrecoverableEntryException::class, NoSuchAlgorithmException::class, KeyStoreException::class, NoSuchProviderException::class, NoSuchPaddingException::class, InvalidKeyException::class, IOException::class, InvalidAlgorithmParameterException::class, SignatureException::class, BadPaddingException::class, IllegalBlockSizeException::class)

fun encryptText(alias: String, textToEncrypt: String): ByteArray? {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        val cipher = Cipher.getInstance(TRANSFORMATION)
        cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(alias))

        iv = cipher.iv
        return cipher.doFinal(textToEncrypt.toByteArray(Charsets.UTF_8))
    }
    else{
        return encrypt(alias,textToEncrypt)
    }
}

@Throws(NoSuchAlgorithmException::class, NoSuchProviderException::class, InvalidAlgorithmParameterException::class)

private fun getSecretKey(alias: String): SecretKey {

    val keyGenerator: KeyGenerator

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, ANDROID_KEY_STORE)

        keyGenerator.init(KeyGenParameterSpec.Builder(alias, KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT)
                .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
                .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
                .build())
    } else {
        // or something like

        keyGenerator = KeyGenerator.getInstance("AES", ANDROID_KEY_STORE)

        // use the supported init method here such as this one: https://developer.android.com/reference/javax/crypto/KeyGenerator.html#init(int, java.security.SecureRandom)
        keyGenerator.init(256)
    }

    return keyGenerator.generateKey()
}

fun getIv():ByteArray? {
    return iv
}

@Throws(Exception::class)
fun encrypt(seed: String, cleartext: String): ByteArray {
    iv = getivNew(seed.toByteArray())
    return encrypt(iv!!, cleartext.toByteArray())
}

@Throws(Exception::class)
private fun encrypt(raw: ByteArray, clear: ByteArray): ByteArray {
    val skeySpec = SecretKeySpec(raw, "AES")
    val cipher = Cipher.getInstance("AES")
    cipher.init(Cipher.ENCRYPT_MODE, skeySpec)
    val encrypted = cipher.doFinal(clear)
    return encrypted
}

@Throws(Exception::class)
private fun getivNew(seed: ByteArray): ByteArray {
    val md = MessageDigest.getInstance("MD5")
    val md5Bytes = md.digest(seed) // 128 Bit = 16 byte SecretKey
    val skey = SecretKeySpec(md5Bytes, "AES")
    return skey.getEncoded()
}

companion object {

    private const val TRANSFORMATION = "AES/GCM/NoPadding"
    private const val ANDROID_KEY_STORE = "AndroidKeyStore"
}

}

解密器.kt

内部类 Decryptor @Throws(CertificateException::class, NoSuchAlgorithmException::class, KeyStoreException::class, IOException::class)

构造函数（）{

private var keyStore: KeyStore? = null

init {
    initKeyStore()
}

@Throws(KeyStoreException::class, CertificateException::class, NoSuchAlgorithmException::class, IOException::class)
private fun initKeyStore() {
    keyStore = KeyStore.getInstance(ANDROID_KEY_STORE)
    keyStore?.load(null)
}

@Throws(UnrecoverableEntryException::class, NoSuchAlgorithmException::class, KeyStoreException::class, NoSuchProviderException::class, NoSuchPaddingException::class, InvalidKeyException::class, IOException::class, BadPaddingException::class, IllegalBlockSizeException::class, InvalidAlgorithmParameterException::class)

fun decryptData(alias: String, encryptedData: ByteArray, encryptionIv: ByteArray): String {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        val cipher = Cipher.getInstance(TRANSFORMATION)
        val spec = GCMParameterSpec(128, encryptionIv)
        cipher.init(Cipher.DECRYPT_MODE, getSecretKey(alias), spec)

        return String(cipher.doFinal(encryptedData), Charsets.UTF_8)
    }
    else{
        return decrypt(encryptionIv,encryptedData)
    }
}

@Throws(NoSuchAlgorithmException::class, UnrecoverableEntryException::class, KeyStoreException::class)

private fun getSecretKey(alias: String): SecretKey {
    return (keyStore?.getEntry(alias, null) as KeyStore.SecretKeyEntry).secretKey
}

@Throws(Exception::class)
private fun decrypt(raw: ByteArray, encrypted: ByteArray): String {
    val skeySpec = SecretKeySpec(raw, "AES")
    val cipher = Cipher.getInstance("AES")
    cipher.init(Cipher.DECRYPT_MODE, skeySpec)
    val decrypted = cipher.doFinal(encrypted)
    return String(decrypted)
}

companion object {

    private const val TRANSFORMATION = "AES/GCM/NoPadding"
    private const val ANDROID_KEY_STORE = "AndroidKeyStore"
}

}

SimpleCrypto.kt

对象 SimpleCrypto {

private val HEX = "0123456789ABCDEF"

@Throws(Exception::class)
fun decryptNew(seed: String, encrypted: String): String {
    val rawKey = getRawKeyNew(seed.toByteArray())
    val enc = toByte(encrypted)
    val result = decrypt(rawKey, enc)
    return String(result)
}

@Throws(Exception::class)
private fun getRawKeyNew(seed: ByteArray): ByteArray {
    val md = MessageDigest.getInstance("MD5")
    val md5Bytes = md.digest(seed) // 128 Bit = 16 byte SecretKey
    val skey = SecretKeySpec(md5Bytes, "AES")
    return skey.getEncoded()
}

@Throws(Exception::class)
private fun decrypt(raw: ByteArray, encrypted: ByteArray): ByteArray {
    val skeySpec = SecretKeySpec(raw, "AES")
    val cipher = Cipher.getInstance("AES")
    cipher.init(Cipher.DECRYPT_MODE, skeySpec)
    return cipher.doFinal(encrypted)
}

fun toByte(hexString: String): ByteArray {
    val len = hexString.length / 2
    val result = ByteArray(len)
    for (i in 0 until len)
        result[i] = Integer.valueOf(hexString.substring(2 * i, 2 * i + 2),
                16).toByte()
    return result
}

}

标签： androidsecuritykotlinencryption