AES Encryption with Kotlin

AESEncryption.kt

interface AESEncryption {
    fun setKey(myKey: String)
    fun encrypt(strToEncrypt: String): String
    fun decrypt(strToDecrypt: String): String
}

class AESEncryptionImpl: AESEncryption {

    private var secretKey: SecretKeySpec? = null

    override fun setKey(myKey: String) {
        try {
            var key = myKey.toByteArray(charset("UTF-8"))
            val sha = MessageDigest.getInstance("SHA-1")
            key = sha.digest(key)
            key = key.copyOf(16)
            secretKey = SecretKeySpec(key, "AES")
        } catch (e: NoSuchAlgorithmException) {
            e.printStackTrace()
        } catch (e: UnsupportedEncodingException) {
            e.printStackTrace()
        }
    }

    override fun encrypt(strToEncrypt: String): String {
        val cipher: Cipher = Cipher.getInstance("AES/ECB/PKCS5Padding")
        cipher.init(Cipher.ENCRYPT_MODE, secretKey)
        return Base64.getEncoder()
            .encodeToString(cipher.doFinal(strToEncrypt.toByteArray(charset("UTF-8"))))
    }

    override fun decrypt(strToDecrypt: String): String {
        val cipher: Cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING")
        cipher.init(Cipher.DECRYPT_MODE, secretKey)
        return String(
            cipher.doFinal(
                Base64.getDecoder()
                    .decode(strToDecrypt)
            )
        )
    }

}