an AES utility

AES.kt

package modes.server

import java.security.MessageDigest
import javax.crypto.Cipher
import javax.crypto.spec.SecretKeySpec

object AES {
    private val encryptCipher: Cipher
    private val decryptCipher: Cipher

    init {
        val seed = Config.AESSeed
        val sha = MessageDigest.getInstance("SHA-256")
            .digest(seed.toByteArray(charset("UTF-8")))
        val secretKey = SecretKeySpec(sha, "AES")

        encryptCipher = Cipher.getInstance("AES/ECB/PKCS5Padding")
        encryptCipher.init(Cipher.ENCRYPT_MODE, secretKey)

        decryptCipher = Cipher.getInstance("AES/ECB/PKCS5PADDING")
        decryptCipher.init(Cipher.DECRYPT_MODE, secretKey)
    }

    fun encrypt(toEncrypt: String) = encryptCipher.doFinal(toEncrypt.toByteArray())

    fun decrypt(toDecrypt: ByteArray) = String(decryptCipher.doFinal(toDecrypt))
}