[Kotlin] 키해시값 얻는 코드

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    try {
        val info = packageManager.getPackageInfo(packageName, PackageManager.GET_SIGNING_CERTIFICATES)
        val signatures = info.signingInfo.apkContentsSigners
        val md = MessageDigest.getInstance("SHA")
        for (signature in signatures) {
            val md: MessageDigest
            md = MessageDigest.getInstance("SHA")
            md.update(signature.toByteArray())
            val key = String(Base64.encode(md.digest(), 0))
            Log.d("Hash key:", "!!!!!!!$key!!!!!!")
        }
    } catch(e: Exception) {
        Log.e("name not found", e.toString())
    }
}