refactor keccak functions

src/commonMain/kotlin/com/infendro/hash/keccak/Keccak.kt

@@ -6,10 +6,16 @@ import com.infendro.bytearray.toULongArray
 import com.infendro.hash.HashFunction
 import kotlin.math.min
 
-abstract class Keccak internal constructor(
+open class Keccak(
+    override val bytes: Int,
     private val rate: Int,
     private val domain: UByte,
 ) : HashFunction() {
+    init {
+        if (bytes < 1) throw IllegalArgumentException()
+        if (rate !in 8..168) throw IllegalArgumentException()
+    }
+
     override val block: Int
         get() = rate
 
@@ -67,7 +73,7 @@ abstract class Keccak internal constructor(
 
                 addAll(
                     state[i++].toUByteArray(LITTLE_ENDIAN)
-                        .take(min(bytes - size, 8))
+                        .sliceArray(0..<min(bytes - size, 8))
                 )
             }
         }.toUByteArray()