I am trying to integrate org.bouncycastle.crypto.macs.ISO9797Alg3Mac on my application. while calling the method, I am getting below error,

java.lang.IllegalArgumentException: Key must be either 112 or 168 bit long at 
org.bouncycastle.crypto.macs.ISO9797Alg3Mac.init(Unknown Source:119)

Here is the method I am using to generate Mac,

fun getISO9797Alg3Mac(key: ByteArray?, data: ByteArray): ByteArray {
    
     //To print the MacKey
     "MacKey : ${macKey} ,ByteArray Size: ${macKey.length}".toLog()
    
    val macSizeBits = 32
    val cipher: BlockCipher = DESEngine()
    val mac = ISO9797Alg3Mac(cipher)
    val keyP = KeyParameter(key)

    mac.init(keyP)
    mac.update(data, 0, data.size)
    val out = ByteArray(macSizeBits / java.lang.Byte.SIZE)
    mac.doFinal(out, 0)
    return out
}

My Mackey is like this,

MacKey : 00000000-6b4b-282b-0000-00006b4b282b24.783063446.7061012
ByteArray Size : 56