Pad a byte[] to a given block size

gistfile1.java

public static byte[] padBytes(byte[] str, int blocksize){
    byte[] barr;
    
    if (str.length > blocksize){
        int padbytes = str.length % blocksize ;
        barr = new byte[str.length + (blocksize-padbytes)];
    }else{
        barr = new byte[blocksize];
    }
    
    System.arraycopy(str, 0, barr, 0, str.length);

    for (int i = str.length; i < barr.length; i++){
        barr[i]=0;
    }

    return barr;
}