java AES Decryption code in VB.net

Question

I have pretty working AES encryption/decryption code in java, but for some reason I needed to migrate it to VB.net but I have no idea how to do that

java code

public class DECODECLASS {
public static final int CHUNK_SIZE = 6144;
public static final String PKCS7_PADDING = "AES/CBC/PKCS7Padding";
public static final int STARTING_LOCATION = 0;
public static final int STREAM_FINISH_LOCATION = -1;

public void encrypt(File inputFile, File outputFile) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IOException, IllegalBlockSizeException, BadPaddingException {
    FileInputStream fis = new FileInputStream(inputFile);
    FileOutputStream fos = new FileOutputStream(outputFile);
    Cipher cipher = Cipher.getInstance(PKCS7_PADDING);
    byte[] keyBytes = new byte[32];
    System.arraycopy(MessageDigest.getInstance("SHA-256").digest(), STARTING_LOCATION, keyBytes, STARTING_LOCATION, keyBytes.length);
    cipher.init(1, new SecretKeySpec(keyBytes, "AES"), new IvParameterSpec(new byte[16]));
    CipherInputStream inputStream = new CipherInputStream(fis, cipher);
    byte[] data = new byte[CHUNK_SIZE];
    while (true) {
        int count = inputStream.read(data, STARTING_LOCATION, CHUNK_SIZE);
        if (count != STREAM_FINISH_LOCATION) {
            fos.write(data, STARTING_LOCATION, count);
        } else {
            fis.close();
            fos.close();
            inputStream.close();
            return;
        }
    }
}

public void decrypt(File inputFile, File outputfile) throws InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, IOException, IllegalBlockSizeException, BadPaddingException {
    FileInputStream fis = new FileInputStream(inputFile);
    FileOutputStream fos = new FileOutputStream(outputfile);
    Cipher cipher = Cipher.getInstance(PKCS7_PADDING);
    byte[] keyBytes = new byte[32];
    System.arraycopy(MessageDigest.getInstance("SHA-256").digest(), STARTING_LOCATION, keyBytes, STARTING_LOCATION, keyBytes.length);
    cipher.init(2, new SecretKeySpec(keyBytes, "AES"), new IvParameterSpec(new byte[16]));
    CipherInputStream inputStream = new CipherInputStream(fis, cipher);
    byte[] data = new byte[CHUNK_SIZE];
    while (true) {
        int count = inputStream.read(data, STARTING_LOCATION, CHUNK_SIZE);
        if (count != STREAM_FINISH_LOCATION) {
            fos.write(data, STARTING_LOCATION, count);
        } else {
            fis.close();
            fos.close();
            inputStream.close();
            return;
        }
    }
} }

I tried java to VB converter but no luck as

javax.crypto.Cipher and java.security.MessageDigest

are not available in VB I found some alternative Here , Here and some from Here but got no clue, Because this is my first post so sorry for any mistake or inconvenience ,and heartily thanks for stackoverflow community for always being there for help. Any help is most welcomed.