MainClass.java Source code

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Here is the source code for MainClass.java

Source

import java.security.Security;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class MainClass {
    public static void main(String[] args) throws Exception {
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

        byte[] input = "input".getBytes();
        byte[] keyBytes = "input123".getBytes();
        byte[] ivBytes = "12345123".getBytes();

        SecretKeySpec key = new SecretKeySpec(keyBytes, "DES");
        IvParameterSpec ivSpec = new IvParameterSpec(new byte[8]);
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS7Padding", "BC");

        cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);

        byte[] cipherText = new byte[cipher.getOutputSize(ivBytes.length + input.length)];

        int ctLength = cipher.update(ivBytes, 0, ivBytes.length, cipherText, 0);

        ctLength += cipher.update(input, 0, input.length, cipherText, ctLength);

        ctLength += cipher.doFinal(cipherText, ctLength);

        cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);

        byte[] buf = new byte[cipher.getOutputSize(ctLength)];

        int bufLength = cipher.update(cipherText, 0, ctLength, buf, 0);

        bufLength += cipher.doFinal(buf, bufLength);

        byte[] plainText = new byte[bufLength - ivBytes.length];

        System.arraycopy(buf, ivBytes.length, plainText, 0, plainText.length);

        System.out.println("plain : " + new String(plainText));
    }
}