MainClass.java Source code

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Here is the source code for MainClass.java

Source

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.security.Security;

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

/**
 * Basic IO example with CTR using AES
 */
public class MainClass {
    public static void main(String[] args) throws Exception {
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
        byte[] input = "www.java2s.com".getBytes();
        byte[] keyBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
                0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 };
        byte[] ivBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x02, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x01 };

        SecretKeySpec key = new SecretKeySpec(keyBytes, "AES");
        IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
        Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
        System.out.println("input : " + new String(input));

        // encryption pass
        cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
        ByteArrayInputStream bIn = new ByteArrayInputStream(input);
        CipherInputStream cIn = new CipherInputStream(bIn, cipher);
        ByteArrayOutputStream bOut = new ByteArrayOutputStream();

        int ch;
        while ((ch = cIn.read()) >= 0) {
            bOut.write(ch);
        }

        byte[] cipherText = bOut.toByteArray();

        System.out.println("cipher: " + new String(cipherText));

        // decryption pass
        cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
        bOut = new ByteArrayOutputStream();
        CipherOutputStream cOut = new CipherOutputStream(bOut, cipher);
        cOut.write(cipherText);
        cOut.close();
        System.out.println("plain : " + new String(bOut.toByteArray()));
    }
}