Basic IO example with CTR using AES : File Secure IO « Security « Java

Basic IO example with CTR using AES


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 = "".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 = >= 0) {

    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);
    System.out.println("plain : " + new String(bOut.toByteArray()));

       1,199 k)

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