Example usage for javax.crypto Cipher init

Introduction

In this page you can find the example usage for javax.crypto Cipher init.

Prototype

public final void init(int opmode, Certificate certificate, SecureRandom random) throws InvalidKeyException

Source Link

Document

Initializes this cipher with the public key from the given certificate and a source of randomness.

Usage

From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    byte[] input = "www.java2s.com".getBytes();

    byte[] ivBytes = new byte[] { 0x00, 0x00, 0x00, 0x01, 0x04, 0x05, 0x06, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00, 0x00, 0x01 };//from   ww  w  .  j a v a2  s  .c om

    Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
    KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");

    generator.init(192);

    Key encryptionKey = generator.generateKey();

    System.out.println("key   : " + Utils.toHex(encryptionKey.getEncoded()));
    System.out.println("input : " + new String(input));

    // encryption pass
    cipher.init(Cipher.ENCRYPT_MODE, encryptionKey, new IvParameterSpec(ivBytes));
    byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
    int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
    ctLength += cipher.doFinal(cipherText, ctLength);

    // decryption pass
    Key decryptionKey = new SecretKeySpec(encryptionKey.getEncoded(), encryptionKey.getAlgorithm());
    cipher.init(Cipher.DECRYPT_MODE, decryptionKey, new IvParameterSpec(ivBytes));
    byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
    int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
    ptLength += cipher.doFinal(plainText, ptLength);
    System.out.println("plain : " + new String(plainText) + " bytes: " + ptLength);
}

From source file:Main.java

private static byte[] decrypt(byte[] key, byte[] encrypted) throws Exception {
    SecretKeySpec skeySpec = new SecretKeySpec(key, "AES");
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.DECRYPT_MODE, skeySpec, new IvParameterSpec(new byte[cipher.getBlockSize()]));
    return cipher.doFinal(encrypted);
}

From source file:Main.java

private static byte[] encrypt(byte[] key, byte[] clear) throws Exception {
    SecretKeySpec skeySpec = new SecretKeySpec(key, "AES");
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.ENCRYPT_MODE, skeySpec, new IvParameterSpec(new byte[cipher.getBlockSize()]));
    return cipher.doFinal(clear);
}

From source file:Main.java

private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {
    SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.DECRYPT_MODE, skeySpec, new IvParameterSpec(new byte[cipher.getBlockSize()]));
    byte[] decrypted = cipher.doFinal(encrypted);
    return decrypted;
}

From source file:MainClass.java

private static String decrypt(char[] password, String text) throws Exception {
    String salt = text.substring(0, 12);
    String ciphertext = text.substring(12, text.length());
    BASE64Decoder decoder = new BASE64Decoder();
    byte[] saltArray = decoder.decodeBuffer(salt);
    byte[] ciphertextArray = decoder.decodeBuffer(ciphertext);

    PBEKeySpec keySpec = new PBEKeySpec(password);

    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithSHAAndTwofish-CBC");

    SecretKey key = keyFactory.generateSecret(keySpec);

    PBEParameterSpec paramSpec = new PBEParameterSpec(saltArray, 1000);

    Cipher cipher = Cipher.getInstance("PBEWithSHAAndTwofish-CBC");
    cipher.init(Cipher.DECRYPT_MODE, key, paramSpec);

    return new String(cipher.doFinal(ciphertextArray));
}

From source file:MainClass.java

static Cipher createCipher(int mode) throws Exception {
    PBEKeySpec keySpec = new PBEKeySpec("test".toCharArray());
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
    SecretKey key = keyFactory.generateSecret(keySpec);
    MessageDigest md = MessageDigest.getInstance("MD5");
    md.update("input".getBytes());
    byte[] digest = md.digest();
    byte[] salt = new byte[8];
    for (int i = 0; i < 8; ++i)
        salt[i] = digest[i];/*from w w w.  ja va2  s. c o m*/
    PBEParameterSpec paramSpec = new PBEParameterSpec(salt, 20);
    Cipher cipher = Cipher.getInstance("PBEWithMD5AndDES");
    cipher.init(mode, key, paramSpec);
    return cipher;
}

From source file:MainClass.java

private static String encrypt(char[] password, String plaintext) throws Exception {

    byte[] salt = new byte[8];
    Random random = new Random();
    random.nextBytes(salt);/*from w  w  w.  j  a v a2s.  c  o m*/

    PBEKeySpec keySpec = new PBEKeySpec(password);

    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithSHAAndTwofish-CBC");

    SecretKey key = keyFactory.generateSecret(keySpec);

    PBEParameterSpec paramSpec = new PBEParameterSpec(salt, 1000);

    Cipher cipher = Cipher.getInstance("PBEWithSHAAndTwofish-CBC");
    cipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);

    byte[] ciphertext = cipher.doFinal(plaintext.getBytes());

    BASE64Encoder encoder = new BASE64Encoder();

    String saltString = encoder.encode(salt);
    String ciphertextString = encoder.encode(ciphertext);

    return saltString + ciphertextString;
}

From source file:MainClass.java

private static byte[] passwordEncrypt(char[] password, byte[] plaintext) throws Exception {
    int MD5_ITERATIONS = 1000;
    byte[] salt = new byte[8];
    SecureRandom random = new SecureRandom();
    random.nextBytes(salt);//from   w w w .  j a v  a  2 s.  c o  m

    PBEKeySpec keySpec = new PBEKeySpec(password);
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithSHAAndTwofish-CBC");
    SecretKey key = keyFactory.generateSecret(keySpec);
    PBEParameterSpec paramSpec = new PBEParameterSpec(salt, MD5_ITERATIONS);
    Cipher cipher = Cipher.getInstance("PBEWithSHAAndTwofish-CBC");
    cipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);

    byte[] ciphertext = cipher.doFinal(plaintext);

    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    baos.write(salt);
    baos.write(ciphertext);
    return baos.toByteArray();
}

From source file:EncDec.AES.java

public static String encrypt(String key, String initVector, String value) {
    try {/* ww w  .  j av  a2  s. c o  m*/
        IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
        SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");

        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);

        byte[] encrypted = cipher.doFinal(value.getBytes());
        //System.out.println("encrypted string: "
        //        + Base64.encodeBase64String(encrypted));

        return Base64.encodeBase64String(encrypted);
    } catch (Exception ex) {
        ex.printStackTrace();
    }

    return null;
}

From source file:Main.java

public static byte[] decrypt(byte[] ivBytes, byte[] keyBytes, byte[] textBytes) {
    try {/*  www. j  av  a2s  . c  o m*/
        AlgorithmParameterSpec ivSpec = new IvParameterSpec(ivBytes);
        SecretKeySpec newKey = new SecretKeySpec(keyBytes, "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, newKey, ivSpec);
        return cipher.doFinal(textBytes);
    } catch (Exception e) {
        return errorbyte;
    }
}