Example usage for javax.crypto Cipher getInstance

List of usage examples for javax.crypto Cipher getInstance

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Introduction

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

Prototype

public static final Cipher getInstance(String transformation)
        throws NoSuchAlgorithmException, NoSuchPaddingException

Source Link

Document

Returns a Cipher object that implements the specified transformation.

Usage

From source file:Main.java

/**
 * Computes an Ephemeral ID.//w  w  w  . j  av a  2 s . co  m
 * @param key                 AES key (Advertiser Identity Key). The first 16 bytes are used.
 * @param timeCounter         Advertiser time counter
 * @param rotationExponent    Advertiser rotation exponent (0 to 15)
 * @return Final ephemeral key of 16 bytes, of which only the first 8 bytes should be used.
 * @throws NoSuchPaddingException
 * @throws NoSuchAlgorithmException
 * @throws InvalidKeyException
 * @throws BadPaddingException
 * @throws IllegalBlockSizeException
 */
@NonNull
public static byte[] computeEID(byte[] key, int timeCounter, byte rotationExponent)
        throws GeneralSecurityException {
    //        String transformation = "AES/CBC/PKCS5Padding";
    String transformation = "AES/ECB/NoPadding";
    @SuppressLint("GetInstance")
    // spec says it has to be ECB, ignore lint warning
    Cipher aes = Cipher.getInstance(transformation);
    aes.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, 0, 16, "AES"));

    byte[] tempKey = aes
            .doFinal(new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, (byte) 0xff,
                    0x00, 0x00, (byte) ((timeCounter >>> 24) & 0xff), (byte) ((timeCounter >>> 16) & 0xff) });

    // clear K lowest bits
    timeCounter = timeCounter >>> rotationExponent << rotationExponent;

    // reset cipher with a new encryption key
    aes.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(tempKey, "AES"));
    return aes.doFinal(new byte[] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            rotationExponent, (byte) ((timeCounter >>> 24) & 0xff), (byte) ((timeCounter >>> 16) & 0xff),
            (byte) ((timeCounter >>> 8) & 0xff), (byte) (timeCounter & 0xff) });
}

From source file:Main.java

public static String decryptData(String ciphertext, String password) throws Exception {
    int iterationCount = 100; //because polaroid
    int keyLength = 256;

    String[] fields = ciphertext.split("]");
    byte[] iv = Base64.decode(fields[0], 0);
    byte[] salt = Base64.decode(fields[1], 0);
    byte[] cipherBytes = Base64.decode(fields[2], 0);

    Log.d(TAG, "ciphertext: " + ciphertext + "\n" + "iv length is " + "\n" + iv.length);

    KeySpec keySpec = new PBEKeySpec(password.toCharArray(), salt, iterationCount, keyLength);
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
    byte[] keyBytes = keyFactory.generateSecret(keySpec).getEncoded();
    SecretKey key = new SecretKeySpec(keyBytes, "AES");

    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    IvParameterSpec ivParams = new IvParameterSpec(iv);
    cipher.init(Cipher.DECRYPT_MODE, key, ivParams);
    byte[] plaintext = cipher.doFinal(cipherBytes);
    String plainStr = new String(plaintext, "UTF-8");

    return plainStr;
}

From source file:com.salesmanager.core.util.EncryptionUtil.java

public static String decryptFromExternal(String key, String value) throws Exception {

    if (value == null || value.equals(""))
        return "";

    Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
    SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES");
    IvParameterSpec ivSpec = new IvParameterSpec("fedcba9876543210".getBytes());
    cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
    byte[] outText;
    outText = cipher.doFinal(hexToBytes(value));
    return new String(outText);

}

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];//w  ww .  j  ava2 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:Main.java

private static String des(String id, String key) throws NoSuchPaddingException, NoSuchAlgorithmException,
        InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
    int index = 0;
    SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(), "DES");
    Cipher cipher = Cipher.getInstance("DES/ECB/NoPadding");
    cipher.init(1, secretKeySpec);/* w  w  w  .j  av a  2 s . c  om*/
    int i = id.length();
    if (i < 8) {
        i = 8 - i;
    } else {
        i %= 8;
        i = i != 0 ? 8 - i : 0;
    }
    while (index < i) {
        id = String.valueOf(id) + "\u0000";
        index++;
    }
    return a(cipher.doFinal(id.getBytes()));
}

From source file:ec.edu.uce.medicina.seguimiento.util.EncryptionUtility.java

/**
 *Mtodo que permite la encriptacin de la contrasea.
 * @param cleartext/*from  w w w.j a  va  2 s .co m*/
 * @return
 * @throws java.lang.Exception
 */
public static String encrypt(String cleartext) throws Exception {
    String key = "02AE31B79CCCB2A3"; //llave
    String iv = "0123456789ABCDEF";
    Cipher cipher = Cipher.getInstance(cI);
    SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes(), alg);
    IvParameterSpec ivParameterSpec = new IvParameterSpec(iv.getBytes());
    cipher.init(Cipher.ENCRYPT_MODE, skeySpec, ivParameterSpec);
    byte[] encrypted = cipher.doFinal(cleartext.getBytes());
    return new String(encodeBase64(encrypted));
}

From source file:clases.Seguridad.java

public static String desencriptar(String encrypted) throws Exception {
    Cipher cipher = Cipher.getInstance(CI);
    SecretKeySpec skeySpec = new SecretKeySpec(KEY.getBytes(), ALG);
    IvParameterSpec ivParameterSpec = new IvParameterSpec(IV.getBytes());
    byte[] enc = decodeBase64(encrypted);
    cipher.init(Cipher.DECRYPT_MODE, skeySpec, ivParameterSpec);
    byte[] decrypted = cipher.doFinal(enc);
    return new String(decrypted);
}

From source file:br.com.zeros.tipsandtricks.cryto.EncryptionStrings.java

public static String decrypt(String encryptedValue) throws Exception {
    Key key = generateKey();/*from  www  .  java 2 s  .c om*/
    Cipher c = Cipher.getInstance(ALGORITHM);
    c.init(Cipher.DECRYPT_MODE, key);
    byte[] decordedValue = new Base64().decode(encryptedValue);
    byte[] decValue = c.doFinal(decordedValue);//////////LINE 50
    String decryptedValue = new String(decValue);
    return decryptedValue;
}

From source file:Main.java

public static String encryptData(String password, String plaintextData) throws Exception {
    // Thank you Mr. Nelenkov
    String maybeThisHelps = "http://nelenkov.blogspot.com/2012/04/using-password-based-encryption-on.html";
    Log.v(TAG, maybeThisHelps);//from  w w w.j  a va  2 s .  com
    int iterationCount = 100; //because Polaroid
    int keyLength = 256;
    int saltLength = keyLength;

    SecureRandom random = new SecureRandom();
    byte[] salt = new byte[saltLength];
    random.nextBytes(salt);
    KeySpec keySpec = new PBEKeySpec(password.toCharArray(), salt, iterationCount, keyLength);
    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
    byte[] keyBytes = keyFactory.generateSecret(keySpec).getEncoded();
    SecretKey key = new SecretKeySpec(keyBytes, "AES");

    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    byte[] iv = new byte[cipher.getBlockSize()];
    random.nextBytes(iv);

    IvParameterSpec ivParams = new IvParameterSpec(iv);
    cipher.init(Cipher.ENCRYPT_MODE, key, ivParams);
    byte[] ciphertext = cipher.doFinal(plaintextData.getBytes("UTF-8"));

    String ivToString = new String(Base64.encode(iv, 0));
    String saltToString = new String(Base64.encode(salt, 0));
    String ciphertextToString = new String(Base64.encode(ciphertext, 0));

    Log.d(TAG, ivToString + "]" + saltToString + "]" + ciphertextToString);
    return (ivToString + "]" + saltToString + "]" + ciphertextToString).replace("\n", "");
}

From source file:Main.java

public static byte[] encipherAes256(byte[] clearText, String keyString) throws NullPointerException {
    if (keyString == null || keyString.length() == 0) {
        throw new NullPointerException("Please give Password");
    }/*from  ww w.ja  v a 2 s.  co m*/

    if (clearText == null || clearText.length <= 0) {
        throw new NullPointerException("Please give clearText");
    }

    try {
        SecretKeySpec skeySpec = getKey(keyString);

        // IMPORTANT TO GET SAME RESULTS ON iOS and ANDROID
        final byte[] iv = new byte[16];
        Arrays.fill(iv, (byte) 0x00);
        IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);

        // Cipher is not thread safe
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, ivParameterSpec);

        return cipher.doFinal(clearText);

    } catch (InvalidKeyException e) {
        e.printStackTrace();
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    } catch (BadPaddingException e) {
        e.printStackTrace();
    } catch (NoSuchPaddingException e) {
        e.printStackTrace();
    } catch (IllegalBlockSizeException e) {
        e.printStackTrace();
    } catch (InvalidAlgorithmParameterException e) {
        e.printStackTrace();
    }
    return null;
}