Example usage for javax.crypto KeyGenerator getInstance

Introduction

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

Prototype

public static final KeyGenerator getInstance(String algorithm) throws NoSuchAlgorithmException

Source Link

Document

Returns a KeyGenerator object that generates secret keys for the specified algorithm.

Usage

From source file:Main.java

public static byte[] generateKey(String password) throws Exception {
    byte[] keyStart = password.getBytes("UTF-8");

    KeyGenerator kgen = KeyGenerator.getInstance("AES");
    SecureRandom sr = SecureRandom.getInstance("SHA1PRNG", "Crypto");
    sr.setSeed(keyStart);/*  w  ww .  jav  a 2  s.com*/
    kgen.init(128, sr);
    SecretKey skey = kgen.generateKey();
    return skey.getEncoded();
}

From source file:Main.java

public static byte[] getRandomKey(byte[] seed) throws Exception {

    KeyGenerator kg = KeyGenerator.getInstance(KEY_ALGORITHM);
    SecureRandom sr = SecureRandom.getInstance("SHA1PRNG"); //random
    sr.setSeed(seed);/*  w  w w.j a va2s  .c  o  m*/
    kg.init(128, sr);
    SecretKey secretKey = kg.generateKey();
    return secretKey.getEncoded();
}

From source file:Main.java

public static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {
    KeyGenerator kgen = KeyGenerator.getInstance("AES");
    kgen.init(128, new SecureRandom(encryptKey.getBytes()));

    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));

    return cipher.doFinal(content.getBytes("utf-8"));
}

From source file:Main.java

public static byte[] initKey(int size) throws NoSuchAlgorithmException {
    KeyGenerator kg = KeyGenerator.getInstance(KEY_ALGORITHM);
    kg.init(size);/*from   w w w .  ja va2s.  c o m*/
    SecretKey secretKey = kg.generateKey();
    return secretKey.getEncoded();
}

From source file:Main.java

public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {
    KeyGenerator kgen = KeyGenerator.getInstance("AES");
    kgen.init(128, new SecureRandom(decryptKey.getBytes()));

    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
    byte[] decryptBytes = cipher.doFinal(encryptBytes);

    return new String(decryptBytes);
}

From source file:Main.java

private static byte[] getRawKey(byte[] seed) throws NoSuchAlgorithmException, NoSuchProviderException {
    KeyGenerator kgen = KeyGenerator.getInstance("AES");
    SecureRandom sr = null;//ww  w  .ja  v  a  2  s  .  c om
    if (android.os.Build.VERSION.SDK_INT >= 17) {
        sr = SecureRandom.getInstance("SHA1PRNG", "Crypto");
    } else {
        sr = SecureRandom.getInstance("SHA1PRNG");
    }
    sr.setSeed(seed);
    kgen.init(128, sr); //256 bits or 128 bits,192bits  
    SecretKey skey = kgen.generateKey();
    byte[] raw = skey.getEncoded();
    return raw;
}

From source file:Main.java

public static String encryption(String string) throws Exception {
    // TODO Auto-generated method stub

    //generate symmetric key
    KeyGenerator keygt = KeyGenerator.getInstance("AES");
    keygt.init(128);/*w w w .  j a  v a2s  . com*/
    SecretKey symkey = keygt.generateKey();

    //get it encoded
    byte[] aes_ba = symkey.getEncoded();

    //create cipher
    SecretKeySpec skeySpec = new SecretKeySpec(aes_ba, "AES");
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.ENCRYPT_MODE, skeySpec);

    //encryption
    byte[] EncSymbyteArray = cipher.doFinal(string.getBytes());

    //encrypt symKey with PublicKey
    //        Key pubKey = getPublicKey();

    Key pubKey = publicKey;

    //RSA cipher
    Cipher cipherAsm = Cipher.getInstance("RSA", "BC");
    cipherAsm.init(Cipher.ENCRYPT_MODE, pubKey);

    //RSA encryption
    byte[] asymEncsymKey = cipherAsm.doFinal(aes_ba);

    //           File f3 = new File(BASE_PATH,"enc.txt");
    //           File f3key = new File(BASE_PATH,"enckey.txt");
    //           File f3file = new File(BASE_PATH,"encfile.txt");
    //           writeToFile2(f3,f3key,f3file, asymEncsymKey, EncSymbyteArray);

    //byte != new String
    //return new String(byteMerger(asymEncsymKey, EncSymbyteArray));
    return Base64.encodeToString(byteMerger(asymEncsymKey, EncSymbyteArray), Base64.DEFAULT);

}

From source file:Main.java

/**
 * Generates a new symmetric key of a given type.
 * @param type Type of key to generate (algorithm).
 * @return Generated new SecretKey.//from w  w  w.j  av  a2s.co m
 * @throws NoSuchAlgorithmException
 */
public static SecretKey generateSymmetricKey(String type) throws NoSuchAlgorithmException {
    int keySize = 192;
    /* SecureRandom seeded automatically */
    SecureRandom secureRandom = new SecureRandom();
    KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
    //128, 192, 256
    /* This is the correct way to initialize the keygenerator */
    keyGenerator.init(keySize, secureRandom);
    SecretKey key = keyGenerator.generateKey();
    return key;
}

From source file:MainClass.java

public static void desEncrypt(String f1, String f2) throws Exception {
    SecretKey key = null;//from  w w  w  .  ja  va2  s  .c  o  m
    ObjectInputStream keyFile = new ObjectInputStream(new FileInputStream("DESKey.ser"));
    key = (SecretKey) keyFile.readObject();
    keyFile.close();

    KeyGenerator keygen = KeyGenerator.getInstance("DES");
    key = keygen.generateKey();
    ObjectOutputStream keyFileout = new ObjectOutputStream(new FileOutputStream("DESKey.ser"));
    keyFileout.writeObject(key);
    keyFileout.close();
    Cipher cipher = null;
    cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
    cipher.init(Cipher.ENCRYPT_MODE, key);
    BufferedInputStream in = new BufferedInputStream(new FileInputStream(f1));

    CipherOutputStream out = new CipherOutputStream(new BufferedOutputStream(new FileOutputStream(f2)), cipher);
    int i;
    do {
        i = in.read();
        if (i != -1)
            out.write(i);
    } while (i != -1);
    in.close();
    out.close();
}

From source file:Main.java

private static Key getKey(Context mContext) {
    if (key == null) {
        try {/* ww w  . jav a  2  s  .c om*/
            KeyGenerator _generator = KeyGenerator.getInstance("DES");
            _generator.init(new SecureRandom(mContext.getPackageName().getBytes()));
            key = _generator.generateKey();
            _generator = null;
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    return key;
}