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copied!<pre><code>import java.security.AlgorithmParameters; import java.security.SecureRandom; import java.security.spec.KeySpec; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.SecretKeyFactory; import javax.crypto.spec.IvParameterSpec; import javax.crypto.spec.PBEKeySpec; import javax.crypto.spec.SecretKeySpec; class SecurityUtils { private static final byte[] salt = { (byte) 0xA4, (byte) 0x0B, (byte) 0xC8, (byte) 0x34, (byte) 0xD6, (byte) 0x95, (byte) 0xF3, (byte) 0x13 }; private static int BLOCKS = 128; public static byte[] encryptAES(String seed, String cleartext) throws Exception { byte[] rawKey = getRawKey(seed.getBytes("UTF8")); SecretKeySpec skeySpec = new SecretKeySpec(rawKey, "AES"); Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec); return cipher.doFinal(cleartext.getBytes("UTF8")); } public static byte[] decryptAES(String seed, byte[] data) throws Exception { byte[] rawKey = getRawKey(seed.getBytes("UTF8")); SecretKeySpec skeySpec = new SecretKeySpec(rawKey, "AES"); Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.DECRYPT_MODE, skeySpec); return cipher.doFinal(data); } private static byte[] getRawKey(byte[] seed) throws Exception { KeyGenerator kgen = KeyGenerator.getInstance("AES"); SecureRandom sr = SecureRandom.getInstance("SHA1PRNG"); sr.setSeed(seed); kgen.init(BLOCKS, sr); // 192 and 256 bits may not be available SecretKey skey = kgen.generateKey(); byte[] raw = skey.getEncoded(); return raw; } private static byte[] pad(byte[] seed) { byte[] nseed = new byte[BLOCKS / 8]; for (int i = 0; i < BLOCKS / 8; i++) nseed[i] = 0; for (int i = 0; i < seed.length; i++) nseed[i] = seed[i]; return nseed; } public static byte[] encryptPBE(String password, String cleartext) throws Exception { SecretKeyFactory factory = SecretKeyFactory .getInstance("PBKDF2WithHmacSHA1"); KeySpec spec = new PBEKeySpec(password.toCharArray(), salt, 1024, 256); SecretKey tmp = factory.generateSecret(spec); SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES"); Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, secret); AlgorithmParameters params = cipher.getParameters(); byte[] iv = params.getParameterSpec(IvParameterSpec.class).getIV(); return cipher.doFinal(cleartext.getBytes("UTF-8")); } public static String decryptPBE(SecretKey secret, String ciphertext, byte[] iv) throws Exception { Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); cipher.init(Cipher.DECRYPT_MODE, secret, new IvParameterSpec(iv)); return new String(cipher.doFinal(ciphertext.getBytes()), "UTF-8"); } } </code></pre>

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