// 'key' should be 32 bytes for AES256, will be null-padded otherwise
char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused)
bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)
CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES256,
NULL /* initialization vector (optional) */,
[self bytes], dataLength, /* input */
buffer, bufferSize, /* output */
&numBytesEncrypted);
private static final String AES_SECRET = "PreDefinedKey";
/**
* Method for AES encryption
* @param raw
* @param plain
* @return
* @throws Exception
*/
private static byte[] encrypt(byte[] raw, byte[] plain) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES/ECB/PKCS7Padding");
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted = cipher.doFinal(plain);
return encrypted;
}
/**
* AES decryption
* @param encryptMsg
* @return
* @throws Exception
*/
public static String AESDecrypt(String encryptMsg)
throws Exception {
byte[] rawKey = getRawKey(AES_SECRET.getBytes());
//byte[] enc = toByte(encryptMsg);
byte[] enc = Base64.decode(encryptMsg, 0);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
/**
* Method for AES decryption
* @param raw
* @param encrypted
* @return
* @throws Exception
*/
private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {
SecretKeySpec keySpec = new SecretKeySpec(raw, "AES/ECB/PKCS7Padding");
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding");
cipher.init(Cipher.DECRYPT_MODE, keySpec);
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
public static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
//Init for 256bit AES key
kgen.init(256);
SecretKey secret = kgen.generateKey();
//Get secret raw key
byte[] raw = secret.getEncoded();
return seed;
}
// zeros by default
byte[] rawKey = new byte[32];
// if you don't specify the encoding you might get weird results
byte[] keyBytes = AES_SECRET.getBytes("ASCII");
System.arraycopy(keyBytes, 0, rawKey, 0, keyBytes.length);
SecretKey key = new SecretKeySpec(rawKey, "AES");
Cipher cipher = ...
// rest of your decryption code
