in-place encryption attempt

gen.m

- (BOOL)encryptWithKey:(NSString *)key
{
    // ... key generation

    CCCryptorRef encryptor;
    CCCryptorStatus encryptionStatus = CCCryptorCreate(kCCEncrypt, kCCAlgorithmAES128, kCCOptionECBMode, keyPtr, kCCKeySizeAES256, NULL, &encryptor);
    if (encryptionStatus != kCCSuccess)
    {
        MCLog(@"Failed to create a cryptographic context (%d CCCryptorStatus status).", encryptionStatus);
    }
    size_t numberOfBytesWritten;
    encryptionStatus = CCCryptorUpdate(encryptor, [self mutableBytes], [self length], [self mutableBytes], [self length], &numberOfBytesWritten);
    
    CCCryptorRelease(encryptor);
    
    free(keyPtr);
    return ( encryptionStatus == kCCSuccess );
}