encryption file example.cs

char[] message = "Secret message!".toCharArray();
char[] userPassword = input("Enter your password: ");

//16 bytes twice PBKDF2 minimum salt recommendation
byte[] salt = SecureRandom.getBytes(16); 

//Why did I use SHA512? see note at the bottom
//produce 64 bytes of secretmaterial from user password
byte[] secretMaterial = PBKDF2(userPassword, salt, 5000, "SHA512", 64);

// 32 bytes
byte[] encKey = secretMaterial.splice(0, 32);

//32 bytes
byte[] authKey = secretMaterial.splice(32, 64);

byte[] iv = SecureRandom.getBytes(16);

//AES256_CBC (has no integrity built in so we need to add MAC)
byte[] cipherText = AES(message, iv, encKey, "CBC");

//array concatenation. "salt" and "iv" are always fixed length (16 and 16)
byte[] cipherPayload = salt + iv + cipherText;

//always 32 bytes
byte[] mac = HMAC_256(cipherPayload, authKey);

cipherPayload = mac + cipherPayload;