AESContext

Inherits: RefCounted < Object

Provides access to AES encryption/decryption of raw data.

Description

This class holds the context information required for encryption and decryption operations with AES (Advanced Encryption Standard). Both AES-ECB and AES-CBC modes are supported.

    extends Node

    var aes = AESContext.new()

    func _ready():
        var key = "My secret key!!!" # Key must be either 16 or 32 bytes.
        var data = "My secret text!!" # Data size must be multiple of 16 bytes, apply padding if needed.
        # Encrypt ECB
        aes.start(AESContext.MODE_ECB_ENCRYPT, key.to_utf8_buffer())
        var encrypted = aes.update(data.to_utf8_buffer())
        aes.finish()
        # Decrypt ECB
        aes.start(AESContext.MODE_ECB_DECRYPT, key.to_utf8_buffer())
        var decrypted = aes.update(encrypted)
        aes.finish()
        # Check ECB
        assert(decrypted == data.to_utf8_buffer())

        var iv = "My secret iv!!!!" # IV must be of exactly 16 bytes.
        # Encrypt CBC
        aes.start(AESContext.MODE_CBC_ENCRYPT, key.to_utf8_buffer(), iv.to_utf8_buffer())
        encrypted = aes.update(data.to_utf8_buffer())
        aes.finish()
        # Decrypt CBC
        aes.start(AESContext.MODE_CBC_DECRYPT, key.to_utf8_buffer(), iv.to_utf8_buffer())
        decrypted = aes.update(encrypted)
        aes.finish()
        # Check CBC
        assert(decrypted == data.to_utf8_buffer())

    using Godot;
    using System.Diagnostics;

    public partial class MyNode : Node
    {
        private AesContext _aes = new AesContext();

        public override void _Ready()
        {
            string key = "My secret key!!!"; // Key must be either 16 or 32 bytes.
            string data = "My secret text!!"; // Data size must be multiple of 16 bytes, apply padding if needed.
            // Encrypt ECB
            _aes.Start(AesContext.Mode.EcbEncrypt, key.ToUtf8Buffer());
            byte[] encrypted = _aes.Update(data.ToUtf8Buffer());
            _aes.Finish();
            // Decrypt ECB
            _aes.Start(AesContext.Mode.EcbDecrypt, key.ToUtf8Buffer());
            byte[] decrypted = _aes.Update(encrypted);
            _aes.Finish();
            // Check ECB
            Debug.Assert(decrypted == data.ToUtf8Buffer());

            string iv = "My secret iv!!!!"; // IV must be of exactly 16 bytes.
            // Encrypt CBC
            _aes.Start(AesContext.Mode.EcbEncrypt, key.ToUtf8Buffer(), iv.ToUtf8Buffer());
            encrypted = _aes.Update(data.ToUtf8Buffer());
            _aes.Finish();
            // Decrypt CBC
            _aes.Start(AesContext.Mode.EcbDecrypt, key.ToUtf8Buffer(), iv.ToUtf8Buffer());
            decrypted = _aes.Update(encrypted);
            _aes.Finish();
            // Check CBC
            Debug.Assert(decrypted == data.ToUtf8Buffer());
        }
    }

Methods

void	finish\ (\ )
PackedByteArray	get_iv_state\ (\ )
Error	start\ (\ mode: Mode, key: PackedByteArray, iv: PackedByteArray = PackedByteArray()\ )
PackedByteArray	update\ (\ src: PackedByteArray\ )

---

Enumerations

enum Mode: 🔗

Mode MODE_ECB_ENCRYPT = 0

AES electronic codebook encryption mode.

Mode MODE_ECB_DECRYPT = 1

AES electronic codebook decryption mode.

Mode MODE_CBC_ENCRYPT = 2

AES cipher blocker chaining encryption mode.

Mode MODE_CBC_DECRYPT = 3

AES cipher blocker chaining decryption mode.

Mode MODE_MAX = 4

Maximum value for the mode enum.

---

Method Descriptions

void finish\ (\ ) 🔗

Close this AES context so it can be started again. See start().

---

PackedByteArray get_iv_state\ (\ ) 🔗

Get the current IV state for this context (IV gets updated when calling update()). You normally don't need this function.

\ Note: This function only makes sense when the context is started with MODE_CBC_ENCRYPT or MODE_CBC_DECRYPT.

---

Error start\ (\ mode: Mode, key: PackedByteArray, iv: PackedByteArray = PackedByteArray()\ ) 🔗

Start the AES context in the given mode. A key of either 16 or 32 bytes must always be provided, while an iv (initialization vector) of exactly 16 bytes, is only needed when mode is either MODE_CBC_ENCRYPT or MODE_CBC_DECRYPT.

---

PackedByteArray update\ (\ src: PackedByteArray\ ) 🔗

Run the desired operation for this AES context. Will return a PackedByteArray containing the result of encrypting (or decrypting) the given src. See start() for mode of operation.

\ Note: The size of src must be a multiple of 16. Apply some padding if needed.