<?xml version="1.0" encoding="UTF-8" ?>
<class name="AESContext" inherits="Reference" version="3.6" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
	<brief_description>
		Interface to low level AES encryption features.
	</brief_description>
	<description>
		This class provides access to AES encryption/decryption of raw data. Both AES-ECB and AES-CBC mode are supported.
		[codeblock]
		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())
		    var encrypted = aes.update(data.to_utf8())
		    aes.finish()
		    # Decrypt ECB
		    aes.start(AESContext.MODE_ECB_DECRYPT, key.to_utf8())
		    var decrypted = aes.update(encrypted)
		    aes.finish()
		    # Check ECB
		    assert(decrypted == data.to_utf8())

		    var iv = "My secret iv!!!!" # IV must be of exactly 16 bytes.
		    # Encrypt CBC
		    aes.start(AESContext.MODE_CBC_ENCRYPT, key.to_utf8(), iv.to_utf8())
		    encrypted = aes.update(data.to_utf8())
		    aes.finish()
		    # Decrypt CBC
		    aes.start(AESContext.MODE_CBC_DECRYPT, key.to_utf8(), iv.to_utf8())
		    decrypted = aes.update(encrypted)
		    aes.finish()
		    # Check CBC
		    assert(decrypted == data.to_utf8())
		[/codeblock]
	</description>
	<tutorials>
	</tutorials>
	<methods>
		<method name="finish">
			<return type="void" />
			<description>
				Close this AES context so it can be started again. See [method start].
			</description>
		</method>
		<method name="get_iv_state">
			<return type="PoolByteArray" />
			<description>
				Get the current IV state for this context (IV gets updated when calling [method update]). You normally don't need this function.
				[b]Note:[/b] This function only makes sense when the context is started with [constant MODE_CBC_ENCRYPT] or [constant MODE_CBC_DECRYPT].
			</description>
		</method>
		<method name="start">
			<return type="int" enum="Error" />
			<argument index="0" name="mode" type="int" enum="AESContext.Mode" />
			<argument index="1" name="key" type="PoolByteArray" />
			<argument index="2" name="iv" type="PoolByteArray" default="PoolByteArray(  )" />
			<description>
				Start the AES context in the given [code]mode[/code]. A [code]key[/code] of either 16 or 32 bytes must always be provided, while an [code]iv[/code] (initialization vector) of exactly 16 bytes, is only needed when [code]mode[/code] is either [constant MODE_CBC_ENCRYPT] or [constant MODE_CBC_DECRYPT].
			</description>
		</method>
		<method name="update">
			<return type="PoolByteArray" />
			<argument index="0" name="src" type="PoolByteArray" />
			<description>
				Run the desired operation for this AES context. Will return a [PoolByteArray] containing the result of encrypting (or decrypting) the given [code]src[/code]. See [method start] for mode of operation.
				[b]Note:[/b] The size of [code]src[/code] must be a multiple of 16. Apply some padding if needed.
			</description>
		</method>
	</methods>
	<constants>
		<constant name="MODE_ECB_ENCRYPT" value="0" enum="Mode">
			AES electronic codebook encryption mode.
		</constant>
		<constant name="MODE_ECB_DECRYPT" value="1" enum="Mode">
			AES electronic codebook decryption mode.
		</constant>
		<constant name="MODE_CBC_ENCRYPT" value="2" enum="Mode">
			AES cipher blocker chaining encryption mode.
		</constant>
		<constant name="MODE_CBC_DECRYPT" value="3" enum="Mode">
			AES cipher blocker chaining decryption mode.
		</constant>
		<constant name="MODE_MAX" value="4" enum="Mode">
			Maximum value for the mode enum.
		</constant>
	</constants>
</class>
