Used to create an HMAC for a message using a key.
The HMACContext class is useful for advanced HMAC use cases, such as streaming the message as it supports creating the message over time rather than providing it all at once. [codeblocks] [gdscript] extends Node var ctx = HMACContext.new()

func _ready(): var key = "supersecret".to_utf8_buffer() var err = ctx.start(HashingContext.HASH_SHA256, key) assert(err == OK) var msg1 = "this is ".to_utf8_buffer() var msg2 = "super duper secret".to_utf8_buffer() err = ctx.update(msg1) assert(err == OK) err = ctx.update(msg2) assert(err == OK) var hmac = ctx.finish() print(hmac.hex_encode())

[/gdscript] [csharp] using Godot; using System.Diagnostics;

public partial class MyNode : Node { private HmacContext _ctx = new HmacContext();

public override void _Ready() { byte[] key = "supersecret".ToUtf8Buffer(); Error err = _ctx.Start(HashingContext.HashType.Sha256, key); Debug.Assert(err == Error.Ok); byte[] msg1 = "this is ".ToUtf8Buffer(); byte[] msg2 = "super duper secret".ToUtf8Buffer(); err = _ctx.Update(msg1); Debug.Assert(err == Error.Ok); err = _ctx.Update(msg2); Debug.Assert(err == Error.Ok); byte[] hmac = _ctx.Finish(); GD.Print(hmac.HexEncode()); } } [/csharp] [/codeblocks]
Returns the resulting HMAC. If the HMAC failed, an empty [PackedByteArray] is returned.
Initializes the HMACContext. This method cannot be called again on the same HMACContext until [method finish] has been called.
Updates the message to be HMACed. This can be called multiple times before [method finish] is called to append [param data] to the message, but cannot be called until [method start] has been called.