HMACContext¶

Used to create an HMAC for a message using a key.

Description¶

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.

extends Node
var ctx = HMACContext.new()

func _ready():
    var key = "supersecret".to_utf8()
    var err = ctx.start(HashingContext.HASH_SHA256, key)
    assert(err == OK)
    var msg1 = "this is ".to_utf8()
    var msg2 = "super duper secret".to_utf8()
    err = ctx.update(msg1)
    assert(err == OK)
    err = ctx.update(msg2)
    assert(err == OK)
    var hmac = ctx.finish()
    print(hmac.hex_encode())

using Godot;
using System;
using System.Diagnostics;

public class CryptoNode : Node
{
    private HMACContext ctx = new HMACContext();
    public override void _Ready()
    {
        PackedByteArray key = String("supersecret").to_utf8();
        Error err = ctx.Start(HashingContext.HASH_SHA256, key);
        GD.Assert(err == OK);
        PackedByteArray msg1 = String("this is ").to_utf8();
        PackedByteArray msg2 = String("super duper secret").to_utf8();
        err = ctx.Update(msg1);
        GD.Assert(err == OK);
        err = ctx.Update(msg2);
        GD.Assert(err == OK);
        PackedByteArray hmac = ctx.Finish();
        GD.Print(hmac.HexEncode());
    }
}

Note: Not available in HTML5 exports.

Methods¶

PackedByteArray	finish ( )
Error	start ( HashType hash_type, PackedByteArray key )
Error	update ( PackedByteArray data )

Method Descriptions¶

PackedByteArray finish ( )

Returns the resulting HMAC. If the HMAC failed, an empty PackedByteArray is returned.

Error start ( HashType hash_type, PackedByteArray key )

Initializes the HMACContext. This method cannot be called again on the same HMACContext until finish has been called.

Error update ( PackedByteArray data )

Updates the message to be HMACed. This can be called multiple times before finish is called to append data to the message, but cannot be called until start has been called.