ServiceNow JS equivalent of the Python SHA256 hash with key?

[Mosh Jah_n1]

I am trying to do the ServiceNow JS equivalent of the following Python code:

hmac = hmac.new("key".encode(), "message".encode(), digestmod=hashlib.sha256).hexdigest()

I thought it would be this, but it's not resulting in the same hash as Python:

var encryption = new GlideCertificateEncryption();
var digest = new GlideDigest();
var util = new GlideStringUtil();

var key = utf8Encode("key");  // utf8Encode() is my own function which is working fine
var message = utf8Encode("message");

var signatureMacBase64 = encryption.generateMac(util.base64Encode(key), "HmacSHA256", message);
var signatureDigest = digest.getSHA256Hex(signatureMacBase64);

The output I'm expecting (for "key" and "message" as inputs) in hex is:

6e9ef29b75fffc5b7abae527d58fdadb2fe42e7219011976917343065f58ed4a


Any help appreciated!

[Mosh Jah_n1 · Accepted solution]

I solved it:

var HexUtil = 

{

  convertByteArrayToHex : function(byteArray)

  {

    var hex = "";

    byteArray.forEach(function(byteValue) { hex += HexUtil.convertByteToHex(byteValue); });

    return hex;  

  },

  convertByteToHex : function(b) 

  {

    var hexChar = ["0", "1", "2", "3", "4", "5", "6", "7","8", "9", "a", "b", "c", "d", "e", "f"];

    return hexChar[(b >> 4) & 0x0f] + hexChar[b & 0x0f];

  }

};

var key = "key";

key = encodeURIComponent(key);

key = GlideStringUtil.base64Encode(key);

var msg = "message";

msg = encodeURIComponent(msg);

var mac = new GlideCertificateEncryption();

signature = mac.generateMac(key, "HmacSHA256", msg);

gs.print(signature);

// Yes! bp7ym3X//Ft6uuUn1Y/a2y/kLnIZARl2kXNDBl9Y7Uo=

var bytes = GlideStringUtil.base64DecodeAsBytes(signature);

gs.print(JSON.stringify(bytes));

gs.print(bytes.length);

// Yes! [110,-98,-14,-101,117,-1,-4,91,122,-70,-27,39,-43,-113,-38,-37,47,-28,46,114,25,1,25,118,-111,115,67,6,95,88,-19,74]

var hex = HexUtil.convertByteArrayToHex(bytes);

gs.print(hex);

// Yes! 6e9ef29b75fffc5b7abae527d58fdadb2fe42e7219011976917343065f58ed4a

var hexB64 = GlideStringUtil.base64Encode(hex);

gs.print(hexB64);

// Yes! NmU5ZWYyOWI3NWZmZmM1YjdhYmFlNTI3ZDU4ZmRhZGIyZmU0MmU3MjE5MDExOTc2OTE3MzQzMDY1ZjU4ZWQ0YQ==