SuiteScript hmac sha256 - netsuite

Question

I'm actually working on a new project based on netsuite product.
I'm trying to encrypt a message using hmac sha256.
What's is the simple way to do it considering that I have the stringToEncrypt and a key.
I've read the documentation in Netsuite but I'm still stucked...
There is my function
function toHmacSHA256Base64(toCrypt, key) {
var inputString = toCrypt;
var myGuid = key;
var sKey = crypto.createSecretKey({
guid: myGuid,
encoding: encode.Encoding.UTF_8
});
var hmacSHA256 = crypto.createHmac({
algorithm: 'SHA256',
key: sKey
});
hmacSHA256.update({
input: inputString,
inputEncoding: encode.Encoding.BASE_64
});
var digestSHA256 = hmacSHA256.digest({
outputEncoding: encode.Encoding.HEX
});
return digestSHA256;
};
of course behind the word crypto I use the module 'N/crypto' and encode 'N/encode'.
Thx a lot.

Answer 1

That's roughly correct and looks exactly like the sample from the NS help. If you have a string then you probably want inputEncoding:encode.Encoding.UTF_8 for the update call.
What's missing is how to generate the guid of the secret key.
For that you use a suitelet. Note the addSecretKeyField not the addCredentialField of the NS help:
/**
*#NApiVersion 2.x
*#NScriptType Suitelet
*/
define(['N/ui/serverWidget', './config.js'],
function(serverWidget, config) {
function onRequest(context) {
if (context.request.method === 'GET') {
var form = serverWidget.createForm({
title: 'SFTP Password'
});
form.addSecretKeyField({
id : 'username',
label : 'Pwd',
restrictToScriptIds : config.targetScript,
restrictToCurrentUser : false
});
form.addSubmitButton({
label: 'Submit Button'
});
context.response.writePage(form);
} else {
var textField = context.request.parameters.username;
context.response.write('You have entered: ' + textField);
}
}
return {
onRequest: onRequest
};
});
FWIW encrypt is the wrong term here. You are creating a hash of the data which will be used for ensuring data integrity. You cannot decrypt a hash.
Once a GUID for a key has been generated I just store it in a config file (same one as is used for the script list above.
in TypeScript it looks like:
/**
* config.js
* #NApiVersion 2.x
*/
export var config = {
'host': '162.242.144.xxx',
'userName': 'unsername',
'targetScript': ['customscript_transmit_dsv_943', 'customscript_transmit_dsv_940', 'customscript_retrieve_dsv_944'],
'hostKey': 'AAAAB3Nza...Wz'
};
Then everything except the config.xs files can be stored in version control. Audience needs to be set appropriately on the files used in the script.