How to HMAC-S256 encrypt a string in Node JS

Question

I am pretty new to Node.

I am trying to get the following PHP code

$signature = base64_encode(hash_hmac('sha256', $canonicalString, $secret, true));
$signature = rtrim($signature,"=");

to work in node . Currently I have the following code implementation in node.

  return crypto.createHmac('sha256', key)
    .update(message)
    .digest('base64');

Still the service not getting authenticated.

Any help is much appreciated. Been stuck at the same line of code for more than a day.

Thank you

Looks like all you're missing is something to trim any `=` off the end. — Sammitch, Jan 18 '20 at 02:24
I even tried the trim. still didn't work. After string is retuned Signature = Signature.substring(0, Signature.length - 1);. Still getting the same error. — LReddy, Jan 18 '20 at 02:27
Apart from trimming, there seems to be no functional difference. Base64 encoded strings can have no, one or two padding characters (`=`). Try trimming with `replace(/=+$/g,'')`, [here](https://stackoverflow.com/a/32516190). Authentication may also fail for another reason. — Topaco, Jan 18 '20 at 08:49

score 0 · Accepted Answer · answered Mar 09 '20 at 14:05

0

Sorry for the late update. the following code worked for me.

return crypto.createHmac('sha256', key)
    .update(message)
    .digest('base64');

The mistake i did was using different keys in the PHP code and the node code.

answered Mar 09 '20 at 14:05

LReddy

1 Answers1