What is the JavaScript/node.js function HMACSHA256()?

Question

I am trying to find information about this JavaScript/node.js function:

HMACSHA256()

Its mentioned e.g. here:

• https://jwt.io/introduction (scroll to section "Signature")

• https://hirosht.medium.com/customized-jwt-encoded-with-hmac-sha256-hs256-267574bd7639 (scroll to section "Signature;")

It's mentioned in other places too.

Neither node.js nor any browser JavaScript provides any function with that name.

So what is it? Is it pseudo code or is it a dummy function or simply a mistake everybody copies and pastes?

Answer 1

You need a plugin named "crypto" It has "createHmac" function where you can give "sha256" as an argument.

https://nodejs.org/api/crypto.html#cryptocreatehmacalgorithm-key-options