JWT in the body

[telecoms-candidate12 (Betwarrior IT)]

Hi, I have to send a request and do not know how to create a pre-request script. The issue is that the payload should be signed in JWT RS256 (Sign with private key), but the token should be sent in the body, so…

If I have the body:

    {
        "client": 31018881,
        "subMethod": null,
        "provider": "6f2dd96b-e48a-4c85-94f9-33dcec9c4acb",
        "Currency": "EUR"
    }

I should send this payload: {"token": "token in RS256"}

Some help will be appreciated.

Thanks

[danny-dainton]

Hey @telecoms-candidate12

I don’t think that there is a straightforward way of doing that (I’m probably wrong though), there going to be a few moving parts and code to get what you need I believe.

We do have a JWT Helper under the Auth tab but as you require this in the request body, I don’t think that’s going to work for you.

I’ve never done it like this so my responses are going to be based on a bit of research and learning as i’m going.

There is this older topic which is bringing an external lib to do some of the heavy lifting:

External libraries for JWT encryption and protecting the Private Key

Hi, In our team we work extensively with Adobe.io and Experience Cloud API’s We’ve recently come across a library that seems to meet our needs when it comes to encrypting a JWT token. For this we are using the Pre-request Script capability of Postman and this library jsrsasign - cryptography library in JavaScript Now I haven’t done a security audit on this library but I am conscious that the private key we are using could in fact be sent to a third party, obviously not good. So my question i…

This is also something similar which was asked and answered by someone who works at Postman so I could ask him to help out here.

Postman Pre-Request Script to create JWT for Google Service Account

A lot of people are mentioned this util lib that could be brought into Postman via a CDN and stored at the global level. I can’t vouch for this though so it’s up to you if that’s something you want to use.

postman-util-lib

[telecoms-candidate12 (Betwarrior IT)]

Thanks for your help, I will check that.