How to create JWT in Javascript

Question

I am new to JWT, I am trying to create a simple JWT in javascript, send it to a controller (using web-api), check it in sql database. when I googled the net I found a examples like: //HEAD

  {"typ":"JWT",
          "alg":"HS256"}

//claims

{
  "Id": 445566,
  "name": "Meme Jhon",
  "password": "ticktack"
}

//and signature.

I want to create in Javascript my First JWT but i feel something is missing.. what is the full structure? it's not seem logical to start only with the head (like example above..)I need a full example or explaination or a link to a full example. Thank you

Answer 1

Refer to the JWT spec to get a full understanding.

To summarize, at the end of the day, it's a way to send data (claims) between 2 parties in a secure fashion:

JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties.

The structure looks like this (taken straight out of the spec):

eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
.
dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk

• 3 base64url encoded segments separated by a dot (.)

  • header
  • claim/payload
  • signature

The core concept of server-side generation has to do with signing - though if you don't want to sign, therefore "unsecured JWT" (refer to spec), then I guess you can do everything client-side.

Implementation details vary - e.g. the above can be the payload of some HTTP request, auth schemes (see link in @M.M. answer for such), etc.

Google Wallet is an example of an implementation of the spec.

Refer to the link provided above by @M.M. for libraries