Hands-On RESTful Web Services with Go - Second Edition

JWT format

Everything we discussed in the preceding section was about passing a JWT token. In this section, we will see what a JWT looks like, and how it is generated. These are the high-level steps for generating a JWT:

1. Create a JWT header by doing Base64Url encoding on the JSON header.
2. Create a JWT payload by doing Base64Url encoding on the JSON payload.
3. Create a signature by encrypting the appended header and payload using a secret key.
4. A JWT string can be obtained by appending the JWT header, JWT payload, and signature.

A header is a simple JSON object. It looks like the following code snippet in Go:

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

HS256 is a short form for the algorithm (HMAC with SHA-256) that's used for creating a signature. The ...