When Base64-decoding a JWT, I found that the JSON data was incomplete. This article mainly introduces the relevant knowledge and solves this problem. 1. Introduction to JWT JWT passes authentication by setting Authorization: Bearer <token> in the Header. A JWT Token is a Base64-encoded string joined by dots, something like

1. Application Scenarios 1.1 Mail RFC821 requires that email content be ASCII. When a message contains other non-ASCII characters or binary data, Content-Transfer-Encoding is needed, and Base64 is one such method. 1.2 URL Some applications need to put binary data into a URL, but URLs only allow a specific set