Guide: Authorization

JWT Authorization: How It Works and Implementing in Your Application

JSON Web Token (JWT) is a commonly used user authentication and authorization standard, used to exchange data in a secure manner. Made up of three components, a header, a payload, and a signature, it’s becoming more and more commonly used. Read on to discover the best use cases for JWT authorization, learn how it works, and access best practices that can help you implement it effectively in your organization.

What Is JWT Authorization?

JWT stands for JSON Web Token. It is a compact, URL-safe means of representing claims to be transferred between two parties. It is used to securely transmit information between parties in a JSON format. JWTs can be used to authorize access to resources and services.

JWT authorization is a stateless mechanism for authentication and authorization that eliminates the need for sessions and cookies. It provides a secure means of transmitting information, because a JWT is digitally signed using a secret key known only to the server. This ensures that the information contained in the JWT is not tampered with or altered during transmission.

For more background, see our article on JWT authentication.

In this article:

How Does JWT Authorization Work? 

JWT authorization works by encoding information into a JSON web token (JWT), which is then passed between the client and server. The steps involved in a typical JWT authorization flow are as follows:

  • Authentication: The client sends the user’s credentials to the server, which authenticates the user and generates a JWT containing information about the user.
  • Issuing the Token: The server sends the JWT back to the client, which stores it for future use.
  • Sending the Token: When the client wants to access a protected resource on the server, it sends the JWT in the Authorization header of the HTTP request.
  • Verifying the Token: The server receives the request and verifies the JWT by checking its signature using the secret key that was used to sign it. If the JWT is valid, the server extracts the information contained in it and uses it to determine what actions the user is authorized to perform.
  • Authorizing the Request: If the user is authorized to access the resource, the server returns the requested data. If the user is not authorized, the server returns an error message.

JWT authorization enables secure and efficient communication between the client and server, as the server does not need to store any session information to keep track of the user’s authentication status. This makes it ideal for use in microservice architectures and other decentralized systems, where multiple independent components need to communicate with each other in a secure manner.

API Keys vs. JWT Authorization 

API keys and JWT authorization are two different mechanisms for authenticating and authorizing access to an API.

What are API keys?

API keys usually consist of a long string of characters, which are sent along with the API request as a parameter or in headers. An API key is typically generated by an API provider and is shared with a client, who needs to include it with every API request. API keys can be used to identify the client and limit the usage of the API.

What are the differences?

JWT authorization uses a JWT to represent the user’s identity and access rights. The JWT is usually generated by the authentication server after the user logs in and contains the user’s identity and access rights. The JWT is then sent with every API request as a bearer token in the authorization header.

Here is a comparison table between API keys and JWT authorization:

FeatureAPI KeysJWT Authorization
PurposeIdentifies the client, limits API usage.Authenticates and authorizes the user.
FormatLong string of characters.Encoded JSON object.
SecurityLess secure, can be easily stolen.More secure, digitally signed and encrypted.
UsageSent as a parameter or header with each request.Sent as a bearer token in the authorization header.
AuthenticationNot used for authentication.Used for authentication.
AuthorizationNot used for authorization.Used for authorization.
FlexibilityLimited flexibility.More flexible, supports complex access control.
Ease of UseSimple to use.More complex, requires token generation and verification.
StandardizationNot standardized, varies by API provider.Standardized, based on JWT standard.

In summary, while API Keys are simpler to use, they are less secure and less flexible than JWT authorization. JWT Authorization provides a more secure and flexible mechanism for authenticating and authorizing access to an API.

General Steps for Implementing JWT Authorization in Your Application

Here are the main steps you will need to implement JWT authorization:

  1. Set up a server-side application: You’ll need a backend application that will generate and verify JWTs. You can use any server-side language and framework, such as Node.js and Express.
  2. Install the necessary packages: You’ll need to install a JWT library for your server-side language. For example, if you’re using Node.js, you can install the jsonwebtoken library.
  3. Implement authentication: Your server-side application will need to implement authentication to verify the user’s credentials. You can use methods like email/password authentication or social media authentication.
  4. Generate the JWT: Once the user has been authenticated, your server-side application will generate a JWT that contains information about the user, such as the user’s ID, name, and roles. You can sign the JWT using a secret key or a public/private key pair.
  5. Send the JWT to the client: The server will send the JWT to the client, which will store it for future use.
  6. Send the JWT with every request: When the client wants to access a protected resource on the server, it will send the JWT in the Authorization header of the HTTP request.
  7. Verify the JWT on the server: The server will receive the request and verify the JWT by checking its signature using the secret key that was used to sign it. If the JWT is valid, the server will extract the information contained in it and use it to determine what actions the user is authorized to perform.
  8. Authorize the request: If the user is authorized to access the resource, the server will return the requested data. If the user is not authorized, the server will return an error message.

With these steps, you can implement JWT authorization in your application and secure the communication between the client and server.

Authentication and Authorization with Frontegg

The industry standard today is to use Authentication providers to “build the door”, but what about Authorization (the door knob)? Most authentication vendors don’t go the extra mile, forcing SaaS vendors to invest in expensive in-house development. This often delays core technology development and impacts developer productivity, something that negatively impacts innovation and time-to-market (TTM) metrics. 

Frontegg’s end-to-end user management platform allows you to authenticate and authorize users with just a few clicks. Integration takes just a few minutes, thanks to its plug-and-play nature. It’s also multi-tenant by design. 

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