10 JWT Token Expiration Best Practices
JWT tokens are a popular way to authenticate users, but there are some best practices to keep in mind to make sure they are used securely.
JSON Web Tokens (JWT) are a popular way to authenticate users and secure data. JWT tokens are used to authenticate users and provide access to resources. However, JWT tokens can be vulnerable to attack if not properly configured.
In this article, we will discuss 10 best practices for setting JWT token expiration times. We will discuss how to set expiration times that are secure and provide the best user experience. We will also discuss how to handle token expiration gracefully.
1. Don’t use JWT for sessions
JWT tokens are designed to be used for authentication, not session management. They are meant to be short-lived and should expire after a certain amount of time.
If you use JWT tokens for sessions, they will become invalid once the token expires, which can cause problems with user experience. Additionally, if an attacker is able to gain access to the token, they could potentially hijack the user’s session.
For these reasons, it’s best practice to use other methods such as cookies or server-side storage for session management instead of relying on JWT tokens.
2. Use short expiration times
Short expiration times help to reduce the risk of token theft. If a malicious user were to gain access to an expired token, they would not be able to use it for long before it expires and becomes invalid. This helps to limit the amount of damage that can be done with stolen tokens.
Additionally, short expiration times also help to ensure that users are regularly re-authenticating themselves when using your application. This is important because it ensures that their session remains secure and up-to-date.
3. Refresh tokens should be long-lived
Refresh tokens are used to generate new access tokens when the existing one expires. If a refresh token is short-lived, then users will have to log in more often and this can be inconvenient for them.
To ensure that your JWT tokens remain secure, it’s important to set an appropriate expiration time for both access tokens and refresh tokens. Access tokens should be short-lived (e.g., 15 minutes) while refresh tokens should be long-lived (e.g., 30 days). This way, users won’t have to log in too frequently but you’ll still maintain security by having shorter-lived access tokens.
4. Revoke refresh tokens when necessary
Refresh tokens are used to generate new access tokens when the current one expires. If a refresh token is not revoked, it can be used indefinitely to generate new access tokens, even if the user has logged out or changed their password.
To prevent this from happening, you should revoke refresh tokens whenever a user logs out of your application, changes their password, or any other action that would invalidate the security of the token. This will ensure that only valid and secure tokens are being used in your application.
5. Rotate signing keys regularly
When a JWT token is signed, the signature is generated using a signing key. If an attacker were to gain access to this key, they could generate their own tokens with any claims they wanted. To prevent this from happening, it’s important to rotate signing keys regularly so that attackers can’t use old keys to create malicious tokens.
Rotating signing keys also helps ensure that tokens are not valid for too long. By setting expiration times on tokens and rotating signing keys regularly, you can make sure that tokens don’t stay valid for longer than necessary. This reduces the risk of someone gaining unauthorized access to your system by using an expired token.
6. Implement rate limiting on authentication endpoints
Rate limiting helps protect against brute force attacks, which are attempts to guess a user’s credentials by repeatedly trying different combinations of usernames and passwords. By rate-limiting authentication requests, you can limit the number of attempts an attacker can make in a given period of time. This makes it much harder for attackers to gain access to your system.
Additionally, rate limiting also helps prevent denial of service (DoS) attacks, where an attacker floods your system with requests in order to overwhelm it and cause it to crash. Rate limiting ensures that only legitimate users can access your system, while malicious actors are blocked from making too many requests.
7. Implement brute force protection
Brute force attacks are a type of attack where an attacker attempts to guess the secret key used to sign JWT tokens. If they can guess it, then they can generate their own valid tokens and gain access to protected resources. To prevent this from happening, you should implement brute force protection by limiting the number of failed login attempts allowed within a certain time period. This will help protect your system from malicious actors who may be trying to guess the secret key. Additionally, you should also consider implementing two-factor authentication for added security.
8. Use HTTPS everywhere
HTTPS is a secure protocol that encrypts data sent between the client and server. This means that any sensitive information, such as JWT tokens, are encrypted before being transmitted over the internet. Without HTTPS, this data could be intercepted by malicious actors who could then use it to gain access to your system.
By using HTTPS everywhere, you can ensure that all of your data is securely transmitted and protected from potential attackers. Additionally, many browsers will display a warning if a website does not have an SSL certificate installed, which can help protect users from unknowingly sending their data over an insecure connection.
9. Always sign your tokens
When you sign a token, it ensures that the data contained within the token has not been tampered with. This is important because if someone were to modify the contents of the token, they could gain access to resources or information that they should not have access to.
By signing your tokens, you can ensure that only authorized users are able to use them and that any changes made to the token will be detected. Additionally, signing your tokens also helps protect against replay attacks, where an attacker attempts to reuse a valid token multiple times in order to gain unauthorized access.
10. Never store sensitive data in the token payload
The JWT token payload is visible to anyone who has access to the token, which means that if you store sensitive data in it, such as passwords or credit card numbers, then those details can be easily accessed by malicious actors. This could lead to serious security issues and potential data breaches.
Instead, use the token payload for non-sensitive information only, such as user IDs, email addresses, etc. If you need to store sensitive data, use a secure database instead.
