implementing OAuth2 Refresh Token Expiry in Spring Boot Application
I'm learning this framework and I'm working on a personal project and I'm currently implementing OAuth2 authentication in my Spring Boot application using Spring Security and I've run into a perplexing scenario with the refresh tokens... When attempting to refresh an access token, I'm receiving a `400 Bad Request` behavior with the message `Refresh token has expired or is invalid`. I have confirmed that my refresh token is still valid according to my database's expiration settings, which is set to 30 days. My configuration for the token validity is as follows: ```java @Bean public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception { http .csrf().disable() .authorizeRequests() .antMatchers("/oauth/token").permitAll() .anyRequest().authenticated() .and() .oauth2ResourceServer() .jwt(); } ``` I am using Spring Security 5.4.6 and Spring Boot 2.5.4. My scenario seems to be arising when creating the JWT according to the following method: ```java public String generateRefreshToken(String username) { return Jwts.builder() .setSubject(username) .setExpiration(new Date(System.currentTimeMillis() + 2592000000L)) // 30 days .signWith(SignatureAlgorithm.HS512, secret) .compact(); } ``` Upon further investigation, I've noticed that when I try to refresh the token, the request payload includes the grant type as `refresh_token`, but I also see that the refresh token is not being sent correctly from the client-side. Here's the Axios call I'm using to refresh the token: ```javascript axios.post('/oauth/token', { grant_type: 'refresh_token', refresh_token: storedRefreshToken }, { headers: { 'Content-Type': 'application/x-www-form-urlencoded' } }); ``` I've tried adjusting the configuration for the token in the authorization server, testing different combinations of headers, and even generating new refresh tokens. However, the same behavior continues. Is there something I'm missing in the token request or the handling of the refresh tokens? Any insights into common pitfalls or best practices would be greatly appreciated. I'm working on a REST API that needs to handle this. Any ideas what could be causing this? My development environment is CentOS. Is there a simpler solution I'm overlooking? My team is using Java for this web app. What are your experiences with this?