Spring OAuth with JWT custom UserDetails - Set Principal inside JwtAccessTokenConverter

Question

Some additional info is sent from OAuth Authorization Server that is needed inside a custom UserDetails class on Resource Server, and preferably inside SpringSe

Answer 1

I can not say if this is the preferred solution, but after trying to solve the same thing myself, I ended up extending the DefaultUserAuthenticationConverter.

So you can do something like this

@Bean
public JwtAccessTokenConverter accessTokenConverter() {
  DefaultAccessTokenConverter defaultConverter = new DefaultAccessTokenConverter();
  defaultConverter.setUserTokenConverter(new CustomUserAuthenticationConverter());

  JwtAccessTokenConverter jwtConverter = new JwtAccessTokenConverter();
  converter.setAccessTokenConverter(defaultConverter);
  return converter;
}

Then the DefaultUserAuthenticationConverter is not very extendable since most methods and properties are private. But here is an example

public class CustomUserAuthenticationConverter extends DefaultUserAuthenticationConverter {

  private static final String CUST_PROP = "custProp";

  @Override
  public Authentication extractAuthentication(Map<String, ?> map) {
    if (map.containsKey(USERNAME) && map.containsKey(CUST_PROP)) {
      String username = (String) map.get(USERNAME);
      String custProp = (String) map.get(CUST_PROP);

      CustomPrincipal principal = new CustomPrincipal();
      pricipal.setUsername(username);
      pricipal.setCustomProp(custProp);

      Collection<? extends GrantedAuthority> authorities = getAuthorities(map);
      return new UsernamePasswordAuthenticationToken(user, "N/A", authorities);
    }
    return null;
  }

  private Collection<? extends GrantedAuthority> getAuthorities(Map<String, ?> map) {
    //Copy this method from DefaultUserAuthenticationConverter or create your own.
  }

}