Securing Spring Boot API with API key and secret

Question

I would like to secure the Spring Boot API so it is accessible only for the clients that has valid API key and secret. However, there is no authentication (standard login with username and password) inside the program as all data is anonymous. All I'm trying to achieve is that all API requests can be used only for specific third party front-end.

I found a lot of articles about how to secure the Spring Boot API with user authentication. But I don't need user authentication. What I am thinking of is just provide my client with API key and secret so he has access to the endpoints.

Could you please suggest me how can I achieve this? Thank you!

Answer 1

Create a filter that grabs what ever header(s) you're using for authentication.

import org.springframework.security.web.authentication.preauth.AbstractPreAuthenticatedProcessingFilter;

public class APIKeyAuthFilter extends AbstractPreAuthenticatedProcessingFilter {

    private String principalRequestHeader;

    public APIKeyAuthFilter(String principalRequestHeader) {
        this.principalRequestHeader = principalRequestHeader;
    }

    @Override
    protected Object getPreAuthenticatedPrincipal(HttpServletRequest request) {
        return request.getHeader(principalRequestHeader);
    }

    @Override
    protected Object getPreAuthenticatedCredentials(HttpServletRequest request) {
        return "N/A";
    }

}

Configure the filter in your Web Security config.

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.config.http.SessionCreationPolicy;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;

@Configuration
@EnableWebSecurity
@Order(1)
public class APISecurityConfig extends WebSecurityConfigurerAdapter {

    @Value("${yourapp.http.auth-token-header-name}")
    private String principalRequestHeader;

    @Value("${yourapp.http.auth-token}")
    private String principalRequestValue;

    @Override
    protected void configure(HttpSecurity httpSecurity) throws Exception {
        APIKeyAuthFilter filter = new APIKeyAuthFilter(principalRequestHeader);
        filter.setAuthenticationManager(new AuthenticationManager() {

            @Override
            public Authentication authenticate(Authentication authentication) throws AuthenticationException {
                String principal = (String) authentication.getPrincipal();
                if (!principalRequestValue.equals(principal))
                {
                    throw new BadCredentialsException("The API key was not found or not the expected value.");
                }
                authentication.setAuthenticated(true);
                return authentication;
            }
        });
        httpSecurity.
            antMatcher("/api/**").
            csrf().disable().
            sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS).
            and().addFilter(filter).authorizeRequests().anyRequest().authenticated();
    }

}