JBear2/src/main/kotlin/at/eisibaer/jbear2/security/SecurityConfiguration.kt

package at.eisibaer.jbear2.security

import at.eisibaer.jbear2.security.jwt.AuthTokenFilter
import jakarta.servlet.FilterChain
import jakarta.servlet.ServletException
import jakarta.servlet.http.HttpServletRequest
import jakarta.servlet.http.HttpServletResponse
import org.slf4j.Logger
import org.slf4j.LoggerFactory
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import org.springframework.security.authentication.AuthenticationManager
import org.springframework.security.authentication.dao.DaoAuthenticationProvider
import org.springframework.security.config.annotation.authentication.configuration.AuthenticationConfiguration
import org.springframework.security.config.annotation.method.configuration.EnableMethodSecurity
import org.springframework.security.config.annotation.web.builders.HttpSecurity
import org.springframework.security.config.annotation.web.configurers.SessionManagementConfigurer
import org.springframework.security.config.http.SessionCreationPolicy
import org.springframework.security.core.userdetails.UserDetailsService
import org.springframework.security.crypto.argon2.Argon2PasswordEncoder
import org.springframework.security.crypto.password.PasswordEncoder
import org.springframework.security.web.SecurityFilterChain
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter
import org.springframework.security.web.authentication.www.BasicAuthenticationFilter
import org.springframework.security.web.csrf.*
import org.springframework.util.StringUtils
import org.springframework.web.filter.OncePerRequestFilter
import java.io.IOException
import java.util.function.Supplier

@Configuration
@EnableMethodSecurity
class SecurityConfiguration(
    private val userDetailService: UserDetailsService,
    private val unauthorizedHandler: AuthTokenFilter,
) {

    final val log: Logger = LoggerFactory.getLogger(SecurityConfiguration::class.java);

    @Bean
    fun securityFilterChain(httpSecurity: HttpSecurity): SecurityFilterChain {
        return httpSecurity
            .csrf { config ->
                config
                    .csrfTokenRepository(CookieCsrfTokenRepository.withHttpOnlyFalse())
                    .csrfTokenRequestHandler(SpaCsrfTokenRequestHandler())
            }
            .addFilterAfter(CsrfCookieFilter(), BasicAuthenticationFilter::class.java)
            .authorizeHttpRequests { config ->
                config
                    .requestMatchers("/api/auth/*").permitAll()
                    .requestMatchers("/api/**").authenticated()
                    .requestMatchers("/profile").authenticated()
                    .requestMatchers("/**").permitAll()
            }
            .sessionManagement { config: SessionManagementConfigurer<HttpSecurity?> ->
                config.sessionCreationPolicy(SessionCreationPolicy.STATELESS)
            }
            .authenticationProvider(authenticationProvider())
            .addFilterBefore(unauthorizedHandler, UsernamePasswordAuthenticationFilter::class.java)
            .build()
    }

    class SpaCsrfTokenRequestHandler : CsrfTokenRequestAttributeHandler() {
        private val delegate: CsrfTokenRequestHandler = XorCsrfTokenRequestAttributeHandler()

        override fun handle(request: HttpServletRequest, response: HttpServletResponse, csrfToken: Supplier<CsrfToken>) {
            /*
             * Always use XorCsrfTokenRequestAttributeHandler to provide BREACH protection of
             * the CsrfToken when it is rendered in the response body.
             */
            delegate.handle(request, response, csrfToken)
        }

        override fun resolveCsrfTokenValue(request: HttpServletRequest, csrfToken: CsrfToken): String? {
            /*
             * If the request contains a request header, use CsrfTokenRequestAttributeHandler
             * to resolve the CsrfToken. This applies when a single-page application includes
             * the header value automatically, which was obtained via a cookie containing the
             * raw CsrfToken.
             */
            return if (StringUtils.hasText(request.getHeader(csrfToken.headerName))) {
                super.resolveCsrfTokenValue(request, csrfToken)
            } else {
                /*
                 * In all other cases (e.g. if the request contains a request parameter), use
                 * XorCsrfTokenRequestAttributeHandler to resolve the CsrfToken. This applies
                 * when a server-side rendered form includes the _csrf request parameter as a
                 * hidden input.
                 */
                delegate.resolveCsrfTokenValue(request, csrfToken)
            }
        }
    }

    class CsrfCookieFilter : OncePerRequestFilter() {

        @Throws(ServletException::class, IOException::class)
        override fun doFilterInternal(request: HttpServletRequest, response: HttpServletResponse, filterChain: FilterChain) {
            val csrfToken = request.getAttribute("_csrf") as CsrfToken
            // Render the token value to a cookie by causing the deferred token to be loaded
            csrfToken.token
            filterChain.doFilter(request, response)
        }
    }

    @Bean
    fun passwordEncoder() : PasswordEncoder {
        return Argon2PasswordEncoder.defaultsForSpringSecurity_v5_8();
    }

    @Bean
    fun authenticationProvider(): DaoAuthenticationProvider{
        val authProvider: DaoAuthenticationProvider = DaoAuthenticationProvider()

        authProvider.setUserDetailsService(userDetailService)
        authProvider.setPasswordEncoder(passwordEncoder());

        return authProvider;
    }

    @Bean
    fun authenticationManager(authConfig: AuthenticationConfiguration): AuthenticationManager{
        return authConfig.authenticationManager;
    }
}