Spring Boot(스프링부트) JWT 토큰 생성/발급

Spring Boot(스프링부트) JWT 토큰 생성/발급

1. Spring API에서 JWT 토큰 발급하기 Spring API에서는 JWT 토큰을 발급하기 위해 Spring Security와 JWT 라이브러리를 사용할 수 있습니다. 예를 들어, 다음과 같이 구성할 수 있습니다.

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Autowired
    private UserDetailsServiceImpl userDetailsService;

    @Autowired
    private JwtRequestFilter jwtRequestFilter;

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService).passwordEncoder(passwordEncoder());
    }

    @Bean
    public PasswordEncoder passwordEncoder() {
        return new BCryptPasswordEncoder();
    }

    @Bean
    public JwtAuthenticationEntryPoint jwtAuthenticationEntryPoint() {
        return new JwtAuthenticationEntryPoint();
    }

    @Bean
    public JwtTokenUtil jwtTokenUtil() {
        return new JwtTokenUtil();
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.csrf().disable()
            .authorizeRequests().antMatchers("/authenticate").permitAll()
            .anyRequest().authenticated()
            .and().exceptionHandling().authenticationEntryPoint(jwtAuthenticationEntryPoint())
            .and().sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS);
        http.addFilterBefore(jwtRequestFilter, UsernamePasswordAuthenticationFilter.class);
    }
}

위 코드에서는 JwtRequestFilter라는 클래스를 사용하여 JWT 토큰을 검증합니다. 이 클래스는 요청 헤더에 Authorization 필드가 있는지 검사하고, JWT 토큰을 파싱하여 인증을 수행합니다.

@Component
public class JwtRequestFilter extends OncePerRequestFilter {
    @Autowired
    private UserDetailsServiceImpl userDetailsService;

    @Autowired
    private JwtTokenUtil jwtTokenUtil;

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws ServletException, IOException {
        final String requestTokenHeader = request.getHeader("Authorization");

        String username = null;
        String jwtToken = null;

        if (requestTokenHeader != null && requestTokenHeader.startsWith("Bearer ")) {
            jwtToken = requestTokenHeader.substring(7);
            try {
                username = jwtTokenUtil.getUsernameFromToken(jwtToken);
            } catch (IllegalArgumentException e) {
                logger.error("Unable to get JWT Token", e);
            } catch (ExpiredJwtException e) {
                logger.warn("JWT Token has expired", e);
            }
        } else {
            logger.warn("JWT Token does not begin with Bearer String");
        }

        if (username != null && SecurityContextHolder.getContext().getAuthentication() == null) {
            UserDetails userDetails = this.userDetailsService.loadUserByUsername(username);

            if (jwtTokenUtil.validateToken(jwtToken, userDetails)) {
                UsernamePasswordAuthenticationToken usernamePasswordAuthenticationToken = new UsernamePasswordAuthenticationToken(
                        userDetails, null, userDetails.getAuthorities());
                usernamePasswordAuthenticationToken.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
                SecurityContextHolder.getContext().setAuthentication(usernamePasswordAuthenticationToken);
            }
        }
        chain.doFilter(request, response);
    }
}