Here is a filter that can do what you need :
public class JWTFilter extends GenericFilterBean {
private static final Logger LOGGER = LoggerFactory.getLogger(JWTFilter.class);
private final TokenProvider tokenProvider;
public JWTFilter(TokenProvider tokenProvider) {
this.tokenProvider = tokenProvider;
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException,
ServletException {
try {
HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;
String jwt = this.resolveToken(httpServletRequest);
if (StringUtils.hasText(jwt)) {
if (this.tokenProvider.validateToken(jwt)) {
Authentication authentication = this.tokenProvider.getAuthentication(jwt);
SecurityContextHolder.getContext().setAuthentication(authentication);
}
}
filterChain.doFilter(servletRequest, servletResponse);
this.resetAuthenticationAfterRequest();
} catch (ExpiredJwtException eje) {
LOGGER.info("Security exception for user {} - {}", eje.getClaims().getSubject(), eje.getMessage());
((HttpServletResponse) servletResponse).setStatus(HttpServletResponse.SC_UNAUTHORIZED);
LOGGER.debug("Exception " + eje.getMessage(), eje);
}
}
private void resetAuthenticationAfterRequest() {
SecurityContextHolder.getContext().setAuthentication(null);
}
private String resolveToken(HttpServletRequest request) {
String bearerToken = request.getHeader(SecurityConfiguration.AUTHORIZATION_HEADER);
if (StringUtils.hasText(bearerToken) && bearerToken.startsWith("Bearer ")) {
String jwt = bearerToken.substring(7, bearerToken.length());
return jwt;
}
return null;
}
}
And the inclusion of the filter in the filter chain :
public class SecurityConfiguration extends WebSecurityConfigurerAdapter {
public final static String AUTHORIZATION_HEADER = "Authorization";
@Autowired
private TokenProvider tokenProvider;
@Autowired
private AuthenticationProvider authenticationProvider;
@Override
protected void configure(AuthenticationManagerBuilder auth) throws Exception {
auth.authenticationProvider(this.authenticationProvider);
}
@Override
protected void configure(HttpSecurity http) throws Exception {
JWTFilter customFilter = new JWTFilter(this.tokenProvider);
http.addFilterBefore(customFilter, UsernamePasswordAuthenticationFilter.class);
// @formatter:off
http.authorizeRequests().antMatchers("/css/**").permitAll()
.antMatchers("/images/**").permitAll()
.antMatchers("/js/**").permitAll()
.antMatchers("/authenticate").permitAll()
.anyRequest().fullyAuthenticated()
.and().formLogin().loginPage("/login").failureUrl("/login?error").permitAll()
.and().logout().permitAll();
// @formatter:on
http.csrf().disable();
}
}
The TokenProvider class :
public class TokenProvider {
private static final Logger LOGGER = LoggerFactory.getLogger(TokenProvider.class);
private static final String AUTHORITIES_KEY = "auth";
@Value("${spring.security.authentication.jwt.validity}")
private long tokenValidityInMilliSeconds;
@Value("${spring.security.authentication.jwt.secret}")
private String secretKey;
public String createToken(Authentication authentication) {
String authorities = authentication.getAuthorities().stream().map(authority -> authority.getAuthority()).collect(Collectors.joining(","));
ZonedDateTime now = ZonedDateTime.now();
ZonedDateTime expirationDateTime = now.plus(this.tokenValidityInMilliSeconds, ChronoUnit.MILLIS);
Date issueDate = Date.from(now.toInstant());
Date expirationDate = Date.from(expirationDateTime.toInstant());
return Jwts.builder().setSubject(authentication.getName()).claim(AUTHORITIES_KEY, authorities)
.signWith(SignatureAlgorithm.HS512, this.secretKey).setIssuedAt(issueDate).setExpiration(expirationDate).compact();
}
public Authentication getAuthentication(String token) {
Claims claims = Jwts.parser().setSigningKey(this.secretKey).parseClaimsJws(token).getBody();
Collection<? extends GrantedAuthority> authorities = Arrays.asList(claims.get(AUTHORITIES_KEY).toString().split(",")).stream()
.map(authority -> new SimpleGrantedAuthority(authority)).collect(Collectors.toList());
User principal = new User(claims.getSubject(), "", authorities);
return new UsernamePasswordAuthenticationToken(principal, "", authorities);
}
public boolean validateToken(String authToken) {
try {
Jwts.parser().setSigningKey(this.secretKey).parseClaimsJws(authToken);
return true;
} catch (SignatureException e) {
LOGGER.info("Invalid JWT signature: " + e.getMessage());
LOGGER.debug("Exception " + e.getMessage(), e);
return false;
}
}
}
Now to answer your questions :
- Done in this filter
- Protect your HTTP request, use HTTPS
- Just permit all on the
/login URI (/authenticate in my code)
