Imported from english-only/NoNotes (.claude/skills/quarkus-security/SKILL.md). Install upstream with npx skills add english-only/NoNotes --skill quarkus-security. Copyright stays with the author.

Quarkus Security Review

Best practices for securing Quarkus applications with authentication, authorization, and input validation.

When to Activate

Adding authentication (JWT, OIDC, Basic Auth)
Implementing authorization with @RolesAllowed or SecurityIdentity
Validating user input (Bean Validation, custom validators)
Configuring CORS or security headers
Managing secrets (Vault, environment variables, config sources)
Adding rate limiting or brute-force protection
Scanning dependencies for CVEs
Working with MicroProfile JWT or SmallRye JWT

Authentication

JWT Authentication

// Resource protected with JWT
@Path("/api/protected")
@Authenticated
public class ProtectedResource {

  @Inject
  JsonWebToken jwt;

  @Inject
  SecurityIdentity securityIdentity;

  @GET
  public Response getData() {
    String username = jwt.getName();
    Set<String> roles = jwt.getGroups();
    return Response.ok(Map.of(
        "username", username,
        "roles", roles,
        "principal", securityIdentity.getPrincipal().getName()
    )).build();
  }
}

Configuration (application.properties):

mp.jwt.verify.publickey.location=publicKey.pem
mp.jwt.verify.issuer=https://auth.example.com

# OIDC
quarkus.oidc.auth-server-url=https://auth.example.com/realms/myrealm
quarkus.oidc.client-id=backend-service
quarkus.oidc.credentials.secret=${OIDC_SECRET}

Custom Authentication Filter

@Provider
@Priority(Priorities.AUTHENTICATION)
public class CustomAuthFilter implements ContainerRequestFilter {

  @Inject
  SecurityIdentity identity;

  @Override
  public void filter(ContainerRequestContext requestContext) {
    String authHeader = requestContext.getHeaderString(HttpHeaders.AUTHORIZATION);

    // Reject immediately if header is absent or malformed
    if (authHeader == null || !authHeader.startsWith("Bearer ")) {
      requestContext.abortWith(Response.status(Response.Status.UNAUTHORIZED).build());
      return;
    }

    String token = authHeader.substring(7);
    if (!validateToken(token)) {
      requestContext.abortWith(Response.status(Response.Status.UNAUTHORIZED).build());
    }
  }

  private boolean validateToken(String token) {
    // Token validation logic
    return true;
  }
}

Authorization

Role-Based Access Control

@Path("/api/admin")
@RolesAllowed("ADMIN")
public class AdminResource {

  @GET
  @Path("/users")
  public List<UserDto> listUsers() {
    return userService.findAll();
  }

  @DELETE
  @Path("/users/{id}")
  @RolesAllowed({"ADMIN", "SUPER_ADMIN"})
  public Response deleteUser(@PathParam("id") Long id) {
    userService.delete(id);
    return Response.noContent().build();
  }
}

@Path("/api/users")
public class UserResource {

  @Inject
  SecurityIdentity securityIdentity;

  @GET
  @Path("/{id}")
  @RolesAllowed("USER")
  public Response getUser(@PathParam("id") Long id) {
    // Check ownership
    if (!securityIdentity.hasRole("ADMIN") &&
        !isOwner(id, securityIdentity.getPrincipal().getName())) {
      return Response.status(Response.Status.FORBIDDEN).build();
    }
    return Response.ok(userService.findById(id)).build();
  }

  private boolean isOwner(Long userId, String username) {
    return userService.isOwner(userId, username);
  }
}

Programmatic Security

@ApplicationScoped
public class SecurityService {

  @Inject
  SecurityIdentity securityIdentity;

  public boolean canAccessResource(Long resourceId) {
    if (securityIdentity.isAnonymous()) {
      return false;
    }

    if (securityIdentity.hasRole("ADMIN")) {
      return true;
    }

    String userId = securityIdentity.getPrincipal().getName();
    return resourceRepository.isOwner(resourceId, userId);
  }
}

Input Validation

Bean Validation

// BAD: No validation
@POST
public Response createUser(UserDto dto) {
  return Response.ok(userService.create(dto)).build();
}

// GOOD: Validated DTO
public record CreateUserDto(
    @NotBlank @Size(max = 100) String name,
    @NotBlank @Email String email,
    @NotNull @Min(18) @Max(150) Integer age,
    @Pattern(regexp = "^\\+?[1-9]\\d{1,14}$") String phone
) {}

@POST
@Path("/users")
public Response createUser(@Valid CreateUserDto dto) {
  User user = userService.create(dto);
  return Response.status(Response.Status.CREATED).entity(user).build();
}

Custom Validators

@Target({ElementType.FIELD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = UsernameValidator.class)
public @interface ValidUsername {
  String message() default "Invalid username format";
  Class<?>[] groups() default {};
  Class<? extends Payload>[] payload() default {};
}

public class UsernameValidator implements ConstraintValidator<ValidUsername, String> {
  @Override
  public boolean isValid(String value, ConstraintValidatorContext context) {
    if (value == null) return false;
    return value.matches("^[a-zA-Z0-9_-]{3,20}$");
  }
}

// Usage
public record CreateUserDto(
    @ValidUsername String username,
    @NotBlank @Email String email
) {}

SQL Injection Prevention

Panache Active Record (Safe by Default)

// GOOD: Parameterized queries with Panache
List<User> users = User.list("email = ?1 and active = ?2", email, true);

Optional<User> user = User.find("username", username).firstResultOptional();

// GOOD: Named parameters
List<User> users = User.list("email = :email and age > :minAge",
    Parameters.with("email", email).and("minAge", 18));

Native Queries (Use Parameters)

// BAD: String concatenation
@Query(value = "SELECT * FROM users WHERE name = '" + name + "'", nativeQuery = true)

// GOOD: Parameterized native query
@Entity
public class User extends PanacheEntity {
  public static List<User> findByEmailNative(String email) {
    return getEntityManager()
        .createNativeQuery("SELECT * FROM users WHERE email = :email", User.class)
        .setParameter("email", email)
        .getResultList();
  }
}

Password Hashing

@ApplicationScoped
public class PasswordService {

  public String hash(String plainPassword) {
    return BcryptUtil.bcryptHash(plainPassword);
  }

  public boolean verify(String plainPassword, String hashedPassword) {
    return BcryptUtil.matches(plainPassword, hashedPassword);
  }
}

// In service
@ApplicationScoped
public class UserService {
  @Inject
  PasswordService passwordService;

  @Transactional
  public User register(CreateUserDto dto) {
    String hashedPassword = passwordService.hash(dto.password());
    User user = new User();
    user.email = dto.email();
    user.password = hashedPassword;
    user.persist();
    return user;
  }

  public boolean authenticate(String email, String password) {
    return User.find("email", email)
        .firstResultOptional()
        .map(u -> passwordService.verify(password, u.password))
        .orElse(false);
  }
}

CORS Configuration

# application.properties
quarkus.http.cors=true
quarkus.http.cors.origins=https://app.example.com,https://admin.example.com
quarkus.http.cors.methods=GET,POST,PUT,DELETE
quarkus.http.cors.headers=accept,authorization,content-type,x-requested-with
quarkus.http.cors.exposed-headers=Content-Disposition
quarkus.http.cors.access-control-max-age=24H
quarkus.http.cors.access-control-allow-credentials=true

Secrets Management

# application.properties - NO SECRETS HERE

# Use environment variables
quarkus.datasource.username=${DB_USER}
quarkus.datasource.password=${DB_PASSWORD}
quarkus.oidc.credentials.secret=${OIDC_CLIENT_SECRET}

# Or use Vault
quarkus.vault.url=https://vault.example.com
quarkus.vault.authentication.kubernetes.role=my-role

HashiCorp Vault Integration

@ApplicationScoped
public class SecretService {

  @ConfigProperty(name = "api-key")
  String apiKey; // Fetched from Vault

  public String getSecret(String key) {
    return ConfigProvider.getConfig().getValue(key, String.class);
  }
}

Rate Limiting

Security Note: Never use X-Forwarded-For directly — clients can spoof it. Use the actual remote address from the servlet request, or an authenticated identity (API key, JWT subject) when available.

@ApplicationScoped
public class RateLimitFilter implements ContainerRequestFilter {
  private final Map<String, RateLimiter> limiters = new ConcurrentHashMap<>();

  @Inject
  HttpServletRequest servletRequest;

  @Override
  public void filter(ContainerRequestContext requestContext) {
    String clientId = getClientIdentifier();
    RateLimiter limiter = limiters.computeIfAbsent(clientId,
        k -> RateLimiter.create(100.0)); // 100 requests per second

    if (!limiter.tryAcquire()) {
      requestContext.abortWith(
          Response.status(429)
              .entity(Map.of("error", "Too many requests"))
              .build()
      );
    }
  }

  private String getClientIdentifier() {
    // Use the container-provided remote address (not X-Forwarded-For).
    // If behind a trusted proxy, configure quarkus.http.proxy.proxy-address-forwarding=true
    // so getRemoteAddr() returns the real client IP.
    return servletRequest.getRemoteAddr();
  }
}

Security Headers

@Provider
public class SecurityHeadersFilter implements ContainerResponseFilter {

  @Override
  public void filter(ContainerRequestContext request, ContainerResponseContext response) {
    MultivaluedMap<String, Object> headers = response.getHeaders();

    // Prevent clickjacking
    headers.putSingle("X-Frame-Options", "DENY");

    // XSS protection
    headers.putSingle("X-Content-Type-Options", "nosniff");
    headers.putSingle("X-XSS-Protection", "1; mode=block");

    // HSTS
    headers.putSingle("Strict-Transport-Security", "max-age=31536000; includeSubDomains");

    // CSP — avoid 'unsafe-inline' for script-src as it negates XSS protection;
    // use nonces or hashes instead. 'unsafe-inline' for style-src is acceptable
    // when CSS frameworks require it, but prefer nonces where possible.
    headers.putSingle("Content-Security-Policy",
        "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'");
  }
}

Audit Logging

@ApplicationScoped
public class AuditService {
  private static final Logger LOG = Logger.getLogger(AuditService.class);

  @Inject
  SecurityIdentity securityIdentity;

  public void logAccess(String resource, String action) {
    String user = securityIdentity.isAnonymous()
        ? "anonymous"
        : securityIdentity.getPrincipal().getName();

    LOG.infof("AUDIT: user=%s action=%s resource=%s timestamp=%s",
        user, action, resource, Instant.now());
  }
}

// Usage in resource
@Path("/api/sensitive")
public class SensitiveResource {
  @Inject
  AuditService auditService;

  @GET
  @RolesAllowed("ADMIN")
  public Response getData() {
    auditService.logAccess("sensitive-data", "READ");
    return Response.ok(data).build();
  }
}

Dependency Security Scanning

# Maven
mvn org.owasp:dependency-check-maven:check

# Gradle
./gradlew dependencyCheckAnalyze

# Check Quarkus extensions
quarkus extension list --installable

Best Practices

Always use HTTPS in production
Enable JWT or OIDC for stateless authentication
Use @RolesAllowed for declarative authorization
Validate all input with Bean Validation
Hash passwords with BCrypt (never plaintext)
Store secrets in Vault or environment variables
Use parameterized queries to prevent SQL injection
Add security headers to all responses
Implement rate limiting for public endpoints
Audit sensitive operations
Keep dependencies updated and scan for CVEs
Use SecurityIdentity for programmatic checks
Set appropriate CORS policies
Test authentication and authorization paths

quarkus-security

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