prevent brute force authentications

spring-security-login-and-registration/src/main/java/org/baeldung/persistence/model/User.java

@@ -2,6 +2,7 @@ package org.baeldung.persistence.model;
 
 import java.util.Collection;
 
+import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
@@ -23,6 +24,7 @@ public class User {
 
     private String email;
 
+    @Column(length = 60)
     private String password;
 
     private boolean enabled;

spring-security-login-and-registration/src/main/java/org/baeldung/security/AuthenticationFailureListener.java

@@ -0,0 +1,19 @@
+package org.baeldung.security;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationListener;
+import org.springframework.security.authentication.event.AuthenticationFailureBadCredentialsEvent;
+import org.springframework.security.web.authentication.WebAuthenticationDetails;
+import org.springframework.stereotype.Component;
+
+@Component
+public class AuthenticationFailureListener implements ApplicationListener<AuthenticationFailureBadCredentialsEvent> {
+
+    @Autowired
+    private LoginAttemptService loginAttemptService;
+
+    public void onApplicationEvent(AuthenticationFailureBadCredentialsEvent e) {
+        WebAuthenticationDetails auth = (WebAuthenticationDetails) e.getAuthentication().getDetails();
+        loginAttemptService.loginFailed(auth.getRemoteAddress());
+    }
+}

spring-security-login-and-registration/src/main/java/org/baeldung/security/AuthenticationSuccessEventListener.java

@@ -0,0 +1,19 @@
+package org.baeldung.security;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationListener;
+import org.springframework.security.authentication.event.AuthenticationSuccessEvent;
+import org.springframework.security.web.authentication.WebAuthenticationDetails;
+import org.springframework.stereotype.Component;
+
+@Component
+public class AuthenticationSuccessEventListener implements ApplicationListener<AuthenticationSuccessEvent> {
+
+    @Autowired
+    private LoginAttemptService loginAttemptService;
+
+    public void onApplicationEvent(AuthenticationSuccessEvent e) {
+        WebAuthenticationDetails auth = (WebAuthenticationDetails) e.getAuthentication().getDetails();
+        loginAttemptService.loginSucceeded(auth.getRemoteAddress());
+    }
+}

spring-security-login-and-registration/src/main/java/org/baeldung/security/LoginAttemptService.java

@@ -0,0 +1,49 @@
+package org.baeldung.security;
+
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+
+import org.springframework.stereotype.Service;
+
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+
+@Service
+public class LoginAttemptService {
+
+    private final int MAX_ATTEMPT = 10;
+    private LoadingCache<String, Integer> attemptsCache;
+
+    public LoginAttemptService() {
+        super();
+        attemptsCache = CacheBuilder.newBuilder().expireAfterWrite(1, TimeUnit.DAYS).build(new CacheLoader<String, Integer>() {
+            public Integer load(String key) {
+                return 0;
+            }
+        });
+    }
+
+    public void loginSucceeded(String key) {
+        attemptsCache.invalidate(key);
+    }
+
+    public void loginFailed(String key) {
+        int attempts = 0;
+        try {
+            attempts = attemptsCache.get(key);
+        } catch (ExecutionException e) {
+            attempts = 0;
+        }
+        attempts++;
+        attemptsCache.put(key, attempts);
+    }
+
+    public boolean isBlocked(String key) {
+        try {
+            return attemptsCache.get(key) >= MAX_ATTEMPT;
+        } catch (ExecutionException e) {
+            return false;
+        }
+    }
+}

spring-security-login-and-registration/src/main/java/org/baeldung/security/MyUserDetailsService.java

@@ -5,6 +5,8 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 
+import javax.servlet.http.HttpServletRequest;
+
 import org.baeldung.persistence.dao.RoleRepository;
 import org.baeldung.persistence.dao.UserRepository;
 import org.baeldung.persistence.model.Privilege;
@@ -34,6 +36,12 @@ public class MyUserDetailsService implements UserDetailsService {
     @Autowired
     private RoleRepository roleRepository;
 
+    @Autowired
+    private LoginAttemptService loginAttemptService;
+
+    @Autowired
+    private HttpServletRequest request;
+
     public MyUserDetailsService() {
         super();
     }
@@ -42,6 +50,11 @@ public class MyUserDetailsService implements UserDetailsService {
 
     @Override
     public UserDetails loadUserByUsername(final String email) throws UsernameNotFoundException {
+        String ip = request.getRemoteAddr();
+        if (loginAttemptService.isBlocked(ip)) {
+            throw new RuntimeException("blocked");
+        }
+
         try {
             final User user = userRepository.findByEmail(email);
             if (user == null) {

spring-security-login-and-registration/src/main/resources/messages_en.properties

@@ -59,3 +59,4 @@ message.forgetPassword=Forget Password
 message.resetPassword=Reset Password
 message.updatePassword=Update Password
 message.userNotFound=User Not Found
+auth.message.blocked=This ip is blocked for 24 hours

spring-security-login-and-registration/src/main/resources/messages_es_ES.properties

@@ -59,3 +59,4 @@ message.forgetPassword=Olvide la contrase
 message.resetPassword=Restablecer contraseña
 message.updatePassword=Actualizar contraseña
 message.userNotFound=Usuario no encontrado
+auth.message.blocked=Esta IP se bloquea durante 24 horas

spring-security-login-and-registration/src/main/webapp/WEB-INF/view/login.jsp

@@ -20,6 +20,12 @@
 			<div class="alert alert-error">
 				<spring:message code="auth.message.expired"></spring:message>
 			</div>
+		</c:when>
+		<c:when
+            test="${SPRING_SECURITY_LAST_EXCEPTION.message == 'blocked'}">
+            <div class="alert alert-error">
+               <spring:message code="auth.message.blocked"></spring:message>
+            </div>
         </c:when>
 		<c:otherwise>
 			<div class="alert alert-error">

spring-security-login-and-registration/src/main/webapp/WEB-INF/web.xml

@@ -17,6 +17,10 @@
         <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
     </listener>
     
+    <listener>
+        <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
+   </listener>
+   
     <servlet>
         <servlet-name>mvc</servlet-name>
         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>