From 3bd6f3b5afe61ce4490348a61fd8412b8c15f3a6 Mon Sep 17 00:00:00 2001
From: Swordsteel <swordsteel@gmail.com>
Date: Wed, 15 Jan 2025 12:41:32 +0100
Subject: [PATCH] Added basic login and logout functionality

- update SecurityConfiguration
  - add logout
  - add login
- add AuthenticationController
- add goodbye.html
- add logout.html
- add login.html
---
 .../configuration/SecurityConfiguration.kt    | 15 ++++++++++++
 .../controller/AuthenticationController.kt    | 22 ++++++++++++++++++
 .../templates/authentication/goodbye.html     | 16 +++++++++++++
 .../templates/authentication/login.html       | 23 +++++++++++++++++++
 .../templates/authentication/logout.html      | 17 ++++++++++++++
 5 files changed, 93 insertions(+)
 create mode 100644 src/main/kotlin/ltd/hlaeja/controller/AuthenticationController.kt
 create mode 100644 src/main/resources/templates/authentication/goodbye.html
 create mode 100644 src/main/resources/templates/authentication/login.html
 create mode 100644 src/main/resources/templates/authentication/logout.html

diff --git a/src/main/kotlin/ltd/hlaeja/configuration/SecurityConfiguration.kt b/src/main/kotlin/ltd/hlaeja/configuration/SecurityConfiguration.kt
index 55aec74..08ebb14 100644
--- a/src/main/kotlin/ltd/hlaeja/configuration/SecurityConfiguration.kt
+++ b/src/main/kotlin/ltd/hlaeja/configuration/SecurityConfiguration.kt
@@ -2,9 +2,11 @@ package ltd.hlaeja.configuration
 
 import org.springframework.context.annotation.Bean
 import org.springframework.context.annotation.Configuration
+import org.springframework.http.HttpStatus.FOUND
 import org.springframework.security.config.annotation.web.reactive.EnableWebFluxSecurity
 import org.springframework.security.config.web.server.ServerHttpSecurity
 import org.springframework.security.config.web.server.ServerHttpSecurity.AuthorizeExchangeSpec
+import org.springframework.security.config.web.server.ServerHttpSecurity.FormLoginSpec
 import org.springframework.security.web.server.SecurityWebFilterChain
 
 @Configuration
@@ -14,8 +16,19 @@ class SecurityConfiguration {
     @Bean
     fun securityWebFilterChain(serverHttpSecurity: ServerHttpSecurity): SecurityWebFilterChain = serverHttpSecurity
         .authorizeExchange(::authorizeExchange)
+        .formLogin(::formLogin)
+        .logout(::logout)
         .build()
 
+    private fun logout(logout: ServerHttpSecurity.LogoutSpec) = logout.logoutUrl("/logout")
+        .logoutSuccessHandler { webFilter, _ ->
+            webFilter.exchange.response.headers.add("Location", "/logout")
+            webFilter.exchange.response.statusCode = FOUND
+            webFilter.exchange.response.setComplete()
+        }
+
+    private fun formLogin(login: FormLoginSpec) = login.loginPage("/login")
+
     private fun authorizeExchange(authorizeExchange: AuthorizeExchangeSpec) = authorizeExchange
         .publicPaths().permitAll()
         .anyExchange().authenticated()
@@ -25,5 +38,7 @@ class SecurityConfiguration {
         "/js/**",
         "/img/**",
         "/actuator/**",
+        "/login",
+        "/logout",
     )
 }
diff --git a/src/main/kotlin/ltd/hlaeja/controller/AuthenticationController.kt b/src/main/kotlin/ltd/hlaeja/controller/AuthenticationController.kt
new file mode 100644
index 0000000..70f413e
--- /dev/null
+++ b/src/main/kotlin/ltd/hlaeja/controller/AuthenticationController.kt
@@ -0,0 +1,22 @@
+package ltd.hlaeja.controller
+
+import org.springframework.http.HttpStatus.UNAUTHORIZED
+import org.springframework.security.core.context.ReactiveSecurityContextHolder
+import org.springframework.stereotype.Controller
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.ResponseStatus
+import reactor.core.publisher.Mono
+
+@Controller
+class AuthenticationController {
+
+    @GetMapping("/login")
+    @ResponseStatus(UNAUTHORIZED)
+    fun login(): Mono<String> = Mono.just("authentication/login")
+
+    @GetMapping("/logout")
+    fun logout(): Mono<String> = ReactiveSecurityContextHolder.getContext()
+        .filter { it.authentication?.isAuthenticated == true }
+        .map { "authentication/logout" }
+        .defaultIfEmpty("authentication/goodbye")
+}
diff --git a/src/main/resources/templates/authentication/goodbye.html b/src/main/resources/templates/authentication/goodbye.html
new file mode 100644
index 0000000..fda425c
--- /dev/null
+++ b/src/main/resources/templates/authentication/goodbye.html
@@ -0,0 +1,16 @@
+<!DOCTYPE HTML>
+<html lang="en" xmlns:th="http://www.thymeleaf.org">
+<head>
+  <title>Goodbye</title>
+  <!--/*/<th:block th:insert="~{layout.html :: documentHead}"/>/*/-->
+</head>
+<body>
+<main>
+  <h1>You are logged out</h1>
+  <hr>
+  <p>We hope to see you again soon!</p>
+  <a th:href="@{/login}">Login Again</a>
+</main>
+<!--/*/<th:block th:replace="~{layout.html :: script}"/>/*/-->
+</body>
+</html>
diff --git a/src/main/resources/templates/authentication/login.html b/src/main/resources/templates/authentication/login.html
new file mode 100644
index 0000000..a310c14
--- /dev/null
+++ b/src/main/resources/templates/authentication/login.html
@@ -0,0 +1,23 @@
+<!DOCTYPE HTML>
+<html lang="en" xmlns:th="http://www.thymeleaf.org">
+<head>
+  <title>Login</title>
+  <!--/*/<th:block th:insert="~{layout.html :: documentHead}"/>/*/-->
+</head>
+<body>
+<main>
+  <h1>Login</h1>
+  <hr>
+  <form id="loginForm" th:action="@{/login}" th:method="post">
+    <label for="username" >Username</label>
+    <input type="text" id="username" name="username" placeholder="Enter your username" required>
+    <br>
+    <label for="password">Password</label>
+    <input type="password" id="password" name="password" placeholder="Enter your password" required>
+    <br>
+    <button type="submit">Login</button>
+  </form>
+</main>
+<!--/*/<th:block th:replace="~{layout.html :: script}"/>/*/-->
+</body>
+</html>
diff --git a/src/main/resources/templates/authentication/logout.html b/src/main/resources/templates/authentication/logout.html
new file mode 100644
index 0000000..20c9bf1
--- /dev/null
+++ b/src/main/resources/templates/authentication/logout.html
@@ -0,0 +1,17 @@
+<!DOCTYPE HTML>
+<html lang="en" xmlns:th="http://www.thymeleaf.org">
+<head>
+  <title>Logout</title>
+  <!--/*/<th:block th:insert="~{layout.html :: documentHead}"/>/*/-->
+</head>
+<body>
+<main>
+  <h1>Logout</h1>
+  <hr>
+  <p>Are you sure you want to logout?</p>
+  <form id="logoutForm" th:action="@{/logout}" th:method="post"></form>
+  <button type="submit" onclick="document.getElementById('logoutForm').submit(); return false;">Logout</button>
+</main>
+<!--/*/<th:block th:replace="~{layout.html :: script}"/>/*/-->
+</body>
+</html>