Use HTTP POST for logout (#7489)

* Use HTTP POST for logout
To avoid potential CSRF risks

* Fixed button font issue

* Minor whitespace

4 files changed, 24 insertions, 11 deletions

diff --git a/app/Controllers/authController.php b/app/Controllers/authController.php
index 9bad837f9..4de8d01f1 100644
--- a/app/Controllers/authController.php
+++ b/app/Controllers/authController.php
@@ -223,9 +223,13 @@ class FreshRSS_auth_Controller extends FreshRSS_ActionController {
 	 * This action removes all accesses of the current user.
 	 */
 	public function logoutAction(): void {
-		invalidateHttpCache();
-		FreshRSS_Auth::removeAccess();
-		Minz_Request::good(_t('feedback.auth.logout.success'), [ 'c' => 'index', 'a' => 'index' ]);
+		if (Minz_Request::isPost()) {
+			invalidateHttpCache();
+			FreshRSS_Auth::removeAccess();
+			Minz_Request::good(_t('feedback.auth.logout.success'), [ 'c' => 'index', 'a' => 'index' ]);
+		} else {
+			Minz_Error::error(403);
+		}
 	}
 
 	/**
diff --git a/app/layout/aside_configure.phtml b/app/layout/aside_configure.phtml
index d107e7f63..9824e7fa8 100644
--- a/app/layout/aside_configure.phtml
+++ b/app/layout/aside_configure.phtml
@@ -2,6 +2,9 @@
 	declare(strict_types=1);
 ?>
 <nav class="nav nav-list aside" id="aside_feed">
+	<form id="post-csrf" method="post">
+		<input type="hidden" name="_csrf" value="<?= FreshRSS_Auth::csrfToken() ?>" />
+	</form>
 	<a class="toggle_aside" href="#close"><?= _i('close') ?></a>
 
 	<ul>
@@ -19,9 +22,8 @@
 					<a href="<?= _url('user', 'profile') ?>"><?= _t('gen.menu.user_profile') ?></a>
 				</li>
 				<li class="item">
-					<a class="signout" href="<?= FreshRSS_auth_Controller::getLogoutUrl() ?>">
-						<?php
-						echo _t('gen.auth.logout'); ?> <?= _i('logout') ?></a>
+					<button class="as-link signout" form="post-csrf" formaction="<?=
+						FreshRSS_auth_Controller::getLogoutUrl() ?>"><?= _t('gen.auth.logout'); ?><?= _i('logout') ?></button>
 				</li>
 			</ul>
 		</li>
diff --git a/app/layout/header.phtml b/app/layout/header.phtml
index b152ed78a..1e4290f98 100644
--- a/app/layout/header.phtml
+++ b/app/layout/header.phtml
@@ -50,6 +50,9 @@
 
 	<?php if (FreshRSS_Auth::hasAccess()) { ?>
 	<nav class="item configure">
+		<form id="post-csrf" method="post">
+			<input type="hidden" name="_csrf" value="<?= FreshRSS_Auth::csrfToken() ?>" />
+		</form>
 		<div class="dropdown">
 			<div id="dropdown-configure" class="dropdown-target"></div>
 			<a class="btn dropdown-toggle" href="#dropdown-configure"><?= _i('configure') ?></a>
@@ -63,7 +66,9 @@
 					<ul>
 						<li class="item"><a href="<?= _url('user', 'profile') ?>"><?= _t('gen.menu.user_profile') ?></a></li>
 						<?php if (FreshRSS_Auth::accessNeedsAction()): ?>
-						<li class="item"><a class="signout" href="<?= _url('auth', 'logout') ?>"><?= _t('gen.auth.logout'); ?><?= _i('logout') ?></a></li>
+						<li class="item">
+							<button class="as-link signout" form="post-csrf" formaction="<?= _url('auth', 'logout') ?>"><?= _t('gen.auth.logout'); ?><?= _i('logout') ?></button>
+						</li>
 						<?php else: ?>
 						<li class="item"><span class="signout">(<?= htmlspecialchars(Minz_User::name() ?? '', ENT_NOQUOTES, 'UTF-8') ?>)</span></li>
 						<?php endif; ?>
diff --git a/app/layout/simple.phtml b/app/layout/simple.phtml
index a79d102af..2a14682c9 100644
--- a/app/layout/simple.phtml
+++ b/app/layout/simple.phtml
@@ -60,13 +60,15 @@
 
 		<div class="item"></div>
 
+		<form id="post-csrf" method="post">
+			<input type="hidden" name="_csrf" value="<?= FreshRSS_Auth::csrfToken() ?>" />
+		</form>
+
 		<?php if (FreshRSS_Auth::accessNeedsAction()): ?>
 			<div class="item configure">
 			<?php if (FreshRSS_Auth::hasAccess()): ?>
-				<a class="signout" href="<?= Minz_Url::display(['c' => 'auth', 'a' => 'logout'], 'html', 'root') ?>">
-					<?= _i('logout') ?><?= _t('gen.auth.logout') ?>
-					(<?= htmlspecialchars(Minz_User::name() ?? '', ENT_NOQUOTES, 'UTF-8') ?>)
-				</a>
+				<button class="as-link signout" form="post-csrf" formaction="<?=
+					_url('auth', 'logout') ?>"><?= _t('gen.auth.logout'); ?><?= _i('logout') ?></button>
 			<?php else: ?>
 				<a class="signin" href="<?= Minz_Url::display(['c' => 'auth', 'a' => 'login'], 'html', 'root') ?>">
 					<?= _i('login') ?><?= _t('gen.auth.login') ?>