update to Magento2.4.1 compatible implementation (beta version).

Author: HirokazuNishi

Model/Config/Source/SameSite.php

@@ -0,0 +1,17 @@
+<?php
+namespace Veriteworks\CookieFix\Model\Config\Source;
+
+class SameSite
+{
+    /**
+     * @return array
+     */
+    public function toOptionArray()
+    {
+        return [
+            ['value' => 'Lax','label' => __('Lax')],
+            ['value' => 'Strict','label' => __('Strict')],
+            ['value' => 'None','label' => __('None')]
+        ];
+    }
+}

Plugin/Session/AddSameSite.php

@@ -0,0 +1,83 @@
+<?php
+namespace Veriteworks\CookieFix\Plugin;
+
+
+use Magento\Framework\App\Config\ScopeConfigInterface;
+use Magento\Framework\HTTP\Header;
+use Magento\Framework\Stdlib\Cookie\PhpCookieManager;
+use Magento\Framework\Stdlib\Cookie\PublicCookieMetadata;
+use Magento\Store\Model\ScopeInterface;
+use Veriteworks\CookieFix\Validator\SameSite;
+
+class SwitchSameSite
+{
+    const CONFIG_PATH = 'web/cookie/samesite';
+    const CONFIG_AFFECTED_KEYS = 'web/cookie/affected_keys';
+    /**
+     * @var SameSite
+     */
+    private $validator;
+    /**
+     * @var Header
+     */
+    private $header;
+    /**
+     * @var ScopeConfigInterface
+     */
+    private $scopeConfig;
+
+    private $affectedKeys = [];
+
+    /**
+     * SwitchSameSite constructor.
+     * @param Header $header
+     * @param ScopeConfigInterface $scopeConfig
+     * @param SameSite $validator
+     */
+    public function __construct(
+        Header $header,
+        ScopeConfigInterface $scopeConfig,
+        SameSite $validator
+    ) {
+        $this->validator = $validator;
+        $this->header = $header;
+        $this->scopeConfig = $scopeConfig;
+    }
+
+    /**
+     * @param PhpCookieManager $subject
+     * @param string $name
+     * @param string $value
+     * @param PublicCookieMetadata|null $metadata
+     * @return array
+     */
+    public function beforeSetPublicCookie(
+        PhpCookieManager $subject,
+        $name,
+        $value,
+        PublicCookieMetadata $metadata = null
+    ) {
+        if ($this->isAffectedKeys($name)) {
+            $agent = $this->header->getHttpUserAgent();
+            $sameSite = $this->validator->shouldSendSameSiteNone($agent);
+            if ($sameSite === false) {
+                $metadata->setSameSite('None');
+            } else {
+                $config = $this->scopeConfig->getValue(self::CONFIG_PATH, ScopeInterface::SCOPE_STORE);
+                $metadata->setSameSite($config);
+            }
+        }
+
+        return [$name, $value, $metadata];
+    }
+
+    private function isAffectedKeys($name)
+    {
+        if (!count($this->affectedKeys)) {
+            $affectedKeys = $this->scopeConfig->getValue(self::CONFIG_AFFECTED_KEYS, ScopeInterface::SCOPE_STORE);
+            $this->affectedKeys = explode(',', strtolower($affectedKeys));
+        }
+
+        return in_array(strtolower($name), $this->affectedKeys);
+    }
+}

Plugin/SwitchSameSite.php

@@ -11,6 +11,11 @@ This extension set SameSite=None and make customers place order via 3DS payment
  + composer require veriteworks/cookiefix
  + bin/magento module:enable Veriteworks_CookieFix
  + bin/magento setup:upgrade
+ 
+# Configuration
+
+After 3.0.0-beta1, you can change SameSite cookie configuration from admin panel. Go to "Stores > configuration > web" and open cookie section. You can see "SameSite" field.
+By default, this extension sets SameSite configuration value to limited cookies. If you hope to update the list, please update web/cookie/affected_keys configuration value. 
 
 # Support