From 8bb2e8c838a18911f3a631d668be7fbfd1cdf58c Mon Sep 17 00:00:00 2001
From: Yasen Pramatarov <yasen@lindeas.com>
Date: Tue, 1 Oct 2024 10:18:53 +0300
Subject: [PATCH] Prepares for agents' JWT

---
 app/classes/agent.php        | 33 +++++++++++++++++++++++++++++++++
 app/templates/agent-list.php | 13 ++++++++++---
 public_html/static/agents.js |  5 ++++-
 3 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/app/classes/agent.php b/app/classes/agent.php
index 7d4c511..f84531a 100644
--- a/app/classes/agent.php
+++ b/app/classes/agent.php
@@ -110,6 +110,7 @@ class Agent {
         }
     }
 
+
     // check for agent cache
     public function checkAgentCache($agent_id) {
         $agent_cache_name = $agent_id . '_cache';
@@ -117,6 +118,38 @@ class Agent {
         return isset($_SESSION[$agent_cache_name]) && isset($_SESSION[$agent_cache_time]) && (time() - $_SESSION[$agent_cache_time] < 600);
     }
 
+
+    // method for base64 URL encoding for JWT tokens
+    private function base64UrlEncode($data) {
+        return rtrim(strtr(base64_encode($data), '+/', '-_'), '=');
+    }
+
+
+    // generate a JWT token for jilo agent
+    public function generateAgentToken($payload, $secret_key) {
+
+        // header
+        $header = json_encode([
+            'typ' => 'JWT',
+            'alg' => 'HS256'
+        ]);
+        $base64Url_header = $this->base64UrlEncode($header);
+
+        // payload
+        $payload = json_encode($payload);
+        $base64Url_payload = $this->base64UrlEncode($payload);
+
+        // signature
+        $signature = hash_hmac('sha256', $base64Url_header . "." . $base64Url_payload, $secret_key, true);
+        $base64Url_signature = $this->base64UrlEncode($signature);
+
+        // build the JWT
+        $jwt = $base64Url_header . "." . $base64Url_payload . "." . $base64Url_signature;
+
+        return $jwt;
+    }
+
+
     // fetch result from jilo agent API
     public function fetchAgent($agent_id, $force = false) {
 
diff --git a/app/templates/agent-list.php b/app/templates/agent-list.php
index e067749..c79c468 100644
--- a/app/templates/agent-list.php
+++ b/app/templates/agent-list.php
@@ -10,6 +10,16 @@
                             <br />
                             endpoint: <strong><?= htmlspecialchars($agent['url']) ?><?= htmlspecialchars($agent['agent_endpoint']) ?></strong>
                             <br />
+<?php
+    $payload = [
+        'iss' => 'Jilo Web',
+        'aud' => $config['domain'],
+        'iat' => time(),
+        'exp' => time() + 3600,
+        'agent_id' => $agent['id']
+    ];
+    $jwt = $agentObject->generateAgentToken($payload, $agent['secret_key']);
+?>
 <?php if (isset($_SESSION["{$agent['id']}_cache"])) { ?>
                             <button class="btn btn-primary" data-toggle="tooltip" data-trigger="hover" data-placement="bottom" title="load recently cached data" onclick="fetchData('<?= htmlspecialchars($agent['id']) ?>', '<?= htmlspecialchars($agent['url']) ?>', '<?= htmlspecialchars($agent['agent_endpoint']) ?>')">load cache</button>
                             <button class="btn btn-primary" data-toggle="tooltip" data-trigger="hover" data-placement="bottom" title="get fresh data from agent" onclick="fetchData('<?= htmlspecialchars($agent['id']) ?>', '<?= htmlspecialchars($agent['url']) ?>', '<?= htmlspecialchars($agent['agent_endpoint']) ?>', true)">force refresh</button>
@@ -20,7 +30,4 @@
                     </p>
                         <p>Result:</p>
                         <pre id="result<?= htmlspecialchars($agent['id']) ?>">click a button to fetch data from the agent.</pre>
-<?php
-    print_r($_SESSION);
-?>
 <?php } ?>
diff --git a/public_html/static/agents.js b/public_html/static/agents.js
index ada61ec..af1f435 100644
--- a/public_html/static/agents.js
+++ b/public_html/static/agents.js
@@ -1,4 +1,4 @@
-function fetchData(agent_id, url, endpoint, force = false) {
+function fetchData(agent_id, url, endpoint, jwtToken, force = false) {
 
     let counter = 0;
     const resultElement = document.getElementById("result" + agent_id);
@@ -28,6 +28,9 @@ function fetchData(agent_id, url, endpoint, force = false) {
         return; // Exit the function early
     }
 
+    // send the token
+    xhr.setRequestHeader("Authorization", "Bearer " + jwtToken);
+
     xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
 
     // Set a timeout in milliseconds (10 seconds = 10000 ms)