diff --git a/README.md b/README.md
index 62849ff..e096e6a 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,7 @@ you can do with this application with web GUI and without any command:
 Requirement:
 
  * nodejs
+ * libpam0g-dev (for PAM authentication)
 
 ## how use:
 
@@ -32,6 +33,7 @@ you can change config in first lines of `pm2panel.js`:
 
 ```javascript
 const PORT = 3001;
+const PAM_AUTH = true; // if set to true, USER and PASS won't be used
 const USER = 'admin';
 const PASS = 'admin';
 const SESSTION_AGE = 10 * 60000; // 10 minutes
@@ -42,4 +44,3 @@ change port or user name and password
 <img src="https://www.uplooder.net/img/image/15/fd8d1c8ed2ea1e09e558f423ff2925ae/login-pm2.png" />
 <br /><br />
 <img src="https://www.uplooder.net/img/image/10/f9f161252a89283a2f5aa85b2b1e1718/pm2index.png" />
-
diff --git a/package.json b/package.json
index a12febf..9308573 100644
--- a/package.json
+++ b/package.json
@@ -30,6 +30,7 @@
     "express": "^4.16.2",
     "express-session": "^1.15.6",
     "fs": "0.0.1-security",
+    "node-linux-pam": "0.0.1",
     "path": "^0.12.7"
   }
 }
diff --git a/pm2panel.js b/pm2panel.js
index e64a068..91191ab 100644
--- a/pm2panel.js
+++ b/pm2panel.js
@@ -3,6 +3,7 @@
 //                             config panel
 //##############################################################################
 const PORT = 3001;
+const PAM_AUTH = true; // if set to true, USER and PASS won't be used
 const USER = 'admin';
 const PASS = 'admin';
 const SESSTION_AGE = 10 * 60000; // 10 minutes
@@ -16,6 +17,7 @@ const express = require('express');
 const app = express();
 const exec = require("child_process").exec;
 const fs = require('fs');
+const { pamAuthenticate, pamErrors } = require('node-linux-pam');
 
 var session = require('express-session');
 
@@ -55,22 +57,48 @@ app.get('/login', function (req, res) {
 });
 
 app.post('/loginCheck', function (req, res) {
-    // check username and password 
-    if (req.body.username === USER && req.body.passwd == PASS) {
-        // login process
-        req.session.islogin = true;
-        // redirect to panel
-        res.writeHead(302, {
-            'Location': '/'
+    // check if local or pam authentication is requested
+    if (PAM_AUTH) {
+        pamAuthenticate({
+            username: req.body.username,
+            password: req.body.passwd
+        }, (err, code) => {
+            if (!err) {
+                // login process
+                req.session.islogin = true;
+                // redirect to panel
+                res.writeHead(302, {
+                    'Location': '/'
+                });
+            } else {
+                // user or password incorrect go back to login and logging PAM code if not 7 (invalid credentials)
+                if (code != 7) console.log('Unsuccessful PAM authentication, code: ' + code);
+                res.writeHead(302, {
+                    'Location': '/login?err=' + (code == 7 ? 'invalid_credentials' : 'system')
+
+                });
+            }
+
+            res.end();
         });
     } else {
-        // user or password incrrect go back to login
-        res.writeHead(302, {
-            'Location': '/login'
+        // check username and password by local authentication
+        if (req.body.username === USER && req.body.passwd == PASS) {
+            // login process
+            req.session.islogin = true;
+            // redirect to panel
+            res.writeHead(302, {
+                'Location': '/'
+            });
+        } else {
+            // user or password incrrect go back to login
+            res.writeHead(302, {
+                'Location': '/login?err=invalid_credentials'
 
-        });
+            });
+        }
+        res.end();
     }
-    res.end();
 });
 
 
@@ -154,7 +182,7 @@ app.get('/restart', function (req, res) {
         res.end();
 
     } else {
-        // check id exits 
+        // check id exits
         if (req.query.id) {
             // restart the process
             exec("pm2 restart " + req.query.id, (error, stdout, stderr) => {
@@ -184,7 +212,7 @@ app.get('/start', function (req, res) {
         res.end();
 
     } else {
-        // check id exits 
+        // check id exits
         if (req.query.id) {
             // start the process
             exec("pm2 start " + req.query.id, (error, stdout, stderr) => {
@@ -214,7 +242,7 @@ app.get('/stop', function (req, res) {
         res.end();
 
     } else {
-        // check id exits 
+        // check id exits
         if (req.query.id) {
             // stop the process
             exec("pm2 stop " + req.query.id, (error, stdout, stderr) => {
@@ -244,7 +272,7 @@ app.get('/delete', function (req, res) {
         res.end();
 
     } else {
-        // check id exits 
+        // check id exits
         if (req.query.id) {
             // delete the process
             exec("pm2 delete " + req.query.id, (error, stdout, stderr) => {
@@ -392,7 +420,7 @@ app.get('/log', function (req, res) {
         res.end();
 
     } else {
-        // check id exits 
+        // check id exits
         if (req.query.id) {
             // log of the process
             var proc = require('child_process').spawn("pm2", ['log', req.query.id]);
@@ -422,4 +450,4 @@ app.get('/log', function (req, res) {
 
 app.listen(PORT, function () {
     console.log('pm2panel app listening on port ' + PORT + '! \n test: http://localhost:' + PORT);
-});
\ No newline at end of file
+});
diff --git a/www/login.html b/www/login.html
index 22f4331..e66a40c 100644
--- a/www/login.html
+++ b/www/login.html
@@ -16,6 +16,7 @@ <h1>
                 Login to Pm2 panel
             </h1>
             <form method="post" action="/loginCheck">
+                <p class="err" style="display:none;color:red;margin:2em auto 1.5em auto;text-align:center;"></p>
                 <fieldset>
                     <label for="user">Username</label>
                     <input type="text" placeholder="Username" id="user" name="username">
@@ -28,5 +29,18 @@ <h1>
             </form>
 
         </div>
+
+        <script type="text/javascript">
+            const urlParams = new URLSearchParams(window.location.search);
+            if (urlParams.get('err') != null) {
+                if (urlParams.get('err') == 'invalid_credentials') {
+                    document.querySelector('#login form p.err').innerText = 'Invalid credentials where provided.';
+                } else {
+                    document.querySelector('#login form p.err').innerText = 'A system error occured.';
+                }
+
+                document.querySelector('#login form p.err').style.display = 'block';
+            }
+        </script>
     </body>
 </html>