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Showing 1 to 5 of 40 blog articles.
17712 views · 5 years ago
Creating a Virus with PHP

In his talk, “Writing Viruses for Fun, Not Profit,”Ben Dechrai (after making the viewer take a pledge to only use this knowledge for good and not evil) walks through how many viruses operate, and just how easy it is to build your own self-replicating virus in PHP.

The danger of many of these viruses according to Ben is that the most dangerous viruses often escape detection by not looking like a virus. Instead they encrypt their code to hide their true intent, while also constantly adapting and evolving.

Perhaps even more dangerously, they act like they’re benign and don’t actually do anything - often times laying dormant until called upon by the malicious actor.

Creating the Virus

What’s scary is just how simple it was for Ben to create such a virus, one that mutated ever so slightly as it infected every other file on the server. Opening up unlimited possibilities from scraping customer data, to DDOS attacks, to simply hijacking your domain.



But those attacks are just the start as Ben demonstrated how easy it is to write new files, delete files, eval() and execute foreign code - which could even be extended to accessing the underlying server itself if shell_exec() is enabled.

To add to the problem, Ben shares how challenging it can be to identify malicious code on your server as many of these attacks are far more sophisticated than the the virus he created in a matter of minutes - hiding themselves and often appearing as if they are part of the original source code.

Deploying the Virus

To drive his point home, Ben demonstrates how even seemingly secure systems can be vulnerable - as all it takes is one tiny misstep within your application.

He highlights this by building what should be a secure photo gallery - one that checks the extension and mime-type of the image - and even stores it outside of the public directory. He goes even farther by adding additional sanity checks with a PHP script that then renders the image.

After walking through the code and it’s security features, he then downloads a simple image from the internet. Opening his editor he quickly injects the virus (written in PHP) into the image and uploads it, passing all of the server checks.

Surely, since it passed these checks the system is secure, right? Ben loads the gallery to proudly show off the image - which is just that… an image, with nothing special or out of the ordinary.
Except that when he opens the image gallery files, each has been infected with the malicious code.

The culprit that allowed for Ben to hijack an entire system and execute foreign code, create new files, and even hijack the entire site? When displaying the image the file was included using PHP’s include() function, instead of pulling in the data using file_get_contents() and echoing it out.

Such a simple mistake provided Ben, if he was a malicious hacker, complete access to all of the files on the system.

Protecting Yourself

Security always exists in layers - and this could have been prevented by including a few more layers, such as using an open source library to rewrite the image, reviewing the image source before pulling it in, or again not giving it executable access by using the PHP include() function.

But what’s terrifying is how simple it is to hijack a site, how easy it is to get access to your system and private data, and how easy it is to overlook security vulnerabilities - especially with open source tooling and those that take plugins.

As Ben explains, sometimes the core code itself is really secure, but then you get two different plugins that when used together accidentally create a security vulnerability. That by itself is one of the most challenging as you can audit each plugin individually, and still not know you’re opening up your system to malicious actors.

This is why it's not just important to stay up to date on the latest security measures and best practices, but to be constantly thinking like a hacker and testing your code for vulnerabilities.

Learn More

You can watch thefull video to learn more how viruses operate, how to quickly build your own PHP virus (but you must promise to use it for good), and what to watch for in order to protect yourself, your customers, and your architecture.
6258 views · 5 years ago
Oprah: You Get Extension! Everyone Get Extension!

Ever wanted to publish your own extension for PHP but stopped by the lack of C language background? Well, maybe it's time for another take. Zephir language is targeted at people like you.

If you follow this link, you will find these words that say a lot about this project:

Zephir, an open source, high-level language designed to ease the creation and

maintainability of extensions for PHP with a focus on type and memory safety.

Its syntax highly resembles that of PHP, only there's no dollars scattered around your code. Dollar signs, I mean, the PHP $variables. You only can create object oriented extensions, and all the classes written in Zephir must be namespaced. A different and stricter type system exists in Zephir, which allows for transpiling the code you write, into a real C extension.

Why would you need it? This question is largely answered here: Why Zephir. I can only add that, from experience, if you expect a crazy performance boost, you probably won't get it. First, most of the time the bottleneck is not PHP but the IO: database interactions, network and filesystem interactions etc. You won't gain anything by switching to different programming language, in that regards. However, some CPU-intensive calculations may run a lot faster, and if you worry about someone stealing you intellectual property - it also might be worth checking out, because then you can ship your software in form of a binary.

Zephir is the language in which the fastest modern PHP framework is written - Phalcon. Whether or not to use it - decide for yourself, it obviously has its pros and cons. But it's certainly interesting to know that you have the ability to approach some of your tasks completely differently!

See you around, and feel free to comment!
24436 views · 4 years ago
PHP CHAT WITH SOCKETS

Hey Friends,

I am sharing a very interesting blog on how to create a chat system in php without using ajax. As we all know ajax based chat system in php is not a good solution
because itincreases the server load and redundant xhr calls on our server.

Instead, I am going to use sockets for incoming messages from and send messages to another user. So lets try them out using the following steps:


Step 1: Cross check in php.ini that sockets extension is enabled


;extension=sockets
extension=sockets


Step 2: Create server.php file


This file will handle the incoming and outgoing messages on sockets, Add following variables in top of the file:

$host = 'localhost';
$port = '9000';
$null = NULL; 


Step 3: After it add helper methods


The following code for handshake with new incoming connections and encrypt and decrypt messages incoming and outgoing over sockets:

function send_message($msg)
{
global $clients;
foreach($clients as $changed_socket)
{
@socket_write($changed_socket,$msg,strlen($msg));
}
return true;
}
function unmask($text) {
$length = ord($text[1]) & 127;
if($length == 126) {
$masks = substr($text, 4, 4);
$data = substr($text, 8);
}
elseif($length == 127) {
$masks = substr($text, 10, 4);
$data = substr($text, 14);
}
else {
$masks = substr($text, 2, 4);
$data = substr($text, 6);
}
$text = "";
for ($i = 0; $i < strlen($data); ++$i) {
$text .= $data[$i] ^ $masks[$i%4];
}
return $text;
}
function mask($text)
{
$b1 = 0x80 | (0x1 & 0x0f);
$length = strlen($text);

if($length <= 125)
$header = pack('CC', $b1, $length);
elseif($length > 125 && $length < 65536)
$header = pack('CCn', $b1, 126, $length);
elseif($length >= 65536)
$header = pack('CCNN', $b1, 127, $length);
return $header.$text;
}
function perform_handshaking($receved_header,$client_conn, $host, $port)
{
$headers = array();
$lines = preg_split("/

/", $receved_header);
foreach($lines as $line)
{
$line = chop($line);
if(preg_match('/\A(\S+): (.*)\z/', $line, $matches))
{
$headers[$matches[1]] = $matches[2];
}
}
$secKey = $headers['Sec-WebSocket-Key'];
$secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));
$upgrade = "HTTP/1.1 101 Web Socket Protocol Handshake

" .
"Upgrade: websocket

" .
"Connection: Upgrade

" .
"WebSocket-Origin: $host

" .
"WebSocket-Location: ws://$host:$port/php-ws/chat-daemon.php

".
"Sec-WebSocket-Accept:$secAccept



";
socket_write($client_conn,$upgrade,strlen($upgrade));
}


Step 4: Now add following code to create bind and listen tcp/ip sockets:


$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
socket_set_option($socket, SOL_SOCKET, SO_REUSEADDR, 1);
socket_bind($socket, 0, $port);
socket_listen($socket);
$clients = array($socket);


Ok now a endless loop that will use for handeling incominga nd send messages:

while (true) {
$changed = $clients;
socket_select($changed, $null, $null, 0, 10);

if (in_array($socket, $changed)) {
$socket_new = socket_accept($socket); $clients[] = $socket_new;
$header = socket_read($socket_new, 1024); perform_handshaking($header, $socket_new, $host, $port);
socket_getpeername($socket_new, $ip); $response = mask(json_encode(array('type'=>'system', 'message'=>$ip.' connected'))); send_message($response);
$found_socket = array_search($socket, $changed);
unset($changed[$found_socket]);
}

foreach ($changed as $changed_socket) {

while(socket_recv($changed_socket, $buf, 1024, 0) >= 1)
{
$received_text = unmask($buf); $tst_msg = json_decode($received_text, true); $user_name = $tst_msg['name']; $user_message = $tst_msg['message']; $user_color = $tst_msg['color'];
$response_text = mask(json_encode(array('type'=>'usermsg', 'name'=>$user_name, 'message'=>$user_message, 'color'=>$user_color)));
send_message($response_text); break 2; }

$buf = @socket_read($changed_socket, 1024, PHP_NORMAL_READ);
if ($buf === false) { $found_socket = array_search($changed_socket, $clients);
socket_getpeername($changed_socket, $ip);
unset($clients[$found_socket]);

$response = mask(json_encode(array('type'=>'system', 'message'=>$ip.' disconnected')));
send_message($response);
}
}
}
socket_close($socket);


So you are ready with server side socket program, Now its time to move on front side where we will implement w3c provided client side Web Socket Apis,

Step 5: create a file named index.php for frontend usage with following initial code


$host = 'localhost';
$port = '9000';
$subfolder = "php_ws/";
$colors = array('#007AFF','#FF7000','#FF7000','#15E25F','#CFC700','#CFC700','#CF1100','#CF00BE','#F00');
$color_pick = array_rand($colors);
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
<div class="chat-wrapper">
<div id="message-box"></div>
<div class="user-panel">
<input type="text" name="name" id="name" placeholder="Your Name" maxlength="15" />
<input type="text" name="message" id="message" placeholder="Type your message here..." maxlength="100" />
<button id="send-message">Send</button>
</div>
</div>
</body>
</html>


Now add some basic styling in the head section using following code:

<style type="text/css">
.chat-wrapper {
font: bold 11px/normal 'lucida grande', tahoma, verdana, arial, sans-serif;
background: #00a6bb;
padding: 20px;
margin: 20px auto;
box-shadow: 2px 2px 2px 0px #00000017;
max-width:700px;
min-width:500px;
}
#message-box {
width: 97%;
display: inline-block;
height: 300px;
background: #fff;
box-shadow: inset 0px 0px 2px #00000017;
overflow: auto;
padding: 10px;
}
.user-panel{
margin-top: 10px;
}
input[type=text]{
border: none;
padding: 5px 5px;
box-shadow: 2px 2px 2px #0000001c;
}
input[type=text]#name{
width:20%;
}
input[type=text]#message{
width:60%;
}
button#send-message {
border: none;
padding: 5px 15px;
background: #11e0fb;
box-shadow: 2px 2px 2px #0000001c;
}
</style>


Ok Style is all set now need to add a jquery script and create web socket object and handle all events on it as following code need to add before closing of bosy tag:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script language="javascript" type="text/javascript">
var msgBox = $('#message-box');
var wsUri = "ws://".$host.":".$port."/php-ws/server.php";
websocket = new WebSocket(wsUri);

websocket.onopen = function(ev) { msgBox.append('<div class="system_msg" style="color:#bbbbbb">Welcome to my "Chat box"!</div>'); }
websocket.onmessage = function(ev) {
var response = JSON.parse(ev.data);
var res_type = response.type; var user_message = response.message; var user_name = response.name; var user_color = response.color; switch(res_type){
case 'usermsg':
msgBox.append('<div><span class="user_name" style="color:' + user_color + '">' + user_name + '</span> : <span class="user_message">' + user_message + '</span></div>');
break;
case 'system':
msgBox.append('<div style="color:#bbbbbb">' + user_message + '</div>');
break;
}
msgBox[0].scrollTop = msgBox[0].scrollHeight; };

websocket.onerror = function(ev){ msgBox.append('<div class="system_error">Error Occurred - ' + ev.data + '</div>'); };
websocket.onclose = function(ev){ msgBox.append('<div class="system_msg">Connection Closed</div>'); };
$('#send-message').click(function(){
send_message();
});

$( "#message" ).on( "keydown", function( event ) {
if(event.which==13){
send_message();
}
});

function send_message(){
var message_input = $('#message'); var name_input = $('#name');
if(message_input.val() == ""){ alert("Enter your Name please!");
return;
}
if(message_input.val() == ""){ alert("Enter Some message Please!");
return;
}
var msg = {
message: message_input.val(),
name: name_input.val(),
color : '<?php echo $colors[$color_pick]; ?>'
};
websocket.send(JSON.stringify(msg));
message_input.val(''); }
</script>


Ok All set, Now need to run the server.php file using following php-cli utility,make sure you have php cli utility installed in your system:

php -q c:\xampp\htdocs\php-ws\server.php


Now you may access the front index.php file via the browser url like following and see a chatbox and connection status, you may use the same url or different browser to check the chat system is working or not.
8976 views · 4 years ago
When PHP Frameworks Suck

INTRO

If you are working as a PHP software developer, there is an extremely high chance that all of your application, you’re currently working on, using frameworks of any kind.
PHP community developers of all levels worship frameworks since there are big historical and practical reasons for that.

Historical reasons

Since early PHP versions, developers were disreputable because not everybody considered PHP as a programming language, similar to JavaScript a couple of years ago. While strong type language existed decades ago, PHP continues to be soft type since now, only in version 7 basic types were introduced. There is also a matter of the fact that you can script in PHP without using a single object.

But that opened a space for frameworks to step in and introduce themselves as a tool or standard which will shape projects, give them right and order, introduce structure and rules.
And finally, they did. Frameworks are good examples of nice structures, using all available new features PHP offers with every version, enforcing some good practice, etc.

Practical reasons

The framework offers a lot of common problems already solved. They offer a nice ecosystem for other developers to contribute and plug their components. There is a lot of online resources for learning and stay updated about any particular framework. Also, what every framework community tries very hard, is to make setup and usage easy.

WHEN PHP FRAMEWORKS SUCKS

I recently had the opportunity to give a talk on a conference and one meetup about why PHP framework sometimes sucks. Sometimes things we see in framework tutorials does not seem to be very much aligned with some object-oriented standards we are striving to enforce, and with basic clean code guidelines. On the other hand, there is nothing wrong with using a framework, if you use it right.

This article is the first "pilot" article in this series. In every new blog in this series, we will go more in-depth about every specific topic I covered during my presentation.
I'm very excited to share this knowledge, as I saw many developers suffer from bonded-to-framework disease.

https://twitter.com/damnjan/status/1058306144458956800

I won’t spend much time here on any particular framework discussion. This series will be just a guide on how to unbind yourself from frameworks and use them as a tool, instead of being independent.

**Here is the link to the presentation slides.**
6975 views · 3 years ago
Ideas to help your PHP dev team grow their skills

Your biggest asset is also your biggest risk... your developers


Your business thrives because of the incredible work and innovation of your developers. With simple keystrokes your developers can completely transform your business, add new features, and drive new sales.

But those same keystrokes can take down production, create security back doors, and put your business at risk. That's why it's more important than ever for your team members to be up to speed with the latest technology, especially around performance and security.

Of course, some things are easier said than done - after all everyone is super busy these days. So how can you help keep your team members learning, and putting your business first in the process?

Conference Parties


There's nothing better than attending a PHP or programming conference in person - the chance to meet speakers face to face, to network, the knowledge, and the hallway track. However, many companies aren't able to afford multiple (or even one) conference for their developers - especially ones that require airfare and hotel.

However, that doesn't mean you shouldn't still participate in these conferences. The good news is that roughly once a quarter Nomad PHP streams talks from a conference right to your computer. This means that your team members can all participate in a multi-day conference from the comfort of your office (or their home) - and you can provide this for your team for less than the cost of a single conference ticket!

Make the conference party even more special by providing lunch during the lunch break, bringing in party gifts, having give-aways during the conference, and planning activities during longer breaks for your team.

Since many conferences take place on Friday, not only are you providing invaluable training and an incredible work benefit, but ending the week on a super positive note that your team members will appreciate (and your risk assessment teams will greatly appreciate as new security practices and compliance practices are put into place).

Monthly Lunch and Learns


Every month Nomad PHP offers live virtual talks by the industry's top experts. With talks at 11am Pacific, and 6pm Pacific it's a perfect time to grab a conference room and order a couple pizzas for lunch (or if Eastern, grab some snacks and maybe a beer) and play the monthly meeting on the large screen.

Your team members will have the opportunity to take notes, discuss with each other, and perhaps most importantly ask the speaker real-world questions that directly impact your business, providing tangible solutions to the problems they are facing.

And since every Nomad PHP Pro meeting is recorded, your team members can refer back to the video at any time, watching sections relevant to them or digging in for more information.

Developer Book Club


Encourage your team members to share what they're learning with others, and help build each other up. Not only are you helping grow skills and ensure your team is following the latest best practices, but you're also fostering a mentor-mentality within your team - where each team member feels invested in the growth of other members.

With Nomad PHP you receive a new issue of [php[architect]](/books) each month and have several additional books available to read on demand - providing the latest updates and an invaluable resource to help your book club get started.

Developer Movie Nights


Sometimes we all just want to get away, grab some popcorn, and watch a movie. Similar to lunch and learns, give your developers a night or two where they can get together and watch one of the 250+ training videos available on Nomad PHP. You can even make it a movie marathon!

Whether it's pizza, popcorn, sodas, beers - your team members will have the chance to kick back, relax a bit, build team camaraderie, and learn valuable skills to help your business succeed. Essentially, turning a training day into a fun team-bonding activity.

Learning Path Challenges


Every company has challenges, and areas they need their team members to master. Whether it's DevOps and containerization, security, performance, management, modernization, or soft skills - work with your team to determine what skills will help them succeed and work with your team members to put together video learning paths.

Your team members can watch through these videos on-demand, go back and replay to refresh their knowledge, and work their way towards mastery in the subjects that will help your company succeed.

Certification


Show that you are invested in your developers by helping them earn Professional Certification. These certifications demonstrate that your team members have a fundamental grasp of the technology they are working with and understand when and how to use this technology.

With free certification exams included with Nomad PHP - you no longer have to worry about failed exams or expensive test credits. Your team members can take the exams at their own pace, discover the areas they need to improve, and take the exam again when they are ready. After all, shouldn't the goal of certification be to help your developers learn these skills and prove their expertise?

You can go even further with certifications by having a special company award, framing their certificate, or calling out newly certified developers at team meetings or all-hands.

Learning Incentives/ Rewards


Of course there are even more ways you can help your developers learn new skills, grow their careers, and build loyalty within your company. With Nomad PHP there are numerous ways for your team members to grow their skills, and numerous ways you can reward/ incentivize them - from rewards for the most active learner, to setting goals for learning new skills, to obtaining certifications, to attending streams, to watching videos on-demand. All of these are included with our Professional Nomad PHP Team subscriptions.

Want to learn more about getting a Nomad Team Subscription for your developers? Give us a call (844) CODE-PHP

Have more ideas on how to help your developers grow their skills or help employers make education more accessible? Please leave your ideas in the comments below!

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