PHP CURL With HTTP Basic Authentication (A Simple Example)

Welcome to a tutorial on how to do a PHP CURL call with HTTP basic authentication. Need to secure a server-to-server call without all the crazy encryption, verification, and login stuff? HTTP basic authentication is a good option.

That should cover the basics, but read on for an actual example.

 

 

TABLE OF CONTENTS

 

 

EXAMPLE CODE DOWNLOAD

Source code on GitHub Gist

Just click on “download zip” or do a git clone. I have released it under the MIT license, so feel free to build on top of it or use it in your own project.

 

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SERVER A) PHP CURL CALL

<?php
// (A) THE SETTINGS
$url = "http://localhost/protected/2-secret.php";
$user = "USER";
$password = "PASS";

// (B) CURL INIT
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
curl_setopt($ch, CURLOPT_USERPWD, "$user:$password");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
if (substr($url, 0, 5)=="https") {
  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, true);
  curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
}

// (C) CURL EXEC
// NOTE: HTTP RESPONSE CODE 200 = OK
$result = curl_exec($ch);
if (curl_errno($ch)) { echo curl_error($ch); }
else {
  $info = curl_getinfo($ch);
  if ($info["http_code"] != 200) { print_r($info); }
  else { echo $result; }
}
curl_close($ch);

This should be pretty self-explanatory.

• As in the introduction, all we need is to set CURL options (CURLOPT_HTTPAUTH and CURLOPT_USERPWD) accordingly.
• If you are having trouble with SSL (https://), try disabling the peer verification – curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false).
• Take note of the “fetch results” part, we can use curl_getinfo() to get more information on the server response. Importantly, check the http_code – A failed authentication will usually return 401 (unauthorized).

 

 

SERVER B) PROTECTED FOLDER

This is a small extra for you guys who are running Apache, and do not know how to secure folders with basic HTTP auth.

1. Apache web servers come with a tool called htpasswd and we can use it to generate a user/password file –  htpasswd -c "PATH/FOLDER/.htpasswd" USER.
2. Next, create a .htaccess file in the folder that you want to protect.
   • AuthType Basic
   • AuthName "Password Required"
   • AuthUserFile PATH/FOLDER/.htpasswd
   • Require valid-user

That’s all.

 

 

 

LINKS & REFERENCES

• CURL Options – PHP
• Basic Authentication and Authorization – Apache
• htpasswd – Manage user files for basic authentication
• Basic Authentication For IIS – Microsoft
• Basic Authentication For NGINX