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.

To perform a PHP CURL call with HTTP basic authentication, we have to set the user and password in the CURL options.

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "HTTP://SITE.COM");
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
curl_setopt($ch, CURLOPT_USERPWD, "USER:PASSWORD");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$result = curl_exec($ch);
curl_close($ch);

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

DOWNLOAD & NOTES

Here is the download link to the example code, so you don’t have to copy-paste everything.

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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PHP CURL WITH HTTP AUTH

All right, let us now get into the example of CURL with HTTP basic authentication.

SERVER A) PHP CURL CALL

1-CURL-auth.php

<?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.

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.
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.

EXTRAS

That’s all for the main tutorial, and here is a small section on some extras and links that may be useful to you.

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

THE END

Thank you for reading, and we have come to the end. I hope that it has helped you to better understand, and if you want to share anything with this guide, please feel free to comment below. Good luck and happy coding!

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