How to secure database passwords in PHP?

Several people misread this as a question about how to store passwords in a database. That is wrong. It is about how to store the password that lets you get to the database.

The usual solution is to move the password out of source-code into a configuration file. Then leave administration and securing that configuration file up to your system administrators. That way developers do not need to know anything about the production passwords, and there is no record of the password in your source-control.

If you're hosting on someone else's server and don't have access outside your webroot, you can always put your password and/or database connection in a file and then lock the file using a .htaccess:

<files mypasswdfile>order allow,denydeny from all</files>

The most secure way is to not have the information specified in your PHP code at all.

If you're using Apache that means to set the connection details in your httpd.conf or virtual hosts file file. If you do that you can call mysql_connect() with no parameters, which means PHP will never ever output your information.

This is how you specify these values in those files:

php_value mysql.default.user      myusernamephp_value mysql.default.password  mypasswordphp_value mysql.default.host      server

Then you open your mysql connection like this:

<?php$db = mysqli_connect();

Or like this:

<?php$db = mysqli_connect(ini_get("mysql.default.user"),                     ini_get("mysql.default.password"),                     ini_get("mysql.default.host"));