Styjun

Or: "Will changing the php/mysql database in this manner create an insecure connection?"

I am thinking of automating my live/test databases. I am a bit mysql naïve, so I thought I better ask this question here:

What would the ramifications and/or security concerns be in the following php/mysql scenario?

// set up the standard database

// Connection codes:
$host="localhost";
$user="imauser";
$password="imapassword";
$dbname="liveDB";

$cxn = mysqli_connect ($host,$user,$password,$dbname)
 or die ("Couldn't connect to the server.");

// check if $testMode is active, and reset $cxn with a new (test) $dbname:

if($testMode == TRUE)
 $dbname="testDB"; // test database
 // reset the cxn:
 $cxn = mysqli_connect ($host,$user,$password,$dbname)
 or die ("Couldn't connect to the server.");

This would allow me to toggle $testMode at a higher level in the code. Will the simple overwriting of $cxn work, or will I have an open and active mysqli_connect connection left hanging?

I don't see anything that I would consider insecure in your code. However, doing mysqli_connect() twice seems unnecessary.

You could create a simple ternary for this;

// set up the standard database

// Connection codes:
$host = "localhost";
$user = "imauser";
$password = "imapassword";

//use a ternary like this
$dbname = $testMode ? 'testDB' : 'liveDB';

$cxn = mysqli_connect($host, $user, $password, $dbname) or die("Couldn't connect to the server: " . mysqli_connect_errno());

Explanation

The ternary in the code above is equivalent to:

if($testMode == true) 
 $dbname = 'testDB';
 else 
 $dbname = 'liveDB';

Ternaries can be simply explained like this $variable = CONDITION ? TRUE : FALSE

If you have a Boolean variable (such as $testMode); you can check if it's true or false by checking it directly as a condition.

if($testMode) is equivalent to if($testMode == true).

Other Changes

• I changed your die() call to actually display the error if it can't
  connect.


• Changed some formatting to be more easily readable.

It's better to keep your database credentials separate from your code. Just in case anyone finds a way to read your code, they shouldn't see your database password.

Keep the database credentials in a config file, which your app reads on startup. I'd use parse_ini_file().

Here's an example config file:

[database]
host=localhost
user=imauser
password=imapassword
dbname=liveDB

Here's how you'd read it:

$config = parse_ini_file('config.ini', true);

If I output print_r($config), I see this:

Array
(
 [database] => Array
 (
 [host] => localhost
 [user] => imauser
 [password] => imapassword
 [dbname] => liveDB
 )

)

That way you can deploy the same code in both test and production environments, and you only need to replace the config file in the test and production servers.

NOTE: Make sure you don't put your config file under the directory that the web server can serve files from. Your PHP code can read a file from anywhere on your server, so make sure no one can simply open the config file in a browser.

I mean there are no security or other issues that would arise from this as long as you remember to change your test mode variable. Though I would do this with a switch statement like so

$devmode = "TEST";
$conn = null;
switch($devmode) 
 case "TEST"
 //conn here
 break;
 //case dev
 default:
 //local host con or prod conn
 break;

There are better ways to do this though, i'd highly suggest looking at something like doctrine to manage all your SQL for you, in doctrine you can easily swap your connections plus its database type independent.