Self validating form php
Hey My site has recently been hacked however it was no where near completion I had only tested it.
There is not as much security on forms that there could be simply because I'm less experianced to just add it in as I go along. So far from what I have found a form script will double in size just to add this security so I'm a bit cautious as to what I really need to do. solid however I cant find anything else about it online so do I really need to use this measure?
From the code we now have, we see that the user Zip must be numerical and must be 5 digits long. Many people try to avoid them, but for this sort of thing they are the right tool for the job.
If it is not, it is of no consequence as it is not a required field and can remain blank. Here is a function that uses a regex to validate an email address.
In this tutorial we will take some user input from a web form, put it into a database and email the user a message thanking them for their input. You can begin here by having a maxlength attribute in your input fields. We will need to keep this in mind as we can check that numbers have been submitted.
This will save the honest users from their own stupidity. With the maxlength set in our form, we can prevent most users from accidentally entering strings of 2 megabytes or something silly. As you can see in our form the action is $_SERVER['PHP_SELF'] so that it posts to itself and htmlentities to ensure safety against Cross Site Scripting (XSS). For now, we will check the inputs that we know are strings.
If you find you have a better regex for email, send it, until then....
For this we will need some extra check if we wish to keep our database intact.
You must first create the database test if it does not exist, and create the table people using the SQL example above.
/** * This function can be used to check the sanity of variables * * @access private * * @param string $type The type of variable can be bool, float, numeric, string, array, or object * @param string $string The variable name you would like to check * @param string $length The maximum length of the variable * * return bool */ /** * This function checks a number is greater than zero * and exactly $length digits.
This article is an attempt to show how input from web based forms can be dealt with safely.
The first and most fundamental rule in security is 'NEVER TRUST USER INPUT'.