How to Sanitize Input with Pdo

How do I sanitize input with PDO?

If you use PDO you can parametize your queries, removing the need to escape any included variables.

See here for a great introductory tutorial for PDO.

Using PDO you can seperate the SQL and passed parameters using prepared statements, this removes the need to escape strings, as because the two are held seperately then combined at execution, the parameters are automatically handled as stings, from the above source:

   // where $dbh is your PDO connection

$stmt = $dbh->prepare("SELECT * FROM animals WHERE animal_id = :animal_id AND animal_name = :animal_name");

/*** bind the paramaters ***/
$stmt->bindParam(':animal_id', $animal_id, PDO::PARAM_INT);
$stmt->bindParam(':animal_name', $animal_name, PDO::PARAM_STR, 5);

/*** execute the prepared statement ***/
$stmt->execute();

Note: sanitization occurs during variable binding ($stmt->bindParam)

Other resources:

http://net.tutsplus.com/tutorials/php/why-you-should-be-using-phps-pdo-for-database-access/

http://www.phpeveryday.com/articles/PDO-Prepared-Statement-P550.html

http://php.net/manual/en/pdo.prepared-statements.php

Correct way to sanitize input in MySQL using PDO

The idea of prepared statements is that you don't concatenate variables, instead you bind the parameters. The difference is the variable never gets inserted into the SQL, rather the MySQL engine handles the variable separately which leaves no possibility of SQL Injection. This also has the added bonus that no escaping or pre-processing of the variable is required.

$query = $db->prepare("SELECT password FROM login WHERE username = :username");
$query->execute(array(':username' => $username));

Do I need to sanitize the input? PDO and mysql escape

No, you do not need to use mysql_escape_string in PDO prepare statements that bind the variables. PDO will take care of that, untill you pass the values directly in the preapare function.

PHP Sanitizing Input With PDO Statements

If you're using prepared statements, then you shouldn't have any issue with MySQL injection.

If an application exclusively uses prepared statements, the developer
can be sure that no SQL injection will occur (however, if other
portions of the query are being built up with unescaped input, SQL
injection is still possible).

You might consider sanitizing your output, however, like only displaying certain HTML tags (if any at all), to avoid issues with someone messing with the site's layout or, worse, executing arbitrary JavaScript.

PDO password_verify, do I need to sanitize?

you don't need to sanitize it as you are going to compare it with the hashed password from the database

plus on register.php you don't need to sanitize the password as you going to hash it using password_hash()
then save it to the database which won't cause any harm because it's already hashed

any sanitize to the password on register may spoil it
for example if the user used password like mypassword'1'2'3 after sanitize it will be
mypassword\'1\'2\'3 which is not the same

hope it helps

Should i sanitize/filter user input and output when using PHP PDO?

You're confusing different sanitizing here :

  • The SQL sanatizing for data to insert to your DB. With prepared query with params, no need to escape, PDO do it internally. If you don't use prepared queries, use them. It's bullet-proof (as far as I know).

  • The data you get from your DB and output as HTML : here you have to sanatize before printing it to your user (to prevent XSS), either by using htmlspecialchars() , htmlentites() or strip_tags(), depending what you want to escape or delete.

How to sanitize query to accept table name as parameter PDO php

Whitelist your existing tables

$db = "database1";
$table = $_GET['table'];

$dbh = new PDO('mysql:host=localhost;dbname=database1', $user, $pass);
$tableSql = "SHOW TABLES FROM " . $db;
$tableRes = $dbh->query($tableSQL);
$tableArr = $tableRes->fetch(PDO::FETCH_ASSOC);
$whitelist = $tableArr[0]['Tables_in_database1'];
if(!in_array($table, $whitelist)){
exit(); //Or RickRoll Them
}

sanitizing variables with PDO

No, you definitely do not need addslashes if you're using PDOStatement properly. You don't need additional sanitization to prevent SQL injection. However, you may still want to validate in other ways. For example, you might check that an email field "looked like" an email address, or make sure that a plain text field did not contain certain characters. Finally, you may have to escape (e.g. with htmlspecialchars) when you output text from the database.

How can I sanitize user input with PHP?

It's a common misconception that user input can be filtered. PHP even has a (now deprecated) "feature", called magic-quotes, that builds on this idea. It's nonsense. Forget about filtering (or cleaning, or whatever people call it).

What you should do, to avoid problems, is quite simple: whenever you embed a a piece of data within a foreign code, you must treat it according to the formatting rules of that code. But you must understand that such rules could be too complicated to try to follow them all manually. For example, in SQL, rules for strings, numbers and identifiers are all different. For your convenience, in most cases there is a dedicated tool for such an embedding. For example, when you need to use a PHP variable in the SQL query, you have to use a prepared statement, that will take care of all the proper formatting/treatment.

Another example is HTML: If you embed strings within HTML markup, you must escape it with htmlspecialchars. This means that every single echo or print statement should use htmlspecialchars.

A third example could be shell commands: If you are going to embed strings (such as arguments) to external commands, and call them with exec, then you must use escapeshellcmd and escapeshellarg.

Also, a very compelling example is JSON. The rules are so numerous and complicated that you would never be able to follow them all manually. That's why you should never ever create a JSON string manually, but always use a dedicated function, json_encode() that will correctly format every bit of data.

And so on and so forth ...

The only case where you need to actively filter data, is if you're accepting preformatted input. For example, if you let your users post HTML markup, that you plan to display on the site. However, you should be wise to avoid this at all cost, since no matter how well you filter it, it will always be a potential security hole.

PHP with PDO: Compare santized input (filter_var) with prepared statement data

No, PHP does not work that way. Variable content isn't interpolated into the source code and then the source code isn't reevaluated with the interpolated variable content. It works like this in shell scripts (insert a ton of asterisks and clarifications here), but not in PHP or most other sane programming languages.

getUserName($email);

Here $email contains whatever was assigned to it. It doesn't matter what that is. There is no vulnerability here under any circumstances. This code says call the function getUserName and pass it the value of $email as its first argument. Nothing more, nothing less. It will never be interpreted to mean anything else. There's no need to sanitise that value for this purpose.

The only time values are interpolated into "code" and that code is then being executed is when you very explicitly do so:

eval("getUserName($email)")
$db->query("SELECT * FROM foo WHERE bar = '$email'")

These are both examples of explicitly interpolating strings into strings to create new strings which are then interpreted as code of some form or another. As long as you stay away from such constructs, this particular vulnerability is of little concern.



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