asked on

Escape and URLDecode for URL passed using Ajax call

I am using xmlhttp (Ajax) requests to call a PHP program from javascript using the GET method.

I am passing the PHP script a string as parameters which includes the characters %20. For example, the current call to the PHP program looks like this:

phpparser.php?sqlstr=WHERE fieldname LIKE '%2007.03%' ORDER BY relid ASC

The %20 is cut off the param string when it reaches the PHP script, therefore messing up the MySQL query string I am passing.

I fooled around with escape and URLDecode, but how much of the URL needs to be escaped when using xmlhttp (Ajax) calls? Should I use escape across the entire URL and then URLDecode in the receiving PHP script?

Thanks

glcummins

A BIG word of caution on this: You are opening up your script to a huge security attack. If you allow an SQL query to be passed as-is to your script and then executed, you have no way of knowing what is in the query. A malicious attacker can wreak havoc on your database with this kind of method.

A better option, if you can, is simple to pass the search term and order by term separately, and reconstruct the SQL statement in the script:

phpparser.php?value1=2007.03&orderby=relid&orderdirection=ASC

mamuscia

ASKER

I have many fields that the form displays to allow a user to enter to search the database. In my PHP script I execute a SELECT so the user is constrained to reading the DB. There is also a check to make sure the construct of the WHERE clause is correct. How would I encode/decode this URL?

Zvonko

You have to encode the query string paramter Values only.
Like this:
"phpparser.php?sqlstr="+escape("WHERE fieldname LIKE '%2007.03%' ORDER BY relid ASC")+"&some="+escape("more parametrs");

You see?
Encoding & and = of the query string is misleading like not encoding special characters in the parameter values.

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Zvonko

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mamuscia

ASKER

this works great, thanks!!

Zvonko

You are welcome.