On 5 Oct 2011, at 01:13, Tommy Pham wrote:

> On Tue, Oct 4, 2011 at 4:49 PM, Stuart Dallas <stu...@3ft9.com> wrote:
> 
> On 5 Oct 2011, at 00:45, Tommy Pham wrote:
> 
>> On Tue, Oct 4, 2011 at 4:11 PM, Stuart Dallas <stu...@3ft9.com> wrote:
>> On 5 Oct 2011, at 00:04, Mark Kelly wrote:
>> 
>> > Hi.
>> >
>> > On Tuesday 04 Oct 2011 at 21:39 Stuart Dallas wrote:
>> >
>> >> http://stut.net/2011/09/15/mysql-real-escape-string-is-not-enough/
>> >
>> > Thanks. I followed this link through and read the full message (having 
>> > missed
>> > it the first time round), and while I find the idea of using base64 to
>> > sanitise text interesting I can also forsee a few difficulties:
>> >
>> > It would prevent anyone from accessing the database directly and getting
>> > meaningful results unless the en/decode is in triggers, or maybe stored
>> > procedures. No more one-off command-line queries.
>> >
>> > How would you search an encoded column for matching text?
>> >
>> > I'd be interested in any ideas folk have about these issues, or any others
>> > they can envisage with this proposal.
>> 
>> Base64 encoding will work when the native base64 functions are available in 
>> MySQL which will allow you to base64 encode the data into a statement like 
>> INSERT INTO table SET field = FROM_BASE64("<?php echo base64_encode($data); 
>> ?>") sorta thing. I'm still not a massive fan of that idea given that 
>> prepared statements are an option, but it would work.
>> 
>> -Stuart
>> 
>> --
>> Stuart Dallas
>> 3ft9 Ltd
>> http://3ft9.com/
>> --
>> 
>> 
>> Inserting and updating isn't the problem.  I think Mark referring to is how 
>> would that be implemented in this simple type of query:
>> 
>> SELECT * FROM my_table WHERE col_name LIKE '%key word%';
>> 
>> If there's no viable mean to filter the data, that storage method/medium is 
>> rather pointless, IMHO.
> 
> Go back and read what I wrote again. Base64 is only being used to transmit 
> the data to MySQL - it's being stored in the database in its decoded form.
> 
> -Stuart
> 
> -- 
> Stuart Dallas
> 3ft9 Ltd
> http://3ft9.com/
> 
> The question still applies as how would you safeguard that 'key word' 
> transmission, especially against SQL injection.  I suppose one could do it 
> this way:
> 
> SELECT * FROM my_table WHERE col_name LIKE CONCAT('%', FROM_BASE64("<?php 
> echo base64_encode($data); ?>"), '%')
> 
> Is the overhead worth it to warrant that kind of safeguard?  That's just a 
> simple query with a simple search criteria.  What about in the case of 
> subselect and multi-table joins?

That would indeed be logical if base64 was your chosen method of protection, 
but I think prepared statements are a far more elegant solution. As for the 
overhead I very much doubt there's much difference between that and the 
overhead of prepared statements.

-Stuart

-- 
Stuart Dallas
3ft9 Ltd
http://3ft9.com/

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