Re: pgcrypto decrypt_iv() issue

On Fri, Jan 27, 2012 at 7:34 PM, Stefan Kaltenbrunner
<stefan(at)kaltenbrunner(dot)cc> wrote:
> On 01/27/2012 04:20 PM, Marko Kreen wrote:
>> On Fri, Jan 27, 2012 at 01:37:11AM -0500, Tom Lane wrote:
>> Yeah, it should be fixed.  But note that "random data" is part of
>> decrypt() spec - the validation it can do is a joke.
>>
>> Its more important to do proper checks in encrypt() to avoid invalid
>> stored data, but there the recommended modes (CBC, CFB) can work
>> with any length data, so even there the impact is low.
>
> I agree - but in my case the input to those functions is actually coming
> from external untrusted systems - so if the data is (completely) invalid
> really want to get a proper error message instead of random memory content.

You *will* get random memory content. If your app is exploitable with
invalid data, you *will* get exploited. The decrypt() checks are
more for developer convenience than anything more serious.

Please fix your app to survive invalid data...

--
marko