Cryptography and D

[Kagamin via Digitalmars-d]

On Saturday, 5 July 2014 at 18:06:34 UTC, Nick Sabalausky wrote:
> On 7/5/2014 8:23 AM, Kagamin wrote:
>>
>> There was a study, showing that most security vulnerabilities 
>> are caused
>> by client code rather than cryptographic library code.
>
> Interesting. Link?

Dunno, can't find it right now. I thought, I found it following 
links from hap thread, but there's nothing there.

>> For example, how
>> would you prevent client code from generating weak encryption 
>> keys or
>> from using weak algorithm for hash comparison, or how would 
>> you force it
>> to do what's not required to get the code compiled? How would 
>> you do
>> that with the quality of library code? Even if you can do 
>> that, it's
>> still not a cryptographic task, but a general programming 
>> task, the
>> standard only hints you that those things are necessary.
>
> FWIW, DAuth (pending a possible name change, to prevent 
> confusion with the completely unrelated OAuth) maintains a list 
> of non-recommended algos:
>
>   
> https://github.com/Abscissa/DAuth/blob/master/src/dauth/core.d#L109

Cryptographic algorithms don't cause cryptographic weaknesses as 
bad as ones from user code.
Example: http://samate.nist.gov/SRD/view_testcase.php?tID=58

> Also, DAuth encourages passwords to be stored in a special 
> structure:
>
>   
> https://github.com/Abscissa/DAuth/blob/master/src/dauth/core.d#L311
>
> which attempts to zero-out the password from memory as early as 
> it can (and encourages the user to populate it via char[] not 
> string to avoid having an un-wipable immutable plain-text copy 
> in memory. See 'toPassword' vs 'dupPassword'). I'm certain the 
> implementation can be improved. And I'd kinda like to make it 
> scoped if I can, instead of refcounted. But it's something.

Yeah, better than nothing, but as it integrates poorly with the 
rest of user code, people will hack it around by writing byte[] 
hashPassword(string) function. Nobody estimates security by 
defending the system, one do it by breaking it.