Crypto, deimos, and ares

[Regan Heath]

On Thu, 23 Mar 2006 15:15:03 -0800, kris <foo at bar.com> wrote:
> Sean Kelly wrote:
>> Regan Heath wrote:
>>
>>> You might be interested in some existing crypto work I've done:
>>>   http://svn.dsource.org/projects/deimos/trunk/etc/crypto/hash/
>>>
>>> The library "deimos" never really got off the ground, I think it may  
>>> be tome to salvage what can be salvaged from deimos and put it  
>>> somewhere else, perhaps in "Ares", Shaun? If the crypto stuff is  
>>> unsuitable for any reason let me know and I can re-work it.
>>   That's a bit past the level of what I've been focusing on, but it's  
>> certainly a candidate for eventual inclusion.
>>   Sean
>
> I've seriously considered adding a crypto package to Mango; particularly  
> in support of network-oriented apps (MD4, MD5, SHA1, some SSL support,  
> and so on). Perhaps that might be a reasonable home for the time being?
>
> Should only need support for void[], right?

(this is essentially a reply to everyone on this thread)

Yes, I believe so.

Kris you're welcome to place the crypto code I wrote into Mango. I believe  
I put a BSD stlye license on it, let me know if that is a problem.

The interface I used is essentially the same as the std.md5 one in phobos.

It's all done with structs and mixins (which essentially emulates class  
inheritance). The reason I used structs was to make it easy to copy/store  
a hash state i.e. you just assign one MD5 to another and it copies the  
context data. Not sure if that is a good enough reason now, perhaps  
classes with dup methods would be better.

Essentially there are some basic methods:

   void start();
   void update(void[] input);
   void finish(T digest);
   void sum(T digest, void[] input);

which are mixed into the real implementation.

The idea behind these methods is that you can call "sum" if you have all  
the data at once (sum calls the other 3, meaning you cannot mix it with  
calls to the other), or you can call start, then update any number of  
times, and finally finish. The latter 3 methods make it easy to integrate  
with a stream, for example.

Each real implementation defines a trasform method in the form:

   void transform(ubyte[] input);

which is called by the mixed methods to process the data, in addition the  
following methods:

   void padMessage(ubyte[] at);
   void padLength(ubyte[] at, ulong length);

are called to perform the padding, and:

   void extend();

was required to handle MD2 being a little different to the others.

This design pattern and interface works for: MD2, MD4, MD5, SHA0, SHA1,  
SHA256, SHA512, and Tiger. Does it work for blowfish as well? What does  
the .NET API look like?

Regan