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Re: crypto class design

daemon@ATHENA.MIT.EDU (travis+ml-cryptography@subspacefie)
Thu Dec 20 14:25:42 2007

Date: Thu, 20 Dec 2007 11:04:00 -0600
From: travis+ml-cryptography@subspacefield.org
To: Luis Martin <luis.mgarc@gmail.com>
Cc: Cryptography <cryptography@metzdowd.com>
Mail-Followup-To: Luis Martin <luis.mgarc@gmail.com>,
	Cryptography <cryptography@metzdowd.com>
In-Reply-To: <4768C6A1.8050907@gmail.com>


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On Wed, Dec 19, 2007 at 08:22:09AM +0100, Luis Martin wrote:
> I am not sure I understood what you want but here's my suggestion.

The problem is that client code assumes that there is a fixed (constant)
relationship between the size of the output and the size of the input,
and does its own memory allocation for the output, and uses pointers.

This makes it difficult to change that relationship safely; I
basically have to track down and change all the calling code, which
may be near-impossible.

I think the right solution in this case is to pass objects and not
pointers, unless performance dictates otherwise.

But, are there similar assumptions implicit in the calling code which
I can avoid through proper design, now?

That having been said, your suggestion for a data type for this
purpose, with semantically-useful subdivisions, is an interesting one;
thank you (and everyone else who gave suggestions!)

--=20
In God We Trust, All Others Must Provide Source Code
<URL:https://www.subspacefield.org/~travis/> Eff the ineffable!
For a good time on my email blacklist, email john@subspacefield.org.

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