[openssl-users] [openssl-dev] Removing obsolete crypto from OpenSSL 1.1 - seeking feedback

Jeffrey Walton noloader at gmail.com
Tue Nov 17 10:19:27 UTC 2015


>> I asked for mainstream use-cases for algorithms whose removal could
>> cause widespread pain. Some individual users, undoubtedly, will be hit
>> by this, and I acknowledge that they may not be reading this list. But I
>> wanted to know if I'd missed something endemic. I also asked elsewhere:
>> Adam Langley pointed me to the MD4 use-case and Steve confirmed that RC2
>> must stay.
>>
>> There is a tradeoff: by attempting to accommodate every single use-case,
>> we will weaken the library for a substantial amount of our user base, by
>> offering them bad defaults, or simply by virtue of the fact that our
>> developer resources are not infinite. (Near)-dead code is a liability.
>
> We can significantly reduce that liability by removing any assembler
> optimisations. Also just because something is available doesn't mean it
> has to be "default". We can have good defaults whilst keeping old crypto.

Zooko Wilcox O'Hearn recently gave a talk at a software assurance
conference on the downsides of assembly language routines in software.
I'm trying to locate it now. All in all, this is probably a move in
the right direction, especially for non-contemporary algorithms, to
help sunset them and maintain them with minimal effort.

Its probably a good idea for mainstream algorithms, too. But the guys
I know who provide the highest-performance implementations probably
won't want to leave it to a compiler.

Jeff


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