Re: Hash algorithm analysis

>>> I imported the optimized 64-bit implementation of KangarooTwelve.
>>> The AVX2 implementation was not considered for licensing reasons
>>> (it's partially generated from external code, which falls foul of
>>> the GPL's "preferred form for modifications" rule). 
>>
>> Indeed part of the AVX2 code in the Keccak code package is an
>> extension of the implementation in OpenSSL (written by Andy
>> Polyakov). The assembly code is generated by a Perl script, and we
>> extended it to fit in the KCP's internal API.
>>
>> Would it solve this licensing problem if we remap our extensions to
>> the Perl script, which would then become "the source"? 
>
> The GPLv2 requires "the preferred form of the work for making
> modifications to it". If that form is the Perl script, then yes, that
> would be sufficient. If your code is dissimilar enough that editing it
> directly is better than editing the Perl script, then it might already
> meet the definition.
>
> I don't do assembly programming, so I don't know what forms one
> generally wants for editing assembly. Apparently OpenSSL wants a Perl
> script, but that is, I understand, less common. What would you use if
> you were going to improve it?