[openssl-dev] use SIPhash for OPENSSL_LH_strhash?

[Benjamin Kaduk]

On 01/10/2017 12:31 PM, Richard Levitte wrote:
>
> Benjamin Kaduk <bkaduk at akamai.com> skrev: (10 januari 2017 18:48:32 CET)
>> On 01/09/2017 10:05 PM, Salz, Rich wrote:
>>> Should we move to using SIPHash for the default string hashing
>>> function in OpenSSL?  It’s now in the kernel
>>> https://lkml.org/lkml/2017/1/9/619
>>>
>> Heck, yes!
>> -Ben
> I fail to see what that would give us. OPENSSL_LH_strhash() is used to get a reasonable index for LHASH entries. Also SIPhash gives at least 64 bits results, do we really expect to see large enough hash tables to warrant that? 
>

We don't need to use the full output width of a good hash function.

My main point is, "why would we want to ignore the last 20 years of
advancement in hash function research?"  Section 7 of the siphash paper
(https://131002.net/siphash/siphash.pdf) explicitly talks about using it
for hash tables, including using hash table indices H(m) mod l.

-Ben
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