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* SHA1dc on mac
@ 2020-02-12  8:56 Mike Hommey
  2020-02-12 16:46 ` Eric Sunshine
  0 siblings, 1 reply; 4+ messages in thread
From: Mike Hommey @ 2020-02-12  8:56 UTC (permalink / raw)
  To: git

Hi,

If I'm not mistaken in my reading of the various files involved, it
looks like for some reason, building git on mac leads to using Apple
Common Crypto for SHA1, rather than SHA1dc, which seems unfortunate.
Is that really expected? More generally, at this point, should anything
other than SHA1dc be supported as a build option at all?

Mike

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: SHA1dc on mac
  2020-02-12  8:56 SHA1dc on mac Mike Hommey
@ 2020-02-12 16:46 ` Eric Sunshine
  2020-02-12 22:31   ` Mike Hommey
  0 siblings, 1 reply; 4+ messages in thread
From: Eric Sunshine @ 2020-02-12 16:46 UTC (permalink / raw)
  To: Mike Hommey; +Cc: Git List

On Wed, Feb 12, 2020 at 3:57 AM Mike Hommey <mh@glandium.org> wrote:
> If I'm not mistaken in my reading of the various files involved, it
> looks like for some reason, building git on mac leads to using Apple
> Common Crypto for SHA1, rather than SHA1dc, which seems unfortunate.
> Is that really expected?

There was a discussion on this topic a while back[1], and it does seem
that the behavior you describe is intentional[2].

> More generally, at this point, should anything
> other than SHA1dc be supported as a build option at all?

The conclusion [2,3] was that it likely would make sense to drop
support for Apple's CommonCrypto altogether, although nobody has yet
stepped up to do the work.

[1]: https://lore.kernel.org/git/CAMYxyaVQyVRQb-b0nVv412tMZ3rEnOfUPRakg2dEREg5_Ba5Ag@mail.gmail.com/T/
[2]: https://lore.kernel.org/git/20160102234923.GA14424@gmail.com/
[3]: https://lore.kernel.org/git/CAPig+cQ5kKAt2_RQnqT7Rn=uGmHV9VvxpQ+UgDPOj=D=pq6arg@mail.gmail.com/

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: SHA1dc on mac
  2020-02-12 16:46 ` Eric Sunshine
@ 2020-02-12 22:31   ` Mike Hommey
  2020-02-12 22:40     ` Junio C Hamano
  0 siblings, 1 reply; 4+ messages in thread
From: Mike Hommey @ 2020-02-12 22:31 UTC (permalink / raw)
  To: Eric Sunshine; +Cc: Git List

On Wed, Feb 12, 2020 at 11:46:31AM -0500, Eric Sunshine wrote:
> On Wed, Feb 12, 2020 at 3:57 AM Mike Hommey <mh@glandium.org> wrote:
> > If I'm not mistaken in my reading of the various files involved, it
> > looks like for some reason, building git on mac leads to using Apple
> > Common Crypto for SHA1, rather than SHA1dc, which seems unfortunate.
> > Is that really expected?
> 
> There was a discussion on this topic a while back[1], and it does seem
> that the behavior you describe is intentional[2].

That discussion predates SHA1dc, though.

> > More generally, at this point, should anything
> > other than SHA1dc be supported as a build option at all?
> 
> The conclusion [2,3] was that it likely would make sense to drop
> support for Apple's CommonCrypto altogether, although nobody has yet
> stepped up to do the work.

I wasn't explicit in my question, but I meant more broadly than Apple
Common Crypto. There is still opt-in support for openssl sha1 and PPC
sha1.

Mike

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: SHA1dc on mac
  2020-02-12 22:31   ` Mike Hommey
@ 2020-02-12 22:40     ` Junio C Hamano
  0 siblings, 0 replies; 4+ messages in thread
From: Junio C Hamano @ 2020-02-12 22:40 UTC (permalink / raw)
  To: Mike Hommey; +Cc: Eric Sunshine, Git List

Mike Hommey <mh@glandium.org> writes:

> On Wed, Feb 12, 2020 at 11:46:31AM -0500, Eric Sunshine wrote:
>> On Wed, Feb 12, 2020 at 3:57 AM Mike Hommey <mh@glandium.org> wrote:
>> > If I'm not mistaken in my reading of the various files involved, it
>> > looks like for some reason, building git on mac leads to using Apple
>> > Common Crypto for SHA1, rather than SHA1dc, which seems unfortunate.
>> > Is that really expected?
>> 
>> There was a discussion on this topic a while back[1], and it does seem
>> that the behavior you describe is intentional[2].
>
> That discussion predates SHA1dc, though.

Yes, but the essense is the same.  It was phrased as "is there a
good reason to prefer CommonCrypto over block-sha1?" but it really
was "is there a good reason to prefer CommonCrypto over the best we
offer?"  And the best we offer, which used to be block-sha1, is now
sha1dc.

^ permalink raw reply	[flat|nested] 4+ messages in thread

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Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2020-02-12  8:56 SHA1dc on mac Mike Hommey
2020-02-12 16:46 ` Eric Sunshine
2020-02-12 22:31   ` Mike Hommey
2020-02-12 22:40     ` Junio C Hamano

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