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Re: [PATCH 3/5] protocol-capabilities.txt: clarify "allow-x-sha1-in-want" re SHA-256

From
Junio C Hamano <gitster@pobox.com>
Date
Aug 14, 2020, 17:33 UTC
Message-ID
<xmqqft8pxhd9.fsf@gitster.c.googlers.com>
In-Reply-To
<13798dfb121c9631e9d811f5f74f9a78c1fcfdf9.1597406877.git.martin.agren@gmail.com>
Martin Ågren <martin.agren@gmail.com> writes:
Show 26 quoted lines
> Two of our extensions contain "sha1" in their names, but that's
> historical. The "want"s will take object names that are not necessarily
> SHA-1s. Make this clear, but also make it clear how there's still just
> one correct hash algo: These extensions don't somehow make the "want"s
> take object names derived using *any* hash algorithm.
>
> Signed-off-by: Martin Ågren <martin.agren@gmail.com>
> ---
>  Documentation/technical/protocol-capabilities.txt | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/technical/protocol-capabilities.txt b/Documentation/technical/protocol-capabilities.txt
> index 36ccd14f97..47f1b30090 100644
> --- a/Documentation/technical/protocol-capabilities.txt
> +++ b/Documentation/technical/protocol-capabilities.txt
> @@ -324,15 +324,18 @@ allow-tip-sha1-in-want
>  ----------------------
>  
>  If the upload-pack server advertises this capability, fetch-pack may
> -send "want" lines with SHA-1s that exist at the server but are not
> -advertised by upload-pack.
> +send "want" lines with object names that exist at the server but are not
> +advertised by upload-pack. (Note that the name of the capability
> +contains "sha1", but that it's more general than that: in SHA-1
> +repositories, the "want" lines provide SHA-1 values, but in SHA-256
> +repositories, they provide SHA-256 values.)

I think we should have either a new sha256 capability or a more generic hash-algo capability whose value can be set to sha256. Neither the connection initiators or the acceptors should talk in sha256 until both ends agreed to do so.

I do not think of any other way to make sure hosting sites to serve projects that migrate at different pace. Per project, you might be able to have a flag day. You cannot have a flag day that spans the world.

Previous: Martin ÅgrenNext: Martin Ågren
Message 21 of 35 in “Documentation updates for SHA-256”
  1. 0/2 Documentation updates for SHA-256brian m. carlson, Aug 13, 2020
  2. 1/2 docs: document SHA-256 pack and indicesbrian m. carlson, Aug 13, 2020
  3. Derrick StoleeAug 14, 2020
  4. 2/2 docs: fix step in transition planbrian m. carlson, Aug 13, 2020
  5. Martin ÅgrenAug 14, 2020
  6. Derrick StoleeAug 14, 2020
  7. Junio C HamanoAug 14, 2020
  8. brian m. carlsonAug 14, 2020
  9. Junio C HamanoAug 14, 2020
  10. 0/5 more SHA-256 documentationMartin Ågren, Aug 14, 2020
  11. 1/5 http-protocol.txt: document SHA-256 "want"/"have" formatMartin Ågren, Aug 14, 2020
  12. Junio C HamanoAug 14, 2020
  13. brian m. carlsonAug 14, 2020
  14. Martin ÅgrenAug 14, 2020
  15. Junio C HamanoAug 14, 2020
  16. Junio C HamanoAug 14, 2020
  17. 4/5 shallow.txt: document SHA-256 shallow formatMartin Ågren, Aug 14, 2020
  18. 3/5 protocol-capabilities.txt: clarify "allow-x-sha1-in-want" re SHA-256Martin Ågren, Aug 14, 2020
  19. Derrick StoleeAug 14, 2020
  20. Martin ÅgrenAug 14, 2020
  21. Junio C HamanoAug 14, 2020
  22. Martin ÅgrenAug 14, 2020
  23. Junio C HamanoAug 14, 2020
  24. 5/5 commit-graph-format.txt: fix "Hash Version" descriptionMartin Ågren, Aug 14, 2020
  25. Derrick StoleeAug 14, 2020
  26. Martin ÅgrenAug 14, 2020
  27. 2/5 index-format.txt: document SHA-256 index formatMartin Ågren, Aug 14, 2020
  28. Derrick StoleeAug 14, 2020
  29. Martin ÅgrenAug 14, 2020
  30. brian m. carlsonAug 14, 2020
  31. 0/4 more SHA-256 documentationMartin Ågren, Aug 15, 2020
  32. 2/4 index-format.txt: document SHA-256 index formatMartin Ågren, Aug 15, 2020
  33. 3/4 protocol-capabilities.txt: clarify "allow-x-sha1-in-want" re SHA-256Martin Ågren, Aug 15, 2020
  34. 4/4 shallow.txt: document SHA-256 shallow formatMartin Ågren, Aug 15, 2020
  35. 1/4 http-protocol.txt: document SHA-256 "want"/"have" formatMartin Ågren, Aug 15, 2020

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