From: Matt Armstrong <matt@rfc20.org>
To: Paul Eggert <eggert@cs.ucla.edu>, Stefan Kangas <stefankangas@gmail.com>
Cc: 58472@debbugs.gnu.org
Subject: bug#58472: [PATCH] Make `message-unique-id' less prone to collisions
Date: Sun, 16 Oct 2022 08:19:57 -0700 [thread overview]
Message-ID: <871qr794o2.fsf@rfc20.org> (raw)
In-Reply-To: <caa7d03f-68e4-7c24-80c7-e272c456f733@cs.ucla.edu>
Paul Eggert <eggert@cs.ucla.edu> writes:
> On 2022-10-12 19:46, Stefan Kangas wrote:
>
>> The main goal is to avoid collisions, but using the time also gives an
>> idea of when the message was sent, which is kind of nice.
>
> That info is in the Date: line, along with zillions of other Received:
> lines. There should be no need to repeat it in the Message-ID line.
>
>> Time also
>> guarantees a somewhat unique value even if the user has happened to set
>> the random seed.
>
> If that's a concern, we should be using more-random data, e.g., with
>
> (base64-encode-string
> (secure-hash 'md5 'iv-auto 128 nil t))
>
> if we want 128 bits of randomness (this yields a string like
> "B8a3usyu5QSE/rTLu0nIHg==").
Small suggestion: `base64-url-encode-string` avoids any trailing `===`
and uses slightly preferable non-alnum chars (I think).
But both can generate Message-Id with "command line switch" chars:
either ?- or ?/. Since some tools expect users to work directly with
Message-ID at times (https://notmuchmail.org/) it might be nice to avoid
leading non-alnum chars, and possibly avoid '-' to avoid any confusion
with a UUID (in the sense of the schema defined by the RFC standard).
Maybe a base 62 encoder could be written just for this, as Emacs'
version of this doesn't need to be fast. Can a string be turned into a
non-negative bignum integer in (simple) elisp?
--
matt (sent from an Emacs running the feature/noverlay branch)
next prev parent reply other threads:[~2022-10-16 15:19 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-12 16:07 bug#58472: [PATCH] Make `message-unique-id' less prone to collisions Stefan Kangas
2022-10-12 18:08 ` Paul Eggert
2022-10-13 2:46 ` Stefan Kangas
2022-10-13 4:53 ` Matt Armstrong
2022-10-13 12:10 ` Stefan Kangas
2022-10-13 16:35 ` Matt Armstrong
2022-10-13 16:38 ` Paul Eggert
2022-10-14 9:22 ` Stefan Kangas
2022-10-13 16:21 ` Paul Eggert
2022-10-14 9:22 ` Stefan Kangas
2022-10-16 7:32 ` Stefan Kangas
2022-10-16 17:05 ` Stefan Kangas
2022-10-16 15:19 ` Matt Armstrong [this message]
2022-10-16 16:49 ` Stefan Kangas
2022-10-17 6:17 ` Matt Armstrong
2022-10-17 7:30 ` Paul Eggert
2022-10-17 8:14 ` Stefan Kangas
2022-10-17 8:23 ` Eli Zaretskii
2022-10-17 18:47 ` Matt Armstrong
2022-10-17 8:16 ` Eli Zaretskii
2022-10-17 8:29 ` Lars Ingebrigtsen
2022-10-17 8:34 ` Eli Zaretskii
2022-10-17 9:30 ` Stefan Kangas
2022-10-17 11:22 ` Lars Ingebrigtsen
2022-10-17 15:40 ` Stefan Kangas
2022-11-25 1:26 ` Stefan Kangas
2022-10-17 18:40 ` Matt Armstrong
2022-10-18 1:38 ` Paul Eggert
2022-10-18 14:05 ` Eli Zaretskii
2022-10-13 11:45 ` Lars Ingebrigtsen
2022-10-13 12:10 ` Stefan Kangas
2022-10-13 19:15 ` Lars Ingebrigtsen
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