From: Stefan Kangas <stefankangas@gmail.com>
To: Paul Eggert <eggert@cs.ucla.edu>
Cc: 58472@debbugs.gnu.org, Matt Armstrong <matt@rfc20.org>
Subject: bug#58472: [PATCH] Make `message-unique-id' less prone to collisions
Date: Fri, 14 Oct 2022 11:22:15 +0200 [thread overview]
Message-ID: <CADwFkm=SeFor7SV2AoV83pHRZyo+d0xesrBLW1BLm8srpFPvtQ@mail.gmail.com> (raw)
In-Reply-To: <caa7d03f-68e4-7c24-80c7-e272c456f733@cs.ucla.edu>
Paul Eggert <eggert@cs.ucla.edu> writes:
> 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.
OK, let's use only random data.
> 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==").
Sounds good to me, but:
The only reference I find to `iv-auto' is in (info "(elisp) Format of
GnuTLS Cryptography Inputs"). The `secure-hash' OBJECT parameter is
documented like this:
The argument OBJECT should be a buffer or a string.
Is the documentation incomplete?
> As an aside, it's weird that there's no easy way to ask Emacs for an
> N-bit random integer, where the randomness is taken from system entropy.
> Shouldn't we extend Emacs to support that? E.g., (make-string 128
> 'iv-auto) could give you an N-byte entropy-derived random string, or
> (random -N) could give you an N-bit entropy-derived random nonnegative
> integer, or something like that. Then we could write something like this:
>
> (base64-encode-string (make-string 16 'iv-auto))
>
> to get a Message-ID component with 16 bytes (128 bits) of entropy.
Yes, we should find a better interface here.
We also have `cl-random', which I think support float values. Perhaps
`random' should do the same? (See also Bug#9103.)
Oh, and whatever we do, we should probably also document it in `(elisp)
Random Numbers'.
next prev parent reply other threads:[~2022-10-14 9:22 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 [this message]
2022-10-16 7:32 ` Stefan Kangas
2022-10-16 17:05 ` Stefan Kangas
2022-10-16 15:19 ` Matt Armstrong
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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