On 04/12/2022 06:33, Victor Sudakov via Exim-users wrote:
> I have sent 10 short messages from the library.tomsk.ru host:
>
> echo "test test" | mail -s "test test" vas@XXXXXX vas@YYYYYY
>
> and its 10 times dkim=pass on FreeBSD and 10 times dkim=fail on Debian
> so I guess it's consistent.
>
> However, I've noticed that when I send a larger mail, like
>
> uuencode /usr/bin/vi vi | mail -s "test test" vas@XXXXXX vas@YYYYYY
>
> then 10 of the 10 mails on Debian have dkim=pass. So the message size
> or encoding is envolved somehow? What gives?
So. Size-dependent, rx-end dependent, and seems consistently reproducible.
Could be the library used for hashing the body, or the way it's being
driven, or the exact sizes of chunks of body being handed it.
> FreeBSD sender:
> Compiler: CLang [10.0.1 (git@???:llvm/llvm-project.git llvmorg-10.0.1-0-gef32c611aa2)]
> Probably Berkeley DB version 1.8x (native mode)
> Library version: OpenSSL: Compile: OpenSSL 1.1.1l-freebsd 24 Aug 2021
> Runtime: OpenSSL 1.1.1l-freebsd 24 Aug 2021
> : built on: reproducible build, date unspecified
> FreeBSD receiver:
>
> Compiler: CLang [10.0.1 (git@???:llvm/llvm-project.git llvmorg-10.0.1-0-gef32c611aa2)]
> Probably Berkeley DB version 1.8x (native mode)
> Library version: OpenSSL: Compile: OpenSSL 1.1.1l-freebsd 24 Aug 2021
> Runtime: OpenSSL 1.1.1l-freebsd 24 Aug 2021
> : built on: reproducible build, date unspecified
> Debian receiver YYYYYY:
>
> Compiler: GCC [10.2.1 20210110]
> Library version: GnuTLS: Compile: 3.7.1
> Runtime: 3.7.1
A test here does not fail:
Sender:
FreeBSD 13.0-ALPHA3
Exim version: 4.96+ (44b6e099b76f403a55e77650821f8a69e9d2682e)
Compiler: CLang [11.0.1 (git@???:llvm/llvm-project.git llvmorg-11.0.1-0-g43ff75f2c3fe)]
OpenSSL 1.1.1i-freebsd 8 Dec 2020
Command-line exim initiation, stdin from "echo -e 'Subject: test\n\nSmall body\n'"
DKIM used ed25519-sha256
Receiver A:
Debian 11
Debian 5.10.127-1 (2022-06-30)
Exim version: 4.96+ (44b6e099b76f403a55e77650821f8a69e9d2682e)
Compiler: GCC [10.2.1 20210110]
GnuTLS: Compile: 3.7.1
Runtime: 3.7.1
Log line: DKIM: d=wizmail.org s=e202001 c=relaxed/relaxed a=ed25519-sha256 b=512 [verification succeeded
Receiver B:
Debian 11
Debian 5.10.127-1 (2022-06-30)
Exim version: 4.96+ (44b6e099b76f403a55e77650821f8a69e9d2682e)
Compiler: GCC [10.2.1 20210110]
OpenSSL: Compile: OpenSSL 1.1.1n 15 Mar 2022
Log line: DKIM: d=wizmail.org s=e202001 c=relaxed/relaxed a=ed25519-sha256 b=512 [verification succeeded]
The body-hash differing implies, I think, that the signature algorithm isn't
involved. I was using sha256; what's yours?
I guess there's also the dkim canonicalisation. Mine was relaxed/relaxed. Yours?
Can you set up the receiver exim with debug enabled? Either commandline option
or ACL modifier can be used to enable that, the latter having the benefit of
being able to only trace certain classes of connection. The interesting part
would be the DKIM receive processing, which is in the debug "acl" channel.
--
Cheers,
Jeremy
