From: Johannes Schindelin <Johannes.Schindelin@gmx•de>
To: Junio C Hamano <gitster@pobox•com>
Cc: Jeff King <peff@peff•net>,
"brian m. carlson" <sandals@crustytoothpaste•net>,
Patrick Steinhardt <ps@pks•im>,
Johannes Schindelin via GitGitGadget <gitgitgadget@gmail•com>,
git@vger•kernel.org, Phillip Wood <phillip.wood123@gmail•com>,
Andreas Schwab <schwab@linux-m68k•org>,
Ondrej Pohorelsky <opohorel@redhat•com>
Subject: Re: [PATCH v2 4/4] sideband: add options to allow more control sequences to be passed through
Date: Fri, 16 Jan 2026 00:12:47 +0100 (CET) [thread overview]
Message-ID: <c0af9072-cf21-a7e2-5b78-eb70217b462c@gmx.de> (raw)
In-Reply-To: <xmqqa4yeblsx.fsf@gitster.g>
Hi Junio, Jeff, and other interested parties,
On Thu, 15 Jan 2026, Junio C Hamano wrote:
> Jeff King <peff@peff•net> writes:
>
> > Is there any reason we cannot introduce the new functionality as a
> > config option but _not_ enable it by default?
> >
> > That gives people the tools to protect themselves if they want to bear
> > the potential cost. It just feels a shame to deny them the tool because
> > we can't agree on the default.
>
> Yeah, I like the suggestion---making it opt-in would have much less
> chance of breaking set-up people are relying on all of a sudden.
Can you help me understand how these existing use cases (which are not
actually in wide-spread use) aren't broken by design, given that they have
no chance to ensure that their ANSI sequences go to an actual terminal
that can understand those sequences?
As such, it looks to me as if they have a valid goal, but go about it in a
way that is easily improved: If they want color in their sideband output,
then Git has to be taught about it, much in the same way as bf1a11f0a10
(sideband: highlight keywords in remote sideband output, 2018-08-07)
taught Git to highlight keywords in the remote sideband output. That is
the actual correct way to do this, not by expecting Git to pass through
all bytes to the terminal without sanitizing, which is a well-known worst
practice (not even GNU tar does that when listing the contents of an
archive, nor does cURL do that, just to list two of the command-line
programs that sanitize properly what they pass on to the terminal).
Given that those use cases are rare (none of the popular Git forges
support this!), and that it is a security issue, I still think that the
default should be as I proposed: To pass through only a small subset of
ANSI control sequences that you gentle people already agreed should be
safe.
Keep in mind that I already accommodated the concern that has been raised
over and over again about _a few_ pre-receive hooks out there making their
errors colorful, by making the default so that color sequences are
actually passed through! In light of that, I am a bit puzzled how much
more you want to be passed through by default, it sounds as if you want to
turn off all sanitizing by default, even if not a single of those
(uncommon) use cases that have been raised need anything else than ANSI
color sequences to be passed through, and even if passing through control
sequences to the terminal completely unsanitized is insecure.
Ciao,
Johannes
next prev parent reply other threads:[~2026-01-15 23:12 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-14 18:19 [PATCH 0/3] Sanitize sideband channel messages Johannes Schindelin via GitGitGadget
2025-01-14 18:19 ` [PATCH 1/3] sideband: mask control characters Johannes Schindelin via GitGitGadget
2025-01-15 14:49 ` Phillip Wood
2025-12-02 15:43 ` Johannes Schindelin
2025-01-15 15:17 ` Andreas Schwab
2025-01-15 16:24 ` Junio C Hamano
2025-01-14 18:19 ` [PATCH 2/3] sideband: introduce an "escape hatch" to allow " Johannes Schindelin via GitGitGadget
2025-01-14 18:19 ` [PATCH 3/3] sideband: do allow ANSI color sequences by default Johannes Schindelin via GitGitGadget
2025-01-14 22:50 ` [PATCH 0/3] Sanitize sideband channel messages brian m. carlson
2025-01-16 6:45 ` Junio C Hamano
2025-01-28 16:03 ` Ondrej Pohorelsky
2025-01-31 17:55 ` Junio C Hamano
2025-12-02 14:11 ` Johannes Schindelin
2025-12-03 0:47 ` brian m. carlson
2025-12-03 8:04 ` Johannes Schindelin
2025-01-15 14:49 ` Phillip Wood
2025-12-02 14:56 ` Johannes Schindelin
2025-12-17 14:23 ` [PATCH v2 0/4] " Johannes Schindelin via GitGitGadget
2025-12-17 14:23 ` [PATCH v2 1/4] sideband: mask control characters Johannes Schindelin via GitGitGadget
2026-01-09 12:38 ` Patrick Steinhardt
2026-01-16 19:29 ` Johannes Schindelin
2025-12-17 14:23 ` [PATCH v2 2/4] sideband: introduce an "escape hatch" to allow " Johannes Schindelin via GitGitGadget
2025-12-18 2:22 ` Junio C Hamano
2025-12-18 17:59 ` Johannes Schindelin
2025-12-19 13:33 ` Junio C Hamano
2026-01-16 19:25 ` Johannes Schindelin
2026-01-09 12:38 ` Patrick Steinhardt
2025-12-17 14:23 ` [PATCH v2 3/4] sideband: do allow ANSI color sequences by default Johannes Schindelin via GitGitGadget
2026-01-09 12:38 ` Patrick Steinhardt
2026-01-16 19:38 ` Johannes Schindelin
2025-12-17 14:23 ` [PATCH v2 4/4] sideband: add options to allow more control sequences to be passed through Johannes Schindelin via GitGitGadget
2026-01-09 12:38 ` Patrick Steinhardt
2026-01-10 17:26 ` brian m. carlson
2026-01-15 21:14 ` Jeff King
2026-01-15 21:36 ` Junio C Hamano
2026-01-15 23:12 ` Johannes Schindelin [this message]
2026-01-16 6:45 ` Patrick Steinhardt
2026-01-16 12:12 ` Ondrej Pohorelsky
2026-01-16 15:21 ` Junio C Hamano
2026-01-16 18:46 ` Johannes Schindelin
2026-01-16 19:24 ` Junio C Hamano
2026-01-19 7:20 ` Patrick Steinhardt
2026-01-19 22:16 ` brian m. carlson
2026-01-20 2:41 ` D. Ben Knoble
2026-01-20 17:05 ` Junio C Hamano
2026-01-20 19:31 ` Jeff King
2026-01-20 20:11 ` Junio C Hamano
2026-01-21 7:39 ` Patrick Steinhardt
2026-01-22 12:29 ` Johannes Schindelin
2026-01-22 17:58 ` Junio C Hamano
2026-01-15 23:10 ` brian m. carlson
2026-02-03 1:11 ` Junio C Hamano
2026-02-03 7:12 ` Johannes Schindelin
2026-02-03 19:00 ` Junio C Hamano
2026-02-04 19:35 ` Junio C Hamano
2026-01-16 19:47 ` Johannes Schindelin
2026-01-16 22:26 ` [PATCH v3 0/5] Sanitize sideband channel messages Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 1/5] sideband: mask control characters Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 2/5] sideband: introduce an "escape hatch" to allow " Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 3/5] sideband: do allow ANSI color sequences by default Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 4/5] sideband: add options to allow more control sequences to be passed through Johannes Schindelin via GitGitGadget
2026-01-16 22:26 ` [PATCH v3 5/5] sideband: offer to configure sanitizing on a per-URL basis Johannes Schindelin via GitGitGadget
2026-01-16 22:32 ` [PATCH v3 0/5] Sanitize sideband channel messages Johannes Schindelin
2026-02-03 10:17 ` [PATCH v4 0/6] " Johannes Schindelin via GitGitGadget
2026-02-03 10:17 ` [PATCH v4 1/6] sideband: mask control characters Johannes Schindelin via GitGitGadget
2026-02-03 10:17 ` [PATCH v4 2/6] sideband: introduce an "escape hatch" to allow " Johannes Schindelin via GitGitGadget
2026-02-03 10:17 ` [PATCH v4 3/6] sideband: do allow ANSI color sequences by default Johannes Schindelin via GitGitGadget
2026-02-03 10:18 ` [PATCH v4 4/6] sideband: add options to allow more control sequences to be passed through Johannes Schindelin via GitGitGadget
2026-02-03 10:18 ` [PATCH v4 5/6] sideband: offer to configure sanitizing on a per-URL basis Johannes Schindelin via GitGitGadget
2026-02-03 10:18 ` [PATCH v4 6/6] sideband: delay sanitizing by default to Git v3.0 Johannes Schindelin via GitGitGadget
2026-02-04 19:26 ` [PATCH v4 0/6] Sanitize sideband channel messages Junio C Hamano
2026-02-05 14:48 ` Junio C Hamano
2026-02-13 23:50 ` Junio C Hamano
2026-03-02 18:11 ` [PATCH 0/3] Sanitizing sideband output Junio C Hamano
2026-03-02 18:11 ` [PATCH 1/3] sideband: drop 'default' configuration Junio C Hamano
2026-03-02 18:11 ` [PATCH 2/3] sideband: delay sanitizing by default to Git v3.0 Junio C Hamano
2026-03-02 18:11 ` [PATCH 3/3] sideband: conditional documentation fix Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 0/7] Sanitizing sideband output Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 1/7] sideband: mask control characters Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 2/7] sideband: introduce an "escape hatch" to allow " Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 3/7] sideband: do allow ANSI color sequences by default Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 4/7] sideband: add options to allow more control sequences to be passed through Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 5/7] sideband: offer to configure sanitizing on a per-URL basis Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 6/7] sideband: drop 'default' configuration Junio C Hamano
2026-03-05 23:34 ` [PATCH v5 7/7] sideband: delay sanitizing by default to Git v3.0 Junio C Hamano
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