From: Taylor Blau <me@ttaylorr.com> To: "brian m. carlson" <sandals@crustytoothpaste.net>, Jeff King <peff@peff.net>, git@vger.kernel.org Subject: Re: [PATCH 0/3] --end-of-options marker Date: Wed, 7 Aug 2019 12:54:31 -0400 Message-ID: <20190807165431.GA60876@syl.local> (raw) In-Reply-To: <20190807041749.GI118825@genre.crustytoothpaste.net> On Wed, Aug 07, 2019 at 04:17:49AM +0000, brian m. carlson wrote: > On 2019-08-06 at 23:43:20, Jeff King wrote: > > On Tue, Aug 06, 2019 at 10:58:53PM +0000, brian m. carlson wrote: > > > Sorry, I hadn't had a chance to look at this series in depth, but I was > > > wondering: could we not just accept two separate "--" arguments, and if > > > there are two of them, interpret the first with the traditional meaning > > > and the second with the Git-specific meaning? That would be much more > > > intuitive for folks, although I suspect it would take a little more work > > > in the options parser. > > > > That also crossed my mind, but I think it opens up some complicated > > corner cases. For instance, if I'm parsing left-to-right and see "--", > > how do I know which separator it is meant to be? I think the only rule > > that makes sense is that you must have two "--", like: > > > > git rev-list [options] -- [revs] -- [paths] > > I was assuming that we wouldn't have a huge number of command-line > arguments and we'd check ahead, although that could of course cause some > pain when used with xargs, I suppose, especially on Linux with its huge > ARG_MAX. > > > but that means parsing the whole thing before we can interpret any of > > it. What kinds of tricks can an attacker play by putting "--" in the > > revs or paths areas? E.g., what does this mean: > > > > # expanded from "git rev-list -- $revs -- $paths" > > git rev-list -- --foo -- -- --bar -- > > > > I think if we at least choose the left-most "--" as the official > > end-of-options then they can't inject an option (they can only inject a > > rev as a path). I guess that's the same as with --end-of-options. But it > > somehow feels less clear to me than a separate marker. This is definitely the secure option among the two, but I'm not sure that it makes me feel better about this alternative direction. I dislike the ambiguity in having two '--'s, and I don't think that this is something we ought to concern callers with. '--end-of-options' is on the one hand, cumbersome to write, but it is clear. I think that this is an acceptable trade-off, because we don't expect users at the command line to ever type this. So, some extra clarity in favor of a drop in convenience for a supposedly smaller number of use cases seems like a favorable trade-off to me. > I suppose if there's more than two, then interpret the first one as the > end-of-options marker, the second one in the traditional way, and any > subsequent ones as pathspecs matching the file "--". Writing such a > command line would be silly, but we'd fail secure. > > > It also doesn't allow this: > > > > # allow paths and revs, with optional separator, but no more options > > git rev-list --end-of-options "$@" > > > > though I'm not sure whether anybody cares. > > That's a good point. I don't have a strong view either way, but I > thought I'd ask about alternatives. > -- > brian m. carlson: Houston, Texas, US > OpenPGP: https://keybase.io/bk2204 Thanks, Taylor
next prev parent reply other threads:[~2019-08-07 16:54 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-08-06 14:38 Jeff King 2019-08-06 14:39 ` [PATCH 1/3] revision: allow --end-of-options to end option parsing Jeff King 2019-08-06 14:40 ` [PATCH 2/3] parse-options: allow --end-of-options as a synonym for "--" Jeff King 2019-08-06 14:40 ` [PATCH 3/3] gitcli: document --end-of-options Jeff King 2019-08-06 16:24 ` [PATCH 0/3] --end-of-options marker Junio C Hamano 2019-08-06 16:36 ` Randall S. Becker 2019-08-06 17:38 ` Jeff King 2019-08-06 17:58 ` Randall S. Becker 2019-08-06 18:14 ` SZEDER Gábor 2019-08-08 10:03 ` Jeff King 2019-08-06 17:33 ` Jeff King 2019-08-06 22:58 ` brian m. carlson 2019-08-06 23:43 ` Jeff King 2019-08-07 4:17 ` brian m. carlson 2019-08-07 16:54 ` Taylor Blau [this message] 2019-08-08 10:28 ` Jeff King
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style List information: http://vger.kernel.org/majordomo-info.html * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20190807165431.GA60876@syl.local \ --to=me@ttaylorr.com \ --cc=git@vger.kernel.org \ --cc=peff@peff.net \ --cc=sandals@crustytoothpaste.net \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
git@vger.kernel.org list mirror (unofficial, one of many) This inbox may be cloned and mirrored by anyone: git clone --mirror https://public-inbox.org/git git clone --mirror http://ou63pmih66umazou.onion/git git clone --mirror http://czquwvybam4bgbro.onion/git git clone --mirror http://hjrcffqmbrq6wope.onion/git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V1 git git/ https://public-inbox.org/git \ git@vger.kernel.org public-inbox-index git Example config snippet for mirrors. Newsgroups are available over NNTP: nntp://news.public-inbox.org/inbox.comp.version-control.git nntp://ou63pmih66umazou.onion/inbox.comp.version-control.git nntp://czquwvybam4bgbro.onion/inbox.comp.version-control.git nntp://hjrcffqmbrq6wope.onion/inbox.comp.version-control.git nntp://news.gmane.io/gmane.comp.version-control.git note: .onion URLs require Tor: https://www.torproject.org/ code repositories for the project(s) associated with this inbox: https://80x24.org/mirrors/git.git AGPL code for this site: git clone https://public-inbox.org/public-inbox.git