Re: [PATCH] documentation: add git transport security notice
- From
Fraser Tweedale <frase@frase.id.au>
- Date
- Jun 24, 2013, 21:57 UTC
- Message-ID
- <20130624215733.GU2457@bacardi.hollandpark.frase.id.au>
- In-Reply-To
- <7vppvbbhoi.fsf@alter.siamese.dyndns.org>
On Mon, Jun 24, 2013 at 09:24:29AM -0700, Junio C Hamano wrote:
Show 31 quoted lines
> Fraser Tweedale <frase@frase.id.au> writes: > > > The fact that the git transport has no end-to-end security is easily > > overlooked. Add a brief security notice to the "GIT URLS" section > > of the documentation stating that the git transport should be used > > with caution on unsecured networks. > > > > Signed-off-by: Fraser Tweedale <frase@frase.id.au> > > --- > > Documentation/urls.txt | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/Documentation/urls.txt b/Documentation/urls.txt > > index 3ca122f..c218af5 100644 > > --- a/Documentation/urls.txt > > +++ b/Documentation/urls.txt > > @@ -11,6 +11,9 @@ and ftps can be used for fetching and rsync can be used for fetching > > and pushing, but these are inefficient and deprecated; do not use > > them). > > > > +The git protocol provides no end-to-end security and should be used > > +with caution on unsecured networks. > > Is this necessary? > > I thought we already say the git protocol does not even authenticate > elsewhere in the document, and if not, I think it is a sensible > thing to say here. And once it is done, I doubt it is necessary to > bring up a narrower concept such as "end-to-end security" which > requires a lot more than authentication. >
Certainly in this part of the documentation there is no mention of (lack of) authentication or security concerns. git-daemon(1) does mention the lack of authentication in the SERVICES/receive-pack section.
Once you are aware that the git transport is insecure it seems obvious in hindsight, but even as a security-minded person I simply overlooked this until recently. A brief note in the GIT URLS section (which is included in the man pages for a number of essential commands) would have brought this to my attention much sooner.
Junio, do you prefer the following more generic wording? If so I will re-roll the patch (also note s/protocol/transport/ which is more appropriate, I think).
The git transport is insecure and should be used with caution on unsecured networks.
Show 17 quoted lines
> The only thing git protocol ensures is that the receiving end > validates that what is fetched from an unknown server, and what is > pushed by an unknown pusher, is internally consistent. > > If you allowed a push over the git protocol by enabling the > receive-pack service in "git daemon" (not recommended), you may > allow anonymous users to delete branches and to do other funky > things unless you protect your repository with pre-receive hook, but > that won't corrupt the repository (of course, deleting all the refs > may make the repository an empty but not corrupt one, which is just > as unusable as a corrupt one, so there may not be a huge practical > difference). If you fetched from an unauthenticated server, > possibly with MITM, over the git protocol, you may end up getting > something you did not ask for, but the resulting history in your > repository would still be internally consistent (the commits may be > malicious ones, of course, but that is what signed tags are there to > protect you against).