The server-end of the v2 protocol to serve "git clone" and "git
fetch" was not prepared to see a delim packets at unexpected
places, which led to a crash.
* jk/harden-protocol-v2-delim-handling:
test-lib-functions: simplify packetize() stdin code
upload-pack: handle unexpected delim packets
test-lib-functions: make packetize() more efficient
Utitiles run via the run_command() API were not spawned correctly
on Cygwin, when the paths to them are given as a full path with
backslashes.
* ak/run-command-on-cygwin-fix:
run-command: trigger PATH lookup properly on Cygwin
When fed a midx that records no objects, some codepaths tried to
loop from 0 through (num_objects-1), which, due to integer
arithmetic wrapping around, made it nonsense operation with out of
bounds array accesses. The code has been corrected to reject such
an midx file.
* dr/midx-avoid-int-underflow:
midx.c: fix an integer underflow
Simplify the commit ancestry connectedness check in a partial clone
repository in which "promised" objects are assumed to be obtainable
lazily on-demand from promisor remote repositories.
* jt/connectivity-check-optim-in-partial-clone:
connected: always use partial clone optimization
"git p4" learned four new hooks and also "--no-verify" option to
bypass them (and the existing "p4-pre-submit" hook).
* bk/p4-pre-edit-changelist:
git-p4: add RCS keyword status message
git-p4: add p4 submit hooks
git-p4: restructure code in submit
git-p4: add --no-verify option
git-p4: add p4-pre-submit exit text
git-p4: create new function run_git_hook
git-p4: rewrite prompt to be Windows compatible
The import-tars importer (in contrib/fast-import/) used to create
phony files at the top-level of the repository when the archive
contains global PAX headers, which made its own logic to detect and
omit the common leading directory ineffective, which has been
corrected.
* js/import-tars-do-not-make-phony-files-from-pax-headers:
import-tars: ignore the global PAX header
Enable tests that require GnuPG on Windows.
* js/tests-gpg-integration-on-windows:
tests: increase the verbosity of the GPG-related prereqs
tests: turn GPG, GPGSM and RFC1991 into lazy prereqs
tests: do not let lazy prereqs inside `test_expect_*` turn off tracing
t/lib-gpg.sh: stop pretending to be a stand-alone script
tests(gpg): allow the gpg-agent to start on Windows
Git's URL parser interprets
https:///example.com/repo.git
to have no host and a path of "example.com/repo.git". Curl, on the
other hand, internally redirects it to https://example.com/repo.git. As
a result, until "credential: parse URL without host as empty host, not
unset", tricking a user into fetching from such a URL would cause Git to
send credentials for another host to example.com.
Teach fsck to block and detect .gitmodules files using such a URL to
prevent sharing them with Git versions that are not yet protected.
A relative URL in a .gitmodules file could also be used to trigger this.
The relative URL resolver used for .gitmodules does not normalize
sequences of slashes and can follow ".." components out of the path part
and to the host part of a URL, meaning that such a relative URL can be
used to traverse from a https://foo.example.com/innocent superproject to
a https:///attacker.example.com/exploit submodule. Fortunately,
redundant extra slashes in .gitmodules are rare, so we can catch this by
detecting one after a leading sequence of "./" and "../" components.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Until "credential: refuse to operate when missing host or protocol",
Git's credential handling code interpreted URLs with empty scheme to
mean "give me credentials matching this host for any protocol".
Luckily libcurl does not recognize such URLs (it tries to look for a
protocol named "" and fails). Just in case that changes, let's reject
them within Git as well. This way, credential_from_url is guaranteed to
always produce a "struct credential" with protocol and host set.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
libcurl permits making requests without a URL scheme specified. In
this case, it guesses the URL from the hostname, so I can run
git ls-remote http::ftp.example.com/path/to/repo
and it would make an FTP request.
Any user intentionally using such a URL is likely to have made a typo.
Unfortunately, credential_from_url is not able to determine the host and
protocol in order to determine appropriate credentials to send, and
until "credential: refuse to operate when missing host or protocol",
this resulted in another host's credentials being leaked to the named
host.
Teach credential_from_url_gently to consider such a URL to be invalid
so that fsck can detect and block gitmodules files with such URLs,
allowing server operators to avoid serving them to downstream users
running older versions of Git.
This also means that when such URLs are passed on the command line, Git
will print a clearer error so affected users can switch to the simpler
URL that explicitly specifies the host and protocol they intend.
One subtlety: .gitmodules files can contain relative URLs, representing
a URL relative to the URL they were cloned from. The relative URL
resolver used for .gitmodules can follow ".." components out of the path
part and past the host part of a URL, meaning that such a relative URL
can be used to traverse from a https://foo.example.com/innocent
superproject to a https::attacker.example.com/exploit submodule.
Fortunately a leading ':' in the first path component after a series of
leading './' and '../' components is unlikely to show up in other
contexts, so we can catch this by detecting that pattern.
Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
When we try to initialize credential loading by URL and find that the
URL is invalid, we set all fields to NULL in order to avoid acting on
malicious input. Later when we request credentials, we diagonse the
erroneous input:
fatal: refusing to work with credential missing host field
This is problematic in two ways:
- The message doesn't tell the user *why* we are missing the host
field, so they can't tell from this message alone how to recover.
There can be intervening messages after the original warning of
bad input, so the user may not have the context to put two and two
together.
- The error only occurs when we actually need to get a credential. If
the URL permits anonymous access, the only encouragement the user gets
to correct their bogus URL is a quiet warning.
This is inconsistent with the check we perform in fsck, where any use
of such a URL as a submodule is an error.
When we see such a bogus URL, let's not try to be nice and continue
without helpers. Instead, die() immediately. This is simpler and
obviously safe. And there's very little chance of disrupting a normal
workflow.
It's _possible_ that somebody has a legitimate URL with a raw newline in
it. It already wouldn't work with credential helpers, so this patch
steps that up from an inconvenience to "we will refuse to work with it
at all". If such a case does exist, we should figure out a way to work
with it (especially if the newline is only in the path component, which
we normally don't even pass to helpers). But until we see a real report,
we're better off being defensive.
Reported-by: Carlo Arenas <carenas@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
In 07259e74ec (fsck: detect gitmodules URLs with embedded newlines,
2020-03-11), git fsck learned to check whether URLs in .gitmodules could
be understood by the credential machinery when they are handled by
git-remote-curl.
However, the check is overbroad: it checks all URLs instead of only
URLs that would be passed to git-remote-curl. In principle a git:// or
file:/// URL does not need to follow the same conventions as an http://
URL; in particular, git:// and file:// protocols are not succeptible to
issues in the credential API because they do not support attaching
credentials.
In the HTTP case, the URL in .gitmodules does not always match the URL
that would be passed to git-remote-curl and the credential machinery:
Git's URL syntax allows specifying a remote helper followed by a "::"
delimiter and a URL to be passed to it, so that
git ls-remote http::https://example.com/repo.git
invokes git-remote-http with https://example.com/repo.git as its URL
argument. With today's checks, that distinction does not make a
difference, but for a check we are about to introduce (for empty URL
schemes) it will matter.
.gitmodules files also support relative URLs. To ensure coverage for the
https based embedded-newline attack, urldecode and check them directly
for embedded newlines.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
The credential helper protocol was designed to be very flexible: the
fields it takes as input are treated as a pattern, and any missing
fields are taken as wildcards. This allows unusual things like:
echo protocol=https | git credential reject
to delete all stored https credentials (assuming the helpers themselves
treat the input that way). But when helpers are invoked automatically by
Git, this flexibility works against us. If for whatever reason we don't
have a "host" field, then we'd match _any_ host. When you're filling a
credential to send to a remote server, this is almost certainly not what
you want.
Prevent this at the layer that writes to the credential helper. Add a
check to the credential API that the host and protocol are always passed
in, and add an assertion to the credential_write function that speaks
credential helper protocol to be doubly sure.
There are a few ways this can be triggered in practice:
- the "git credential" command passes along arbitrary credential
parameters it reads from stdin.
- until the previous patch, when the host field of a URL is empty, we
would leave it unset (rather than setting it to the empty string)
- a URL like "example.com/foo.git" is treated by curl as if "http://"
was present, but our parser sees it as a non-URL and leaves all
fields unset
- the recent fix for URLs with embedded newlines blanks the URL but
otherwise continues. Rather than having the desired effect of
looking up no credential at all, many helpers will return _any_
credential
Our earlier test for an embedded newline didn't catch this because it
only checked that the credential was cleared, but didn't configure an
actual helper. Configuring the "verbatim" helper in the test would show
that it is invoked (it's obviously a silly helper which doesn't look at
its input, but the point is that it shouldn't be run at all). Since
we're switching this case to die(), we don't need to bother with a
helper. We can see the new behavior just by checking that the operation
fails.
We'll add new tests covering partial input as well (these can be
triggered through various means with url-parsing, but it's simpler to
just check them directly, as we know we are covered even if the url
parser changes behavior in the future).
[jn: changed to die() instead of logging and showing a manual
username/password prompt]
Reported-by: Carlo Arenas <carenas@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
We may feed a URL like "cert:///path/to/cert.pem" into the credential
machinery to get the key for a client-side certificate. That
credential has no hostname field, which is about to be disallowed (to
avoid confusion with protocols where a helper _would_ expect a
hostname).
This means as of the next patch, credential helpers won't work for
unlocking certs. Let's fix that by doing two things:
- when we parse a url with an empty host, set the host field to the
empty string (asking only to match stored entries with an empty
host) rather than NULL (asking to match _any_ host).
- when we build a cert:// credential by hand, similarly assign an
empty string
It's the latter that is more likely to impact real users in practice,
since it's what's used for http connections. But we don't have good
infrastructure to test it.
The url-parsing version will help anybody using git-credential in a
script, and is easy to test.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Many of the tests in t0300 give partial inputs to git-credential,
omitting a protocol or hostname. We're checking only high-level things
like whether and how helpers are invoked at all, and we don't care about
specific hosts. However, in preparation for tightening up the rules
about when we're willing to run a helper, let's start using input that's
a bit more realistic: pretend as if http://example.com is being
examined.
This shouldn't change the point of any of the tests, but do note we have
to adjust the expected output to accommodate this (filling a credential
will repeat back the protocol/host fields to stdout, and the helper
debug messages and askpass prompt will change on stderr).
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
We test a toy credential helper that writes "quit=1" and confirms that
we stop running other helpers. However, that helper is unrealistic in
that it does not bother to read its stdin at all.
For now we don't send any input to it, because we feed git-credential a
blank credential. But that will change in the next patch, which will
cause this test to racily fail, as git-credential will get SIGPIPE
writing to the helper rather than exiting because it was asked to.
Let's make this one-off helper more like our other sample helpers, and
have it source the "dump" script. That will read stdin, fixing the
SIGPIPE problem. But it will also write what it sees to stderr. We can
make the test more robust by checking that output, which confirms that
we do run the quit helper, don't run any other helpers, and exit for the
reason we expected.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Git is an enormously flexible and powerful piece of software. However,
it can be intimidating for many users and there are a set of common
questions that users often ask. While we already have some new user
documentation, it's worth adding a FAQ to address common questions that
users often have. Even though some of this is addressed elsewhere in
the documentation, experience has shown that it is difficult for users
to find, so a centralized location is helpful.
Add such a FAQ and fill it with some common questions and answers.
While there are few entries now, we can expand it in the future to cover
more things as we find new questions that users have. Let's also add
section markers so that people answering questions can directly link
users to the proper answer.
The FAQ also addresses common configuration questions that apply not
only to Git as an independent piece of software but also the ecosystem
of CI tools and hosting providers that people use, since these are the
source of common questions. An attempt has been made to avoid
mentioning any particular provider or tool, but to nevertheless cover
common configurations that apply to a wide variety of such tools.
Note that the long lines for certain questions are required, since
Asciidoctor does not permit broken lines there.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With 50033772d5 ("connected: verify promisor-ness of partial clone",
2020-01-30), the fast path (checking promisor packs) in
check_connected() now passes a subset of the slow path (rev-list) - if
all objects to be checked are found in promisor packs, both the fast
path and the slow path will pass; otherwise, the fast path will
definitely not pass. This means that we can always attempt the fast path
whenever we need to do the slow path.
The fast path is currently guarded by a flag; therefore, remove that
flag. Also, make the fast path fallback to the slow path - if the fast
path fails, the failing OID and all remaining OIDs will be passed to
rev-list.
The main user-visible benefit is the performance of fetch from a partial
clone - specifically, the speedup of the connectivity check done before
the fetch. In particular, a no-op fetch into a partial clone on my
computer was sped up from 7 seconds to 0.01 seconds. This is a
complement to the work in 2df1aa239c ("fetch: forgo full
connectivity check if --filter", 2020-01-30), which is the child of the
aforementioned 50033772d5. In that commit, the connectivity check
*after* the fetch was sped up.
The addition of the fast path might cause performance reductions in
these cases:
- If a partial clone or a fetch into a partial clone fails, Git will
fruitlessly run rev-list (it is expected that everything fetched
would go into promisor packs, so if that didn't happen, it is most
likely that rev-list will fail too).
- Any connectivity checks done by receive-pack, in the (in my opinion,
unlikely) event that a partial clone serves receive-pack.
I think that these cases are rare enough, and the performance reduction
in this case minor enough (additional object DB access), that the
benefit of avoiding a flag outweighs these.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'pack.useSparse' configuration variable now defaults to 'true',
enabling an optimization that has been experimental since Git 2.21.
* ds/default-pack-use-sparse-to-true:
pack-objects: flip the use of GIT_TEST_PACK_SPARSE
config: set pack.useSparse=true by default
The code path in packetize() for reading stdin needs to handle NUL
bytes, so we can't rely on shell variables. However, the current code
takes a whopping 4 processes and uses a temporary file. We can do this
much more simply and efficiently by using a single perl invocation (and
we already rely on perl in the matching depacketize() function).
We'll keep the non-stdin code path as it is, since that uses zero extra
processes.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When verifying a midx index with 0 objects, the
m->num_objects - 1
underflows and wraps around to 4294967295.
Fix this both by checking that the midx contains at least one oid,
and also that we don't write any midx when there is no packfiles.
Update the tests to check that `git multi-pack-index write` does
not write an midx when there is no objects, and another to check
that `git multi-pack-index verify` warns when it verifies an midx with no
objects. For this last test, use t5319/no-objects.midx which was
generated by an older version of git.
Signed-off-by: Damien Robert <damien.olivier.robert+git@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 645c432d61 (pack-objects: use reachability bitmap index when
generating non-stdout pack, 2016-09-10) added two timing tests for
packing to an on-disk file, both with and without bitmaps. However, the
non-bitmap one isn't interesting to have as part of p5310's regression
suite. It _could_ be used as a baseline to show off the improvement in
the bitmap case, but:
- the point of the t/perf suite is to find performance regressions,
and it won't help with that. We don't compare the numbers between
two tests (which the perf suite has no idea are even related), and
any change in its numbers would have nothing to do with bitmaps.
- it did show off the improvement in the commit message of 645c432d61,
but it wasn't even necessary there. The bitmap case already shows an
improvement (because before the patch, it behaved the same as the
non-bitmap case), and the perf suite is even able to show the
difference between the before and after measurements.
On top of that, it's one of the most expensive tests in the suite,
clocking in around 60s for linux.git on my machine (as compared to 16s
for the bitmapped version). And by default when using "./run", we'd run
it three times!
So let's just drop it. It's not useful and is adding minutes to perf
runs.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When processing the arguments list for a v2 ls-refs or fetch command, we
loop like this:
while (packet_reader_read(request) != PACKET_READ_FLUSH) {
const char *arg = request->line;
...handle arg...
}
to read and handle packets until we see a flush. The hidden assumption
here is that anything except PACKET_READ_FLUSH will give us valid packet
data to read. But that's not true; PACKET_READ_DELIM or PACKET_READ_EOF
will leave packet->line as NULL, and we'll segfault trying to look at
it.
Instead, we should follow the more careful model demonstrated on the
client side (e.g., in process_capabilities_v2): keep looping as long
as we get normal packets, and then make sure that we broke out of the
loop due to a real flush. That fixes the segfault and correctly
diagnoses any unexpected input from the client.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The packetize() function takes its input on stdin, and requires 4
separate sub-processes to format a simple string. We can do much better
by getting the length via the shell's "${#packet}" construct. The one
caveat is that the shell can't put a NUL into a variable, so we'll have
to continue to provide the stdin form for a few calls.
There are a few other cleanups here in the touched code:
- the stdin form of packetize() had an extra stray "%s" when printing
the packet
- the converted calls in t5562 can be made simpler by redirecting
output as a block, rather than repeated appending
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There's no need for shell libraries to have the executable bit. They're
meant to be sourced, and running them stand-alone is pointless. Let's
reduce any possible confusion by making it more clear they're not meant
to be run this way.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The purpose of lib-credential.sh is to be sourced into other test
scripts. It doesn't need a "#!/bin/sh" line, as running it directly
makes no sense. Nor does it serve any real filetype documentation
purpose, as the file is clearly named with a ".sh" extension.
In the spirit of c74c72034f (test: replace shebangs with descriptions in
shell libraries, 2013-11-25), let's replace it with a human-readable
description.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On Cygwin, the codepath for POSIX-like systems is taken in
run-command.c::start_command(). The prepare_cmd() helper
function is called to decide if the command needs to be looked
up in the PATH. The logic there is to do the PATH-lookup if
and only if it does not have any slash '/' in it. If this test
passes we end up attempting to run the command by appending the
string after each colon-separated component of PATH.
The Cygwin environment supports both Windows and POSIX style
paths, so both forwardslahes '/' and back slashes '\' can be
used as directory separators for any external program the user
supplies.
Examples for path strings which are being incorrectly searched
for in the PATH instead of being executed as is:
- "C:\Program Files\some-program.exe"
- "a\b\c.exe"
To handle these, the PATH lookup detection logic in prepare_cmd()
is taught to know about this Cygwin quirk, by introducing
has_dir_sep(path) helper function to abstract away the difference
between true POSIX and Cygwin systems.
Signed-off-by: Andras Kucsma <r0maikx02b@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before, testing if two refs weren't equal with compare_refs() was done
with `test_must_fail compare_refs`. This was wrong for two reasons.
First, test_must_fail should only be used on git commands. Second,
negating the error code is a little heavy-handed since in the case where
one of the git invocations within compare_refs() fails, we will report
success, even though it failed at an unexpected point.
Teach compare_refs() to accept `!` as the first argument which would
_only_ negate the test_cmp()'s return code.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
