"git merge $signed_tag" started to drop the tag message from the
default merge message it uses by accident, which has been corrected.
* fs/ssh-signing-key-lifetime:
fmt-merge-msg: prevent use-after-free with signed tags
When merging a signed tag, fmt_merge_msg_sigs() is responsible for
populating the body of the merge message with the names of the signed
tags, their signatures, and the validity of those signatures.
In 02769437e1 (ssh signing: use sigc struct to pass payload,
2021-12-09), check_signature() was taught to pass the object payload via
the sigc struct instead of passing the payload buffer separately.
In effect, 02769437e1 causes buf, and sigc.payload to point at the same
region in memory. This causes a problem for fmt_tag_signature(), which
wants to read from this location, since it is freed beforehand by
signature_check_clear() (which frees it via sigc's `payload` member).
That makes the subsequent use in fmt_tag_signature() a use-after-free.
As a result, merge messages did not contain the body of any signed tags.
Luckily, they tend not to contain garbage, either, since the result of
strstr()-ing the object buffer in fmt_tag_signature() is guarded:
const char *tag_body = strstr(buf, "\n\n");
if (tag_body) {
tag_body += 2;
strbuf_add(tagbuf, tag_body, buf + len - tag_body);
}
Unfortunately, the tests in t6200 did not catch this at the time because
they do not search for the body of signed tags in fmt-merge-msg's
output.
Resolve this by waiting to call signature_check_clear() until after its
contents can be safely discarded. Harden ourselves against any future
regressions in this area by making sure we can find signed tag messages
in the output of fmt-merge-msg, too.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The default merge message prepared by "git merge" records the name
of the current branch; the name can be overridden with a new option
to allow users to pretend a merge is made on a different branch.
* jc/merge-detached-head-name:
merge: allow to pretend a merge is made into a different branch
When a series of patches for a topic-B depends on having topic-A,
the workflow to prepare the topic-B branch would look like this:
$ git checkout -b topic-B main
$ git merge --no-ff --no-edit topic-A
$ git am <mbox-for-topic-B
When topic-A gets updated, recreating the first merge and rebasing
the rest of the topic-B, all on detached HEAD, is a useful
technique. After updating topic-A with its new round of patches:
$ git checkout topic-B
$ prev=$(git rev-parse 'HEAD^{/^Merge branch .topic-A. into}')
$ git checkout --detach $prev^1
$ git merge --no-ff --no-edit topic-A
$ git rebase --onto HEAD $prev @{-1}^0
$ git checkout -B @{-1}
This will
(0) check out the current topic-B.
(1) find the previous merge of topic-A into topic-B.
(2) detach the HEAD to the parent of the previous merge.
(3) merge the updated topic-A to it.
(4) reapply the patches to rebuild the rest of topic-B.
(5) update topic-B with the result.
without contaminating the reflog of topic-B too much. topic-B@{1}
is the "logically previous" state before topic-A got updated, for
example. At (4), comparison (e.g. range-diff) between HEAD and
@{-1} is a meaningful way to sanity check the result, and the same
can be done at (5) by comparing topic-B and topic-B@{1}.
But there is one glitch. The merge into the detached HEAD done in
the step (3) above gives us "Merge branch 'topic-A' into HEAD", and
does not say "into topic-B".
Teach the "--into-name=<branch>" option to "git merge" and its
underlying "git fmt-merge-message", to pretend as if we were merging
into <branch>, no matter what branch we are actually merging into,
when they prepare the merge message. The pretend name honors the
usual "into <target>" suppression mechanism, which can be seen in
the tests added here.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Set the payload_type for check_signature() when generating merge messages to
verify merged tags signatures key lifetimes.
Implements the same tests as for verify-commit.
Signed-off-by: Fabian Stelzer <fs@gigacodes.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To be able to extend the payload metadata with things like its creation
timestamp or the creators ident we remove the payload parameters to
check_signature() and use the already existing sigc->payload field
instead, only adding the length field to the struct. This also allows
us to get rid of the xmemdupz() calls in the verify functions. Since
sigc is now used to input data as well as output the result move it to
the front of the function list.
- Add payload_length to struct signature_check
- Populate sigc.payload/payload_len on all call sites
- Remove payload parameters to check_signature()
- Remove payload parameters to internal verify_* functions and use sigc
instead
- Remove xmemdupz() used for verbose output since payload is now already
populated.
Signed-off-by: Fabian Stelzer <fs@gigacodes.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When merging a signed tag fmt-merge-msg was unable to verify its
validity missing the necessary ssh allowedSignersFile config.
Adds gpg config parsing to fmt-merge-msg.
Adds tests for ssh signed tags to fmt-merge-msg tests.
Signed-off-by: Fabian Stelzer <fs@gigacodes.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* fs/ssh-signing:
ssh signing: test that gpg fails for unknown keys
ssh signing: tests for logs, tags & push certs
ssh signing: duplicate t7510 tests for commits
ssh signing: verify signatures using ssh-keygen
ssh signing: provide a textual signing_key_id
ssh signing: retrieve a default key from ssh-agent
ssh signing: add ssh key format and signing code
ssh signing: add test prereqs
ssh signing: preliminary refactoring and clean-up
Openssh v8.2p1 added some new options to ssh-keygen for signature
creation and verification. These allow us to use ssh keys for git
signatures easily.
In our corporate environment we use PIV x509 Certs on Yubikeys for email
signing/encryption and ssh keys which I think is quite common
(at least for the email part). This way we can establish the correct
trust for the SSH Keys without setting up a separate GPG Infrastructure
(which is still quite painful for users) or implementing x509 signing
support for git (which lacks good forwarding mechanisms).
Using ssh agent forwarding makes this feature easily usable in todays
development environments where code is often checked out in remote VMs / containers.
In such a setup the keyring & revocationKeyring can be centrally
generated from the x509 CA information and distributed to the users.
To be able to implement new signing formats this commit:
- makes the sigc structure more generic by renaming "gpg_output" to
"output"
- introduces function pointers in the gpg_format structure to call
format specific signing and verification functions
- moves format detection from verify_signed_buffer into the check_signature
api function and calls the format specific verify
- renames and wraps sign_buffer to handle format specific signing logic
as well
Signed-off-by: Fabian Stelzer <fs@gigacodes.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
origin starts off pointing to somewhere within line, which is owned by
the caller. Later we might allocate a new string using xmemdupz() or
xstrfmt(). To avoid leaking these new strings, we introduce a to_free
pointer - which allows us to safely free the newly allocated string when
we're done (we cannot just free origin directly as it might still be
pointing to line).
LSAN output from t0090:
Direct leak of 8 byte(s) in 1 object(s) allocated from:
#0 0x49a82d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
#1 0xa71f49 in do_xmalloc wrapper.c:41:8
#2 0xa720b0 in do_xmallocz wrapper.c:75:8
#3 0xa720b0 in xmallocz wrapper.c:83:9
#4 0xa720b0 in xmemdupz wrapper.c:99:16
#5 0x8092ba in handle_line fmt-merge-msg.c:187:23
#6 0x8092ba in fmt_merge_msg fmt-merge-msg.c:666:7
#7 0x5ce2e6 in prepare_merge_message builtin/merge.c:1119:2
#8 0x5ce2e6 in collect_parents builtin/merge.c:1215:3
#9 0x5c9c1e in cmd_merge builtin/merge.c:1454:16
#10 0x4ce83e in run_builtin git.c:475:11
#11 0x4ccafe in handle_builtin git.c:729:3
#12 0x4cb01c in run_argv git.c:818:4
#13 0x4cb01c in cmd_main git.c:949:19
#14 0x6b3fad in main common-main.c:52:11
#15 0x7fb929620349 in __libc_start_main (/lib64/libc.so.6+0x24349)
SUMMARY: AddressSanitizer: 8 byte(s) leaked in 1 allocation(s).
Signed-off-by: Andrzej Hunt <andrzej@ahunt.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead. It shortens the code and infers the
element size automatically.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed commits and tags now allow verification of objects, whose
two object names (one in SHA-1, the other in SHA-256) are both
signed.
* bc/signed-objects-with-both-hashes:
gpg-interface: remove other signature headers before verifying
ref-filter: hoist signature parsing
commit: allow parsing arbitrary buffers with headers
gpg-interface: improve interface for parsing tags
commit: ignore additional signatures when parsing signed commits
ref-filter: switch some uses of unsigned long to size_t
We have a function which parses a buffer with a signature at the end,
parse_signature, and this function is used for signed tags. However,
we'll need to store values for multiple algorithms, and we'll do this by
using a header for the non-default algorithm.
Adjust the parse_signature interface to store the parsed data in two
strbufs and turn the existing function into parse_signed_buffer. The
latter is still used in places where we know we always have a signed
buffer, such as push certs.
Adjust all the callers to deal with this new interface.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git log" learned a new "--diff-merges=<how>" option.
* so/log-diff-merge: (32 commits)
t4013: add tests for --diff-merges=first-parent
doc/git-show: include --diff-merges description
doc/rev-list-options: document --first-parent changes merges format
doc/diff-generate-patch: mention new --diff-merges option
doc/git-log: describe new --diff-merges options
diff-merges: add '--diff-merges=1' as synonym for 'first-parent'
diff-merges: add old mnemonic counterparts to --diff-merges
diff-merges: let new options enable diff without -p
diff-merges: do not imply -p for new options
diff-merges: implement new values for --diff-merges
diff-merges: make -m/-c/--cc explicitly mutually exclusive
diff-merges: refactor opt settings into separate functions
diff-merges: get rid of now empty diff_merges_init_revs()
diff-merges: group diff-merge flags next to each other inside 'rev_info'
diff-merges: split 'ignore_merges' field
diff-merges: fix -m to properly override -c/--cc
t4013: add tests for -m failing to override -c/--cc
t4013: support test_expect_failure through ':failure' magic
diff-merges: revise revs->diff flag handling
diff-merges: handle imply -p on -c/--cc logic for log.c
...
This function sets all the relevant flags to disabled state, so that
no code that checks only one of them get it wrong.
Then we call this new function everywhere where diff merges output
suppression is needed.
Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In preparation for changing the default branch name to `main`, let's
skip the suffix "into main" in merge commit messages, the same way that
"into master" has been skipped by default.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In Git 2.28, we stopped special casing 'master' when producing the
default merge message by just removing the code to squelch "into
'master'" at the end of the message.
Introduce multi-valued merge.suppressDest configuration variable
that gives a set of globs to match against the name of the branch
into which the merge is being made, to let users specify for which
branch fmt-merge-msg's output should be shortened. When it is not
set, 'master' is used as the sole value of the variable by default.
The above move mostly reverts the pre-2.28 default in repositories
that have no relevant configuration.
Add a few tests to protect the behaviour with the new configuration
variable from future regression.
Helped-by: Linus Torvalds <torvalds@linux-foundation.org>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit 489947cee5, which
stopped treating merges into the 'master' branch as special when
preparing the default merge message. As the goal was not to have
any single branch designated as special, it solved it by leaving the
"into <branchname>" at the end of the title of the default merge
message for any and all branches. An obvious and easy alternative
to treat everybody equally could have been to remove it for every
branch, but that involves loss of information.
We'll introduce a new mechanism to let end-users specify merges into
which branches would omit the "into <branchname>" from the title of
the default merge message, and make the mechanism, when unconfigured,
treat the traditional 'master' special again, so all the changes to
the tests we made earlier will become unnecessary, as these tests
will be run without configuring the said new mechanism.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the context of many projects renaming their primary branch names away
from `master`, Git wants to stop treating the `master` branch specially.
Let's start with `git fmt-merge-msg`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Compilation fix.
* dd/sparse-fixes:
progress.c: silence cgcc suggestion about internal linkage
graph.c: limit linkage of internal variable
compat/regex: move stdlib.h up in inclusion chain
test-parse-pathspec-file.c: s/0/NULL/ for pointer type
Code in builtin/*, i.e. those can only be called from within
built-in subcommands, that implements bulk of a couple of
subcommands have been moved to libgit.a so that they could be used
by others.
* dl/libify-a-few:
Lib-ify prune-packed
Lib-ify fmt-merge-msg
In builtin.h, there exists the distinctly "lib-ish" function
fmt_merge_msg(). This function can currently only be called by built-in
commands but, unlike most of the other functions in the header, it does
not make sense to impose this restriction as the functionality can be
logically reused in libgit.
Extract this function into fmt-merge-msg.c so that related definitions
can exist clearly in their own header file.
While we're at it, clean up #includes that are unused.
This patch is best viewed with --color-moved.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
