Commit graph

3587 commits

Author SHA1 Message Date
Junio C Hamano bc92d2c7ac Merge branch 'mh/credential-erase-improvements-more'
Update two credential helpers to correctly match which credential
to erase; they dropped not the ones with stale password.

* mh/credential-erase-improvements-more:
  credential/wincred: erase matching creds only
  credential/libsecret: erase matching creds only
2023-08-28 09:51:16 -07:00
Junio C Hamano e839608295 Merge branch 'mh/credential-libsecret-attrs'
The way authentication related data other than passwords (e.g.
oath token and password expiration data) are stored in libsecret
keyrings has been rethought.

* mh/credential-libsecret-attrs:
  credential/libsecret: store new attributes
2023-08-28 09:51:16 -07:00
Junio C Hamano 6d159f5757 Merge branch 'rs/parse-options-negation-help'
"git cmd -h" learned to signal which options can be negated by
listing such options like "--[no-]opt".

* rs/parse-options-negation-help:
  parse-options: simplify usage_padding()
  parse-options: no --[no-]no-...
  parse-options: factor out usage_indent() and usage_padding()
  parse-options: show negatability of options in short help
  t1502: test option negation
  t1502: move optionspec help output to a file
  t1502, docs: disallow --no-help
  subtree: disallow --no-{help,quiet,debug,branch,message}
2023-08-25 10:37:37 -07:00
Junio C Hamano 32f4fa8d3b Merge branch 'ds/maintenance-on-windows-fix'
Windows updates.

* ds/maintenance-on-windows-fix:
  git maintenance: avoid console window in scheduled tasks on Windows
  win32: add a helper to run `git.exe` without a foreground window
2023-08-15 10:19:47 -07:00
Johannes Schindelin 4b8a2717bb win32: add a helper to run git.exe without a foreground window
On Windows, there are two kinds of executables, console ones and
non-console ones. Git's executables are all console ones.

When launching the former e.g. in a scheduled task, a CMD window pops
up. This is not what we want for the tasks installed via the `git
maintenance` command.

To work around this, let's introduce `headless-git.exe`, which is a
non-console program that does _not_ pop up any window. All it does is to
re-launch `git.exe`, suppressing that console window, passing through
all command-line arguments as-are.

Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Helped-by: Yuyi Wang <Strawberry_Str@hotmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-09 13:58:13 -07:00
René Scharfe e8e5d294dc parse-options: show negatability of options in short help
Add a "[no-]" prefix to options without the flag PARSE_OPT_NONEG to
document the fact that you can negate them.

This looks a bit strange for options that already start with "no-", e.g.
for the option --no-name of git show-branch:

    --[no-]no-name        suppress naming strings

You can actually use --no-no-name as an alias of --name, so the short
help is not wrong.  If we strip off any of the "no-"s, we lose either
the ability to see if the remaining one belongs to the documented
variant or to see if it can be negated.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-06 17:16:50 -07:00
René Scharfe d716512870 subtree: disallow --no-{help,quiet,debug,branch,message}
"git subtree" only handles the negated variant of the options annotate,
prefix, onto, rejoin, ignore-joins and squash explicitly.  help is
handled by "git rev-parse --parseopt" implicitly, but not its negated
form.  Disable negation for it and the for the rest of the options to
get a helpful error message when trying them.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-06 17:16:49 -07:00
M Hickford cb626f8e5c credential/wincred: erase matching creds only
The credential erase request typically includes protocol, host, username
and password.

credential-wincred erases stored credentials that match protocol,
host and username, regardless of password.

This is confusing in the case the stored password differs from that
in the request. This case can occur when multiple credential helpers are
configured.

Only erase credential if stored password matches request (or request
omits password).

This fixes test "helper (wincred) does not erase a password distinct
from input" when t0303 is run with GIT_TEST_CREDENTIAL_HELPER set to
"wincred". This test was added in aeb21ce22e (credential: avoid
erasing distinct password, 2023-06-13).

Signed-off-by: M Hickford <mirth.hickford@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-26 13:27:34 -07:00
M Hickford 7144dee3ec credential/libsecret: erase matching creds only
The credential erase request typically includes protocol, host, username
and password.

credential-libsecret erases a stored credential if it matches protocol,
host and username, regardless of password.

This is confusing in the case the stored password differs from that
in the request. This case can occur when multiple credential helpers are
configured.

Only erase credential if stored password matches request (or request
omits password).

This fixes test "helper (libsecret) does not erase a password distinct
from input" when t0303 is run with GIT_TEST_CREDENTIAL_HELPER set to
"libsecret". This test was added in aeb21ce22e (credential: avoid
erasing distinct password, 2023-06-13).

Signed-off-by: M Hickford <mirth.hickford@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-26 13:27:31 -07:00
Junio C Hamano b3d1c85d48 Merge branch 'gc/config-context'
Reduce reliance on a global state in the config reading API.

* gc/config-context:
  config: pass source to config_parser_event_fn_t
  config: add kvi.path, use it to evaluate includes
  config.c: remove config_reader from configsets
  config: pass kvi to die_bad_number()
  trace2: plumb config kvi
  config.c: pass ctx with CLI config
  config: pass ctx with config files
  config.c: pass ctx in configsets
  config: add ctx arg to config_fn_t
  urlmatch.h: use config_fn_t type
  config: inline git_color_default_config
2023-07-06 11:54:48 -07:00
Junio C Hamano f4c18e58be Merge branch 'pb/complete-diff-options'
Completion updates.

* pb/complete-diff-options: (24 commits)
  diff.c: mention completion above add_diff_options
  completion: complete --remerge-diff
  completion: complete --diff-merges, its options and --no-diff-merges
  completion: move --pickaxe-{all,regex} to __git_diff_common_options
  completion: complete --ws-error-highlight
  completion: complete --unified
  completion: complete --output-indicator-{context,new,old}
  completion: complete --output
  completion: complete --no-stat
  completion: complete --no-relative
  completion: complete --line-prefix
  completion: complete --ita-invisible-in-index and --ita-visible-in-index
  completion: complete --irreversible-delete
  completion: complete --ignore-matching-lines
  completion: complete --function-context
  completion: complete --find-renames
  completion: complete --find-object
  completion: complete --find-copies
  completion: complete --default-prefix
  completion: complete --compact-summary
  ...
2023-07-06 11:54:46 -07:00
Glen Choo 8868b1ebfb config: pass kvi to die_bad_number()
Plumb "struct key_value_info" through all code paths that end in
die_bad_number(), which lets us remove the helper functions that read
analogous values from "struct config_reader". As a result, nothing reads
config_reader.config_kvi any more, so remove that too.

In config.c, this requires changing the signature of
git_configset_get_value() to 'return' "kvi" in an out parameter so that
git_configset_get_<type>() can pass it to git_config_<type>(). Only
numeric types will use "kvi", so for non-numeric types (e.g.
git_configset_get_string()), pass NULL to indicate that the out
parameter isn't needed.

Outside of config.c, config callbacks now need to pass "ctx->kvi" to any
of the git_config_<type>() functions that parse a config string into a
number type. Included is a .cocci patch to make that refactor.

The only exceptional case is builtin/config.c, where git_config_<type>()
is called outside of a config callback (namely, on user-provided input),
so config source information has never been available. In this case,
die_bad_number() defaults to a generic, but perfectly descriptive
message. Let's provide a safe, non-NULL for "kvi" anyway, but make sure
not to change the message.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-28 14:06:40 -07:00
Glen Choo a4e7e317f8 config: add ctx arg to config_fn_t
Add a new "const struct config_context *ctx" arg to config_fn_t to hold
additional information about the config iteration operation.
config_context has a "struct key_value_info kvi" member that holds
metadata about the config source being read (e.g. what kind of config
source it is, the filename, etc). In this series, we're only interested
in .kvi, so we could have just used "struct key_value_info" as an arg,
but config_context makes it possible to add/adjust members in the future
without changing the config_fn_t signature. We could also consider other
ways of organizing the args (e.g. moving the config name and value into
config_context or key_value_info), but in my experiments, the
incremental benefit doesn't justify the added complexity (e.g. a
config_fn_t will sometimes invoke another config_fn_t but with a
different config value).

In subsequent commits, the .kvi member will replace the global "struct
config_reader" in config.c, making config iteration a global-free
operation. It requires much more work for the machinery to provide
meaningful values of .kvi, so for now, merely change the signature and
call sites, pass NULL as a placeholder value, and don't rely on the arg
in any meaningful way.

Most of the changes are performed by
contrib/coccinelle/config_fn_ctx.pending.cocci, which, for every
config_fn_t:

- Modifies the signature to accept "const struct config_context *ctx"
- Passes "ctx" to any inner config_fn_t, if needed
- Adds UNUSED attributes to "ctx", if needed

Most config_fn_t instances are easily identified by seeing if they are
called by the various config functions. Most of the remaining ones are
manually named in the .cocci patch. Manual cleanups are still needed,
but the majority of it is trivial; it's either adjusting config_fn_t
that the .cocci patch didn't catch, or adding forward declarations of
"struct config_context ctx" to make the signatures make sense.

The non-trivial changes are in cases where we are invoking a config_fn_t
outside of config machinery, and we now need to decide what value of
"ctx" to pass. These cases are:

- trace2/tr2_cfg.c:tr2_cfg_set_fl()

  This is indirectly called by git_config_set() so that the trace2
  machinery can notice the new config values and update its settings
  using the tr2 config parsing function, i.e. tr2_cfg_cb().

- builtin/checkout.c:checkout_main()

  This calls git_xmerge_config() as a shorthand for parsing a CLI arg.
  This might be worth refactoring away in the future, since
  git_xmerge_config() can call git_default_config(), which can do much
  more than just parsing.

Handle them by creating a KVI_INIT macro that initializes "struct
key_value_info" to a reasonable default, and use that to construct the
"ctx" arg.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-28 14:06:39 -07:00
Philippe Blain 55245d669a completion: complete --remerge-diff
--remerge-diff only makes sense for 'git log' and 'git show', so add it
to __git_log_show_options which is referenced in the completion for
these two commands.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:14 -07:00
Philippe Blain 98aaeb2f77 completion: complete --diff-merges, its options and --no-diff-merges
The flags --[no-]diff-merges only make sense for 'git log' and 'git
show', so add a new variable __git_log_show_options for options only
relevant to these two commands, and add them there. Also add
__git_diff_merges_opts and list the accepted values for --diff-merges,
and use it in _git_log and _git_show.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:14 -07:00
Philippe Blain d520d98382 completion: move --pickaxe-{all,regex} to __git_diff_common_options
The options --pickaxe-all and --pickaxe-regex are listed in
__git_diff_difftool_options and repeated in _git_log. Move them to
__git_diff_common_options instead, which makes them available
automatically in the completion of other commands referencing this
variable.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:13 -07:00
Philippe Blain da260f6188 completion: complete --ws-error-highlight
Add --ws-error-highlight= to the list in __git_diff_common_options, and
add the accepted values in a new list __git_ws_error_highlight_opts.

Use __git_ws_error_highlight_opts in _git_diff, _git_log and _git_show
to offer the accepted values.

As noted in fd0bc17557 (completion: add diff --color-moved[-ws],
2020-02-21), there is no easy way to offer completion for several
comma-separated values, so this is limited to completing a single
value.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:13 -07:00
Philippe Blain 3b698111d5 completion: complete --unified
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:13 -07:00
Philippe Blain b5c3edc17e completion: complete --output-indicator-{context,new,old}
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:13 -07:00
Philippe Blain 8fe2bd7905 completion: complete --output
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:13 -07:00
Philippe Blain 5727be06c6 completion: complete --no-stat
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:13 -07:00
Philippe Blain ffcccc62b0 completion: complete --no-relative
Add --no-relative to __git_diff_common_options in the completion script,
and move --relative from __git_diff_difftool_options to
__git_diff_common_options since it applies to more than just diff and
difftool.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:12 -07:00
Philippe Blain 3a4d453246 completion: complete --line-prefix
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:12 -07:00
Philippe Blain 08a9a6d615 completion: complete --ita-invisible-in-index and --ita-visible-in-index
The options --ita-invisible-in-index and --ita-visible-in-index are
listed in diff-options.txt and so are included in the documentation of
commands which include this file (diff, diff-*, log, show, format-patch)
but they only make sense for diffs relating to the index. As such, add
them to '__git_diff_difftool_options' instead of
'__git_diff_common_options' since it makes more sense to add them there.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:12 -07:00
Philippe Blain 8885532abb completion: complete --irreversible-delete
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:12 -07:00
Philippe Blain b454ed2c5d completion: complete --ignore-matching-lines
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:11 -07:00
Philippe Blain 57159d5daa completion: complete --function-context
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:11 -07:00
Philippe Blain 1eb638a5db completion: complete --find-renames
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:11 -07:00
Philippe Blain 04d430ff8d completion: complete --find-object
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:11 -07:00
Philippe Blain 2f677ad348 completion: complete --find-copies
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:11 -07:00
Philippe Blain a4d13aaf22 completion: complete --default-prefix
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:11 -07:00
Philippe Blain fd9058649a completion: complete --compact-summary
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:10 -07:00
Philippe Blain de4898d7d8 completion: complete --combined-all-paths
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:10 -07:00
Philippe Blain 93ec6111a6 completion: complete --cc
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:10 -07:00
Philippe Blain 6a38b0a0dc completion: complete --break-rewrites
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:10 -07:00
Philippe Blain f0b9e15378 completion: add comments describing __git_diff_* globals
Add descriptive comments for '__git_diff_common_options' and
'__git_diff_difftool_options', so that it is clearer when looking at
these variables to know in which command's completion they are used.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-26 09:40:10 -07:00
Elijah Newren bc5c5ec044 cache.h: remove this no-longer-used header
Since this header showed up in some places besides just #include
statements, update/clean-up/remove those other places as well.

Note that compat/fsmonitor/fsm-path-utils-darwin.c previously got
away with violating the rule that all files must start with an include
of git-compat-util.h (or a short-list of alternate headers that happen
to include it first).  This change exposed the violation and caused it
to stop building correctly; fix it by having it include
git-compat-util.h first, as per policy.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-21 13:39:53 -07:00
Junio C Hamano 0899beb63c Merge branch 'pb/complete-and-document-auto-merge-and-friends'
Document more pseudo-refs and teach the command line completion
machinery to complete AUTO_MERGE.

* pb/complete-and-document-auto-merge-and-friends:
  completion: complete AUTO_MERGE
  Documentation: document AUTO_MERGE
  git-merge.txt: modernize word choice in "True merge" section
  completion: complete REVERT_HEAD and BISECT_HEAD
  revisions.txt: document more special refs
  revisions.txt: use description list for special refs
2023-06-20 15:53:12 -07:00
M Hickford 0ce02e2fec credential/libsecret: store new attributes
d208bfd (credential: new attribute password_expiry_utc, 2023-02-18)
and a5c76569e7 (credential: new attribute oauth_refresh_token)
introduced new credential attributes.

libsecret assumes attribute values are non-confidential and
unchanging, so we encode the new attributes in the secret, separated by
newline:

    hunter2
    password_expiry_utc=1684189401
    oauth_refresh_token=xyzzy

This is extensible and backwards compatible. The credential protocol
already assumes that attribute values do not contain newlines.

Alternatives considered: store password_expiry_utc in a libsecret
attribute. This has the problem that libsecret creates new items
rather than overwrites when attribute values change.

Signed-off-by: M Hickford <mirth.hickford@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-16 13:06:57 -07:00
Junio C Hamano 4c7d878df6 Merge branch 'gc/doc-cocci-updates'
Update documentation regarding Coccinelle patches.

* gc/doc-cocci-updates:
  cocci: codify authoring and reviewing practices
  cocci: add headings to and reword README
2023-06-13 12:29:45 -07:00
Philippe Blain 982ff3a649 completion: complete AUTO_MERGE
The pseudoref AUTO_MERGE is documented since the previous commit. To
make it easier to use, let __git_refs in the Bash completion code
complete it.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-23 17:21:47 +09:00
Philippe Blain 1ef3c61b78 completion: complete REVERT_HEAD and BISECT_HEAD
The pseudorefs REVERT_HEAD and BISECT_HEAD are not suggested
by the __git_refs function. Add them there.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-23 17:21:47 +09:00
Junio C Hamano ef06676c36 Merge branch 'sg/retire-unused-cocci'
Retire a rather expensive-to-run Coccinelle check patch.

* sg/retire-unused-cocci:
  cocci: remove 'unused.cocci'
2023-05-15 13:59:06 -07:00
Junio C Hamano db13ea835b Merge branch 'js/subtree-fully-spelt-quiet-and-debug-options'
"git subtree" (in contrib/) update.

* js/subtree-fully-spelt-quiet-and-debug-options:
  subtree: support long global flags
2023-05-15 13:59:06 -07:00
Junio C Hamano 5bc069e383 Merge branch 'mh/credential-password-expiry-wincred'
Teach the recently invented "password expiry time" trait to the
wincred credential helper.

* mh/credential-password-expiry-wincred:
  credential/wincred: store password_expiry_utc
2023-05-11 12:16:16 -07:00
Junio C Hamano cb29fb86f3 Merge branch 'mh/use-wincred-from-system'
Code clean-up.

* mh/use-wincred-from-system:
  credential/wincred: include wincred.h
2023-05-11 12:16:15 -07:00
Junio C Hamano fbbf60a9bc Merge branch 'tb/credential-long-lines'
The implementation of credential helpers used fgets() over fixed
size buffers to read protocol messages, causing the remainder of
the folded long line to trigger unexpected behaviour, which has
been corrected.

* tb/credential-long-lines:
  contrib/credential: embiggen fixed-size buffer in wincred
  contrib/credential: avoid fixed-size buffer in libsecret
  contrib/credential: .gitignore libsecret build artifacts
  contrib/credential: remove 'gnome-keyring' credential helper
  contrib/credential: avoid fixed-size buffer in osxkeychain
  t/lib-credential.sh: ensure credential helpers handle long headers
  credential.c: store "wwwauth[]" values in `credential_read()`
2023-05-10 10:23:27 -07:00
Josh Soref b4de9239bf subtree: support long global flags
The documentation at e75d1da38a claimed support, but it was never present

Signed-off-by: Josh Soref <jsoref@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-08 07:58:27 -07:00
Junio C Hamano 4ca12e10e6 Merge branch 'ek/completion-use-read-r-to-read-literally'
The completion script used to use bare "read" without the "-r"
option to read the contents of various state files, which risked
getting confused with backslashes in them.  This has been
corrected.

* ek/completion-use-read-r-to-read-literally:
  completion: suppress unwanted unescaping of `read`
2023-05-02 10:13:34 -07:00
Taylor Blau 0a3a972c16 contrib/credential: embiggen fixed-size buffer in wincred
As in previous commits, harden the wincred credential helper against the
aforementioned protocol injection attack.

Unlike the approached used for osxkeychain and libsecret, where a
fixed-size buffer was replaced with `getline()`, we must take a
different approach here. There is no `getline()` equivalent in Windows,
and the function is not available to us with ordinary compiler settings.

Instead, allocate a larger (still fixed-size) buffer in which to process
each line. The value of 100 KiB is chosen to match the maximum-length
header that curl will allow, CURL_MAX_HTTP_HEADER.

To ensure that we are reading complete lines at a time, and that we
aren't susceptible to a similar injection attack (albeit with more
padding), ensure that each read terminates at a newline (i.e., that no
line is more than 100 KiB long).

Note that it isn't sufficient to turn the old loop into something like:

    while (len && strchr("\r\n", buf[len - 1])) {
      buf[--len] = 0;
      ends_in_newline = 1;
    }

because if an attacker sends something like:

    [aaaaa.....]\r
    host=example.com\r\n

the credential helper would fill its buffer after reading up through the
first '\r', call fgets() again, and then see "host=example.com\r\n" on
its line.

Note that the original code was written in a way that would trim an
arbitrary number of "\r" and "\n" from the end of the string. We should
get only a single "\n" (since the point of `fgets()` is to return the
buffer to us when it sees one), and likewise would not expect to see
more than one associated "\r". The new code trims a single "\r\n", which
matches the original intent.

[1]: https://curl.se/libcurl/c/CURLOPT_HEADERFUNCTION.html

Tested-by: Matthew John Cheetham <mjcheetham@outlook.com>
Helped-by: Matthew John Cheetham <mjcheetham@outlook.com>
Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-01 09:27:02 -07:00