Fixes#19109 - GSSAPI authentication fails on macOS with Apple's Heimdal
implementation which lacks GSS_C_CHANNEL_BOUND_FLAG support for TLS
channel binding.
Commit 0a5ea09a91 introduced TLS channel binding for SPNEGO/GSSAPI
authentication unconditionally, but Apple's Heimdal fork (used on macOS)
does not support this feature, causing "unsupported mechanism" errors
when authenticating to corporate HTTP services with Kerberos.
Solution:
- Add CURL_GSSAPI_HAS_CHANNEL_BINDING detection in curl_gssapi.h based
on GSS_C_CHANNEL_BOUND_FLAG presence (MIT Kerberos >= 1.19)
- Make negotiatedata.channel_binding_data field conditional in vauth.h
- Guard channel binding collection/cleanup in http_negotiate.c
- Guard channel binding usage in spnego_gssapi.c
This follows the same pattern as GSS_C_DELEG_POLICY_FLAG detection and
ensures graceful degradation when channel binding is unavailable while
maintaining full support for implementations that have it.
Changes:
- lib/curl_gssapi.h: Add feature detection macro
- lib/vauth/vauth.h: Make struct field conditional
- lib/http_negotiate.c: Conditional init/cleanup (2 locations)
- lib/vauth/spnego_gssapi.c: Conditional channel binding usage
Tested on macOS with Apple Heimdal (no channel binding) and Linux with
MIT Kerberos (with channel binding). Both configurations authenticate
successfully without errors.
Closes#19164
socks_gssapi: the malloc + memcpy was superflous and can be skipped
cleartext: avoid malloc + three memcpy with aprintf()
digest_sspi: use memdup0 instead of malloc + memcpy
vtls: use memdup0 instead of malloc + memcpy
Closes#19282
Previous minimum was: 1.2.4 (2002-02-28)
- assume `gssapi/gssapi.h` header for MIT Kerberos.
Drop logic detecting this header, and drop alternate logic including
a bare "gssapi.h". Bare `gssapi.h` is Heimdal-specific. MIT Kerberos
added support for it for Heimdal compatibility on 2006-11-09,
redirecting to `gssapi/gssapi.h`. MIT Kerberos supported the latter
header in the 1990s already.
Ref: 40e1a016f9 (2008-03-06)
Ref: d119352001 (2006-11-09)
- configure.ac: stop using `HAVE_GSSAPI_GSSAPI_H`.
Added in 2010 to support "ancient distros such as RHEL-3" where
`gssapi/gssapi_krb5.h` did not include `gssapi/gssapi.h`.
MIT Kerberos includes it since commit:
d9e959edfa (2003-03-06)
Released in 1.3 (2003-07-08).
Bump minimum required version to avoid this issue.
Reverts cca192e58f (2010-04-16)
Ref: https://web.mit.edu/kerberos/dist/historic.html
Ref: https://sources.debian.org/src/krb5/Closes#18992
It's a legacy MIT Kerberos header that's no longer used by curl since:
355bf01c82 (2015-01-09)
There were still mentions of it after this patch, when using versions
<1.2.3, but those versions aren't supported since:
9918541795 (2008-06-12)
This header remains in use by autotools and cmake to detect MIT Kerberos
(vs. Heimdal, which doesn't have it.)
Ref: https://github.com/curl/curl/pull/18978#issuecomment-3387414995Closes#18990
Previously, if for example the nonce would end with "realm=" etc it
would get the wrong piece, due to the naive parser.
Reported-by: Joshua Rogers
Closes#18975
After this patch, the codebase no longer overrides system printf
functions. Instead it explicitly calls either the curl printf functions
`curl_m*printf()` or the system ones using their original names.
Also:
- drop unused `curl_printf.h` includes.
- checksrc: ban system printf functions, allow where necessary.
Follow-up to db98daab05#18844
Follow-up to 4deea9396b#18814Closes#18866
For `GetLastError()` and `SECURITY_STATUS`:
0x-prefixed, 8-digit, lowercase, hex: 0x1234abcd
Also: say `GetLastError()` instead of `errno` in one message.
Closes#18877
- curlx_get_winapi_error: accept DWORD (was: int), move casts one level
up the callstack.
- sspi: bump some types to `SECURITY_STATUS` (int -> LONG).
- digest_sspi: drop unnecessary cast.
Closes#18868
Also:
- tests/server: replace local `sstrerror()` with `curlx_strerror()`.
- tests/server: show the error code next to the string, where missing.
- curlx: use `curl_msnprintf()` when building for src and tests.
(units was already using it.)
- lib: drop unused includes found along the way.
- curlx_strerror(): avoid compiler warning (and another similar one):
```
In file included from servers.c:14:
../../lib/../../lib/curlx/strerr.c: In function ‘curlx_strerror’:
../../lib/../../lib/curlx/strerr.c:328:32: error: ‘snprintf’ output may be truncated before the last format character [-Werror=format-truncation=]
328 | SNPRINTF(buf, buflen, "%s", msg);
| ^
../../lib/../../lib/curlx/strerr.c:47:18: note: ‘snprintf’ output 1 or more bytes (assuming 2) into a destination of size 1
47 | #define SNPRINTF snprintf
| ^
../../lib/../../lib/curlx/strerr.c:328:7: note: in expansion of macro ‘SNPRINTF’
328 | SNPRINTF(buf, buflen, "%s", msg);
| ^~~~~~~~
```
Follow-up to 45438c8d6f#18823Closes#18840
By making them defaults, then fixing and/or reshuffling remaining
exceptions as necessary.
- checksrc: ban by default: `snprintf`, `vsnprintf`, `sscanf`, `strtol`.
- examples: replace `strtol` with `atoi` to avoid a checksrc exception.
- tests/libtest: replace `strtol` with `atol`.
- tests/server: replace most `strtol` with `atol`.
- tests/server: replace most `strtoul` with `atol`/`atoi`.
- tests/server: drop no longer used `util_ultous`.
- fix typo in checksrc rules: `vsnprint` -> `vsnprintf`.
- update local exceptions.
Also:
- examples: ban curl printf functions. They're discouraged in user code.
- examples: replace curl printf with system printf.
Add `snprintf` workaround for <VS2015.
- examples/synctime: fix `-Wfloat-equal`.
- examples/synctime: exclude for non-Windows and non-UWP Windows.
- examples/synctime: build by default.
Closes#18823
- update Microsoft documentation links.
(also drop language designator where present.)
- checksrc: allow longer than 78 character lines if they
contain a https URL. To make these links easier to use and parse.
- merge links that were split into two lines.
Closes#18626
To avoid hitting `-Wreserved-macro-identifier` where possible.
- amigaos: introduce local macro instead of reusing `__request()`.
- easy_lock: avoid redefining `__has_builtin()`.
Follow-up to 33fd57b8ff#9062
- rand: drop interim macro `_random()`.
- windows: rename local macro `_tcsdup()` to `Curl_tcsdup()`.
To avoid using the reserved macro namespace and to avoid
colliding with `_tcsdup()` as defined by Windows headers.
- checksrc: ban `_tcsdup()` in favor of `Curl_tcsdup()`.
- tool_doswin: avoid redefining `_use_lfn()` (MS-DOS).
- tool_findfile: limit `__NO_NET_API` hack to AmigaOS.
Syncing this pattern with `lib/netrc.c`.
Follow-up to 784a8ec2c1#16279
- examples/http2-upload: avoid reserved namespace for local macro.
More cases will be removed when dropping WinCE support via #17927.
Cases remain when defining external macros out of curl's control.
Ref: #18477Closes#18482
This callback was permanently mapped to libcurl's internal
`Curl_wcsdup()`, which always uses the customizable malloc for
allocation, thus making a custom mapping redundant anyway.
To simplify, drop the callback and map `_tcsdup()` in Unicode mode
directly to `Curl_wcsdup()`.
Also fixes:
- `curl_global_init()` which, before this patch, (re)initialized its
mapping to `_wcsdup()`, returning buffers potentially incompatible
with a custom allocator.
Bug: https://github.com/curl/curl/pull/17840#issuecomment-3044361245
Bug: https://github.com/curl/curl/pull/7540#issuecomment-2380995349
Co-reported-by: Luca Kellermann
Follow-up to 76e047fc27#7540
Assisted-by: Jay Satiro
Closes#17843
Replace the `libstubgss.so`-based overload solution with one built into
libcurl at compile-time.
The previous, `LD_PRELOAD`-based, solution was non-portable, allowlisted
for Linux, BSD and Solaris. It also required non-debug builds, which
turned out to be an accidental condition:
7d342c723c. It also required a curl tool
built against a shared libcurl. Detecting this condition wasn't always
accurate, e.g. with certain cmake configurations.
The overload solution also didn't work on macOS, though it theoretically
should have:
- #17653
- #2394
Experiments on making the overload solution work in more envs:
- #17759
That revealed that it also did not work on NetBSD, in CI.
The replacement solution is overloading the necessary GSS-API functions
for test 2056 and 2057 at compile time. It requires a debug-enabled curl
build (due to its insecure nature).
This makes these tests run on all platforms. Including most GSS jobs in
CI, that are running tests. (the exception is old-linux, non-debug jobs,
where it felt overkill to enable debug for this.)
The refactored GSS stub code needs to overload less than before because
it's free to use the official GSS API. (This didn't work with
the overload solution on Alpine for example). It can also use libcurl
functions, allowing to replace `snprintf()` with `msnprintf()`.
OS/400 is also overloading GSS API functions. I haven't tested how this
works after this PR. In theory it should, because this PR doesn't rely
on preprocessor overrides.
Note that for future GSS tests, it may be necessary to stub these GSS
API functions: `gss_inquire_context()`, `gss_unwrap()`, `gss_wrap()`.
They are on codepaths not (yet) touched by tests.
Also:
- stub-gss: check for token buffer overrun.
- stub-gss: replace size macros with `sizeof()`.
- GHA: enable debug for some jobs with GSS.
- GHA/linux: ignore results for 2056 and 2057 in the valgrind job.
They leak the same way as seen with 2077 and 2078.
Ref: 7020ba7979#17462
Ref: 146759716c#14430
- GHA/linux: fix to ignore `gss_import_name()` leaks in valgrind builds.
only.
- lib/vauth/krb5_gssapi: reduce variable scope.
- lib/vauth/spnego_gssapi: reduce variable scope.
- tests/libtest: drop code and build logic dealing with `libstubgss`.
- runtests:
- drop `ld_preload` feature.
- drop special handling of `LD_PRELOAD` env in tests.
- drop logic dealing with shared curl tool detection.
- drop `LD_PRELOAD` envs from tests.
Follow-up to 56d949d31a#1687Closes#17752
Drop `strcasecompare` and `strncasecompare` in favor of libcurl API
calls `curl_strequal` and `curl_strnequal` respectively.
Also drop unnecessary `strcase.h` includes. Include `curl/curl.h`
instead where it wasn't included before.
Closes#17772
- tests/libtest: move exception to `stub_gssapi.h`.
- tests/libtest: move remaining exception to `testtrace.c`.
- tests/server: drop obsolete exception.
- docs/examples: move `BANNEDFUNC` exceptions to local files (3 lines).
- docs/examples: move `ERRNOVAR` exception to `ephiperfifo.c`.
- docs/examples: drop `typedef struct` (8 files).
- lib/curlx: add `.checksrc` with banned funcs copied from lib.
- checksrc: ban `strncpy`, `strtok_r`, `strtoul` by default.
Drop local bans. Add exception for `strtoul` to `tests/server'.
- lib, src: sync banned funcs.
Also:
- REUSE: drop `stunnel.pem`, it no longer exists.
- docs/examples: formatting.
- docs/examples: simplify some `sizeof()`s.
Closes#17764
Fix building with `--disable-digest-auth`. Make test cases run in such
a build. Add such a build to our CI jobs.
Reported-by: Tristan Perrault
Fixes#17612Closes#17614
Remove structs for negotiate, krb5, ntlm and gsasl from connectdata and
store them as connection meta data with auto cleanup.
De-complexify sasl mech selection by moving code into static functions.
Closes#17557
With a dash, using two Ls. Also for different forms of the word.
Use NULL in all uppercase if it means a zero pointer.
Follow-up to 307b7543eaCloses#17489
When SASL is unable to select an AUTH mechanism, give user help
in info message why no AUTH could be selected.
Fixes#17420Closes#17427
Reported-by: Aditya Garg
Move curlx_ functions into its own subdir.
The idea is to use the curlx_ prefix proper on these functions, and use
these same function names both in tool, lib and test suite source code.
Stop the previous special #define setup for curlx_ names.
The printf defines are now done for the library alone. Tests no longer
use the printf defines. The tool code sets its own defines. The printf
functions are not curlx, they are publicly available.
The strcase defines are not curlx_ functions and should not be used by
tool or server code.
dynbuf, warnless, base64, strparse, timeval, timediff are now proper
curlx functions.
When libcurl is built statically, the functions from the library can be
used as-is. The key is then that the functions must work as-is, without
having to be recompiled for use in tool/tests. This avoids symbol
collisions - when libcurl is built statically, we use those functions
directly when building the tool/tests. When libcurl is shared, we
build/link them separately for the tool/tests.
Assisted-by: Jay Satiro
Closes#17253
by including headers using "../[header]" when done from C files in
subdirectories, we do not need to specify the lib source dir as an
include path and we reduce the risk of header name collisions with
headers in the SDK using the same file names.
Idea-by: Kai Pastor
Ref: #16949Closes#16991
Add a DEBUGASSERT() in Curl_dyn_free() that checks that Curl_dyn_init()
has been performed before.
Fix code places that did it wrong.
Fixes#16725Closes#16775
The issues found fell into these categories, with the applied fixes:
- const was accidentally stripped.
Adjust code to not cast or cast with const.
- const/volatile missing from arguments, local variables.
Constify arguments or variables, adjust/delete casts. Small code
changes in a few places.
- const must be stripped because an API dependency requires it.
Strip `const` with `CURL_UNCONST()` macro to silence the warning out
of our control. These happen at API boundaries. Sometimes they depend
on dependency version, which this patch handles as necessary. Also
enable const support for the zlib API, using `ZLIB_CONST`. Supported
by zlib 1.2.5.2 and newer.
- const must be stripped because a curl API requires it.
Strip `const` with `CURL_UNCONST()` macro to silence the warning out
of our immediate control. For example we promise to send a non-const
argument to a callback, though the data is const internally.
- other cases where we may avoid const stripping by code changes.
Also silenced with `CURL_UNCONST()`.
- there are 3 places where `CURL_UNCONST()` is cast again to const.
To silence this type of warning:
```
lib/vquic/curl_osslq.c:1015:29: error: to be safe all intermediate
pointers in cast from 'unsigned char **' to 'const unsigned char **'
must be 'const' qualified [-Werror=cast-qual]
lib/cf-socket.c:734:32: error: to be safe all intermediate pointers in
cast from 'char **' to 'const char **' must be 'const' qualified
[-Werror=cast-qual]
```
There may be a better solution, but I couldn't find it.
These cases are handled in separate subcommits, but without further
markup.
If you see a `-Wcast-qual` warning in curl, we appreciate your report
about it.
Closes#16142
To reduce the number `-Wunused-macro` compiler warnings:
- delete unused macros.
- comment out unused macro that are part of a set.
- move macros into the scope they are used.
This may be useful to enable by default, but there are tricky cases that
I didn't manage to fix and paused the effort. E.g. internal features
checks in `openssl.c`. There is more, once those are fixed.
Closes#16279
On apple builds, the gssapi/ldap/securetransport headers deprecate
almost everything which leads to a wall of compiler warnings on use in
code.
Suppress those warning that may hide other warnings/errors.
Closes#15763
Other programs (Postman, Chrome, Python request) use a 16 byte cnonce
and there are instances of server-side implementations that don't
support the larger lengths curl used previously.
Fixes#15653
Reported-by: Florian Eckert
Closes#15670
krb5 defines `strtok_r` for Windows unconditionally in its public
header:
dc5554394e/src/include/win-mac.h (L214-L215)
resulting in this warning:
```
lib\strtok.h(31,9): warning C4005: 'strtok_r': macro redefinition
C:\vcpkg\installed\x64-windows\include\win-mac.h(215,9):
see previous definition of 'strtok_r'
```
The krb5 macro collides with curl's internal definition, in case
the `strtok_r` function is undetected and falling back to a local
replacement.
Reported-by: Tal Regev
Bug: https://github.com/curl/curl/pull/15549#issuecomment-2468251761Closes#15564
