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
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
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
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
Channel Bindings are used to tie the session context to a specific TLS
channel. This is to provide additional proof of valid identity,
mitigating authentication relay attacks.
Major web servers have the ability to require (None/Accept/Require)
GSSAPI channel binding, rendering Curl unable to connect to such
websites unless support for channel bindings is implemented.
IIS calls this feature Extended Protection (EPA), which is used in
Enterprise environments using Kerberos for authentication.
This change require krb5 >= 1.19, otherwise channel bindings won't be
forwarded through SPNEGO.
Co-Authored-By: Steffen Kieß <947515+steffen-kiess@users.noreply.github.com>
Closes#13098
Based on the standards and guidelines we use for our documentation.
- expand contractions (they're => they are etc)
- host name = > hostname
- file name => filename
- user name = username
- man page => manpage
- run-time => runtime
- set-up => setup
- back-end => backend
- a HTTP => an HTTP
- Two spaces after a period => one space after period
Closes#14073
- they are mostly pointless in all major jurisdictions
- many big corporations and projects already don't use them
- saves us from pointless churn
- git keeps history for us
- the year range is kept in COPYING
checksrc is updated to allow non-year using copyright statements
Closes#10205
Add licensing and copyright information for all files in this repository. This
either happens in the file itself as a comment header or in the file
`.reuse/dep5`.
This commit also adds a Github workflow to check pull requests and adapts
copyright.pl to the changes.
Closes#8869
- the data needs to be "line-based" anyway since it's also passed to the
debug callback/application
- it makes infof() work like failf() and consistency is good
- there's an assert that triggers on newlines in the format string
- Also removes a few instances of "..."
- Removes the code that would append "..." to the end of the data *iff*
it was truncated in infof()
Closes#7357
* Adjusted unit tests 2056, 2057
* do not generally close connections with CURLAUTH_NEGOTIATE after every request
* moved negotiatedata from UrlState to connectdata
* Added stream rewind logic for CURLAUTH_NEGOTIATE
* introduced negotiatedata::GSS_AUTHDONE and negotiatedata::GSS_AUTHSUCC
* Consider authproblem state for CURLAUTH_NEGOTIATE
* Consider reuse_forbid for CURLAUTH_NEGOTIATE
* moved and adjusted negotiate authentication state handling from
output_auth_headers into Curl_output_negotiate
* Curl_output_negotiate: ensure auth done is always set
* Curl_output_negotiate: Set auth done also if result code is
GSS_S_CONTINUE_NEEDED/SEC_I_CONTINUE_NEEDED as this result code may
also indicate the last challenge request (only works with disabled
Expect: 100-continue and CURLOPT_KEEP_SENDING_ON_ERROR -> 1)
* Consider "Persistent-Auth" header, detect if not present;
Reset/Cleanup negotiate after authentication if no persistent
authentication
* apply changes introduced with #2546 for negotiate rewind logic
Fixes#1261Closes#1975
When multiple rounds are needed to establish a security context
(usually ntlm), we overwrite old token with a new one without free.
Found by proposed gss tests using stub a gss implementation (by
valgrind error), though I have confirmed the leak with a real
gssapi implementation as well.
Closes https://github.com/curl/curl/pull/1733
As Windows SSPI authentication calls fail when a particular mechanism
isn't available, introduced these functions for DIGEST, NTLM, Kerberos 5
and Negotiate to allow both HTTP and SASL authentication the opportunity
to query support for a supported mechanism before selecting it.
For now each function returns TRUE to maintain compatability with the
existing code when called.
Also display the GSS_C_GSS_CODE (major code) when specified instead of
only GSS_C_MECH_CODE (minor code).
In addition, the old code was printing a colon twice after the prefix
and also miscalculated the length of the buffer in between calls to
gss_display_status (the length of ": " was missing).
Also, gss_buffer is not guaranteed to be NULL terminated and thus need
to restrict reading by its length.
Closes#738
