- Implement new option CURLSSLOPT_REVOKE_BEST_EFFORT and
--ssl-revoke-best-effort to allow a "best effort" revocation check.
A best effort revocation check ignores errors that the revocation check
was unable to take place. The reasoning is described in detail below and
discussed further in the PR.
---
When running e.g. with Fiddler, the schannel backend fails with an
unhelpful error message:
Unknown error (0x80092012) - The revocation function was unable
to check revocation for the certificate.
Sadly, many enterprise users who are stuck behind MITM proxies suffer
the very same problem.
This has been discussed in plenty of issues:
https://github.com/curl/curl/issues/3727,
https://github.com/curl/curl/issues/264, for example.
In the latter, a Microsoft Edge developer even made the case that the
common behavior is to ignore issues when a certificate has no recorded
distribution point for revocation lists, or when the server is offline.
This is also known as "best effort" strategy and addresses the Fiddler
issue.
Unfortunately, this strategy was not chosen as the default for schannel
(and is therefore a backend-specific behavior: OpenSSL seems to happily
ignore the offline servers and missing distribution points).
To maintain backward-compatibility, we therefore add a new flag
(`CURLSSLOPT_REVOKE_BEST_EFFORT`) and a new option
(`--ssl-revoke-best-effort`) to select the new behavior.
Due to the many related issues Git for Windows and GitHub Desktop, the
plan is to make this behavior the default in these software packages.
The test 2070 was added to verify this behavior, adapted from 310.
Based-on-work-by: georgeok <giorgos.n.oikonomou@gmail.com>
Co-authored-by: Markus Olsson <j.markus.olsson@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Closes https://github.com/curl/curl/pull/4981
- Disable warning C4127 "conditional expression is constant" globally
in curl_setup.h for when building with Microsoft's compiler.
This mainly affects building with the Visual Studio project files found
in the projects dir.
Prior to this change the cmake and winbuild build systems already
disabled 4127 globally for when building with Microsoft's compiler.
Also, 4127 was already disabled for all build systems in the limited
circumstance of the WHILE_FALSE macro which disabled the warning
specifically for while(0). This commit removes the WHILE_FALSE macro and
all other cruft in favor of disabling globally in curl_setup.
Background:
We have various macros that cause 0 or 1 to be evaluated, which would
cause warning C4127 in Visual Studio. For example this causes it:
#define Curl_resolver_asynch() 1
Full behavior is not clearly defined and inconsistent across versions.
However it is documented that since VS 2015 Update 3 Microsoft has
addressed this somewhat but not entirely, not warning on while(true) for
example.
Prior to this change some C4127 warnings occurred when I built with
Visual Studio using the generated projects in the projects dir.
Closes https://github.com/curl/curl/pull/4658
Improved estimation of expected_len and updated related comments;
increased strictness of QNAME-encoding, adding error detection for empty
labels and names longer than the overall limit; avoided treating DNAME
as unexpected;
updated unit test 1655 with more thorough set of proofs and tests
Closes#4598
Otherwise curl may be told to use for instance pop3 to
communicate with the doh server, which most likely
is not what you want.
Found through fuzzing.
Closes#4406
If you set the same URL for target as for DoH (and it isn't a DoH
server), like "https://example.com" in both, the easy handles used for
the DoH requests could be left "dangling" and end up not getting freed.
Reported-by: Paul Dreik
Closes#4366
The undefined behaviour is annoying when running fuzzing with
sanitizers. The codegen is the same, but the meaning is now not up for
dispute. See https://cppinsights.io/s/516a2ff4
By incrementing the pointer first, both gcc and clang recognize this as
a bswap and optimizes it to a single instruction. See
https://godbolt.org/z/994ZpxCloses#4350
Added unit test case 1655 to verify.
Close#4352
the code correctly finds the flaws in the old code,
if one temporarily restores doh.c to the old version.
- Inherit SSL options for the doh handle but not SSL client certs,
SSL ALPN/NPN, SSL engine, SSL version, SSL issuer cert,
SSL pinned public key, SSL ciphers, SSL id cache setting,
SSL kerberos or SSL gss-api settings.
- Fix inheritance of verbose setting.
- Inherit NOSIGNAL.
There is no way for the user to set options for the doh (DNS-over-HTTPS)
handles and instead we inherit some options from the user's easy handle.
My thinking for the SSL options not inherited is they are most likely
not intended by the user for the DOH transfer. I did inherit insecure
because I think that should still be in control of the user.
Prior to this change doh did not work for me because CAINFO was not
inherited. Also verbose was set always which AFAICT was a bug (#3660).
Fixes https://github.com/curl/curl/issues/3660
Closes https://github.com/curl/curl/pull/3661
The function does not return the same value as snprintf() normally does,
so readers may be mislead into thinking the code works differently than
it actually does. A different function name makes this easier to detect.
Reported-by: Tomas Hoger
Assisted-by: Daniel Gustafsson
Fixes#3296Closes#3297
The gcc typecheck macros and coverity combined made it warn on the 2nd
argument for ERROR_CHECK_SETOPT(). Here's minor rearrange to please it.
Coverity CID 1439115 and CID 1439114.
