- 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
- Support hostname verification via alternative names (SAN) in the
peer certificate when CURLOPT_CAINFO is used in Windows 7 and earlier.
CERT_NAME_SEARCH_ALL_NAMES_FLAG doesn't exist before Windows 8. As a
result CertGetNameString doesn't quite work on those versions of
Windows. This change provides an alternative solution for
CertGetNameString by iterating through CERT_ALT_NAME_INFO for earlier
versions of Windows.
Prior to this change many certificates failed the hostname validation
when CURLOPT_CAINFO was used in Windows 7 and earlier. Most certificates
now represent multiple hostnames and rely on the alternative names field
exclusively to represent their hostnames.
Reported-by: Jeroen Ooms
Fixes https://github.com/curl/curl/issues/3711
Closes https://github.com/curl/curl/pull/4761
- In all code call Curl_winapi_strerror instead of Curl_strerror when
the error code is known to be from Windows GetLastError.
Curl_strerror prefers CRT error codes (errno) over Windows API error
codes (GetLastError) when the two overlap. When we know the error code
is from GetLastError it is more accurate to prefer the Windows API error
messages.
Reported-by: Richard Alcock
Fixes https://github.com/curl/curl/issues/4550
Closes https://github.com/curl/curl/pull/4581
- Open the CA file using FILE_SHARE_READ mode so that others can read
from it as well.
Prior to this change our schannel code opened the CA file without
sharing which meant concurrent openings (eg an attempt from another
thread or process) would fail during the time it was open without
sharing, which in curl's case would cause error:
"schannel: failed to open CA file".
Bug: https://curl.haxx.se/mail/lib-2019-10/0104.html
Reported-by: Richard Alcock
Instead of using a fixed 256 byte buffer in the connectdata struct.
In my build, this reduces the size of the connectdata struct by 11.8%,
from 2160 to 1904 bytes with no functionality or performance loss.
This also fixes a bug in schannel's Curl_verify_certificate where it
called Curl_sspi_strerror when it should have called Curl_strerror for
string from GetLastError. the only effect would have been no text or the
wrong text being shown for the error.
Co-authored-by: Jay Satiro
Closes#3612
When building with Unicode on MSVC, the compiler warns about freeing a
pointer to const in Curl_unicodefree. Fix this by declaring it as
non-const and casting the argument to Curl_convert_UTF8_to_tchar to
non-const too, like we do in all other places.
Closes https://github.com/curl/curl/pull/3435
The productname from Microsoft is "Schannel", but in infof/failf
reporting we use "schannel". This removes different versions.
Closes#3243
Reviewed-by: Daniel Stenberg <daniel@haxx.se>
Curl_verify_certificate() must use the Curl_ prefix since it is globally
available in the lib and otherwise steps outside of our namespace!
Closes#3201
The result of a memory allocation should always be checked, as we may
run under memory pressure where even a small allocation can fail. This
adds checking and error handling to a few cases where the allocation
wasn't checked for success. In the ftp case, the freeing of the path
variable is moved ahead of the allocation since there is little point
in keeping it around across the strdup, and the separation makes for
more readable code. In nwlib, the lock is aslo freed in the error path.
Also bumps the copyright years on affected files.
Closes#3084
Reviewed-by: Jay Satiro <raysatiro@yahoo.com>
Reviewed-by: Daniel Stenberg <daniel@haxx.se>
Strings broken on multiple rows in the .c file need to have appropriate
whitespace padding on either side of the concatenation point to render
a correct amalgamated string. Fix by adding a space at the occurrences
found.
Closes#2986
Reviewed-by: Daniel Stenberg <daniel@haxx.se>
with clang-6.0:
```
vtls/schannel_verify.c: In function 'add_certs_to_store':
vtls/schannel_verify.c:212:30: warning: passing argument 11 of 'CryptQueryObject' from incompatible pointer type [-Wincompatible-pointer-types]
&cert_context)) {
^
In file included from /usr/share/mingw-w64/include/schannel.h:10:0,
from /usr/share/mingw-w64/include/schnlsp.h:9,
from vtls/schannel.h:29,
from vtls/schannel_verify.c:40:
/usr/share/mingw-w64/include/wincrypt.h:4437:26: note: expected 'const void **' but argument is of type 'CERT_CONTEXT ** {aka struct _CERT_CONTEXT **}'
WINIMPM WINBOOL WINAPI CryptQueryObject (DWORD dwObjectType, const void *pvObject, DWORD dwExpectedContentTypeFlags, DWORD dwExpectedFormatTypeFlags, DWORD dwFlags,
^~~~~~~~~~~~~~~~
```
Ref: https://msdn.microsoft.com/library/windows/desktop/aa380264
Closes https://github.com/curl/curl/pull/2648
OpenSSL has supported --cacert for ages, always accepting LF-only line
endings ("Unix line endings") as well as CR/LF line endings ("Windows
line endings").
When we introduced support for --cacert also with Secure Channel (or in
cURL speak: "WinSSL"), we did not take care to support CR/LF line
endings, too, even if we are much more likely to receive input in that
form when using Windows.
Let's fix that.
Happily, CryptQueryObject(), the function we use to parse the ca-bundle,
accepts CR/LF input already, and the trailing LF before the END
CERTIFICATE marker catches naturally any CR/LF line ending, too. So all
we need to care about is the BEGIN CERTIFICATE marker. We do not
actually need to verify here that the line ending is CR/LF. Just
checking for a CR or an LF is really plenty enough.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Closes https://github.com/curl/curl/pull/2592
- Move verify_certificate functionality in schannel.c into a new
file called schannel_verify.c. Additionally, some structure defintions
from schannel.c have been moved to schannel.h to allow them to be
used in schannel_verify.c.
- Make verify_certificate functionality for Schannel available on
all versions of Windows instead of just Windows CE. verify_certificate
will be invoked on Windows CE or when the user specifies
CURLOPT_CAINFO and CURLOPT_SSL_VERIFYPEER.
- In verify_certificate, create a custom certificate chain engine that
exclusively trusts the certificate store backed by the CURLOPT_CAINFO
file.
- doc updates of --cacert/CAINFO support for schannel
- Use CERT_NAME_SEARCH_ALL_NAMES_FLAG when invoking CertGetNameString
when available. This implements a TODO in schannel.c to improve
handling of multiple SANs in a certificate. In particular, all SANs
will now be searched instead of just the first name.
- Update tool_operate.c to not search for the curl-ca-bundle.crt file
when using Schannel to maintain backward compatibility. Previously,
any curl-ca-bundle.crt file found in that search would have been
ignored by Schannel. But, with CAINFO support, the file found by
that search would have been used as the certificate store and
could cause issues for any users that have curl-ca-bundle.crt in
the search path.
- Update url.c to not set the build time CURL_CA_BUNDLE if the selected
SSL backend is Schannel. We allow setting CA location for schannel
only when explicitly specified by the user via CURLOPT_CAINFO /
--cacert.
- Add new test cases 3000 and 3001. These test cases check that the first
and last SAN, respectively, matches the connection hostname. New test
certificates have been added for these cases. For 3000, the certificate
prefix is Server-localhost-firstSAN and for 3001, the certificate
prefix is Server-localhost-secondSAN.
- Remove TODO 15.2 (Add support for custom server certificate
validation), this commit addresses it.
Closes https://github.com/curl/curl/pull/1325
