- 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
TLS servers may request a certificate from the client. This request
includes a list of 0 or more acceptable issuer DNs. The client may use
this list to determine which certificate to send. GnuTLS's default
behavior is to not send a client certificate if there is no
match. However, OpenSSL's default behavior is to send the configured
certificate. The `GNUTLS_FORCE_CLIENT_CERT` flag mimics OpenSSL
behavior.
Authored-by: jethrogb on github
Fixes#1411Closes#4958
Avoid "reparsing" the content and instead deliver more exactly what is
provided in the certificate and avoid truncating the data after 512
bytes as done previously. This no longer removes embedded newlines.
Fixes#4837
Reported-by: bnfp on github
Closes#4841
As detailed in DEPRECATE.md, the polarssl support is now removed after
having been disabled for 6 months and nobody has missed it.
The threadlock files used by mbedtls are renamed to an 'mbedtls' prefix
instead of the former 'polarssl' and the common functions that
previously were shared between mbedtls and polarssl and contained the
name 'polarssl' have now all been renamed to instead say 'mbedtls'.
Closes#4825
- 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
Factor out common I/O loop as bearssl_run_until, which reads/writes TLS
records until the desired engine state is reached. This is now used for
the handshake, read, write, and close.
Match OpenSSL SSL_write behavior, and don't return the number of bytes
written until the corresponding records have been completely flushed
across the socket. This involves keeping track of the length of data
buffered into the TLS engine, and assumes that when CURLE_AGAIN is
returned, the write function will be called again with the same data
and length arguments. This is the same requirement of SSL_write.
Handle TLS close notify as EOF when reading by returning 0.
Closes https://github.com/curl/curl/pull/4748
Have intermediate certificates in the trust store be treated as
trust-anchors, in the same way as self-signed root CA certificates
are. This allows users to verify servers using the intermediate cert
only, instead of needing the whole chain.
Other TLS backends already accept partial chains.
Reported-by: Jeffrey Walton
Bug: https://curl.haxx.se/mail/lib-2019-11/0094.html
- 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
- 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
Prior to this change schannel ignored --tls-max (CURL_SSLVERSION_MAX_
macros) when --tlsv1 (CURL_SSLVERSION_TLSv1) or default TLS
(CURL_SSLVERSION_DEFAULT), using a max of TLS 1.2 always.
Closes https://github.com/curl/curl/pull/4633
- Disable the extra sensitivity except in debug builds (--enable-debug).
- Improve SYSCALL error message logic in ossl_send and ossl_recv so that
"No error" / "Success" socket error text isn't shown on SYSCALL error.
Prior to this change 0ab38f5 (precedes 7.67.0) increased the sensitivity
of OpenSSL's SSL_ERROR_SYSCALL error so that abrupt server closures were
also considered errors. For example, a server that does not send a known
protocol termination point (eg HTTP content length or chunked encoding)
_and_ does not send a TLS termination point (close_notify alert) would
cause an error if it closed the connection.
To be clear that behavior made it into release build 7.67.0
unintentionally. Several users have reported it as an issue.
Ultimately the idea is a good one, since it can help prevent against a
truncation attack. Other SSL backends may already behave similarly (such
as Windows native OS SSL Schannel). However much more of our user base
is using OpenSSL and there is a mass of legacy users in that space, so I
think that behavior should be partially reverted and then rolled out
slowly.
This commit changes the behavior so that the increased sensitivity is
disabled in all curl builds except curl debug builds (DEBUGBUILD). If
after a period of time there are no major issues then it can be enabled
in dev and release builds with the newest OpenSSL (1.1.1+), since users
using the newest OpenSSL are the least likely to have legacy problems.
Bug: https://github.com/curl/curl/issues/4409#issuecomment-555955794
Reported-by: Bjoern Franke
Fixes https://github.com/curl/curl/issues/4624
Closes https://github.com/curl/curl/pull/4623
- 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
... as it can make it wait there for a long time for no good purpose.
Patched-by: Jay Satiro
Reported-by: Bylon2 on github
Adviced-by: Nikos Mavrogiannopoulos
Fixes#4487Closes#4541
It was already fixed for BoringSSL in commit a0f8fccb1e.
LibreSSL has had the second argument to SSL_CTX_set_min_proto_version
as uint16_t ever since the function was added in [0].
[0] 56f107201b
Closes https://github.com/curl/curl/pull/4397
For FTPS transfers, curl gets close_notify on the data connection
without that being a signal to close the control connection!
Regression since 3f5da4e59a (7.65.0)
Reported-by: Zenju on github
Reviewed-by: Jay Satiro
Fixes#4329Closes#4340
OpenSSL 1.1.0 adds SSL_CTX_set_<min|max>_proto_version() that we now use
when available. Existing code is preserved for older versions of
OpenSSL.
Closes#4304
SSL_VersionRangeGetDefault returns (TLSv1.0, TLSv1.2) as supported
range in NSS 3.45. It looks like the intention is to raise the minimum
version rather than lowering the maximum, so adjust accordingly. Note
that the caller (nss_setup_connect) initializes the version range to
(TLSv1.0, TLSv1.3), so there is no need to check for >= TLSv1.0 again.
Closes#4187
Reviewed-by: Daniel Stenberg
Reviewed-by: Kamil Dudka
