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
... 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
They serve very little purpose and mostly just add noise. Most of them
have been around for a very long time. I read them all before removing
or rephrasing them.
Ref: #3876Closes#3883
As soon as a TLS backend gets ALPN conformation about the specific HTTP
version it can now set the multiplex situation for the "bundle" and
trigger moving potentially queued up transfers to the CONNECT state.
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
- Treat CURL_SSLVERSION_MAX_NONE the same as
CURL_SSLVERSION_MAX_DEFAULT. Prior to this change NONE would mean use
the minimum version also as the maximum.
This is a follow-up to 6015cef which changed the behavior of setting
the SSL version so that the requested version would only be the minimum
and not the maximum. It appears it was (mostly) implemented in OpenSSL
but not other backends. In other words CURL_SSLVERSION_TLSv1_0 used to
mean use just TLS v1.0 and now it means use TLS v1.0 *or later*.
- Fix CURL_SSLVERSION_MAX_DEFAULT for OpenSSL.
Prior to this change CURL_SSLVERSION_MAX_DEFAULT with OpenSSL was
erroneously treated as always TLS 1.3, and would cause an error if
OpenSSL was built without TLS 1.3 support.
Co-authored-by: Daniel Gustafsson
Fixes https://github.com/curl/curl/issues/2969
Closes https://github.com/curl/curl/pull/3012
... instead of previous separate struct fields, to make it easier to
extend and change individual backends without having to modify them all.
closes#2547
unit1309 and vtls/gtls: error: arithmetic on a null pointer treated as a
cast from integer to pointer is a GNU extension
Reported-by: Rikard Falkeborn
Fixes#2466Closes#2468
When targeting x64, MinGW-w64 complains about conversions between
32-bit long and 64-bit pointers. Fix this by reusing the
GNUTLS_POINTER_TO_SOCKET_CAST / GNUTLS_SOCKET_TO_POINTER_CAST logic
from gtls.c, moving it to warnless.h as CURLX_POINTER_TO_INTEGER_CAST /
CURLX_INTEGER_TO_POINTER_CAST.
Closes https://github.com/curl/curl/pull/2341
There is information about the compiled-in SSL backends that is really
no concern of any code other than the SSL backend itself, such as which
function (if any) implements SHA-256 summing.
And there is information that is really interesting to the user, such as
the name, or the curl_sslbackend value.
Let's factor out the latter into a publicly visible struct. This
information will be used in the upcoming API to set the SSL backend
globally.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When building software for the masses, it is sometimes not possible to
decide for all users which SSL backend is appropriate.
Git for Windows, for example, uses cURL to perform clones, fetches and
pushes via HTTPS, and some users strongly prefer OpenSSL, while other
users really need to use Secure Channel because it offers
enterprise-ready tools to manage credentials via Windows' Credential
Store.
The current Git for Windows versions use the ugly work-around of
building libcurl once with OpenSSL support and once with Secure Channel
support, and switching out the binaries in the installer depending on
the user's choice.
Needless to say, this is a super ugly workaround that actually only
works in some cases: Git for Windows also comes in a portable form, and
in a form intended for third-party applications requiring Git
functionality, in which cases this "swap out libcurl-4.dll" simply is
not an option.
Therefore, the Git for Windows project has a vested interest in teaching
cURL to make the SSL backend a *runtime* option.
This patch makes that possible.
By running ./configure with multiple --with-<backend> options, cURL will
be built with multiple backends.
For the moment, the backend can be configured using the environment
variable CURL_SSL_BACKEND (valid values are e.g. "openssl" and
"schannel").
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
So far, all of the SSL backends' private data has been declared as
part of the ssl_connect_data struct, in one big #if .. #elif .. #endif
block.
This can only work as long as the SSL backend is a compile-time option,
something we want to change in the next commits.
Therefore, let's encapsulate the exact data needed by each SSL backend
into a private struct, and let's avoid bleeding any SSL backend-specific
information into urldata.h. This is also necessary to allow multiple SSL
backends to be compiled in at the same time, as e.g. OpenSSL's and
CyaSSL's headers cannot be included in the same .c file.
To avoid too many malloc() calls, we simply append the private structs
to the connectdata struct in allocate_conn().
This requires us to take extra care of alignment issues: struct fields
often need to be aligned on certain boundaries e.g. 32-bit values need to
be stored at addresses that divide evenly by 4 (= 32 bit / 8
bit-per-byte).
We do that by assuming that no SSL backend's private data contains any
fields that need to be aligned on boundaries larger than `long long`
(typically 64-bit) would need. Under this assumption, we simply add a
dummy field of type `long long` to the `struct connectdata` struct. This
field will never be accessed but acts as a placeholder for the four
instances of ssl_backend_data instead. the size of each ssl_backend_data
struct is stored in the SSL backend-specific metadata, to allow
allocate_conn() to know how much extra space to allocate, and how to
initialize the ssl[sockindex]->backend and proxy_ssl[sockindex]->backend
pointers.
This would appear to be a little complicated at first, but is really
necessary to encapsulate the private data of each SSL backend correctly.
And we need to encapsulate thusly if we ever want to allow selecting
CyaSSL and OpenSSL at runtime, as their headers cannot be included within
the same .c file (there are just too many conflicting definitions and
declarations for that).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
At the moment, cURL's SSL backend needs to be configured at build time.
As such, it is totally okay for them to hard-code their backend-specific
data in the ssl_connect_data struct.
In preparation for making the SSL backend a runtime option, let's make
the access of said private data a bit more abstract so that it can be
adjusted later in an easy manner.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In the ongoing endeavor to abstract out all SSL backend-specific
functionality, this is the next step: Instead of hard-coding how the
different SSL backends access their internal data in getinfo.c, let's
implement backend-specific functions to do that task.
This will also allow for switching SSL backends as a runtime option.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
These functions are all available via the Curl_ssl struct now, no need
to declare them separately anymore.
As the global declarations are removed, the corresponding function
definitions are marked as file-local. The only two exceptions here are
Curl_mbedtls_shutdown() and Curl_polarssl_shutdown(): only the
declarations were removed, there are no function definitions to mark
file-local.
Please note that Curl_nss_force_init() is *still* declared globally, as
the only SSL backend-specific function, because it was introduced
specifically for the use case where cURL was compiled with
`--without-ssl --with-nss`. For details, see f3b77e561 (http_ntlm: add
support for NSS, 2010-06-27).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The entire idea of introducing the Curl_ssl struct to describe SSL
backends is to prepare for choosing the SSL backend at runtime.
To that end, convert all the #ifdef have_curlssl_* style conditionals
to use bit flags instead.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The SHA-256 checksumming is also an SSL backend-specific function.
Let's include it in the struct declaring the functionality of SSL
backends.
In contrast to MD5, there is no fall-back code. To indicate this, the
respective entries are NULL for those backends that offer no support for
SHA-256 checksumming.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The MD5 summing is also an SSL backend-specific function. So let's
include it, offering the previous fall-back code as a separate function
now: Curl_none_md5sum(). To allow for that, the signature had to be
changed so that an error could be returned from the implementation
(Curl_none_md5sum() can run out of memory).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is the first step to unify the SSL backend handling. Now all the
SSL backend-specific functionality is accessed via a global instance of
the Curl_ssl struct.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The idea of introducing the Curl_ssl struct was to unify how the SSL
backends are declared and called. To this end, we now provide an
instance of the Curl_ssl struct for each and every SSL backend.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This patch makes the signature of the _cleanup() functions consistent
among the SSL backends, in preparation for unifying the way all SSL
backends are accessed.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
- Change gnutls pointer/int macros to pointer/curl_socket_t.
Prior to this change they used long type as well.
The size of the `long` data type can be shorter than that of pointer
types. This is the case most notably on Windows.
If C99 were acceptable, we could simply use `intptr_t` here. But we
want to retain C89 compatibility.
Simply use the trick of performing pointer arithmetic with the NULL
pointer: to convert an integer `i` to a pointer, simply take the
address of the `i`th element of a hypothetical character array
starting at address NULL. To convert back, simply cast the pointer
difference.
Thanks to Jay Satiro for the initial modification to use curl_socket_t
instead of int/long.
Closes#1617
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This commit introduces the CURL_SSLVERSION_MAX_* constants as well as
the --tls-max option of the curl tool.
Closes https://github.com/curl/curl/pull/1166
Check for presence of gnutls_alpn_* and gnutls_ocsp_* functions during
configure instead of relying on the version number. GnuTLS has options
to turn these features off and we ca just work with with such builds
like we work with older versions.
Signed-off-by: Marcus Hoffmann <m.hoffmann@cartelsol.com>
Closes#1204
