Coverity scan picked up on the result on g_chmod_hex() not being
checked. This call has now been moved to the place where the file is
checked for writeability, as we only really need to make it when the
file is created.
SSL_CTX_set_ecdh_auto() was introduced for OpenSSL 1.0.2. It
has no effect for OpenSSL 1.1.0 and later. For versions before
1.0.2 and after (and including 1.1.0) it should not be called.
The macro was erroneously being called twice for OpenSSL 3.0.0 and
later - this has also been remedied
Actually, TLSv1.3 will be enabled without this change if xrdp is compiled
with OpenSSL or alternatives which support TLSv1.3. This commit makes to
enable or disable TLSv1.3 explicitly. Also, this commit adds a log
"TLSv1.3 enabled by config, but not supported by system OpenSSL". if
xrdp installation doesn't support TLSv1.3. It should be user-friendly.
make it possible to use regular (non EC) EDH ciphers. To make this
possible a Diffie-Hellman parameter must be passed to the openssl
library. There are a few options possible as described in the manuals at
[1] and [2]. Simplest approach is to generate a DH parameter using
openssl dhparam -C <lenght> and include the code into the application.
The lenght used for this commit is 2236 bits long, which is the longest
possible without risking backward incompatibilities with old systems as
stated in [1]. Newer systems should use ECDH anyway, so it makes sense
to keep this method as compatible with older system as possible.
Paramters longer than 2048 should still be secure enough at the time of
writing.
[1] https://wiki.openssl.org/index.php/Diffie-Hellman_parameters
[2] https://wiki.openssl.org/index.php/Manual:SSL_CTX_set_tmp_dh_callback(3)
In C, an empty argument list in a declaration means that the function
can accept any arguments. Use "void" instead, it means "no arguments".
C++ treats void and empty list as "no arguments".
Conditional preprocessor directives spread throughout the code set a bad
example.
The new backport code is located in one place. The compiler checks
argument types. The backport code has no access to the caller variables.
The main code has all advantages of the new, more compact API.
matt335672