The code already assumes the presence of fopen(3) and errno, and, by
extension, fclose(3) and strerror(3), so just use those instead of the
BIO wrappers.
Additionally, don't fail to initialise if the DH file does exist but
parsing it fails, as per the pre-existing comment about them being
optional.
* Don't manually initialise libssl 1.1.0 -- it does this automatically
* SSL_library_init() should be called first otherwise
* Move SSL_CTX construction to rb_setup_ssl_server()
* Test for all required files (certificate & key) before doing anything
* Free the old CTX before constructing a new one (Fixes#186)
* Don't try to set options / ciphers etc on a NULL CTX
* Clean up ifdef indentation
* Fix DH parameters memory leak
The OpenSSL backend is the only one that assigns a non-constant
value to the length variable. Use the correct type for its
pointer and cast instead.
[ci skip]
* Certificate fingerprint length functions return an "int", so use an
int when calculating the length
* Clean up the OpenSSL certificate fingerprint if() and indentation mess
These operate on the SubjectPublicKeyInfo of the certificate, which does
change unless the private key is changed. This allows the fingerprint to
stay constant even if the certificate is reissued.
(The same fingerprint is also used by DANE)
