setup-vms.h: More symbols for SHA256, hacks for older VAX
openssl.h: Use OpenSSL OPENSSL_NO_SHA256 macro to allow building on VAX.
openssl.c: Use OpenSSL version checks and OPENSSL_NO_SHA256 macro to
allow building on VAX and 64 bit VMS.
This makes curl pick better (stronger) ciphers by default. The strongest
available ciphers are fine according to the HTTP/2 spec so an OpenSSL
built curl is no longer rejected by string HTTP/2 servers.
Bug: http://curl.haxx.se/bug/view.cgi?id=1487
SSLeay was the name of the library that was subsequently turned into
OpenSSL many moons ago (1999). curl does not work with the old SSLeay
library since years. This is now reflected by only using USE_OPENSSL in
code that depends on OpenSSL.
curl_schannel.h:123: warning: right-hand operand of comma expression
has no effect
Some instances of the curlssl_close_all() function were declared with a
void return type whilst others as int. The schannel version returned
CURLE_NOT_BUILT_IN and others simply returned zero, but in all cases the
return code was ignored by the calling function Curl_ssl_close_all().
For the time being and to keep the internal API consistent, changed all
declarations to use a void return type.
To reduce code we might want to consider removing the unimplemented
versions and use a void #define like schannel does.
To force each backend implementation to really attempt to provide proper
random. If a proper random function is missing, then we can explicitly
make use of the default one we use when TLS support is missing.
This commit makes sure it works for darwinssl, gnutls, nss and openssl.
By default even recent versions of OpenSSL support and accept both
"export strength" ciphers, small-bitsize ciphers as well as downright
deprecated ones.
This change sets a default cipher set that avoids the worst ciphers, and
subsequently makes https://www.howsmyssl.com/a/check no longer grade
curl/OpenSSL connects as 'Bad'.
Bug: http://curl.haxx.se/bug/view.cgi?id=1323
Reported-by: Jeff Hodges
