add two RSA based ciphers for Windows/depends compatibility
also enforce server cipher ordering
also set ECDH to auto because vtnerd says it is good :)
When built with the depends system, openssl does not include any
cipher on the current whitelist, so add this one, which fixes the
problem, and does seem sensible.
It can allocate a lot when getting a lot of connections
(in particular, the stress test on windows apparently pushes
that memory to actual use, rather than just allocated)
When closing connections due to exiting, the IO service is
already gone, so the data exchange needed for a gracious SSL
shutdown cannot happen. We just close the socket in that case.
An override for the wallet to daemon connection is provided, but not for
other SSL contexts. The intent is to prevent users from supplying a
system CA as the "user" whitelisted certificate, which is less secure
since the key is controlled by a third party.
If the verification mode is `system_ca`, clients will now do hostname
verification. Thus, only certificates from expected hostnames are
allowed when SSL is enabled. This can be overridden by forcible setting
the SSL mode to autodetect.
Clients will also send the hostname even when `system_ca` is not being
performed. This leaks possible metadata, but allows servers providing
multiple hostnames to respond with the correct certificate. One example
is cloudflare, which getmonero.org is currently using.
If SSL is "enabled" via command line without specifying a fingerprint or
certificate, the system CA list is checked for server verification and
_now_ fails the handshake if that check fails. This change was made to
remain consistent with standard SSL/TLS client behavior. This can still
be overridden by using the allow any certificate flag.
If the SSL behavior is autodetect, the system CA list is still checked
but a warning is logged if this fails. The stream is not rejected
because a re-connect will be attempted - its better to have an
unverified encrypted stream than an unverified + unencrypted stream.
Specifying SSL certificates for peer verification does an exact match,
making it a not-so-obvious alias for the fingerprints option. This
changes the checks to OpenSSL which loads concatenated certificate(s)
from a single file and does a certificate-authority (chain of trust)
check instead. There is no drop in security - a compromised exact match
fingerprint has the same worse case failure. There is increased security
in allowing separate long-term CA key and short-term SSL server keys.
This also removes loading of the system-default CA files if a custom
CA file or certificate fingerprint is specified.
Manually initialize the array_entry_t iterator to ensure it points
to the correct m_array, thereby preventing a potential use-after-free
situation.
Signed-off-by: Guido Vranken <guidovranken@gmail.com>
