since early versions of 1.0.2 openssl supports -curves command line
option, it allows us to set the curves advertised as supported
use the same approach to testing: advertise all, check what server
accepts, remove the accepted from list, repeat. When server aborts
connection or selects non ECC cipher, we know that we've tested all.
CApath is about 20% faster than CAfile so use it, also
save the received certificates from the servers for later analysis
(proper hostname checking, looking for certificates sharing private key,
etc.)
Use the mechanism from cipherscan to find location of ca cert bundle
firstly, test_cipher_on_target() will try at least 4 connections before
incurring the sleep, for aggressive rate limiter on server side it may be
too much, so sleep before every connection
secondly, because running external commands like sleep incurs a fork
penalty, we first check if it is necessary
it's relatively easy to make the cipher selection generic,
so that adding different clients is as easy as converting their
client hello cipher ordering to openssl cipher names
since now we know if server honours client order or not, we can use it
to properly simulate handshakes for a given client, also report
the general stats of this server configuration variable
the ECDH parameters come from server certificate - the point
on elliptic curve. The RSA comes from the signature on the certificate
which comes from CA
because neither M2crypto nor OpenSSL packages provide extensive
enough API to do certificate chain building, verification
and outputting of details, we have to pre-parse the data
with a C app that can access the full OpenSSL API.
I've also tried monkey patching the packages, but unfortunately
the result wasn't working reliably
The actual statistic collection (both about the chains and
specific certificates) will be done in a python script
While preferring RC4 in TLS1.0 or SSL3 was recommended before,
it was always known that TLS1.1 and TLS1.2 were not vulnerable against
BEAST, so forcing RC4 there is a mistake. Report number of such servers.
Two interesting server configurations are ones that support
only SSL3 or TLS1 only (old, but otherwise correctly configured servers)
and ones that support only TLS1.1 or up (brave admins that support
only new clients)
If server negotiates ADH or AECDH suite, openssl returns "ok" in
cert checking. Don't mark server as trusted because of that.
Don't collect statistics on servers that provide only untrusted
connections.
