For the various string-compare routines (strcmp, strcasecmp, str.*cmp)
use "strcmp()==0" instead of "!strcmp()"
Reviewed-by: Tim Hudson <tjh@openssl.org>
New ctrl sets current certificate based on certain criteria. Currently
two options: set the first valid certificate as current and set the
next valid certificate as current. Using these an application can
iterate over all certificates in an SSL_CTX or SSL structure.