Apache Reference: mod_ssl, SSLRequire
Allow Access Only When a Boolean Expression Is True
Syntax: SSLRequire A
Example: SSLRequire %{SSL_CIPHER} !~ m/^(EXP|NULL)-/
Since: Apache 1.3
This directive specifies a general access requirement that must
be fulfilled to allow access. It is a very powerful
directive because the expression is an arbitrarily complex
Boolean expression containing any number of access checks. See
the mod_ssl user manual for more details.