--- /dev/null
+# Valid certificate SSL
+# Pattern quality: good notsofast
+# Protocol groups: ietf_proposed_standard secure
+
+# This matches anything claiming to use a valid certificate from a well
+# known certificate authority.
+#
+# This is a subset of ssl, so it needs to come first to match.
+#
+# Note that opening a website that has a valid certificate will
+# open one connection that matches this and many ssl connections that
+# only match the ssl pattern. Thus, this pattern may not be very useful.
+#
+# This pattern is believed match only the above, but may not match all
+# of it.
+#
+# To get or provide more information about this protocol and/or pattern:
+# http://www.protocolinfo.org/wiki/SSL
+# http://lists.sourceforge.net/lists/listinfo/l7-filter-developers
+#
+# the certificate authority info is sent in quasi plain text, if it matches
+# a well known certificate authority then we will assume it is a
+# web/imaps/etc server. Other ssl may be good too, but it should fall under
+# a different rule
+
+validcertssl
+^.?.?\x01\x03\x01?.*\x0b.*(thawte|equifax secure certificate authority|rsa data security, inc|verisign, inc|gte cybertrust root|entrust\.net limited)