Snort rules with openAppId feature

[Guillaume DALEUX <guillaume.daleux () gmail com>]

Hello,

I have one question about snort with openappid.

I know that the 'metadata service" keyword is now very important with
Sourcefire v5 because rules without this keyword are not inspected even if
the port variable is correct.

For example, this rule will never match on http (even if the destination
port is 80) :
alert tcp any any -> any 80 (content:"toto");

And this rule will match :
alert tcp any any -> any 80 (content:"toto"; metadata:"service http");

I would like to know if I will have the same behaviour with the last snort
version with openappid feature ?

If yes, I will have a problem to detect non standard port.

For example, if I want to detect a non standard port for http server, I
would like to try something like that :

alert tcp any any -> any !80 (msg:"non standard HTTP port"; appid: http;
sid:1000000; rev:1; )

But, if http rules are only inspected if "metadata service http" keyword is
present. I will add it and my rule will always match....

Regards,

Guillaume

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