Snort mailing list archives

Interpretation of "offset" in context of "uricontent" keyword


From: "Intru Defender" <intrusec () rediffmail com>
Date: 7 Jan 2006 20:54:18 -0000

Hi All,
I am reposting this question in the hope of getting some replies:

======================================================================
I need a little clarification about interpretation of "offset" modifier in conjuction with "uricontent" keyword. 

Does Snort treats "offset" differently in case of "uricontent" keyword?

Does in case of "uricontent" keyword, snort treat "offset:0" from the start of URI, and, not from the start of the 
payload?

The snort manual says that the "offset" tells how many bytes to skip before starting looking for the specified 
"content" keyword and "offset" is calculated from the start of payload. For example: 

content: ".html"; offset:4; would mean start looking for ".html" after 4 bytes.

However, in case of "uricontent" keyword, will uricontent: ".html"; offset:0; depth:5; would mean start looking for 
start of URI and in next 5 characters? Or it will mean, start looking for ".html" in first 5 bytes of payload.

Any help will be highly appricated.

Thanks,

Intru Defender

Current thread: