Filestore keyword by default (... filestore; ... ) marks only the file in the
same direction as the rule match for storing. This makes sense when inspecting
individual files (filemagic, filename, etc) but not so much when looking at
suspicious file requests, where the actual file is in the response.
The filestore keyword now takes 2 optional options:
filestore:<direction>,<scope>;
By default the direction is "same as rule match", and scope is "currently
inspected file".
For direction the following values are possible: "request" and "to_server",
"response" and "to_client", "both".
For scope the following values are possible: "tx" for all files in the current
HTTP/1.1 transation, "ssn" and "flow" for all files in the session/flow.
For the above case, where a suspious request should lead to a response file
download, this would work:
alert http ... content:"/suspicious/"; http_uri; filestore:response; ...
- Enable response body tracking
- Enable file extraction for responses
- File store meta file includes magic, close reason.
- Option to force magic lookup for all stored files.
- Fix libmagic calls thead safety.
Stateful detection for app layer detection keywords, except uricontent. Stores it's partial results in the flow structure. Other modifications:
- Generalize transaction tracking, logging and inspection.
- Adapt http and dcerpc to use the new transaction handling.
- Stream engine now always notifies app layer of a stream eof.
This commit fixes bug #124.
- improve locking of application layer handling, making sure that the flow cannot be freed/cleared when the detection engine is still working with it.
- add a check to the app layer detection to make sure that a match function will only inspect an app layer state if it's of the right type.