zeek/scripts/base/protocols/http/entities.bro

121 lines
2.9 KiB
Text

##! Analysis and logging for MIME entities found in HTTP sessions.
@load base/frameworks/files
@load base/utils/strings
@load base/utils/files
@load ./main
module HTTP;
export {
type Entity: record {
## Filename for the entity if discovered from a header.
filename: string &optional;
};
redef record Info += {
## An ordered vector of file unique IDs.
orig_fuids: vector of string &log &optional;
## An ordered vector of mime types.
orig_mime_types: vector of string &log &optional;
## An ordered vector of file unique IDs.
resp_fuids: vector of string &log &optional;
## An ordered vector of mime types.
resp_mime_types: vector of string &log &optional;
## The current entity.
current_entity: Entity &optional;
## Current number of MIME entities in the HTTP request message
## body.
orig_mime_depth: count &default=0;
## Current number of MIME entities in the HTTP response message
## body.
resp_mime_depth: count &default=0;
};
redef record fa_file += {
http: HTTP::Info &optional;
};
}
event http_begin_entity(c: connection, is_orig: bool) &priority=10
{
set_state(c, F, is_orig);
if ( is_orig )
++c$http$orig_mime_depth;
else
++c$http$resp_mime_depth;
c$http$current_entity = Entity();
}
event http_header(c: connection, is_orig: bool, name: string, value: string) &priority=3
{
if ( name == "CONTENT-DISPOSITION" &&
/[fF][iI][lL][eE][nN][aA][mM][eE]/ in value )
{
c$http$current_entity$filename = extract_filename_from_content_disposition(value);
}
else if ( name == "CONTENT-TYPE" &&
/[nN][aA][mM][eE][:blank:]*=/ in value )
{
c$http$current_entity$filename = extract_filename_from_content_disposition(value);
}
}
event file_over_new_connection(f: fa_file, c: connection, is_orig: bool) &priority=5
{
if ( f$source == "HTTP" && c?$http )
{
f$http = c$http;
if ( c$http?$current_entity && c$http$current_entity?$filename )
f$info$filename = c$http$current_entity$filename;
if ( f$is_orig )
{
if ( ! c$http?$orig_fuids )
c$http$orig_fuids = string_vec(f$id);
else
c$http$orig_fuids[|c$http$orig_fuids|] = f$id;
}
else
{
if ( ! c$http?$resp_fuids )
c$http$resp_fuids = string_vec(f$id);
else
c$http$resp_fuids[|c$http$resp_fuids|] = f$id;
}
}
}
event file_mime_type(f: fa_file, mime_type: string) &priority=5
{
if ( ! f?$http || ! f?$is_orig )
return;
if ( f$is_orig )
{
if ( ! f$http?$orig_mime_types )
f$http$orig_mime_types = string_vec(mime_type);
else
f$http$orig_mime_types[|f$http$orig_mime_types|] = mime_type;
}
else
{
if ( ! f$http?$resp_mime_types )
f$http$resp_mime_types = string_vec(mime_type);
else
f$http$resp_mime_types[|f$http$resp_mime_types|] = mime_type;
}
}
event http_end_entity(c: connection, is_orig: bool) &priority=5
{
if ( c?$http && c$http?$current_entity )
delete c$http$current_entity;
}