zeek/scripts/base/protocols/socks/main.zeek
Jon Siwek 05cf511f18 GH-1119: add base/protcols/conn/removal-hooks.zeek
This adds two new functions: `Conn::register_removal_hook()` and
`Conn::unregister_removal_hook()` for registering a hook function to be
called back during `connection_state_remove`.  The benefit of using hook
callback approach is better scalability: the overhead of unrelated
protocols having to dispatch no-op `connection_state_remove` handlers is
avoided.
2020-09-11 12:12:10 -07:00

127 lines
3.9 KiB
Text

@load base/frameworks/tunnels
@load ./consts
@load base/protocols/conn/removal-hooks
module SOCKS;
export {
redef enum Log::ID += { LOG };
## Whether passwords are captured or not.
option default_capture_password = F;
## The record type which contains the fields of the SOCKS log.
type Info: record {
## Time when the proxy connection was first detected.
ts: time &log;
## Unique ID for the tunnel - may correspond to connection uid
## or be non-existent.
uid: string &log;
## The connection's 4-tuple of endpoint addresses/ports.
id: conn_id &log;
## Protocol version of SOCKS.
version: count &log;
## Username used to request a login to the proxy.
user: string &log &optional;
## Password used to request a login to the proxy.
password: string &log &optional;
## Server status for the attempt at using the proxy.
status: string &log &optional;
## Client requested SOCKS address. Could be an address, a name
## or both.
request: SOCKS::Address &log &optional;
## Client requested port.
request_p: port &log &optional;
## Server bound address. Could be an address, a name or both.
bound: SOCKS::Address &log &optional;
## Server bound port.
bound_p: port &log &optional;
## Determines if the password will be captured for this request.
capture_password: bool &default=default_capture_password;
};
## Event that can be handled to access the SOCKS
## record as it is sent on to the logging framework.
global log_socks: event(rec: Info);
## SOCKS finalization hook. Remaining SOCKS info may get logged when it's called.
global finalize_socks: Conn::RemovalHook;
}
const ports = { 1080/tcp };
redef likely_server_ports += { ports };
event zeek_init() &priority=5
{
Log::create_stream(SOCKS::LOG, [$columns=Info, $ev=log_socks, $path="socks"]);
Analyzer::register_for_ports(Analyzer::ANALYZER_SOCKS, ports);
}
redef record connection += {
socks: SOCKS::Info &optional;
};
function set_session(c: connection, version: count)
{
if ( ! c?$socks )
{
c$socks = [$ts=network_time(), $id=c$id, $uid=c$uid, $version=version];
Conn::register_removal_hook(c, finalize_socks);
}
}
event socks_request(c: connection, version: count, request_type: count,
sa: SOCKS::Address, p: port, user: string) &priority=5
{
set_session(c, version);
c$socks$request = sa;
c$socks$request_p = p;
# Copy this conn_id and set the orig_p to zero because in the case of SOCKS proxies there will
# be potentially many source ports since a new proxy connection is established for each
# proxied connection. We treat this as a singular "tunnel".
local cid = copy(c$id);
cid$orig_p = 0/tcp;
Tunnel::register([$cid=cid, $tunnel_type=Tunnel::SOCKS]);
}
event socks_reply(c: connection, version: count, reply: count, sa: SOCKS::Address, p: port) &priority=5
{
set_session(c, version);
if ( version == 5 )
c$socks$status = v5_status[reply];
else if ( version == 4 )
c$socks$status = v4_status[reply];
c$socks$bound = sa;
c$socks$bound_p = p;
}
event socks_login_userpass_request(c: connection, user: string, password: string) &priority=5
{
# Authentication only possible with the version 5.
set_session(c, 5);
c$socks$user = user;
if ( c$socks$capture_password )
c$socks$password = password;
}
event socks_login_userpass_reply(c: connection, code: count) &priority=5
{
# Authentication only possible with the version 5.
set_session(c, 5);
c$socks$status = v5_status[code];
}
hook finalize_socks(c: connection)
{
# This will handle the case where the analyzer failed in some way and was
# removed. We probably don't want to log these connections.
if ( "SOCKS" in c$service )
Log::write(SOCKS::LOG, c$socks);
}