feat: close rdp.login.success on rdp.session.logoff (v0.5.12)

Ingest correlates direct RDP logoff with open login events on the same host and user. Terminate-session treats missing qwinsta as already logged off.

backend/app/services/rdp_session_logoff.py

@@ -0,0 +1,148 @@
+"""Correlate direct RDP logoff (Security 4634/4647) with workstation rdp.login.success."""
+
+from __future__ import annotations
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+from sqlalchemy.orm.attributes import flag_modified
+
+from app.models import Event
+from app.services.host_sessions import (
+    SESSION_TERMINATED_AT_KEY,
+    _details_dict,
+    _event_login_user,
+)
+from app.services.rdg_workstation_session import (
+    WORKSTATION_LOGIN_TYPE,
+    event_closed_by_rdg,
+    users_match_rdg,
+)
+
+SESSION_CLOSED_BY_LOGOFF_AT_KEY = "session_closed_by_logoff_at"
+SESSION_CLOSED_BY_LOGOFF_EVENT_ID_KEY = "session_closed_by_logoff_event_id"
+
+LOGOFF_EVENT_TYPE = "rdp.session.logoff"
+LOGOFF_EVENT_TYPES = frozenset({LOGOFF_EVENT_TYPE})
+
+
+def event_closed_by_logoff(event: Event) -> bool:
+    details = _details_dict(event)
+    at = details.get(SESSION_CLOSED_BY_LOGOFF_AT_KEY)
+    return at is not None and str(at).strip() != ""
+
+
+def mark_login_closed_by_logoff(login_event: Event, *, logoff_event: Event) -> None:
+    details = dict(_details_dict(login_event))
+    details[SESSION_CLOSED_BY_LOGOFF_AT_KEY] = logoff_event.occurred_at.isoformat()
+    details[SESSION_CLOSED_BY_LOGOFF_EVENT_ID_KEY] = logoff_event.id
+    login_event.details = details
+    flag_modified(login_event, "details")
+
+
+def _login_already_closed(login_event: Event) -> bool:
+    details = _details_dict(login_event)
+    if details.get("session_terminated") is True:
+        return True
+    at = details.get(SESSION_TERMINATED_AT_KEY)
+    if at is not None and str(at).strip() != "":
+        return True
+    if event_closed_by_rdg(login_event):
+        return True
+    return event_closed_by_logoff(login_event)
+
+
+def find_workstation_login_for_logoff(db: Session, logoff_event: Event) -> Event | None:
+    if logoff_event.type not in LOGOFF_EVENT_TYPES:
+        return None
+
+    logoff_user = _event_login_user(logoff_event)
+    if not logoff_user:
+        return None
+    logoff_at = logoff_event.occurred_at
+    host_id = logoff_event.host_id
+    if host_id is None:
+        return None
+
+    candidates = db.scalars(
+        select(Event)
+        .where(
+            Event.host_id == host_id,
+            Event.type == WORKSTATION_LOGIN_TYPE,
+            Event.occurred_at <= logoff_at,
+            Event.id != logoff_event.id,
+        )
+        .order_by(Event.occurred_at.desc())
+    ).all()
+
+    logoff_details = _details_dict(logoff_event)
+    logoff_ip = str(logoff_details.get("ip_address") or "").strip()
+
+    for login in candidates:
+        if _login_already_closed(login):
+            continue
+        login_user = _event_login_user(login)
+        if not users_match_rdg(login_user, logoff_user):
+            continue
+        if logoff_ip and logoff_ip not in ("", "-"):
+            login_ip = str(_details_dict(login).get("ip_address") or "").strip()
+            if login_ip and login_ip not in ("", "-") and login_ip != logoff_ip:
+                continue
+        return login
+    return None
+
+
+def find_logoff_after_workstation_login(db: Session, login_event: Event) -> Event | None:
+    """Runtime lookup for historical logins without persisted close flag."""
+    if login_event.type != WORKSTATION_LOGIN_TYPE:
+        return None
+    if _login_already_closed(login_event):
+        return None
+
+    host_id = login_event.host_id
+    if host_id is None:
+        return None
+
+    login_user = _event_login_user(login_event)
+    if not login_user:
+        return None
+    login_at = login_event.occurred_at
+    login_ip = str(_details_dict(login_event).get("ip_address") or "").strip()
+
+    candidates = db.scalars(
+        select(Event)
+        .where(
+            Event.host_id == host_id,
+            Event.type == LOGOFF_EVENT_TYPE,
+            Event.occurred_at >= login_at,
+            Event.id != login_event.id,
+        )
+        .order_by(Event.occurred_at.asc())
+    ).all()
+
+    for logoff in candidates:
+        if not users_match_rdg(_event_login_user(logoff), login_user):
+            continue
+        logoff_ip = str(_details_dict(logoff).get("ip_address") or "").strip()
+        if login_ip and login_ip not in ("", "-") and logoff_ip and logoff_ip not in ("", "-"):
+            if login_ip != logoff_ip:
+                continue
+        return logoff
+    return None
+
+
+def resolve_workstation_login_closed_by_logoff(db: Session, login_event: Event) -> bool:
+    if event_closed_by_logoff(login_event):
+        return True
+    return find_logoff_after_workstation_login(db, login_event) is not None
+
+
+def close_workstation_session_for_rdp_logoff(db: Session, logoff_event: Event) -> Event | None:
+    """On direct RDP logoff, mark matching open workstation login as session-closed."""
+    if logoff_event.type not in LOGOFF_EVENT_TYPES:
+        return None
+
+    login = find_workstation_login_for_logoff(db, logoff_event)
+    if login is None:
+        return None
+    mark_login_closed_by_logoff(login, logoff_event=logoff_event)
+    return login