From 75747824e9c7893b59319aede7101b2540957a1a Mon Sep 17 00:00:00 2001
From: Stephane de Labrusse <stephdl@de-labrusse.fr>
Date: Fri, 20 Sep 2024 09:49:48 +0200
Subject: [PATCH] Add tainted nextcloud-logs.yaml parser to crowdsec.service
 (#54)

* Add tainted nextcloud-logs.yaml parser NethServer/dev#7018
---
 imageroot/actions/create-module/90reload | 12 +++++++
 imageroot/bin/expand-configuration       |  6 +++-
 imageroot/tainted/nextcloud-logs.yaml    | 41 ++++++++++++++++++++++++
 3 files changed, 58 insertions(+), 1 deletion(-)
 create mode 100755 imageroot/actions/create-module/90reload
 create mode 100644 imageroot/tainted/nextcloud-logs.yaml

diff --git a/imageroot/actions/create-module/90reload b/imageroot/actions/create-module/90reload
new file mode 100755
index 0000000..be1be98
--- /dev/null
+++ b/imageroot/actions/create-module/90reload
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+#
+# Copyright (C) 2024 Nethesis S.r.l.
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+
+set -e
+exec 1>&2 # Send any output to stderr, to not alter the action response protocol
+
+# We have introduced a tainted configuration file, we need to reload the service
+systemctl reload ${MODULE_ID}.service
diff --git a/imageroot/bin/expand-configuration b/imageroot/bin/expand-configuration
index a3dbc5a..d3ea478 100755
--- a/imageroot/bin/expand-configuration
+++ b/imageroot/bin/expand-configuration
@@ -6,10 +6,10 @@
 #
 
 import os
-import json
 import agent
 import agent.tasks
 import re
+import shutil
 
 from jinja2 import Environment, FileSystemLoader, select_autoescape
 
@@ -160,3 +160,7 @@ if whitelists:
         output = template.render(properties)
         with open("crowdsec_config/postoverflows/s01-whitelist/nethserver-postoverflows-whitelists.yaml","w") as f:
             f.write(output)
+
+## expand the tainted configuration files
+os.makedirs("crowdsec_config/hub/parsers/s01-parse/crowdsecurity", exist_ok=True)
+shutil.copyfile("../tainted/nextcloud-logs.yaml", "crowdsec_config/hub/parsers/s01-parse/crowdsecurity/nextcloud-logs.yaml")
diff --git a/imageroot/tainted/nextcloud-logs.yaml b/imageroot/tainted/nextcloud-logs.yaml
new file mode 100644
index 0000000..07fd872
--- /dev/null
+++ b/imageroot/tainted/nextcloud-logs.yaml
@@ -0,0 +1,41 @@
+---
+onsuccess: next_stage
+filter: "Upper(evt.Parsed.program) == 'NEXTCLOUD-APP'"
+name: crowdsecurity/nextcloud-logs
+description: "Parse nextcloud logs"
+pattern_syntax:
+  NEXTCLOUD_USER: '[a-zA-Z0-9\.\@\-\+_%]+'
+nodes:
+  - grok:
+      pattern: 'Login failed: %{NEXTCLOUD_USER:target_user} \(Remote IP: %{IP:source_ip}\)'
+      apply_on: message
+    statics:
+      - meta: target_user
+        expression: "evt.Parsed.target_user"
+      - meta: log_type
+        value: nextcloud_failed_auth
+  - grok:
+      pattern: 'Bruteforce attempt from \\?"%{IP:source_ip}\\?" detected for action \\?"%{DATA:action}\\?"'
+      apply_on: message
+    statics:
+      - meta: action
+        expression: "evt.Parsed.action"
+      - meta: log_type
+        value: nextcloud_bruteforce_attempt
+
+#{"reqId":"dCA39mNG3NHLwbibVCFp","level":1,"time":"2023-02-14T17:28:33+00:00","remoteAddr":"172.18.0.200","user":"--","app":"core","method":"GET","url":"/","message":"Trusted domain error. \"172.18.0.200\" tried to access using \"kloot.ronsmans.eu\" as host.","userAgent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/109.0","version":"25.0.3.2","data":{"app":"core"}}
+
+  - grok:
+      pattern: 'Trusted domain error. \\"%{IP:source_ip}\\".*'
+      apply_on: message
+    statics:
+      - meta: log_type
+        value: nextcloud_domain_error
+
+statics:
+  - meta: service
+    value: nextcloud
+  - meta: source_ip
+    expression: "evt.Parsed.source_ip"
+  - target: evt.StrTime
+    expression: "evt.Parsed.time_local"