From a07580a1161995220e8f96c8bcc15305615a1ae2 Mon Sep 17 00:00:00 2001
From: Yannik Schmidt <sheppy@atlantishq.de>
Date: Mon, 9 Jan 2023 17:08:16 +0100
Subject: [PATCH] feat: checkscript for imap & smpt

---
 check_smtp_imap.py | 108 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 check_smtp_imap.py

diff --git a/check_smtp_imap.py b/check_smtp_imap.py
new file mode 100644
index 0000000..59439dd
--- /dev/null
+++ b/check_smtp_imap.py
@@ -0,0 +1,108 @@
+#!/usr/bin/python3
+
+import smtplib, ssl
+import sys
+import secrets
+import datetime
+import argparse
+import socket
+import time
+import imaplib
+import json
+
+def exit(status, info):
+    print("{}{}".format(status, info))
+    if status == "OK":
+        sys.exit(0)
+    elif status == "WARNING":
+        sys.exit(2)
+    else:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description='Email STMP/IMAP Monitor',
+                        formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+
+    parser.add_argument("--target",    required=True, help="Target Server to check")
+    parser.add_argument("--sender",    required=True, help="Sender Email to use")
+    parser.add_argument("--receiver",  required=True, help="Receiver Mail (must exits on target)")
+    parser.add_argument("--imap-user",                help="IMAP User for receiver Mail")
+    parser.add_argument("--imap-pass", required=True, help="IMAP Password for receiver Mail")
+    parser.add_argument("--port",      default=587,   help="Target (START_TLS) port")
+
+    args = parser.parse_args()
+    imap_user = args.imap_user
+    if not imap_user:
+        imap_user = args.receiver
+
+    challenge = {
+        "time" : datetime.datetime.now().timestamp(),
+        "token" : secrets.token_urlsafe(),
+        "origin" : socket.gethostname(),
+    }
+
+    message = message = 'Subject: Monitoring Challenge\n\n{}dd'.format(json.dumps(challenge))
+
+    context = ssl.create_default_context()
+
+    # send mail #
+    server = smtplib.SMTP(args.target, args.port)
+    server.starttls(context=context)
+    server.sendmail(args.sender, args.receiver, message)
+
+    # give server some time to deliver #
+    time.sleep(5)
+
+    # check imap #
+    for x in range(0,5):
+
+        with imaplib.IMAP4_SSL(args.target) as imap:
+            imap.login(imap_user, args.imap_pass)
+            imap.select('INBOX')
+            status, messages = imap.search(None, 'ALL')
+
+            # check search status #
+            if not status == "OK":
+                exit("CRITICAL", "IMAP search failed")
+
+            for message in messages[0].split(b' '):
+
+                status, data = imap.fetch(message, '(RFC822)')
+
+                # check search status #
+                if not status == "OK":
+                    exit("CRITICAL", "IMAP fetch failed")
+
+                # parse mail
+                info = None
+                body = None
+
+                # ignore badly formated messages #
+                try:
+                    body = data[0][1].decode("utf-8").split("\r\n")[-2]
+                except IndexError:
+                    continue
+
+                # ignore badly formated messages (json-body) #
+                try:
+                    info = json.loads(body)
+                except json.decoder.JSONDecodeError:
+                    continue
+
+                # ignore mail if it's not ours otherwise cleanup #
+                if info["origin"] != challenge["origin"]:
+                    continue
+                else:
+                    imap.store(message, '+FLAGS', '\\Deleted')
+
+                if info["token"] == challenge["token"]:
+                    exit("OK", "")
+
+            imap.logout()
+
+        # backoff and try again #
+        time.sleep(10)
+
+    # if we didn't find anything #
+    exit("CRITICAL", "Challange not found via IMAP")