add check_certificate.py, to warn about expiring or not valid client certs

modules/check_certificate.py

@@ -0,0 +1,33 @@
+import datetime
+from src import ModuleManager, utils
+import cryptography.x509, cryptography.hazmat.backends
+
+class Module(ModuleManager.BaseModule):
+    @utils.hook("preprocess.connect")
+    def preprocess_connect(self, event):
+        certificate_filename = self.bot.config.get("tls-certificate", None)
+        if not certificate_filename == None:
+            with open(certificate_filename, "rb") as certificate_file:
+                certificate = cryptography.x509.load_pem_x509_certificate(
+                    certificate_file.read(),
+                    cryptography.hazmat.backends.default_backend())
+
+            today = datetime.datetime.utcnow().date()
+            week = datetime.timedelta(days=7)
+
+            not_valid_until = (today-certificate.not_valid_before.date()).days
+            not_valid_after = (certificate.not_valid_after.date()-today).days
+
+            if not_valid_until < 0:
+                self.log.warn(
+                    "Connecting to %s but client certificate is not valid yet",
+                    [str(event["server"])])
+            elif not_valid_after < 0:
+                self.log.warn(
+                    "Connecting to %s but client certificate is no longer "
+                    "valid", [str(event["server"])])
+            elif not_valid_after <= 7:
+                self.log.warn(
+                    "Connecting to %s but client certificate expires in a week",
+                    [str(event["server"])])
+