When decoding inbound emails, decode encoded headers. Fixes #420

CHANGELOG.md

@@ -18,6 +18,7 @@ All notable changes to this project will be documented in this file.
 - Don't allow duplicate team memberships
 - When copying a check, copy all fields from the "Filtering Rules" dialog (#417)
 - Fix missing Resume button (#421)
+- When decoding inbound emails, decode encoded headers (#420)
 
 ## v1.16.0 - 2020-08-04
 

hc/api/management/commands/smtpd.py

@@ -1,5 +1,6 @@
 import asyncore
 import email
+import email.policy
 import re
 from smtpd import SMTPServer
 
@@ -41,7 +42,9 @@ def _process_message(remote_addr, mailfrom, mailto, data):
     action = "success"
     if check.subject or check.subject_fail:
         action = "ign"
-        subject = email.message_from_string(data).get("subject", "")
+        # Specify policy, the default policy does not decode encoded headers:
+        parsed = email.message_from_string(data, policy=email.policy.SMTP)
+        subject = parsed.get("subject", "")
         if check.subject and _match(subject, check.subject):
             action = "success"
         elif check.subject_fail and _match(subject, check.subject_fail):

hc/api/tests/test_smtpd.py

@@ -98,3 +98,15 @@ class SmtpdTestCase(BaseTestCase):
         self.assertEqual(ping.scheme, "email")
         self.assertEqual(ping.ua, "Email from foo@example.org")
         self.assertEqual(ping.kind, "fail")
+
+    def test_it_handles_encoded_subject(self):
+        self.check.subject = "SUCCESS"
+        self.check.save()
+
+        body = PAYLOAD_TMPL % "=?US-ASCII?B?W1NVQ0NFU1NdIEJhY2t1cCBjb21wbGV0ZWQ=?="
+        _process_message("1.2.3.4", "foo@example.org", self.email, body.encode("utf8"))
+
+        ping = Ping.objects.latest("id")
+        self.assertEqual(ping.scheme, "email")
+        self.assertEqual(ping.ua, "Email from foo@example.org")
+        self.assertEqual(ping.kind, None)