Don't base64 encode encrypted reports, it's not RFC 3156 compliant and some mailclients (e.g. K-9) have issues with that.

CHANGELOG.md

@@ -1,5 +1,18 @@
 # MultiSchleuder Changelog
 
+<!-- BEGIN RELEASE v0.1.3 -->
+## Version 0.1.3
+
+Bugfix release
+
+### Changes
+
+<!-- BEGIN CHANGES 0.1.3 -->
+- RFC 3156 compliance: Don't base64-encode encrypted reports
+<!-- END CHANGES 0.1.3 -->
+
+<!-- END RELEASE v0.1.3 -->
+
 <!-- BEGIN RELEASE v0.1.2 -->
 ## Version 0.1.2
 

multischleuder/reporting.py

@@ -2,6 +2,7 @@
 from typing import Dict, List, Optional, Set
 
 import abc
+import email.encoders
 import email.mime.base
 import email.mime.application
 import email.mime.multipart
@@ -42,6 +43,7 @@ class Message(abc.ABC):
         try:
             self._mime = self._encrypt_message(content)
         except Exception:
+            logging.exception('Encryption failed; falling back to unencrypted message')
             self._mime = email.mime.text.MIMEText(content, _subtype='plain', _charset='utf-8')
         # Set all the email headers
         self._mime['From'] = self._from
@@ -69,15 +71,21 @@ class Message(abc.ABC):
             del sessionkey
         # Build the MIME message
         # First the small "version" part ...
-        mp1 = email.mime.application.MIMEApplication('Version: 1', _subtype='pgp-encrypted')
+        mp1 = email.mime.application.MIMEApplication('Version: 1',
+                                                     _subtype='pgp-encrypted',
+                                                     _encoder=email.encoders.encode_noop)
         mp1['Content-Description'] = 'PGP/MIME version identification'
         mp1['Content-Disposition'] = 'attachment'
         # ... then the actual encrypted payload ...
-        mp2 = email.mime.application.MIMEApplication(str(pgp), _subtype='octet-stream', name='encrypted.asc')
+        mp2 = email.mime.application.MIMEApplication(str(pgp),
+                                                     _subtype='octet-stream',
+                                                     _encoder=email.encoders.encode_noop,
+                                                     name='encrypted.asc')
         mp2['Content-Description'] = 'OpenPGP encrypted message'
         mp2['Content-Disposition'] = 'inline; filename="message.asc"'
         # ... and finally the root multipart container
-        mp0 = email.mime.multipart.MIMEMultipart(_subtype='encrypted', protocol='application/pgp-encrypted')
+        mp0 = email.mime.multipart.MIMEMultipart(_subtype='encrypted',
+                                                 protocol='application/pgp-encrypted')
         mp0.attach(mp1)
         mp0.attach(mp2)
         return mp0