Discover public key via attachment

3 files changed, 63 insertions, 14 deletions

diff --git a/changes/feature-5937_key_attachment b/changes/feature-5937_key_attachment
new file mode 100644
index 0000000..08c37e0
--- /dev/null
+++ b/changes/feature-5937_key_attachment
@@ -0,0 +1 @@
+- Discover public keys via attachment (Closes: #5937)
diff --git a/src/leap/mail/imap/fetch.py b/src/leap/mail/imap/fetch.py
index 863f5fe..01373be 100644
--- a/src/leap/mail/imap/fetch.py
+++ b/src/leap/mail/imap/fetch.py
@@ -581,8 +581,8 @@ class LeapIncomingMail(object):
 
     def _extract_keys(self, msgtuple):
         """
-        Parse message headers for an *OpenPGP* header as described on the
-        `IETF draft
+        Retrieve attached keys to the mesage and parse message headers for an
+        *OpenPGP* header as described on the `IETF draft
         <http://tools.ietf.org/html/draft-josefsson-openpgp-mailnews-header-06>`
         only urls with https and the same hostname than the email are supported
         for security reasons.
@@ -600,31 +600,35 @@ class LeapIncomingMail(object):
         #     we should do it in this module so we don't need to parse it again
         #     here
         msg = self._parser.parsestr(data)
+        _, fromAddress = parseaddr(msg['from'])
+
         header = msg.get(OpenPGP_HEADER, None)
         if header is not None:
-            self._extract_openpgp_header(msg, header)
+            self._extract_openpgp_header(header, fromAddress)
+
+        if msg.is_multipart():
+            self._extract_attached_key(msg.get_payload(), fromAddress)
 
         return msgtuple
 
-    def _extract_openpgp_header(self, msg, header):
+    def _extract_openpgp_header(self, header, address):
         """
         Import keys from the OpenPGP header
 
-        :param msg: parsed email
-        :type msg: email.Message
         :param header: OpenPGP header string
         :type header: str
+        :param address: email address in the from header
+        :type address: str
         """
         fields = dict([f.strip(' ').split('=') for f in header.split(';')])
         if 'url' in fields:
             url = shlex.split(fields['url'])[0]  # remove quotations
-            _, fromAddress = parseaddr(msg['from'])
             urlparts = urlparse(url)
-            fromHostname = fromAddress.split('@')[1]
+            addressHostname = address.split('@')[1]
             if (urlparts.scheme == 'https'
-                    and urlparts.hostname == fromHostname):
+                    and urlparts.hostname == addressHostname):
                 try:
-                    self._keymanager.fetch_key(fromAddress, url, OpenPGPKey)
+                    self._keymanager.fetch_key(address, url, OpenPGPKey)
                     logger.info("Imported key from header %s" % (url,))
                 except keymanager_errors.KeyNotFound:
                     logger.warning("Url from OpenPGP header %s failed"
@@ -632,13 +636,32 @@ class LeapIncomingMail(object):
                 except keymanager_errors.KeyAttributesDiffer:
                     logger.warning("Key from OpenPGP header url %s didn't "
                                    "match the from address %s"
-                                   % (url, fromAddress))
+                                   % (url, address))
             else:
                 logger.debug("No valid url on OpenPGP header %s" % (url,))
         else:
             logger.debug("There is no url on the OpenPGP header: %s"
                          % (header,))
 
+    def _extract_attached_key(self, attachments, address):
+        """
+        Import keys from the attachments
+
+        :param attachments: email attachment list
+        :type attachments: list(email.Message)
+        :param address: email address in the from header
+        :type address: str
+        """
+        MIME_KEY = "application/pgp-keys"
+
+        for attachment in attachments:
+            if MIME_KEY == attachment.get_content_type():
+                logger.debug("Add key from attachment")
+                self._keymanager.put_raw_key(
+                    attachment.get_payload(),
+                    OpenPGPKey,
+                    address=address)
+
     def _add_message_locally(self, msgtuple):
         """
         Adds a message to local inbox and delete it from the incoming db
diff --git a/src/leap/mail/imap/tests/test_incoming_mail.py b/src/leap/mail/imap/tests/test_incoming_mail.py
index 5b72fac..ce6d56a 100644
--- a/src/leap/mail/imap/tests/test_incoming_mail.py
+++ b/src/leap/mail/imap/tests/test_incoming_mail.py
@@ -24,6 +24,8 @@ Test case for leap.email.imap.fetch
 
 import json
 
+from email.mime.application import MIMEApplication
+from email.mime.multipart import MIMEMultipart
 from email.parser import Parser
 from mock import Mock
 from twisted.trial import unittest
@@ -105,13 +107,13 @@ subject: independence of cyberspace
         email = self._create_incoming_email(message.as_string())
         self._mock_soledad_get_from_index(fields.JUST_MAIL_IDX, [email])
         self.fetcher._keymanager.fetch_key = Mock()
-        d = self.fetcher.fetch()
 
         def fetch_key_called(ret):
             self.fetcher._keymanager.fetch_key.assert_called_once_with(
                 self.FROM_ADDRESS, KEYURL, OpenPGPKey)
-        d.addCallback(fetch_key_called)
 
+        d = self.fetcher.fetch()
+        d.addCallback(fetch_key_called)
         return d
 
     def testExtractOpenPGPHeaderInvalidUrl(self):
@@ -126,12 +128,35 @@ subject: independence of cyberspace
         email = self._create_incoming_email(message.as_string())
         self._mock_soledad_get_from_index(fields.JUST_MAIL_IDX, [email])
         self.fetcher._keymanager.fetch_key = Mock()
-        d = self.fetcher.fetch()
 
         def fetch_key_called(ret):
             self.assertFalse(self.fetcher._keymanager.fetch_key.called)
+
+        d = self.fetcher.fetch()
         d.addCallback(fetch_key_called)
+        return d
 
+    def testExtractAttachedKey(self):
+        """
+        Test the OpenPGP header key extraction
+        """
+        KEY = "-----BEGIN PGP PUBLIC KEY BLOCK-----\n..."
+
+        message = MIMEMultipart()
+        message.add_header("from", self.FROM_ADDRESS)
+        key = MIMEApplication("", "pgp-keys")
+        key.set_payload(KEY)
+        message.attach(key)
+        email = self._create_incoming_email(message.as_string())
+        self._mock_soledad_get_from_index(fields.JUST_MAIL_IDX, [email])
+        self.fetcher._keymanager.put_raw_key = Mock()
+
+        def put_raw_key_called(ret):
+            self.fetcher._keymanager.put_raw_key.assert_called_once_with(
+                KEY, OpenPGPKey, address=self.FROM_ADDRESS)
+
+        d = self.fetcher.fetch()
+        d.addCallback(put_raw_key_called)
         return d
 
     def _create_incoming_email(self, email_str):