Reject senders if they aren't the logged in user

3 files changed, 20 insertions, 5 deletions

diff --git a/changes/bug_reject_bad_sender b/changes/bug_reject_bad_sender
new file mode 100644
index 0000000..0e46c28
--- /dev/null
+++ b/changes/bug_reject_bad_sender
@@ -0,0 +1,2 @@
+  o Reject senders that aren't the user that is currently logged
+    in. Fixes #3952.
\ No newline at end of file
diff --git a/src/leap/mail/smtp/__init__.py b/src/leap/mail/smtp/__init__.py
index b30cd20..be568b8 100644
--- a/src/leap/mail/smtp/__init__.py
+++ b/src/leap/mail/smtp/__init__.py
@@ -29,7 +29,7 @@ from leap.common.events import proto, signal
 from leap.mail.smtp.smtprelay import SMTPFactory
 
 
-def setup_smtp_relay(port, keymanager, smtp_host, smtp_port,
+def setup_smtp_relay(port, userid, keymanager, smtp_host, smtp_port,
                      smtp_cert, smtp_key, encrypted_only):
     """
     Setup SMTP relay to run with Twisted.
@@ -39,6 +39,8 @@ def setup_smtp_relay(port, keymanager, smtp_host, smtp_port,
 
     :param port: The port in which to run the server.
     :type port: int
+    :param userid: The user currently logged in
+    :type userid: unicode
     :param keymanager: A Key Manager from where to get recipients' public
                        keys.
     :type keymanager: leap.common.keymanager.KeyManager
@@ -75,7 +77,7 @@ def setup_smtp_relay(port, keymanager, smtp_host, smtp_port,
     }
 
     # configure the use of this service with twistd
-    factory = SMTPFactory(keymanager, config)
+    factory = SMTPFactory(userid, keymanager, config)
     try:
         tport = reactor.listenTCP(port, factory,
                                   interface="localhost")
diff --git a/src/leap/mail/smtp/smtprelay.py b/src/leap/mail/smtp/smtprelay.py
index fca66c0..92a9f0e 100644
--- a/src/leap/mail/smtp/smtprelay.py
+++ b/src/leap/mail/smtp/smtprelay.py
@@ -153,7 +153,7 @@ class SMTPFactory(ServerFactory):
     Factory for an SMTP server with encrypted relaying capabilities.
     """
 
-    def __init__(self, keymanager, config):
+    def __init__(self, userid, keymanager, config):
         """
         Initialize the SMTP factory.
 
@@ -169,11 +169,14 @@ class SMTPFactory(ServerFactory):
                     ENCRYPTED_ONLY_KEY: <bool>,
                 }
         @type config: dict
+        @param userid: The user currently logged in
+        @type userid: unicode
         """
         # assert params
         leap_assert_type(keymanager, KeyManager)
         assert_config_structure(config)
         # and store them
+        self._userid = userid
         self._km = keymanager
         self._config = config
 
@@ -187,7 +190,8 @@ class SMTPFactory(ServerFactory):
         @return: The protocol.
         @rtype: SMTPDelivery
         """
-        smtpProtocol = smtp.SMTP(SMTPDelivery(self._km, self._config))
+        smtpProtocol = smtp.SMTP(SMTPDelivery(self._userid, self._km,
+                                              self._config))
         smtpProtocol.factory = self
         return smtpProtocol
 
@@ -203,7 +207,7 @@ class SMTPDelivery(object):
 
     implements(smtp.IMessageDelivery)
 
-    def __init__(self, keymanager, config):
+    def __init__(self, userid, keymanager, config):
         """
         Initialize the SMTP delivery object.
 
@@ -219,11 +223,14 @@ class SMTPDelivery(object):
                     ENCRYPTED_ONLY_KEY: <bool>,
                 }
         @type config: dict
+        @param userid: The user currently logged in
+        @type userid: unicode
         """
         # assert params
         leap_assert_type(keymanager, KeyManager)
         assert_config_structure(config)
         # and store them
+        self._userid = userid
         self._km = keymanager
         self._config = config
         self._origin = None
@@ -310,6 +317,10 @@ class SMTPDelivery(object):
         """
         # accept mail from anywhere. To reject an address, raise
         # smtp.SMTPBadSender here.
+        if str(origin) != str(self._userid):
+            log.msg("Rejecting sender {0}, expected {1}".format(origin,
+                                                                self._userid))
+            raise smtp.SMTPBadSender(origin)
         self._origin = origin
         return origin