Strip message headers that could possibly lead to loss of anonymity

src/bitmessageqt/__init__.py

@@ -1757,6 +1757,10 @@ class MyForm(QtGui.QMainWindow):
                 self.settingsDialogInstance.ui.lineEditPOP3Port.text()))
             shared.config.set('bitmessagesettings', 'pop3ssl', str(
                 self.settingsDialogInstance.ui.checkBoxEnablePOP3SSL.isChecked()))
+            shared.config.set('bitmessagesettings', 'stripmessageheadersenable', str(
+                self.settingsDialogInstance.ui.checkBoxStripMessageHeaders.isChecked()))
+            shared.config.set('bitmessagesettings', 'stripmessageheaders', str(
+                self.settingsDialogInstance.ui.lineEditMessageHeadersToStrip.text()))
             if self.settingsDialogInstance.sslCertFile is None:
                 shared.config.remove_option('bitmessagesettings', 'certfile')
             else:
@@ -2728,6 +2732,15 @@ class settingsDialog(QtGui.QDialog):
             shared.config.getboolean('bitmessagesettings', 'showtraynotifications'))
         self.ui.checkBoxStartInTray.setChecked(
             shared.config.getboolean('bitmessagesettings', 'startintray'))
+        try:
+            self.ui.checkBoxStripMessageHeaders.setChecked(
+                shared.config.getboolean('bitmessagesettings', 'stripmessageheadersenable'))
+            self.ui.lineEditMessageHeadersToStrip.setText(
+                shared.config.get('bitmessagesettings', 'stripmessageheaders'))
+        except:
+            self.ui.checkBoxStripMessageHeaders.setChecked(True)
+            self.ui.lineEditMessageHeadersToStrip.setText('Message-ID, User-Agent')
+
         if shared.appdata == '':
             self.ui.checkBoxPortableMode.setChecked(True)
         if 'darwin' in sys.platform:
@@ -2869,6 +2882,9 @@ class settingsDialog(QtGui.QDialog):
             "clicked()"), self.click_FindSSLCertificate)
         QtCore.QObject.connect(self.ui.pushButtonFindSSLKeyfile, QtCore.SIGNAL(
             "clicked()"), self.click_FindSSLKeyfile)
+        QtCore.QObject.connect(self.ui.checkBoxStripMessageHeaders, QtCore.SIGNAL(
+            "clicked()"), self.click_StripMessageHeaders)
+        self.click_StripMessageHeaders()
 
         QtGui.QWidget.resize(self, QtGui.QWidget.sizeHint(self))
 
@@ -2879,6 +2895,9 @@ class settingsDialog(QtGui.QDialog):
             QtGui.QMessageBox.information(self, 'SSL Files', _translate(
                     "Settings", "Because you have enabled SSL on either SMTP or POP3 servers, you must specify valid SSL Certificate and Key files before continuing."), QMessageBox.Ok)
 
+    def click_StripMessageHeaders(self):
+        self.ui.lineEditMessageHeadersToStrip.setEnabled(self.ui.checkBoxStripMessageHeaders.isChecked())
+
     def configurePushButtonFindSSLCerficiate(self, fn):
         self.ui.pushButtonFindSSLCertificate.setText('Find SSL Certificate...')
         try:

src/bitmessageqt/settings.py

@@ -2,7 +2,7 @@
 
 # Form implementation generated from reading ui file 'settings.ui'
 #
-# Created: Sat Jul 06 18:24:20 2013
+# Created: Wed Jul 10 16:19:56 2013
 #      by: PyQt4 UI code generator 4.10.1
 #
 # WARNING! All changes made in this file will be lost!
@@ -26,7 +26,7 @@ except AttributeError:
 class Ui_settingsDialog(object):
     def setupUi(self, settingsDialog):
         settingsDialog.setObjectName(_fromUtf8("settingsDialog"))
-        settingsDialog.resize(623, 343)
+        settingsDialog.resize(623, 406)
         self.gridLayout = QtGui.QGridLayout(settingsDialog)
         self.gridLayout.setObjectName(_fromUtf8("gridLayout"))
         self.buttonBox = QtGui.QDialogButtonBox(settingsDialog)
@@ -354,6 +354,19 @@ class Ui_settingsDialog(object):
         self.horizontalLayout_5.addWidget(self.lineEditEmailAddress)
         self.gridLayout_9.addLayout(self.horizontalLayout_5, 1, 0, 1, 2)
         self.gridLayout_8.addWidget(self.groupBox_3, 7, 0, 1, 7)
+        self.groupBox_4 = QtGui.QGroupBox(self.tab_3)
+        self.groupBox_4.setObjectName(_fromUtf8("groupBox_4"))
+        self.gridLayout_10 = QtGui.QGridLayout(self.groupBox_4)
+        self.gridLayout_10.setObjectName(_fromUtf8("gridLayout_10"))
+        self.checkBoxStripMessageHeaders = QtGui.QCheckBox(self.groupBox_4)
+        self.checkBoxStripMessageHeaders.setChecked(True)
+        self.checkBoxStripMessageHeaders.setTristate(False)
+        self.checkBoxStripMessageHeaders.setObjectName(_fromUtf8("checkBoxStripMessageHeaders"))
+        self.gridLayout_10.addWidget(self.checkBoxStripMessageHeaders, 0, 0, 1, 1)
+        self.lineEditMessageHeadersToStrip = QtGui.QLineEdit(self.groupBox_4)
+        self.lineEditMessageHeadersToStrip.setObjectName(_fromUtf8("lineEditMessageHeadersToStrip"))
+        self.gridLayout_10.addWidget(self.lineEditMessageHeadersToStrip, 1, 0, 1, 1)
+        self.gridLayout_8.addWidget(self.groupBox_4, 5, 0, 1, 7)
         self.tabWidgetSettings.addTab(self.tab_3, _fromUtf8(""))
         self.gridLayout.addWidget(self.tabWidgetSettings, 0, 0, 1, 1)
 
@@ -426,5 +439,8 @@ class Ui_settingsDialog(object):
         self.labelAccountStatus.setText(_translate("settingsDialog", "Account Inaccessible via SMTP/POP3. Set a password to allow access.", None))
         self.label_18.setText(_translate("settingsDialog", "E-Mail Address for this Identity:", None))
         self.lineEditEmailAddress.setText(_translate("settingsDialog", "fsdpffffffffffffffffffffffffffffffffffffffffffffffasdpofiasjdf", None))
+        self.groupBox_4.setTitle(_translate("settingsDialog", "Mail Content", None))
+        self.checkBoxStripMessageHeaders.setText(_translate("settingsDialog", "Strip these non-anonymizing message meaders from outgoing messages (comma-separated list):", None))
+        self.lineEditMessageHeadersToStrip.setText(_translate("settingsDialog", "User-Agent, Message-ID", None))
         self.tabWidgetSettings.setTabText(self.tabWidgetSettings.indexOf(self.tab_3), _translate("settingsDialog", "SMTP && POP3", None))
 

src/bitmessageqt/settings.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>623</width>
-    <height>343</height>
+    <height>406</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -823,6 +823,35 @@
          </layout>
         </widget>
        </item>
+       <item row="5" column="0" colspan="7">
+        <widget class="QGroupBox" name="groupBox_4">
+         <property name="title">
+          <string>Mail Content</string>
+         </property>
+         <layout class="QGridLayout" name="gridLayout_10">
+          <item row="0" column="0">
+           <widget class="QCheckBox" name="checkBoxStripMessageHeaders">
+            <property name="text">
+             <string>Strip these non-anonymizing message meaders from outgoing messages (comma-separated list):</string>
+            </property>
+            <property name="checked">
+             <bool>true</bool>
+            </property>
+            <property name="tristate">
+             <bool>false</bool>
+            </property>
+           </widget>
+          </item>
+          <item row="1" column="0">
+           <widget class="QLineEdit" name="lineEditMessageHeadersToStrip">
+            <property name="text">
+             <string>User-Agent, Message-ID</string>
+            </property>
+           </widget>
+          </item>
+         </layout>
+        </widget>
+       </item>
       </layout>
      </widget>
     </widget>

src/class_smtpServer.py

@@ -333,6 +333,25 @@ class bitmessageSMTPServer(smtpd.SMTPServer):
             sock = ssl.wrap_socket(sock, server_side=True, certfile=self.certfile, keyfile=self.keyfile, ssl_version=ssl.PROTOCOL_SSLv23)
         bitmessageSMTPChannel(self, sock, peer_address)
 
+    @staticmethod
+    def stripMessageHeaders(message):
+        try:
+            if not shared.config.getboolean('bitmessagesettings', 'stripmessageheadersenable'):
+                return
+        except:
+            pass
+
+        try:
+            headersToStrip = shared.config.get('bitmessagesettings', 'stripmessageheaders')
+        except:
+            headersToStrip = "Message-ID, User-Agent"
+
+        headersToStrip = [x.strip() for x in headersToStrip.split(',') if len(x.strip()) > 0]
+        print(headersToStrip)
+        for h in headersToStrip:
+            if h in message:
+                del message[h]
+
     def process_message(self, peer, address, rcpttos, data):
         #print("Peer", peer)
         #print("Mail From", address)
@@ -344,12 +363,13 @@ class bitmessageSMTPServer(smtpd.SMTPServer):
 
         message = parser.Parser().parsestr(data)
         message['X-Bitmessage-Sending-Version'] = shared.softwareVersion
-        print(message)
 
+        bitmessageSMTPServer.stripMessageHeaders(message)
         fp = StringIO()
         gen = generator.Generator(fp, mangle_from_=False, maxheaderlen=128)
         gen.flatten(message)
         message_as_text = fp.getvalue()
+        print(message_as_text)
 
         checksum = hashlib.sha256(message_as_text).digest()[:2]
         checksum = (ord(checksum[0]) << 8) | ord(checksum[1])