Added new data handler "sunsetsha1"

The new handler "sunsetsha1" detects TLS certificates using the SHA-1 signature algorithm which expire during or after the Google Chrome SHA-1 sunset period. See Google security blog entry:
https://googleonlinesecurity.blogspot.com.au/2014/09/gradually-sunsetting-sha-1.html.

Note. The signature algorithm is checked for the "leaf" and "intermediate" certificates in the chain.

docs/gce/_update_dev.sh

@@ -0,0 +1,66 @@
+#!/bin/sh
+
+set -e
+
+# Directory paths used for nogotofail.
+INSTALL_DIR=/opt/nogotofail
+CONFIG_DIR=/etc/nogotofail
+LOG_DIR=/var/log/nogotofail
+
+# Stop the nogotofail-mitm and other associated services if they're running.
+if (ps ax | grep -v grep | grep nogotofail-mitm > /dev/null) then
+sudo /etc/init.d/nogotofail-mitm stop
+fi
+if (ps ax | grep -v grep | grep dnsmasq > /dev/null) then
+sudo /etc/init.d/dnsmasq stop
+fi
+if (ps ax | grep -v grep | grep openvpn > /dev/null) then
+sudo /etc/init.d/openvpn stop
+fi
+# Remove Python files and compiled versions i.e. *.py and *.pyc files.
+# TODO: Find a more elegant method for uninstalling a Python program.
+#rm -rf $INSTALL_DIR
+#rm -rf $CONFIG_DIR
+#rm -rf $LOG_DIR
+find $INSTALL_DIR -type f -name '*.py' -delete
+find $INSTALL_DIR -type f -name '*.pyc' -delete
+
+# Install toolchain dependencies
+sudo apt-get update
+sudo apt-get -y upgrade
+#sudo apt-get -y install patch make gcc libssl-dev python-openssl liblzo2-dev libpam-dev
+
+# Install OpenVPN and dnsmasq
+#sudo apt-get -y install openvpn dnsmasq
+
+# Build and install a patched version of OpenVPN.
+# This is needed because the OpenVPN 2.3.x still does not properly handle
+# floating clients (those whose source IP address as seen by the server changes
+# from time to time) which is a regular occurrence in the mobile world.
+# OpenVPN 2.4 might ship with proper support out of the box. In that case, this
+# kludge can be removed.
+#./build_openvpn.sh
+
+# Build and install a patched version of dnsmasq.
+# This is needed because GCE does not support IPv6. We thus blackhole IPv6
+# traffic from clients so that they are forced to use IPv4. However, default
+# DNS servers will still resolve hostnames to IPv6 addresses causing clients to
+# attempt IPv6. To avoid clients attempting IPv6, we run a patched dnsmasq DNS
+# server which empties AAAA records thus causing clients to go for A records
+# which provide IPv4 addresses.
+#./build_dnsmasq.sh
+
+# Set up OpenVPN server
+#sudo ./setup_openvpn.sh
+
+# Set up the MiTM daemons
+sudo ./setup_mitm.sh
+
+# Move dev mitm.conf file into /etc/nogotofail directory
+sudo cp /home/michael/noseyp_setup/ngtf_mitm.conf /etc/nogotofail/mitm.conf
+
+# Restart all the relevant daemons
+sudo /etc/init.d/dnsmasq start
+sudo /etc/init.d/openvpn start
+#sudo /etc/init.d/nogotofail-mitm stop || true
+sudo /etc/init.d/nogotofail-mitm start

nogotofail/clients/android/app/src/main/java/net/nogotofail/AttacksPreferenceFragment.java

@@ -49,6 +49,7 @@ public class AttacksPreferenceFragment extends PreferenceFragment {
     BUNDLED_SUPPORTED_DATA_ATTACK_IDS.add("httpdetection");
     BUNDLED_SUPPORTED_DATA_ATTACK_IDS.add("imagereplace");
     BUNDLED_SUPPORTED_DATA_ATTACK_IDS.add("sslstrip");
+    BUNDLED_SUPPORTED_DATA_ATTACK_IDS.add("sunsetsha1");
   }
 
   private static final String ATTACK_ENABLED_PREF_KEY_PREFIX = "attack_enabled_";

nogotofail/clients/android/app/src/main/res/values/strings.xml

@@ -94,6 +94,8 @@
     <string name="vuln_sslstrip">Downgrade of HTTPS to HTTP</string>
     <!-- Vulnerability: XMPP STARTTLS strip -->
     <string name="vuln_xmppstarttlsstrip">Downgrade of STARTTLS-protected XMPP to cleartext</string>
+    <!-- Vulnerability: Certificate uses SHA-1 and expires after a Chrome sunset date -->
+    <string name="vuln_sunsetsha1">Certificate uses SHA-1 and expires after a Chrome sunset date</string>
 
     <string name="notifications_pref_screen_title">Notifications</string>
     <string name="vuln_notifications_enabled_pref_title">Notifications</string>
@@ -159,6 +161,8 @@
     <string name="attack_summary_xmppauthdetection">XMPP credentials/auth token compromise</string>
     <string name="attack_title_xmppstarttlsstrip">XMPP STARTTLS strip</string>
     <string name="attack_summary_xmppstarttlsstrip">Downgrade of STARTTLS-protected XMPP to cleartext</string>
+    <string name="attack_title_sunsetsha1">Certificate uses SHA-1 and expires after sunset date</string>
+    <string name="attack_summary_sunsetsha1">Certificate uses SHA-1 and expires after a Chrome sunset date</string>
 
     <string name="advanced_pref_screen_title">Advanced</string>
 

nogotofail/mitm/connection/handlers/data/ssl.py

@@ -19,7 +19,12 @@
 from nogotofail.mitm.connection.handlers.data import DataHandler
 from nogotofail.mitm.connection.handlers.store import handler
 from nogotofail.mitm.event import connection
+from nogotofail.mitm import util
 from nogotofail.mitm.util import ssl2, tls, vuln
+from nogotofail.mitm.util.tls.types import HandshakeMessage
+from datetime import datetime
+import OpenSSL.crypto
+
 
 class _TlsRecordHandler(DataHandler):
     """Base class for a handler that acts on TlsRecords in a Tls connection.
@@ -172,3 +177,110 @@ def on_ssl(self, client_hello):
                 self.log(logging.ERROR,
                         "Client enabled SSLv3 protocol without TLS_FALLBACK_SCSV")
             self.log_attack_event(data="SSLv3")
+
+
+@handler.passive(handlers)
+class SunsetSHA1(_TlsRecordHandler):
+    name = "sunsetsha1"
+    description = (
+        "Detects TLS certificates using the SHA-1 signature algorithm that "
+        "expire during of after the Google Chrome sunset period.")
+
+    # Certificate type constants
+    LEAF_CERT = 1
+    INTERMEDIATE_CERT = 2
+
+    def on_tls_response(self, record):
+        CRT_DATE_FORMAT = "%Y%m%d%H%M%SZ"
+        try:
+            for i, message in enumerate(record.messages):
+                # Check for Certificate message
+                if (isinstance(message, tls.types.HandshakeMessage) and
+                        message.type == HandshakeMessage.TYPE.CERTIFICATE):
+                    certificate = message.obj
+                    crt_chain_length = len(certificate.certificates)
+                    crt_chain_index = 0
+                    # Loop through certificate chain starting from the leaf
+                    # cert to the last intermediate cert (before the root).
+                    for crt_byte_string in certificate.certificates[
+                            :crt_chain_length-1]:
+                        if (crt_chain_index == 0):
+                            crt_type = self.LEAF_CERT
+                        else:
+                            crt_type = self.INTERMEDIATE_CERT
+                        a_cert = OpenSSL.crypto.load_certificate(
+                            OpenSSL.crypto.FILETYPE_ASN1, crt_byte_string)
+                        # Check certificates in chain for SHA-1 sunset issue
+                        crt_signature_algorithm = \
+                            a_cert.get_signature_algorithm()
+                        if ("sha1" in crt_signature_algorithm):
+                            crt_CN = a_cert.get_subject().CN
+                            crt_not_before = a_cert.get_notBefore()
+                            crt_not_after = a_cert.get_notAfter()
+                            debug_message = \
+                                ["Certicate using SHA-1 with attributes ",
+                                 "- CN \"", crt_CN, "\", notBefore \"",
+                                 str(crt_not_before or ''),
+                                 "\", notAfter \"", str(crt_not_after or ''),
+                                 "\", signature_algorithm \"",
+                                 str(crt_signature_algorithm or ''), "\""]
+                            self.log(logging.DEBUG, "".join(debug_message))
+                            crt_not_after = datetime.strptime(crt_not_after,
+                                                        CRT_DATE_FORMAT)
+                            self._alert_on_sunset_sha1(crt_not_after, crt_CN,
+                                                       crt_type)
+                        crt_chain_index += 1
+        except AttributeError:
+            pass
+        return record.to_bytes()
+
+    def _alert_on_sunset_sha1(self, crt_not_after, crt_CN, crt_type):
+        """ Raises an alert if a certificate signature algorithm uses SHA-1 and
+            it expires during or after the Google Chrome sunset period.
+        """
+        # SHA-1 sunset dates based on Google Chrome dates published dates. See
+        # http://googleonlinesecurity.blogspot.com/2014/09/gradually-sunsetting-sha-1.html
+        logging_level = logging.WARNING
+        CRT_DATE_FORMAT = "%d-%m-%Y"
+        sunset_critical_date = datetime.strptime("31-12-2016", CRT_DATE_FORMAT)
+        sunset_error_date = datetime.strptime("30-06-2016", CRT_DATE_FORMAT)
+        sunset_warning_date = datetime.strptime("31-12-2015", CRT_DATE_FORMAT)
+
+        if (crt_type == self.LEAF_CERT):
+            crt_type_name = "Leaf"
+        elif (crt_type == self.INTERMEDIATE_CERT):
+            crt_type_name = "Intermediate"
+
+        if (crt_not_after > sunset_critical_date):
+            if (crt_type == self.LEAF_CERT):
+                logging_level = logging.CRITICAL
+            elif (crt_type == self.INTERMEDIATE_CERT):
+                logging_level = logging.WARNING
+            log_message = \
+                [crt_type_name, " certificate with CN ", crt_CN,
+                 " uses SHA-1 and expires after 31 Dec 2016"]
+            self.log(logging_level, "".join(log_message))
+            self.log_event(logging_level, connection.AttackEvent(
+                           self.connection, self.name, True, ""))
+            self.connection.vuln_notify(util.vuln.VULN_SUNSET_SHA1)
+        elif (crt_not_after > sunset_error_date):
+            if (crt_type == self.LEAF_CERT):
+                logging_level = logging.ERROR
+            elif (crt_type == self.INTERMEDIATE_CERT):
+                logging_level = logging.WARNING
+            log_message = \
+                [crt_type_name, " certificate with CN ",  crt_CN,
+                 " uses SHA-1 and expires after 30 Jun 2016"]
+            self.log(logging_level, "".join(log_message))
+            self.log_event(logging_level, connection.AttackEvent(
+                           self.connection, self.name, True, ""))
+            self.connection.vuln_notify(util.vuln.VULN_SUNSET_SHA1)
+        elif (crt_not_after > sunset_warning_date):
+            logging_level = logging.WARNING
+            log_message = \
+                [crt_type_name, " certificate with CN ", crt_CN,
+                 " uses SHA-1 and expires after 31 Dec 2015"]
+            self.log(logging_level, "".join(log_message))
+            self.log_event(logging_level, connection.AttackEvent(
+                           self.connection, self.name, True, ""))
+            self.connection.vuln_notify(util.vuln.VULN_SUNSET_SHA1)

nogotofail/mitm/util/vuln.py

@@ -30,3 +30,4 @@
 VULN_WEAK_TLS_VERSION = "weaktlsversion"
 VULN_TLS_SERVER_KEY_REPLACEMENT = "serverkeyreplace"
 VULN_TLS_SUPERFISH_TRUSTED = "superfishca"
+VULN_SUNSET_SHA1 = "sunsetsha1"