Add tests for TLS fallback on connection reset and close.

third_party/tlslite/patches/intolerance_options.patch

+diff --git a/third_party/tlslite/tlslite/handshakesettings.py b/third_party/tlslite/tlslite/handshakesettings.py
+index e0bc0e6..0d4ccf2 100644
+--- a/third_party/tlslite/tlslite/handshakesettings.py
++++ b/third_party/tlslite/tlslite/handshakesettings.py
+@@ -18,6 +18,7 @@ ALL_MAC_NAMES = ["sha", "md5"]
+ KEY_EXCHANGE_NAMES = ["rsa", "dhe_rsa", "srp_sha", "srp_sha_rsa", "dh_anon"]
+ CIPHER_IMPLEMENTATIONS = ["openssl", "pycrypto", "python"]
+ CERTIFICATE_TYPES = ["x509"]
++TLS_INTOLERANCE_TYPES = ["alert", "close", "reset"]
+ 
+ class HandshakeSettings(object):
+     """This class encapsulates various parameters that can be used with
+@@ -92,6 +93,21 @@ class HandshakeSettings(object):
+     The default is (3,2).  (WARNING: Some servers may (improperly)
+     reject clients which offer support for TLS 1.1.  In this case,
+     try lowering maxVersion to (3,1)).
++
++    @type tlsIntolerant: tuple
++    @ivar tlsIntolerant: The TLS ClientHello version which the server
++    simulates intolerance of.
++
++    If tlsIntolerant is not None, the server will simulate TLS version
++    intolerance by aborting the handshake in response to all TLS versions
++    tlsIntolerant or higher.
++
++    @type tlsIntoleranceType: str
++    @ivar tlsIntoleranceType: How the server should react when simulating TLS
++    intolerance.
++
++    The allowed values are "alert" (return a fatal handshake_failure alert),
++    "close" (abruptly close the connection), and "reset" (send a TCP reset).
+     
+     @type useExperimentalTackExtension: bool
+     @ivar useExperimentalTackExtension: Whether to enabled TACK support.
+@@ -109,6 +125,8 @@ class HandshakeSettings(object):
+         self.certificateTypes = CERTIFICATE_TYPES
+         self.minVersion = (3,0)
+         self.maxVersion = (3,2)
++        self.tlsIntolerant = None
++        self.tlsIntoleranceType = 'alert'
+         self.useExperimentalTackExtension = False
+ 
+     # Validates the min/max fields, and certificateTypes
+@@ -124,6 +142,8 @@ class HandshakeSettings(object):
+         other.certificateTypes = self.certificateTypes
+         other.minVersion = self.minVersion
+         other.maxVersion = self.maxVersion
++        other.tlsIntolerant = self.tlsIntolerant
++        other.tlsIntoleranceType = self.tlsIntoleranceType
+ 
+         if not cipherfactory.tripleDESPresent:
+             other.cipherNames = [e for e in self.cipherNames if e != "3des"]
+@@ -165,6 +185,10 @@ class HandshakeSettings(object):
+             if s not in CERTIFICATE_TYPES:
+                 raise ValueError("Unknown certificate type: '%s'" % s)
+ 
++        if other.tlsIntoleranceType not in TLS_INTOLERANCE_TYPES:
++            raise ValueError(
++                "Unknown TLS intolerance type: '%s'" % other.tlsIntoleranceType)
++
+         if other.minVersion > other.maxVersion:
+             raise ValueError("Versions set incorrectly")
+ 
+diff --git a/third_party/tlslite/tlslite/tlsconnection.py b/third_party/tlslite/tlslite/tlsconnection.py
+index 044ad59..7c1572f 100644
+--- a/third_party/tlslite/tlslite/tlsconnection.py
++++ b/third_party/tlslite/tlslite/tlsconnection.py
+@@ -1065,7 +1065,7 @@ class TLSConnection(TLSRecordLayer):
+                         reqCAs = None, reqCertTypes = None,
+                         tacks=None, activationFlags=0,
+                         nextProtos=None, anon=False,
+-                        tlsIntolerant=None, signedCertTimestamps=None,
++                        signedCertTimestamps=None,
+                         fallbackSCSV=False, ocspResponse=None):
+         """Perform a handshake in the role of server.
+ 
+@@ -1139,11 +1139,6 @@ class TLSConnection(TLSRecordLayer):
+         clients through the Next-Protocol Negotiation Extension, 
+         if they support it.
+ 
+-        @type tlsIntolerant: (int, int) or None
+-        @param tlsIntolerant: If tlsIntolerant is not None, the server will
+-        simulate TLS version intolerance by returning a fatal handshake_failure
+-        alert to all TLS versions tlsIntolerant or higher.
+-
+         @type signedCertTimestamps: str
+         @param signedCertTimestamps: A SignedCertificateTimestampList (as a
+         binary 8-bit string) that will be sent as a TLS extension whenever
+@@ -1175,7 +1170,7 @@ class TLSConnection(TLSRecordLayer):
+                 certChain, privateKey, reqCert, sessionCache, settings,
+                 checker, reqCAs, reqCertTypes,
+                 tacks=tacks, activationFlags=activationFlags, 
+-                nextProtos=nextProtos, anon=anon, tlsIntolerant=tlsIntolerant,
++                nextProtos=nextProtos, anon=anon,
+                 signedCertTimestamps=signedCertTimestamps,
+                 fallbackSCSV=fallbackSCSV, ocspResponse=ocspResponse):
+             pass
+@@ -1187,7 +1182,6 @@ class TLSConnection(TLSRecordLayer):
+                              reqCAs=None, reqCertTypes=None,
+                              tacks=None, activationFlags=0,
+                              nextProtos=None, anon=False,
+-                             tlsIntolerant=None,
+                              signedCertTimestamps=None,
+                              fallbackSCSV=False,
+                              ocspResponse=None
+@@ -1210,7 +1204,6 @@ class TLSConnection(TLSRecordLayer):
+             reqCAs=reqCAs, reqCertTypes=reqCertTypes,
+             tacks=tacks, activationFlags=activationFlags, 
+             nextProtos=nextProtos, anon=anon,
+-            tlsIntolerant=tlsIntolerant,
+             signedCertTimestamps=signedCertTimestamps,
+             fallbackSCSV=fallbackSCSV,
+             ocspResponse=ocspResponse)
+@@ -1223,7 +1216,7 @@ class TLSConnection(TLSRecordLayer):
+                              settings, reqCAs, reqCertTypes,
+                              tacks, activationFlags, 
+                              nextProtos, anon,
+-                             tlsIntolerant, signedCertTimestamps, fallbackSCSV,
++                             signedCertTimestamps, fallbackSCSV,
+                              ocspResponse):
+ 
+         self._handshakeStart(client=False)
+@@ -1261,7 +1254,7 @@ class TLSConnection(TLSRecordLayer):
+         # Handle ClientHello and resumption
+         for result in self._serverGetClientHello(settings, certChain,\
+                                             verifierDB, sessionCache,
+-                                            anon, tlsIntolerant, fallbackSCSV):
++                                            anon, fallbackSCSV):
+             if result in (0,1): yield result
+             elif result == None:
+                 self._handshakeDone(resumed=True)                
+@@ -1376,7 +1369,7 @@ class TLSConnection(TLSRecordLayer):
+ 
+ 
+     def _serverGetClientHello(self, settings, certChain, verifierDB,
+-                                sessionCache, anon, tlsIntolerant, fallbackSCSV):
++                                sessionCache, anon, fallbackSCSV):
+         #Initialize acceptable cipher suites
+         cipherSuites = []
+         if verifierDB:
+@@ -1413,11 +1406,21 @@ class TLSConnection(TLSRecordLayer):
+                 yield result
+ 
+         #If simulating TLS intolerance, reject certain TLS versions.
+-        elif (tlsIntolerant is not None and
+-            clientHello.client_version >= tlsIntolerant):
+-            for result in self._sendError(\
++        elif (settings.tlsIntolerant is not None and
++              clientHello.client_version >= settings.tlsIntolerant):
++            if settings.tlsIntoleranceType == "alert":
++                for result in self._sendError(\
+                     AlertDescription.handshake_failure):
+-                yield result
++                    yield result
++            elif settings.tlsIntoleranceType == "close":
++                self._abruptClose()
++                raise TLSUnsupportedError("Simulating version intolerance")
++            elif settings.tlsIntoleranceType == "reset":
++                self._abruptClose(reset=True)
++                raise TLSUnsupportedError("Simulating version intolerance")
++            else:
++                raise ValueError("Unknown intolerance type: '%s'" %
++                                 settings.tlsIntoleranceType)
+ 
+         #If client's version is too high, propose my highest version
+         elif clientHello.client_version > settings.maxVersion:
+diff --git a/third_party/tlslite/tlslite/tlsrecordlayer.py b/third_party/tlslite/tlslite/tlsrecordlayer.py
+index 370dc9a..23c2a2f 100644
+--- a/third_party/tlslite/tlslite/tlsrecordlayer.py
++++ b/third_party/tlslite/tlslite/tlsrecordlayer.py
+@@ -19,6 +19,7 @@ from .constants import *
+ from .utils.cryptomath import getRandomBytes
+ 
+ import socket
++import struct
+ import errno
+ import traceback
+ 
+@@ -523,6 +524,13 @@ class TLSRecordLayer(object):
+         self._shutdown(False)
+         raise TLSLocalAlert(alert, errorStr)
+ 
++    def _abruptClose(self, reset=False):
++        if reset:
++            #Set an SO_LINGER timeout of 0 to send a TCP RST.
++            self.setsockopt(socket.SOL_SOCKET, socket.SO_LINGER,
++                            struct.pack('ii', 1, 0))
++        self._shutdown(False)
++
+     def _sendMsgs(self, msgs):
+         randomizeFirstBlock = True
+         for msg in msgs: