Add a dedicated error code for TLS 1.3 interference.

third_party/tlslite/tlslite/messages.py

 # Authors: 
 #   Trevor Perrin
 #   Google - handling CertificateRequest.certificate_types
 #   Google (adapted by Sam Rushing and Marcelo Fernandez) - NPN support
 #   Dimitris Moraitis - Anon ciphersuites
 #   Yngve Pettersen (ported by Paul Sokolovsky) - TLS 1.2
 #
 # See the LICENSE file for legal information regarding use of this file.
 
 """Classes representing TLS messages."""
@@ skipping 122 matching lines @@
         self.srp_username = None        # a string
         self.tack = False
         self.alpn_protos_advertised = None
         self.supports_npn = False
         self.server_name = bytearray(0)
         self.channel_id = False
         self.extended_master_secret = False
         self.tb_client_params = []
         self.support_signed_cert_timestamps = False
         self.status_request = False
+        self.has_supported_versions = False
         self.ri = False
 
     def create(self, version, random, session_id, cipher_suites,
                certificate_types=None, srpUsername=None,
                tack=False, alpn_protos_advertised=None,
                supports_npn=False, serverName=None):
         self.client_version = version
         self.random = random
         self.session_id = session_id
         self.cipher_suites = cipher_suites
@@ skipping 91 matching lines @@
                         # when selecting an OCSP responder and SHOULD include
                         # request_extensions in the OCSP request.
                         p.getFixBytes(extLength)
                         self.status_request = True
                     elif extType == ExtensionType.renegotiation_info:
                         # We don't support renegotiation, so if we receive this
                         # extension, it should contain a single null byte.
                         if extLength != 1 or p.getFixBytes(extLength)[0] != 0:
                             raise SyntaxError()
                         self.ri = True
+                    elif extType == ExtensionType.supported_versions:
+                        # Ignore the extension, but make a note of it for
+                        # intolerance simulation.
+                        self.has_supported_versions = True
+                        _ = p.getFixBytes(extLength)
                     else:
                         _ = p.getFixBytes(extLength)
                     index2 = p.index
                     if index2 - index1 != extLength:
                         raise SyntaxError("Bad length for extension_data")
                     soFar += 4 + extLength
             if CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV in self.cipher_suites:
                 self.ri = True
             p.stopLengthCheck()
         return self
@@ skipping 614 matching lines @@
         newMsg = ApplicationData().create(self.bytes[:1])
         self.bytes = self.bytes[1:]
         return newMsg
 
     def parse(self, p):
         self.bytes = p.bytes
         return self
 
     def write(self):
         return self.bytes