1 diff --git a/third_party/tlslite/tlslite/TLSConnection.py b/third_party/tlslite/tlslite/TLSConnection.py 2 index d2270a9..e6ce187 100644 3 --- a/third_party/tlslite/tlslite/TLSConnection.py 4 +++ b/third_party/tlslite/tlslite/TLSConnection.py 5 @@ -937,7 +937,8 @@ class TLSConnection(TLSRecordLayer): 6 certChain=None, privateKey=None, reqCert=False, 7 sessionCache=None, settings=None, checker=None, 8 reqCAs=None, tlsIntolerant=0, 9 - signedCertTimestamps=None): 10 + signedCertTimestamps=None, 11 + fallbackSCSV=False): 12 """Perform a handshake in the role of server. 13 14 This function performs an SSL or TLS handshake. Depending on 15 @@ -1014,6 +1014,19 @@ class TLSConnection(TLSRecordLayer): 16 binary 8-bit string) that will be sent as a TLS extension whenever 17 the client announces support for the extension. 18 19 + @type tlsIntolerant: int 20 + @param tlsIntolerant: if non-zero, the server will simulate TLS 21 + version intolerance by returning a fatal, handshake_failure alert. 22 + The versions to which it's intolerant vary depending on the value: 23 + 1: reject all TLS versions. 24 + 2: reject TLS 1.1 or higher. 25 + 3: reject TLS 1.2 or higher. 26 + 27 + @type fallbackSCSV: bool 28 + @param fallbackSCSV: if true, the server will implement 29 + TLS_FALLBACK_SCSV and thus reject connections using less than the 30 + server's maximum TLS version that include this cipher suite. 31 + 32 @raise socket.error: If a socket error occurs. 33 @raise tlslite.errors.TLSAbruptCloseError: If the socket is closed 34 without a preceding alert. 35 @@ -1022,7 +1023,8 @@ class TLSConnection(TLSRecordLayer): 36 """ 37 for result in self.handshakeServerAsync(sharedKeyDB, verifierDB, 38 certChain, privateKey, reqCert, sessionCache, settings, 39 - checker, reqCAs, tlsIntolerant, signedCertTimestamps): 40 + checker, reqCAs, tlsIntolerant, signedCertTimestamps, 41 + fallbackSCSV): 42 pass 43 44 45 @@ -1030,7 +1032,8 @@ class TLSConnection(TLSRecordLayer): 46 certChain=None, privateKey=None, reqCert=False, 47 sessionCache=None, settings=None, checker=None, 48 reqCAs=None, tlsIntolerant=0, 49 - signedCertTimestamps=None): 50 + signedCertTimestamps=None, 51 + fallbackSCSV=False): 52 """Start a server handshake operation on the TLS connection. 53 54 This function returns a generator which behaves similarly to 55 @@ -1049,7 +1052,8 @@ class TLSConnection(TLSRecordLayer): 56 sessionCache=sessionCache, settings=settings, 57 reqCAs=reqCAs, 58 tlsIntolerant=tlsIntolerant, 59 - signedCertTimestamps=signedCertTimestamps) 60 + signedCertTimestamps=signedCertTimestamps, 61 + fallbackSCSV=fallbackSCSV) 62 for result in self._handshakeWrapperAsync(handshaker, checker): 63 yield result 64 65 @@ -1057,7 +1061,8 @@ class TLSConnection(TLSRecordLayer): 66 def _handshakeServerAsyncHelper(self, sharedKeyDB, verifierDB, 67 certChain, privateKey, reqCert, 68 sessionCache, settings, reqCAs, 69 - tlsIntolerant, signedCertTimestamps): 70 + tlsIntolerant, signedCertTimestamps, 71 + fallbackSCSV): 72 73 self._handshakeStart(client=False) 74 75 @@ -1141,12 +1146,18 @@ class TLSConnection(TLSRecordLayer): 76 yield result 77 78 #If client's version is too high, propose my highest version 79 - elif clientHello.client_version > settings.maxVersion: 80 + if clientHello.client_version > settings.maxVersion: 81 self.version = settings.maxVersion 82 - 83 else: 84 #Set the version to the client's version 85 self.version = clientHello.client_version 86 + if (fallbackSCSV and 87 + clientHello.client_version < settings.maxVersion): 88 + for cipherSuite in clientHello.cipher_suites: 89 + if cipherSuite == 0x5600: 90 + for result in self._sendError(\ 91 + AlertDescription.inappropriate_fallback): 92 + yield result 93 94 #Get the client nonce; create server nonce 95 clientRandom = clientHello.random 96 diff --git a/third_party/tlslite/tlslite/constants.py b/third_party/tlslite/tlslite/constants.py 97 index b5a345a..23e3dcb 100644 98 --- a/third_party/tlslite/tlslite/constants.py 99 +++ b/third_party/tlslite/tlslite/constants.py 100 @@ -91,6 +91,7 @@ class AlertDescription: 101 protocol_version = 70 102 insufficient_security = 71 103 internal_error = 80 104 + inappropriate_fallback = 86 105 user_canceled = 90 106 no_renegotiation = 100 107 unknown_srp_username = 120 108 diff --git a/third_party/tlslite/tlslite/errors.py b/third_party/tlslite/tlslite/errors.py 109 index c7f7ba8..45087e6 100644 110 --- a/third_party/tlslite/tlslite/errors.py 111 +++ b/third_party/tlslite/tlslite/errors.py 112 @@ -48,6 +48,7 @@ class TLSAlert(TLSError): 113 AlertDescription.protocol_version: "protocol_version",\ 114 AlertDescription.insufficient_security: "insufficient_security",\ 115 AlertDescription.internal_error: "internal_error",\ 116 + AlertDescription.inappropriate_fallback: "inappropriate_fallback",\ 117 AlertDescription.user_canceled: "user_canceled",\ 118 AlertDescription.no_renegotiation: "no_renegotiation",\ 119 AlertDescription.unknown_srp_username: "unknown_srp_username",\ 120
