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diff --git a/third_party/tlslite/tlslite/TLSConnection.py b/third_party/tlslite/tlslite/TLSConnection.py
index d2270a9..e6ce187 100644
--- a/third_party/tlslite/tlslite/TLSConnection.py
+++ b/third_party/tlslite/tlslite/TLSConnection.py
@@ -937,7 +937,8 @@ class TLSConnection(TLSRecordLayer):
certChain=None, privateKey=None, reqCert=False,
sessionCache=None, settings=None, checker=None,
reqCAs=None, tlsIntolerant=0,
- signedCertTimestamps=None):
+ signedCertTimestamps=None,
+ fallbackSCSV=False):
"""Perform a handshake in the role of server.
This function performs an SSL or TLS handshake. Depending on
@@ -1014,6 +1014,19 @@ class TLSConnection(TLSRecordLayer):
binary 8-bit string) that will be sent as a TLS extension whenever
the client announces support for the extension.
+ @type tlsIntolerant: int
+ @param tlsIntolerant: if non-zero, the server will simulate TLS
+ version intolerance by returning a fatal, handshake_failure alert.
+ The versions to which it's intolerant vary depending on the value:
+ 1: reject all TLS versions.
+ 2: reject TLS 1.1 or higher.
+ 3: reject TLS 1.2 or higher.
+
+ @type fallbackSCSV: bool
+ @param fallbackSCSV: if true, the server will implement
+ TLS_FALLBACK_SCSV and thus reject connections using less than the
+ server's maximum TLS version that include this cipher suite.
+
@raise socket.error: If a socket error occurs.
@raise tlslite.errors.TLSAbruptCloseError: If the socket is closed
without a preceding alert.
@@ -1022,7 +1023,8 @@ class TLSConnection(TLSRecordLayer):
"""
for result in self.handshakeServerAsync(sharedKeyDB, verifierDB,
certChain, privateKey, reqCert, sessionCache, settings,
- checker, reqCAs, tlsIntolerant, signedCertTimestamps):
+ checker, reqCAs, tlsIntolerant, signedCertTimestamps,
+ fallbackSCSV):
pass
@@ -1030,7 +1032,8 @@ class TLSConnection(TLSRecordLayer):
certChain=None, privateKey=None, reqCert=False,
sessionCache=None, settings=None, checker=None,
reqCAs=None, tlsIntolerant=0,
- signedCertTimestamps=None):
+ signedCertTimestamps=None,
+ fallbackSCSV=False):
"""Start a server handshake operation on the TLS connection.
This function returns a generator which behaves similarly to
@@ -1049,7 +1052,8 @@ class TLSConnection(TLSRecordLayer):
sessionCache=sessionCache, settings=settings,
reqCAs=reqCAs,
tlsIntolerant=tlsIntolerant,
- signedCertTimestamps=signedCertTimestamps)
+ signedCertTimestamps=signedCertTimestamps,
+ fallbackSCSV=fallbackSCSV)
for result in self._handshakeWrapperAsync(handshaker, checker):
yield result
@@ -1057,7 +1061,8 @@ class TLSConnection(TLSRecordLayer):
def _handshakeServerAsyncHelper(self, sharedKeyDB, verifierDB,
certChain, privateKey, reqCert,
sessionCache, settings, reqCAs,
- tlsIntolerant, signedCertTimestamps):
+ tlsIntolerant, signedCertTimestamps,
+ fallbackSCSV):
self._handshakeStart(client=False)
@@ -1141,12 +1146,18 @@ class TLSConnection(TLSRecordLayer):
yield result
#If client's version is too high, propose my highest version
- elif clientHello.client_version > settings.maxVersion:
+ if clientHello.client_version > settings.maxVersion:
self.version = settings.maxVersion
-
else:
#Set the version to the client's version
self.version = clientHello.client_version
+ if (fallbackSCSV and
+ clientHello.client_version < settings.maxVersion):
+ for cipherSuite in clientHello.cipher_suites:
+ if cipherSuite == 0x5600:
+ for result in self._sendError(\
+ AlertDescription.inappropriate_fallback):
+ yield result
#Get the client nonce; create server nonce
clientRandom = clientHello.random
diff --git a/third_party/tlslite/tlslite/constants.py b/third_party/tlslite/tlslite/constants.py
index b5a345a..23e3dcb 100644
--- a/third_party/tlslite/tlslite/constants.py
+++ b/third_party/tlslite/tlslite/constants.py
@@ -91,6 +91,7 @@ class AlertDescription:
protocol_version = 70
insufficient_security = 71
internal_error = 80
+ inappropriate_fallback = 86
user_canceled = 90
no_renegotiation = 100
unknown_srp_username = 120
diff --git a/third_party/tlslite/tlslite/errors.py b/third_party/tlslite/tlslite/errors.py
index c7f7ba8..45087e6 100644
--- a/third_party/tlslite/tlslite/errors.py
+++ b/third_party/tlslite/tlslite/errors.py
@@ -48,6 +48,7 @@ class TLSAlert(TLSError):
AlertDescription.protocol_version: "protocol_version",\
AlertDescription.insufficient_security: "insufficient_security",\
AlertDescription.internal_error: "internal_error",\
+ AlertDescription.inappropriate_fallback: "inappropriate_fallback",\
AlertDescription.user_canceled: "user_canceled",\
AlertDescription.no_renegotiation: "no_renegotiation",\
AlertDescription.unknown_srp_username: "unknown_srp_username",\
|
