diff --git a/third_party/tlslite/tlslite/constants.py b/third_party/tlslite/tlslite/constants.py
index 6d78a20..f9c8676 100644
--- a/third_party/tlslite/tlslite/constants.py
+++ b/third_party/tlslite/tlslite/constants.py
@@ -55,6 +55,7 @@ class ExtensionType:    # RFC 6066 / 4366
     srp = 12            # RFC 5054  
     cert_type = 9       # RFC 6091
     signed_cert_timestamps = 18  # RFC 6962
+    extended_master_secret = 23  # draft-ietf-tls-session-hash-06
     tack = 0xF300
     supports_npn = 13172
     channel_id = 30032
diff --git a/third_party/tlslite/tlslite/handshakesettings.py b/third_party/tlslite/tlslite/handshakesettings.py
index 605ed42..a7b6ab9 100644
--- a/third_party/tlslite/tlslite/handshakesettings.py
+++ b/third_party/tlslite/tlslite/handshakesettings.py
@@ -111,6 +111,10 @@ class HandshakeSettings(object):
     @type alertAfterHandshake: bool
     @ivar alertAfterHandshake: If true, the server will send a fatal
     alert immediately after the handshake completes.
+
+    @type enableExtendedMasterSecret: bool
+    @ivar enableExtendedMasterSecret: If true, the server supports the extended
+    master secret TLS extension and will negotiated it with supporting clients.
     
     Note that TACK support is not standardized by IETF and uses a temporary
     TLS Extension number, so should NOT be used in production software.
@@ -129,6 +133,7 @@ class HandshakeSettings(object):
         self.tlsIntoleranceType = 'alert'
         self.useExperimentalTackExtension = False
         self.alertAfterHandshake = False
+        self.enableExtendedMasterSecret = True
 
     # Validates the min/max fields, and certificateTypes
     # Filters out unsupported cipherNames and cipherImplementations
@@ -146,6 +151,7 @@ class HandshakeSettings(object):
         other.tlsIntolerant = self.tlsIntolerant
         other.tlsIntoleranceType = self.tlsIntoleranceType
         other.alertAfterHandshake = self.alertAfterHandshake
+        other.enableExtendedMasterSecret = self.enableExtendedMasterSecret
 
         if not cipherfactory.tripleDESPresent:
             other.cipherNames = [e for e in self.cipherNames if e != "3des"]
diff --git a/third_party/tlslite/tlslite/mathtls.py b/third_party/tlslite/tlslite/mathtls.py
index 60a331a..0a23fe1 100644
--- a/third_party/tlslite/tlslite/mathtls.py
+++ b/third_party/tlslite/tlslite/mathtls.py
@@ -67,16 +67,20 @@ def PRF_SSL(secret, seed, length):
             index += 1
     return bytes
 
-def calcMasterSecret(version, premasterSecret, clientRandom, serverRandom):
+def calcMasterSecret(version, premasterSecret, clientRandom, serverRandom,
+                     handshakeHash, useExtendedMasterSecret):
+    label = b"master secret"
+    seed = clientRandom + serverRandom
+    if useExtendedMasterSecret:
+        label = b"extended master secret"
+        seed = handshakeHash
+
     if version == (3,0):
-        masterSecret = PRF_SSL(premasterSecret,
-                            clientRandom + serverRandom, 48)
+        masterSecret = PRF_SSL(premasterSecret, seed, 48)
     elif version in ((3,1), (3,2)):
-        masterSecret = PRF(premasterSecret, b"master secret",
-                            clientRandom + serverRandom, 48)
+        masterSecret = PRF(premasterSecret, label, seed, 48)
     elif version == (3,3):
-        masterSecret = PRF_1_2(premasterSecret, b"master secret",
-                            clientRandom + serverRandom, 48)
+        masterSecret = PRF_1_2(premasterSecret, label, seed, 48)
     else:
         raise AssertionError()
     return masterSecret
diff --git a/third_party/tlslite/tlslite/messages.py b/third_party/tlslite/tlslite/messages.py
index 9aeff6d..9b553ce 100644
--- a/third_party/tlslite/tlslite/messages.py
+++ b/third_party/tlslite/tlslite/messages.py
@@ -114,6 +114,7 @@ class ClientHello(HandshakeMsg):
         self.supports_npn = False
         self.server_name = bytearray(0)
         self.channel_id = False
+        self.extended_master_secret = False
         self.support_signed_cert_timestamps = False
         self.status_request = False
 
@@ -185,6 +186,8 @@ class ClientHello(HandshakeMsg):
                                 break
                     elif extType == ExtensionType.channel_id:
                         self.channel_id = True
+                    elif extType == ExtensionType.extended_master_secret:
+                        self.extended_master_secret = True
                     elif extType == ExtensionType.signed_cert_timestamps:
                         if extLength:
                             raise SyntaxError()
@@ -267,6 +270,7 @@ class ServerHello(HandshakeMsg):
         self.next_protos_advertised = None
         self.next_protos = None
         self.channel_id = False
+        self.extended_master_secret = False
         self.signed_cert_timestamps = None
         self.status_request = False
 
@@ -358,6 +362,9 @@ class ServerHello(HandshakeMsg):
         if self.channel_id:
             w2.add(ExtensionType.channel_id, 2)
             w2.add(0, 2)
+        if self.extended_master_secret:
+            w2.add(ExtensionType.extended_master_secret, 2)
+            w2.add(0, 2)
         if self.signed_cert_timestamps:
             w2.add(ExtensionType.signed_cert_timestamps, 2)
             w2.addVarSeq(bytearray(self.signed_cert_timestamps), 1, 2)
diff --git a/third_party/tlslite/tlslite/tlsconnection.py b/third_party/tlslite/tlslite/tlsconnection.py
index dfac274..04161513 100644
--- a/third_party/tlslite/tlslite/tlsconnection.py
+++ b/third_party/tlslite/tlslite/tlsconnection.py
@@ -981,7 +981,8 @@ class TLSConnection(TLSRecordLayer):
                 masterSecret = calcMasterSecret(self.version,
                                          premasterSecret,
                                          clientRandom,
-                                         serverRandom)
+                                         serverRandom,
+                                         b"", False)
                 verifyBytes = self._calcSSLHandshakeHash(masterSecret, b"")
             elif self.version in ((3,1), (3,2)):
                 verifyBytes = self._handshake_md5.digest() + \
@@ -1036,7 +1037,7 @@ class TLSConnection(TLSRecordLayer):
                         cipherSuite, cipherImplementations, nextProto):
 
         masterSecret = calcMasterSecret(self.version, premasterSecret,
-                            clientRandom, serverRandom)
+                            clientRandom, serverRandom, b"", False)
         self._calcPendingStates(cipherSuite, masterSecret, 
                                 clientRandom, serverRandom, 
                                 cipherImplementations)
@@ -1326,6 +1327,9 @@ class TLSConnection(TLSRecordLayer):
                             cipherSuite, CertificateType.x509, tackExt,
                             nextProtos)
         serverHello.channel_id = clientHello.channel_id
+        serverHello.extended_master_secret = \
+            clientHello.extended_master_secret and \
+            settings.enableExtendedMasterSecret
         if clientHello.support_signed_cert_timestamps:
             serverHello.signed_cert_timestamps = signedCertTimestamps
         if clientHello.status_request:
@@ -1383,7 +1387,8 @@ class TLSConnection(TLSRecordLayer):
         for result in self._serverFinished(premasterSecret, 
                                 clientHello.random, serverHello.random,
                                 cipherSuite, settings.cipherImplementations,
-                                nextProtos, clientHello.channel_id):
+                                nextProtos, clientHello.channel_id,
+                                serverHello.extended_master_secret):
                 if result in (0,1): yield result
                 else: break
         masterSecret = result
@@ -1523,6 +1528,9 @@ class TLSConnection(TLSRecordLayer):
                 serverHello.create(self.version, getRandomBytes(32),
                                    session.sessionID, session.cipherSuite,
                                    CertificateType.x509, None, None)
+                serverHello.extended_master_secret = \
+                    clientHello.extended_master_secret and \
+                    settings.enableExtendedMasterSecret
                 for result in self._sendMsg(serverHello):
                     yield result
 
@@ -1743,7 +1751,8 @@ class TLSConnection(TLSRecordLayer):
         if clientCertChain:
             if self.version == (3,0):
                 masterSecret = calcMasterSecret(self.version, premasterSecret,
-                                         clientHello.random, serverHello.random)
+                                         clientHello.random, serverHello.random,
+                                         b"", False)
                 verifyBytes = self._calcSSLHandshakeHash(masterSecret, b"")
             elif self.version in ((3,1), (3,2)):
                 verifyBytes = self._handshake_md5.digest() + \
@@ -1827,9 +1836,11 @@ class TLSConnection(TLSRecordLayer):
 
     def _serverFinished(self,  premasterSecret, clientRandom, serverRandom,
                         cipherSuite, cipherImplementations, nextProtos,
-                        doingChannelID):
+                        doingChannelID, useExtendedMasterSecret):
         masterSecret = calcMasterSecret(self.version, premasterSecret,
-                                      clientRandom, serverRandom)
+                                      clientRandom, serverRandom,
+                                      self._ems_handshake_hash,
+                                      useExtendedMasterSecret)
         
         #Calculate pending connection states
         self._calcPendingStates(cipherSuite, masterSecret, 
diff --git a/third_party/tlslite/tlslite/tlsrecordlayer.py b/third_party/tlslite/tlslite/tlsrecordlayer.py
index c3bcd8c..d2320b8 100644
--- a/third_party/tlslite/tlslite/tlsrecordlayer.py
+++ b/third_party/tlslite/tlslite/tlsrecordlayer.py
@@ -119,6 +119,7 @@ class TLSRecordLayer(object):
         self._handshake_md5 = hashlib.md5()
         self._handshake_sha = hashlib.sha1()
         self._handshake_sha256 = hashlib.sha256()
+        self._ems_handshake_hash = b""
 
         #TLS Protocol Version
         self.version = (0,0) #read-only
@@ -814,6 +815,8 @@ class TLSRecordLayer(object):
                 self._handshake_md5.update(compat26Str(p.bytes))
                 self._handshake_sha.update(compat26Str(p.bytes))
                 self._handshake_sha256.update(compat26Str(p.bytes))
+                if subType == HandshakeType.client_key_exchange:
+                    self._ems_handshake_hash = self._getHandshakeHash()
 
                 #Parse based on handshake type
                 if subType == HandshakeType.client_hello:
@@ -1112,6 +1115,7 @@ class TLSRecordLayer(object):
         self._handshake_md5 = hashlib.md5()
         self._handshake_sha = hashlib.sha1()
         self._handshake_sha256 = hashlib.sha256()
+        self._ems_handshake_hash = b""
         self._handshakeBuffer = []
         self.allegedSrpUsername = None
         self._refCount = 1
@@ -1256,3 +1260,9 @@ class TLSRecordLayer(object):
 
         return md5Bytes + shaBytes
 
+    def _getHandshakeHash(self):
+        if self.version in ((3,1), (3,2)):
+            return self._handshake_md5.digest() + \
+                self._handshake_sha.digest()
+        elif self.version == (3,3):
+            return self._handshake_sha256.digest()