Implement Token Binding Negotiation in tlslite

third_party/tlslite/patches/token_binding_negotiation.patch

+diff --git a/third_party/tlslite/tlslite/constants.py b/third_party/tlslite/tlslite/constants.py
+index f9c8676..84bb703 100644
+--- a/third_party/tlslite/tlslite/constants.py
++++ b/third_party/tlslite/tlslite/constants.py
+@@ -59,6 +59,7 @@ class ExtensionType:    # RFC 6066 / 4366
+     tack = 0xF300
+     supports_npn = 13172
+     channel_id = 30032
++    token_binding = 30033
+ 
+ class HashAlgorithm:
+     none = 0
+diff --git a/third_party/tlslite/tlslite/handshakesettings.py b/third_party/tlslite/tlslite/handshakesettings.py
+index a7b6ab9..8f25f62 100644
+--- a/third_party/tlslite/tlslite/handshakesettings.py
++++ b/third_party/tlslite/tlslite/handshakesettings.py
+@@ -115,6 +115,13 @@ class HandshakeSettings(object):
+     @type enableExtendedMasterSecret: bool
+     @ivar enableExtendedMasterSecret: If true, the server supports the extended
+     master secret TLS extension and will negotiated it with supporting clients.
++
++    @type supportedTokenBindingParams: list
++    @ivar supportedTokenBindingParams: A list of token binding parameters that
++    the server supports when negotiating token binding. List values are integers
++    corresponding to the TokenBindingKeyParameters enum in the Token Binding
++    Negotiation spec (draft-ietf-tokbind-negotiation-00). Values are in server's
++    preference order, with most preferred params first.
+     
+     Note that TACK support is not standardized by IETF and uses a temporary
+     TLS Extension number, so should NOT be used in production software.
+@@ -134,6 +141,7 @@ class HandshakeSettings(object):
+         self.useExperimentalTackExtension = False
+         self.alertAfterHandshake = False
+         self.enableExtendedMasterSecret = True
++        self.supportedTokenBindingParams = []
+ 
+     # Validates the min/max fields, and certificateTypes
+     # Filters out unsupported cipherNames and cipherImplementations
+@@ -152,6 +160,7 @@ class HandshakeSettings(object):
+         other.tlsIntoleranceType = self.tlsIntoleranceType
+         other.alertAfterHandshake = self.alertAfterHandshake
+         other.enableExtendedMasterSecret = self.enableExtendedMasterSecret
++        other.supportedTokenBindingParams = self.supportedTokenBindingParams
+ 
+         if not cipherfactory.tripleDESPresent:
+             other.cipherNames = [e for e in self.cipherNames if e != "3des"]
+diff --git a/third_party/tlslite/tlslite/messages.py b/third_party/tlslite/tlslite/messages.py
+index 9b553ce..ab2be57 100644
+--- a/third_party/tlslite/tlslite/messages.py
++++ b/third_party/tlslite/tlslite/messages.py
+@@ -115,6 +115,7 @@ class ClientHello(HandshakeMsg):
+         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
+ 
+@@ -188,6 +189,15 @@ class ClientHello(HandshakeMsg):
+                         self.channel_id = True
+                     elif extType == ExtensionType.extended_master_secret:
+                         self.extended_master_secret = True
++                    elif extType == ExtensionType.token_binding:
++                        tokenBindingBytes = p.getFixBytes(extLength)
++                        p2 = Parser(tokenBindingBytes)
++                        ver_minor = p2.get(1)
++                        ver_major = p2.get(1)
++                        if (ver_major, ver_minor) >= (0, 2):
++                            p2.startLengthCheck(1)
++                            while not p2.atLengthCheck():
++                                self.tb_client_params.append(p2.get(1))
+                     elif extType == ExtensionType.signed_cert_timestamps:
+                         if extLength:
+                             raise SyntaxError()
+@@ -271,6 +281,7 @@ class ServerHello(HandshakeMsg):
+         self.next_protos = None
+         self.channel_id = False
+         self.extended_master_secret = False
++        self.tb_params = None
+         self.signed_cert_timestamps = None
+         self.status_request = False
+ 
+@@ -365,6 +376,17 @@ class ServerHello(HandshakeMsg):
+         if self.extended_master_secret:
+             w2.add(ExtensionType.extended_master_secret, 2)
+             w2.add(0, 2)
++        if self.tb_params:
++            w2.add(ExtensionType.token_binding, 2)
++            # length of extension
++            w2.add(4, 2)
++            # version
++            w2.add(0, 1)
++            w2.add(2, 1)
++            # length of params (defined as variable length <1..2^8-1>, but in
++            # this context the server can only send a single value.
++            w2.add(1, 1)
++            w2.add(self.tb_params, 1)
+         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 04161513..06404fe 100644
+--- a/third_party/tlslite/tlslite/tlsconnection.py
++++ b/third_party/tlslite/tlslite/tlsconnection.py
+@@ -1330,6 +1330,10 @@ class TLSConnection(TLSRecordLayer):
+         serverHello.extended_master_secret = \
+             clientHello.extended_master_secret and \
+             settings.enableExtendedMasterSecret
++        for param in clientHello.tb_client_params:
++            if param in settings.supportedTokenBindingParams:
++                serverHello.tb_params = param
++                break
+         if clientHello.support_signed_cert_timestamps:
+             serverHello.signed_cert_timestamps = signedCertTimestamps
+         if clientHello.status_request: