Implement extended master secret in tlslite

third_party/tlslite/tlslite/tlsrecordlayer.py

Index: third_party/tlslite/tlslite/tlsrecordlayer.py
diff --git a/third_party/tlslite/tlslite/tlsrecordlayer.py b/third_party/tlslite/tlslite/tlsrecordlayer.py
index c3bcd8c40ca64a12e426bc1f23ff3eff3d0305b4..8faea59eaa8c20c7ab163080a189f402dca61161 100644
--- a/third_party/tlslite/tlslite/tlsrecordlayer.py
+++ b/third_party/tlslite/tlslite/tlsrecordlayer.py
@@ -115,6 +115,9 @@ class TLSRecordLayer(object):
         self.clearReadBuffer()
         self.clearWriteBuffer()
 
+        #All handshake messages, for use in extended master secret
+        self.handshakeMessages = []

[davidben, 2015/08/14 22:31:18]

You should be able to just use the handshake digests below rather than enable a
handshake buffer I think. (Handshake buffer in TLS is only needed in TLS 1.2
before ServerHello and for client auth  which this doesn't implement.)

They're sampled in _calcFinished in tlsconnection.py. I would suggest factoring
that out into a method like _handshakeHash or _getHandshakeHash whatever the
right naming convention is.

[nharper, 2015/08/15 00:37:43]

Ah, I should have read the surrounding code and seen the handshake digests that
were already there.

I created a _getHandshakeHash method to use with extended master secret. I could
do more refactoring to use it elsewhere as well, but that might make it harder
to cleanly apply the patch in the future.

+
         #Handshake digests
         self._handshake_md5 = hashlib.md5()
         self._handshake_sha = hashlib.sha1()
@@ -558,6 +561,7 @@ class TLSRecordLayer(object):
                 yield result                                            
 
         b = msg.write()
+        self.handshakeMessages.append(b)
         
         # If a 1-byte message was passed in, and we "split" the 
         # first(only) byte off above, we may have a 0-length msg:
@@ -814,6 +818,7 @@ class TLSRecordLayer(object):
                 self._handshake_md5.update(compat26Str(p.bytes))
                 self._handshake_sha.update(compat26Str(p.bytes))
                 self._handshake_sha256.update(compat26Str(p.bytes))
+                self.handshakeMessages.append(p.bytes)
 
                 #Parse based on handshake type
                 if subType == HandshakeType.client_hello: