[TLS] What's the right version number in the PreMasterSecret for renegotiation

[Xuelei Fan <[e-mail]>]

In RFC4346/5246, the specification for client_version in the
PreMasterSecret is described as:
---------------
      struct {
          ProtocolVersion client_version;
          opaque random[46];
      } PreMasterSecret;

      client_version The latest (newest) version supported by the
         client.  This is used to detect version roll-back attacks.
         Upon receiving the premaster secret, the server SHOULD check
         that this value matches the value transmitted by the client in
         the client hello message.

      ....

   Note: The version number in the PreMasterSecret MUST be the version
         offered by the client in the ClientHello, not the version
         negotiated for the connection.  This feature is designed to
         prevent rollback attacks.
---------------

The spec is clear for initial handshaking. But while testing
renegotiation, we get two different interpretations of the version
number in the PreMasterSecret. We noticed Opera (10.50) uses the version
number offered by the renegotiation ClientHello, while Microsoft IE 8
(IE 8 at Windows 7) uses the version number offered by the ClientHello
in the initial handshaking.

For Opera, the scenario looks like:

    Opera <--------------> TLS server
         --->ClientHello V1.2--->
         <---ServerHello V1.1<---
         ...
         --->PreMasterSecret (v1.2)--->  (as expected)
         ...
         <---HelloRequest<----
         ---->ClientHello v1.1----> (ask for an abbreviated handshake)
         <---ServerHello V1.1<---   (not resumable, new session)
         ...
         --->PreMasterSecret (v1.1)---> (*)


For IE 8, the scenario looks like:

    IE 8<--------------> TLS server
         --->ClientHello V1.2--->
         <---ServerHello V1.1<---
         ...
         --->PreMasterSecret (v1.2)--->  (as expected)
         ...
         <---HelloRequest<----
         ---->ClientHello v1.1----> (ask for an abbreviated handshake)
         <---ServerHello V1.1<---   (not resumable, new session)
         ...
         --->PreMasterSecret (v1.2)---> (**)

(*) Opera uses the version number offered by the ClientHello in the
renegotiation handshaking.
(**) IE 8 uses the version number offered by the ClientHello in the
initial handshaking.

Please help to clarify what's the correct version number choice for
renegotiation.

Thanks,
Xuelei (Andrew) Fan