Glen Zorn wrote: > > > Glen Zorn wrote: > > > Section 3 says "TLS clients MUST NOT send SSL 2.0 CLIENT-HELLO > > messages." > > > and "TLS servers MUST NOT negotiate or use SSL 2.0" and later "TLS > > servers > > > that do not support SSL 2.0 MAY accept version 2.0 CLIENT-HELLO > > messages as > > > the first message of a TLS handshake for interoperability with old > > clients." > > > Taken together, I find these statements quite confusing, if not > > outright > > > self-contradictory. Maybe, a "However" might fix the problem, though: > > > > > > TLS servers MUST NOT negotiate or use SSL 2.0; however, TLS > > servers > > > MAY accept SSL 2.0 CLIENT-HELLO messages as the first message of a > > > TLS handshake in order to maintain interoperability with legacy > > > clients. > > Maybe I just don't understand the word "use". It seems like if a server > accepts a protocol message it's using the protocol... With "negotiate" I meant returning a ServerHello handshake message with that version number (neither an SSL 2.0 SERVER-HELLO, nor an SSLv3 ServerHello with a server version of { 0x02,0x00 }). With "use" I meant to successfully complete the handshake and start exchanging application data protected under protocol version {0x02,0x00}. The Server accepts the SSL 2.0 CLIENT-HELLO protocol data unit (PDU), but not the SSL 2.0 protocol. If there are no SSLv3 or TLS cipher suites in that CLIENT-HELLO, or if the (version) field of the SSL 2.0 CLIENT-HELLO does not indicate at least 3.0, then the server still MUST abort. -Martin _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf