client hello
2 TopicsF5 Server SSL Profile using TLS 1.0 instead of TLS 1.2
Hi I have an F5 virtual server that does SSL inspection so it has a client ssl profile and a server ssl profile. The backend server is running on a Windows Server 2019 / IIS and it only accepts TLS 1.1 and 1.2 clients. Since the F5 acts as a client in this case towards the Windows Server 2019, I have created a server ssl profile which forces the F5 to use TLS 1.2 only (SSL Proxy is disabled). My problem is that during the Client Hello from the F5 towards the Windows Server, TLS 1.0 is used. So the backend server immediatelly sends a RST ACK without sending Server Hello for supported ciphers etc. While doing a capture on Wireshark, I saw that TLS 1.0 is used. And further down in the same TCP packet it mentions TLS 1.2. This is driving me crazy. Is there any way we can enforce F5 to use 1.2 only during Client Hello?Solved15KViews0likes32CommentsForce Client-SSL Profile to X25519, Instead of Post-Quantum Cryptography
There is a TLS implementation that was working perfectly before, even though, there is SSL ClientHello extension addition, by a middle-box device. With Clienthello packets of 540bytes, this worked perfectly. An example is the "Extension Unknown Type 17516" added there. Recent tests show the extension addition is no longer working. The only significant change is that CLIENTSSL HELLO packets are now fragmented on TLS 1.3 with the Post-Quantum Cryptography implementation on clients (browsers), with CLIENTSSL HELLO now regularly abover 1500 bytes causing fragmentation. How is it possible if F5 is Client-side server to force all clients to use X25519 ciphers instead of X25519Kyber512Draft00 and X25519Kyber768Draft00 to ensure that full flow is not broken. is there any changes on CLIENTSSL Profile to implement this. Traffic Flow is Mobile browser--Mobile Packet gateway (header enrichment)-- F5 (Server)99Views0likes2Comments