I have the requirement of configuring all of our applications to use only PFS ciphersuites where possible.
I have an application (HP Network Automation), which supports DHE key exchange (although not ECDHE), but when I limit it down to only the following two suites:
I cannot connect via IE11, FF or Chrome.
I have looked at wireshark traces, and when I have no restrictions on the server end, the Firefox Client Hello contains 66 suites, including 6b and 67, which are the two listed above.
However, when I restrict the server to only offering the above 2 suites, my Client Hello only contains 11 suites, and doesn't include 6b or 67.
I thought the Client Hello was the first real communication, (not including TCP handshake), so how can server configuration influence the CLient Hello?
N.B. These applications can only be accessed via intranet and VPN, so we have control over which clients will connect. We don't need to offer legacy suites.