Does TLS protect against replay attacks?
The SSL/TLS channel itself is protected against replay attacks using the MAC (Message Authentication Code), computed using the MAC secret and the sequence number. (The MAC mechanism is what ensures the TLS communication integrity).
What is SSL TLS client authentication?
SSL/TLS client authentication, as the name implies, is intended for the client rather than a server. In server certificates, the client (browser) verifies the identity of the server. The private key, the heart of an SSL certificate, is kept with the client instead of the server. It’s stored in the browser.
Is there a replay attack against SSL / TLS?
Thus, it is not a replay attack against SSL/TLS since it counts on having the plain (not encrypted) data in the first place. There are several ways to get to the plain data when SSL/TLS is used but all of these involve somehow compromising client or server or relying on security vulnerabilities in these.
What do you need to know about TLS client authentication?
But TLS supports client authentication as well. Client authentication is a means to provide an identity for yourself — after you verify that the server you’re talking to has the right DNS and a certificate you trust. It’s a handy way to limit access to servers to individuals or devices without having to entirely rely on firewalls.
Where do I find the TLS certificate for my server?
/etc/haproxy/server.pem has your server TLS information. It should be in the order of public certificate, private key, and then any intermediate certificates. /etc/haproxy/verify.pem has your client CA TLS public certificate, along with the appropriate root certificate.
Is there a way to debug TLS authentication in OpenSSL?
OpenSSL’s s_client is an extremely handy tool to debug TLS connections — and can also help you debug client authentication. One problem with OpenSSL is that it does not have native support for PKCS11 — and the OpenSC libraries are too low level for OpenSSL to just use them.