Following on the heels of the previously posted question here, Taxonomy of Ciphers/MACs/Kex available in SSH?, I need some help to obtain the following design goals:
- Disable any 96-bit HMAC Algorithms.
- Disable any MD5-based HMAC Algorithms.
- Disable CBC Mode Ciphers and use CTR Mode Ciphers.
To this end, the following is the default list for supported ciphers:
I was looking at changing it to this:
Next, for the HMAC, it supports the following:
And I was looking at changing it to this:
Will this provide the most benefit in terms of security while mitigating the known weaknesses and attacks against common SSH configurations? Note that this question is not about 0-days or other related flaws in the SSH code and is specifically about the best possible arrangement and configuration of the ciphers, KexAlgorithms, and MACs. If the order is wrong, please suggest a better method to arrange them. This is also for the sshd_config file and not client connections.