We use SSH as a secure way to gain remote access to our critical servers. These SSH servers are configured to only use a set of highly secure ciphers, key exchange algorithms, and MACs. We also don’t allow connecting as root, and authentication can only occur using strong SSH keys—no passwords allowed. We use intermediate SSH bastion hosts to segregate production infrastructure from the open internet. These machines only accept traffic from addresses on an IP whitelist.
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All of this configuration is defined in code, so it is peer reviewed and reproducible.