A collection of awesome security hardening guides, best practices, checklists, benchmarks, tools and other resources.
Wants to be the "cryptographic right answers" document, but for SSH.
Archived.
Maybe have Glitch monitor it?
/etc/ssh/sshd_config:
Protocol 2
AuthenticationMethods publickey
PasswordAuthentication no
PermitEmptyPasswords no
X11Forwarding no
AllowAgentForwarding no
# The problem with having "MaxAuthTries 2" is, the more keys your
# SSH agent has, the more chances you'll have to get locked out.
# I set it to <my number of SSH keys> +2.
MaxAuthTries 10
MaxSessions 10
HostbasedAuthentication no
IgnoreRhosts yes
PermitRootLogin no
KexAlgorithms curve25519-sha256@libssh.org,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,umac-128@openssh.comThis guide arose out of the need for system administrators to have an updated, solid, well researched and thought-through guide for configuring SSL, PGP, SSH and other cryptographic tools in the post-Snowden age. Triggered by the NSA leaks in the summer of 2013, many system administrators and IT security officers saw the need to strengthen their encryption settings. This guide is specifically written for these system administrators.
The focus of this guide is merely to give current best practices for configuring complex cipher suites and related parameters in a copy & paste-able manner. The guide tries to stay as concise as is possible for such a complex topic as cryptography. Naturally, it can not be complete. There are many excellent guides (II & SYM, 2012) and best practice documents available when it comes to cryptography. However none of them focuses specifically on what an average system administrator needs for hardening his or her systems' crypto settings.
A number of Github repos of code meant to be used to harden servers in various ways prior to deployment.
A ruleset-based access control system for the Linux kernel.
An excellent tutorial on hardening CenOS Linux (and by extension Redhat Advanced Server).
How to harden SSL support on your web server to mitigate attacks like BREACH, BEAST, and Lucky 13. Updated regularly.
A tutorial on how to harden SSL and TLS in Nginx. Includes changing and increasing the size of Diffie-Hellman parameters for better security.