From b7c92e4dc15e40916888b5040b41ac7bc026c485 Mon Sep 17 00:00:00 2001 From: Alan Orth Date: Tue, 16 Aug 2016 14:28:58 +0300 Subject: [PATCH] roles/common: Remove 128-bit Ciphers and MACs from sshd_config I had removed them from Debian 8 and Ubuntu 14.04 configs last year when the NSA's Suite B crypto guidelines dropped 128-bit algorithms but those changes didn't make it to my new Ubuntu 16.04 config. It is probably overkill and paranoid, but this server is mine, so I can make those decisions (and I only connect from modern clients). --- roles/common/templates/sshd_config_Ubuntu-16.04.j2 | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/roles/common/templates/sshd_config_Ubuntu-16.04.j2 b/roles/common/templates/sshd_config_Ubuntu-16.04.j2 index a58f814..688adbc 100644 --- a/roles/common/templates/sshd_config_Ubuntu-16.04.j2 +++ b/roles/common/templates/sshd_config_Ubuntu-16.04.j2 @@ -85,9 +85,11 @@ Subsystem sftp /usr/lib/openssh/sftp-server # and ChallengeResponseAuthentication to 'no'. UsePAM yes -# https://stribika.github.io/2015/01/04/secure-secure-shell.html -Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes128-ctr -MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-ripemd160-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256 +# Originally from: https://stribika.github.io/2015/01/04/secure-secure-shell.html +# ... but with ciphers and MACs with < 256 bits removed, as NSA's Suite B now +# does away with these! See: https://www.nsa.gov/ia/programs/suiteb_cryptography/index.shtml +Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes256-ctr +MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512,hmac-sha2-256 KexAlgorithms curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256 {% if ssh_allowed_users is defined and ssh_allowed_users %}