Merge pull request #28 from lukecyca/sshd-sec

SSH security improvements

README.textile

 * Web hosting (ex: for your blog) via "Apache":https://www.apache.org/.
 * Firewall management via "ferm":http://ferm.foo-projects.org/.
 * Intrusion prevention via "fail2ban":http://www.fail2ban.org/ and rootkit detection via "rkhunter":http://rkhunter.sourceforge.net.
+* SSH configuration preventing root login and insecure password authentication
 * Nightly backups to "Tarsnap":https://www.tarsnap.com/.
 * A bunch of nice-to-have tools like "mosh":http://mosh.mit.edu and "htop":http://htop.sourceforge.net that make life with a server a little easier.
 
 # Put your SSL certificate's components in the respective files that start with @wildcard_ca@ in @roles/common/files@, and a combined version in @roles/ircbouncer/files/etc_ssl_znc-combined.pem@.
 # Set up SPF and reverse DNS "as per the inspirational post":http://sealedabstract.com/code/nsa-proof-your-e-mail-in-2-hours/. Make sure to validate that it's all working, for example by sending an email to <a href="mailto:check-auth@verifier.port25.com">check-auth@verifier.port25.com</a> and reviewing the report that will be emailed back to you.
 # Sign in to the ZNC web interface and set things up to your liking.
-# You should probably disable remote root login and password-based logins in @/etc/ssh/sshd_config@ but that's up to you.
 
 Now, the time-consuming part: grep through the files for the string @TODO@ and replace as necessary. You'll probably want to check out all the files in the respective @vars/@ sub-directories in each playbook directory.
 

roles/common/handlers/main.yml

 - name: restart fail2ban
   service: name=fail2ban state=restarted
 
+- name: restart sshd
+  service: name=ssh state=restarted
+
 - include: ferm.yml

roles/common/tasks/security.yml

   copy: src=etc_fail2ban_filter.d_dovecot-pop3imap.conf dest=/etc/fail2ban/filter.d/dovecot-pop3imap.conf
 - template: src=etc_fail2ban_jail.local.j2 dest=/etc/fail2ban/jail.local
   notify: restart fail2ban
+
+- name: Copy sshd_config into place
+  template: src=etc_ssh_sshd_config.j2 dest=/etc/ssh/sshd_config
+  notify: restart ssh
+

roles/common/templates/etc_ssh_sshd_config.j2

+# Package generated configuration file
+# See the sshd_config(5) manpage for details
+
+# What ports, IPs and protocols we listen for
+Port 22
+# Use these options to restrict which interfaces/protocols sshd will bind to
+#ListenAddress ::
+#ListenAddress 0.0.0.0
+Protocol 2
+# HostKeys for protocol version 2
+HostKey /etc/ssh/ssh_host_rsa_key
+HostKey /etc/ssh/ssh_host_dsa_key
+HostKey /etc/ssh/ssh_host_ecdsa_key
+#Privilege Separation is turned on for security
+UsePrivilegeSeparation yes
+
+# Lifetime and size of ephemeral version 1 server key
+KeyRegenerationInterval 3600
+ServerKeyBits 768
+
+# Logging
+SyslogFacility AUTH
+LogLevel INFO
+
+# Authentication:
+LoginGraceTime 120
+PermitRootLogin no
+StrictModes yes
+
+RSAAuthentication yes
+PubkeyAuthentication yes
+#AuthorizedKeysFile	%h/.ssh/authorized_keys
+
+# Don't read the user's ~/.rhosts and ~/.shosts files
+IgnoreRhosts yes
+# For this to work you will also need host keys in /etc/ssh_known_hosts
+RhostsRSAAuthentication no
+# similar for protocol version 2
+HostbasedAuthentication no
+# Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication
+#IgnoreUserKnownHosts yes
+
+# To enable empty passwords, change to yes (NOT RECOMMENDED)
+PermitEmptyPasswords no
+
+# Change to yes to enable challenge-response passwords (beware issues with
+# some PAM modules and threads)
+ChallengeResponseAuthentication no
+
+# Change to no to disable tunnelled clear text passwords
+PasswordAuthentication no
+
+# Kerberos options
+#KerberosAuthentication no
+#KerberosGetAFSToken no
+#KerberosOrLocalPasswd yes
+#KerberosTicketCleanup yes
+
+# GSSAPI options
+#GSSAPIAuthentication no
+#GSSAPICleanupCredentials yes
+
+X11Forwarding yes
+X11DisplayOffset 10
+PrintMotd no
+PrintLastLog yes
+TCPKeepAlive yes
+#UseLogin no
+
+#MaxStartups 10:30:60
+#Banner /etc/issue.net
+
+# Allow client to pass locale environment variables
+AcceptEnv LANG LC_*
+
+Subsystem sftp /usr/lib/openssh/sftp-server
+
+# Set this to 'yes' to enable PAM authentication, account processing,
+# and session processing. If this is enabled, PAM authentication will
+# be allowed through the ChallengeResponseAuthentication and
+# PasswordAuthentication.  Depending on your PAM configuration,
+# PAM authentication via ChallengeResponseAuthentication may bypass
+# the setting of "PermitRootLogin without-password".
+# If you just want the PAM account and session checks to run without
+# PAM authentication, then enable this but set PasswordAuthentication
+# and ChallengeResponseAuthentication to 'no'.
+UsePAM yes