Add a $hostkey_type variable that allows you to set which hostkey

types you want to support in your sshd_config.

We use the ssh_version fact to determine the default hostkey types.
Only enable rsa and ed25519 for ssh versions greater or equal
to 6.5, otherwise enable rsa and dsa.

Some distributions, such as debian, also enable ecdsa as a hostkey
type, but this is a known bad NIST curve, so we do not enable that
by default (thus deviating from the stock sshd config)

10 files changed, 35 insertions, 21 deletions

diff --git a/manifests/init.pp b/manifests/init.pp
index 5a38293..2455887 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -49,6 +49,10 @@ class sshd(
   $shorewall_source = 'net',
   $sshkey_ipaddress = $::ipaddress,
   $manage_client = true,
+  $hostkey_type = versioncmp($::ssh_version, '6.5') ? {
+    /(^1|0)/ => [ 'rsa', 'ed25519' ],
+    /-1/    => [ 'rsa', 'dsa' ]
+  }
 ) {
 
   validate_bool($manage_shorewall)
diff --git a/templates/sshd_config/CentOS_7.erb b/templates/sshd_config/CentOS_7.erb
index 1a2e339..7db2277 100644
--- a/templates/sshd_config/CentOS_7.erb
+++ b/templates/sshd_config/CentOS_7.erb
@@ -35,9 +35,9 @@ ListenAddress <%= address %>
 # HostKey for protocol version 1
 #HostKey /etc/ssh/ssh_host_key
 # 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
+<% scope.lookupvar('sshd::hostkey_type').to_a.each do |hostkey_type| -%>
+HostKey /etc/ssh/ssh_host_<%=hostkey_type %>_key
+<% end -%>
 
 # Lifetime and size of ephemeral version 1 server key
 #KeyRegenerationInterval 1h
diff --git a/templates/sshd_config/Debian_etch.erb b/templates/sshd_config/Debian_etch.erb
index ef4a5d1..104e641 100644
--- a/templates/sshd_config/Debian_etch.erb
+++ b/templates/sshd_config/Debian_etch.erb
@@ -20,6 +20,10 @@ ListenAddress <%= address %>
 <% end -%>
 Protocol 2
 # HostKeys for protocol version 2
+<% scope.lookupvar('sshd::hostkey_type').to_a.each do |hostkey_type| -%>
+HostKey /etc/ssh/ssh_host_<%=hostkey_type %>_key
+<% end -%>
+
 HostKey /etc/ssh/ssh_host_rsa_key
 HostKey /etc/ssh/ssh_host_dsa_key
 #Privilege Separation is turned on for security
diff --git a/templates/sshd_config/Debian_jessie.erb b/templates/sshd_config/Debian_jessie.erb
index d717856..033f409 100644
--- a/templates/sshd_config/Debian_jessie.erb
+++ b/templates/sshd_config/Debian_jessie.erb
@@ -22,10 +22,9 @@ ListenAddress <%= address %>
 <% end -%>
 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
-HostKey /etc/ssh/ssh_host_ed25519_key
+<% scope.lookupvar('sshd::hostkey_type').to_a.each do |hostkey_type| -%>
+HostKey /etc/ssh/ssh_host_<%=hostkey_type %>_key
+<% end -%>
 #Privilege Separation is turned on for security
 UsePrivilegeSeparation yes
 
diff --git a/templates/sshd_config/Debian_sid.erb b/templates/sshd_config/Debian_sid.erb
index d717856..033f409 100644
--- a/templates/sshd_config/Debian_sid.erb
+++ b/templates/sshd_config/Debian_sid.erb
@@ -22,10 +22,9 @@ ListenAddress <%= address %>
 <% end -%>
 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
-HostKey /etc/ssh/ssh_host_ed25519_key
+<% scope.lookupvar('sshd::hostkey_type').to_a.each do |hostkey_type| -%>
+HostKey /etc/ssh/ssh_host_<%=hostkey_type %>_key
+<% end -%>
 #Privilege Separation is turned on for security
 UsePrivilegeSeparation yes
 
diff --git a/templates/sshd_config/Debian_squeeze.erb b/templates/sshd_config/Debian_squeeze.erb
index befd25f..0ba323f 100644
--- a/templates/sshd_config/Debian_squeeze.erb
+++ b/templates/sshd_config/Debian_squeeze.erb
@@ -22,8 +22,10 @@ ListenAddress <%= address %>
 <% end -%>
 Protocol 2
 # HostKeys for protocol version 2
-HostKey /etc/ssh/ssh_host_rsa_key
-HostKey /etc/ssh/ssh_host_dsa_key
+<% scope.lookupvar('sshd::hostkey_type').to_a.each do |hostkey_type| -%>
+HostKey /etc/ssh/ssh_host_<%=hostkey_type %>_key
+<% end -%>
+
 #Privilege Separation is turned on for security
 UsePrivilegeSeparation yes
 
diff --git a/templates/sshd_config/Debian_wheezy.erb b/templates/sshd_config/Debian_wheezy.erb
index 70bb4bf..cd4bf48 100644
--- a/templates/sshd_config/Debian_wheezy.erb
+++ b/templates/sshd_config/Debian_wheezy.erb
@@ -22,8 +22,9 @@ ListenAddress <%= address %>
 <% end -%>
 Protocol 2
 # HostKeys for protocol version 2
-HostKey /etc/ssh/ssh_host_rsa_key
-HostKey /etc/ssh/ssh_host_dsa_key
+<% scope.lookupvar('sshd::hostkey_type').to_a.each do |hostkey_type| -%>
+HostKey /etc/ssh/ssh_host_<%=hostkey_type %>_key
+<% end -%>
 #Privilege Separation is turned on for security
 UsePrivilegeSeparation yes
 
diff --git a/templates/sshd_config/FreeBSD.erb b/templates/sshd_config/FreeBSD.erb
index 090149b..d4cd9b5 100644
--- a/templates/sshd_config/FreeBSD.erb
+++ b/templates/sshd_config/FreeBSD.erb
@@ -40,8 +40,9 @@ Protocol 2
 # HostKey for protocol version 1
 #HostKey /etc/ssh/ssh_host_key
 # HostKeys for protocol version 2
-HostKey /etc/ssh/ssh_host_rsa_key
-HostKey /etc/ssh/ssh_host_dsa_key
+<% scope.lookupvar('sshd::hostkey_type').to_a.each do |hostkey_type| -%>
+HostKey /etc/ssh/ssh_host_<%=hostkey_type %>_key
+<% end -%>
 
 # Lifetime and size of ephemeral version 1 server key
 #KeyRegenerationInterval 1h
diff --git a/templates/sshd_config/Ubuntu.erb b/templates/sshd_config/Ubuntu.erb
index befd25f..0ba323f 100644
--- a/templates/sshd_config/Ubuntu.erb
+++ b/templates/sshd_config/Ubuntu.erb
@@ -22,8 +22,10 @@ ListenAddress <%= address %>
 <% end -%>
 Protocol 2
 # HostKeys for protocol version 2
-HostKey /etc/ssh/ssh_host_rsa_key
-HostKey /etc/ssh/ssh_host_dsa_key
+<% scope.lookupvar('sshd::hostkey_type').to_a.each do |hostkey_type| -%>
+HostKey /etc/ssh/ssh_host_<%=hostkey_type %>_key
+<% end -%>
+
 #Privilege Separation is turned on for security
 UsePrivilegeSeparation yes
 
diff --git a/templates/sshd_config/Ubuntu_lucid.erb b/templates/sshd_config/Ubuntu_lucid.erb
index cc6e921..cff95a7 100644
--- a/templates/sshd_config/Ubuntu_lucid.erb
+++ b/templates/sshd_config/Ubuntu_lucid.erb
@@ -20,8 +20,10 @@ ListenAddress <%= address %>
 <% end -%>
 Protocol 2
 # HostKeys for protocol version 2
-HostKey /etc/ssh/ssh_host_rsa_key
-HostKey /etc/ssh/ssh_host_dsa_key
+<% scope.lookupvar('sshd::hostkey_type').to_a.each do |hostkey_type| -%>
+HostKey /etc/ssh/ssh_host_<%=hostkey_type %>_key
+<% end -%>
+
 #Privilege Separation is turned on for security
 UsePrivilegeSeparation yes