Use the first configured ssh key type for authn

Previously, the authentication key was always generated using rsa. Now
it uses the first configured ssh key type.

Signed-off-by: Jonathon Anderson <janderson@ciq.com>

internal/pkg/configure/ssh.go

@@ -52,21 +52,26 @@ func SSH(keyTypes ...string) error {
 	}
 
 	authorizedKeys := path.Join(homeDir, "/.ssh/authorized_keys")
-	rsaPriv := path.Join(homeDir, "/.ssh/id_rsa")
-	rsaPub := path.Join(homeDir, "/.ssh/id_rsa.pub")
 
 	if !util.IsFile(authorizedKeys) {
-		fmt.Printf("Setting up: %s\n", authorizedKeys)
-		err = util.ExecInteractive("ssh-keygen", "-q", "-t", "rsa", "-f", rsaPriv, "-C", "", "-N", "")
-		if err != nil {
-			return errors.Wrap(err, "failed to exec ssh-keygen command")
-		}
-		err := util.CopyFile(rsaPub, authorizedKeys)
-		if err != nil {
-			return errors.Wrap(err, "failed to copy keys")
+		if len(keyTypes) > 0 {
+			keyType := keyTypes[0]
+			fmt.Printf("Setting up: %s\n", authorizedKeys)
+			privKey := path.Join(homeDir, "/.ssh/id_"+keyType)
+			pubKey := privKey + ".pub"
+			err = util.ExecInteractive("ssh-keygen", "-q", "-t", keyType, "-f", privKey, "-C", "", "-N", "")
+			if err != nil {
+				return errors.Wrap(err, "Failed to exec ssh-keygen command")
+			}
+			err := util.CopyFile(pubKey, authorizedKeys)
+			if err != nil {
+				return errors.Wrap(err, fmt.Sprintf("Failed to copy %s to authorized_keys", pubKey))
+			}
+		} else {
+			fmt.Printf("Skipping authorized_keys: no key types configured\n")
 		}
 	} else {
-		fmt.Printf("Skipping, authorized_keys already exists: %s\n", authorizedKeys)
+		fmt.Printf("Skipping authorized_keys: already exists: %s\n", authorizedKeys)
 	}
 
 	return nil

internal/pkg/overlay/datastructure.go

@@ -31,6 +31,7 @@ type TemplateStruct struct {
 	Ipv6          bool
 	Dhcp          warewulfconf.DHCPConf
 	Nfs           warewulfconf.NFSConf
+	Ssh           warewulfconf.SSHConf
 	Warewulf      warewulfconf.WarewulfConf
 	Tftp          warewulfconf.TFTPConf
 	Paths         warewulfconf.BuildConfig
@@ -60,6 +61,7 @@ func InitStruct(nodeInfo *node.NodeInfo) TemplateStruct {
 	tstruct.Id = nodeInfo.Id.Get()
 	tstruct.Hostname = nodeInfo.Id.Get()
 	tstruct.Nfs = *controller.NFS
+	tstruct.Ssh = *controller.SSH
 	tstruct.Dhcp = *controller.DHCP
 	tstruct.Tftp = *controller.TFTP
 	tstruct.Paths = *controller.Paths

overlays/host/rootfs/etc/profile.d/ssh_setup.csh.ww

@@ -3,12 +3,13 @@
 ## Automatically configure SSH keys for a user on C SHell login
 ## Copy this file to /etc/profile.d along with ssh_setup.sh
 
+{{- if gt (len .Ssh.KeyTypes) 0 }}
+{{ $keyType := index .Ssh.KeyTypes 0 }}
 set _UID=`id -u`
-
 if ( ( $_UID > 500 || $_UID == 0 ) && ( ! -f "$HOME/.ssh/config" && ! -f "$HOME/.ssh/cluster" ) ) then
     echo "Configuring SSH for cluster access"
     install -d -m 700 $HOME/.ssh
-    ssh-keygen -t rsa -f $HOME/.ssh/cluster -N '' -C "Warewulf Cluster key" >& /dev/null
+    ssh-keygen -t {{ $keyType }} -f $HOME/.ssh/cluster -N '' -C "Warewulf Cluster key" >& /dev/null
     cat $HOME/.ssh/cluster.pub >>! $HOME/.ssh/authorized_keys
     chmod 0600 $HOME/.ssh/authorized_keys
 
@@ -20,3 +21,6 @@ if ( ( $_UID > 500 || $_UID == 0 ) && ( ! -f "$HOME/.ssh/config" && ! -f "$HOME/
     echo "   StrictHostKeyChecking=no" >> $HOME/.ssh/config
     chmod 0600 $HOME/.ssh/config
 endif
+{{- else }}
+# No ssh key types configured
+{{- end }}

overlays/host/rootfs/etc/profile.d/ssh_setup.sh.ww

@@ -11,12 +11,13 @@
 ## Automatically configure SSH keys for a user on login
 ## Copy this file to /etc/profile.d
 
+{{- if gt (len .Ssh.KeyTypes) 0 }}
+{{ $keyType := index .Ssh.KeyTypes 0 }}
 _UID=`id -u`
-
 if [ $_UID -ge 500 -o $_UID -eq 0 ] && [ ! -f "$HOME/.ssh/config" -a ! -f "$HOME/.ssh/cluster" ]; then
     echo "Configuring SSH for cluster access"
     install -d -m 700 $HOME/.ssh
-    ssh-keygen -t rsa -f $HOME/.ssh/cluster -N '' -C "Warewulf Cluster key" > /dev/null 2>&1
+    ssh-keygen -t {{ $keyType }} -f $HOME/.ssh/cluster -N '' -C "Warewulf Cluster key" > /dev/null 2>&1
     cat $HOME/.ssh/cluster.pub >> $HOME/.ssh/authorized_keys
     chmod 0600 $HOME/.ssh/authorized_keys
 
@@ -26,3 +27,6 @@ if [ $_UID -ge 500 -o $_UID -eq 0 ] && [ ! -f "$HOME/.ssh/config" -a ! -f "$HOME
     echo "   StrictHostKeyChecking=no" >> $HOME/.ssh/config
     chmod 0600 $HOME/.ssh/config
 fi
+{{- else }}
+# No ssh key types configured
+{{- end }}