From 5e5328cb2e2ed7a9b6e9062dcdfe8fe87c5c8925 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Sat, 5 Nov 2011 01:44:56 +0000 Subject: [PATCH] * Get the SSH host key from the user data if available. This allows the user to create an instance with a known host key, and thus permit a secure connection. svn path=/nixos/trunk/; revision=30242 --- modules/virtualisation/ec2-data.nix | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/modules/virtualisation/ec2-data.nix b/modules/virtualisation/ec2-data.nix index b0072f4f890c..42e3cb675667 100644 --- a/modules/virtualisation/ec2-data.nix +++ b/modules/virtualisation/ec2-data.nix @@ -15,11 +15,15 @@ with pkgs.lib; task = true; + path = [ pkgs.curl ]; + script = '' + curl="curl --retry 3 --retry-delay 0 --fail" + echo "setting host name..." ${optionalString (config.networking.hostName == "") '' - ${pkgs.nettools}/bin/hostname $(${pkgs.curl}/bin/curl http://169.254.169.254/1.0/meta-data/hostname) + ${pkgs.nettools}/bin/hostname $($curl http://169.254.169.254/1.0/meta-data/hostname) ''} # Don't download the SSH key if it has already been injected @@ -27,9 +31,7 @@ with pkgs.lib; if ! [ -e /root/.ssh/authorized_keys ]; then echo "obtaining SSH key..." mkdir -p /root/.ssh - ${pkgs.curl}/bin/curl --retry 3 --retry-delay 0 --fail \ - -o /root/key.pub \ - http://169.254.169.254/1.0/meta-data/public-keys/0/openssh-key + $curl -o /root/key.pub http://169.254.169.254/1.0/meta-data/public-keys/0/openssh-key if [ $? -eq 0 -a -e /root/key.pub ]; then if ! grep -q -f /root/key.pub /root/.ssh/authorized_keys; then cat /root/key.pub >> /root/.ssh/authorized_keys @@ -39,6 +41,18 @@ with pkgs.lib; rm -f /root/key.pub fi fi + + # Extract the intended SSH host key for this machine from + # the supplied user data, if available. Otherwise sshd will + # generate one normally. + $curl http://169.254.169.254/2011-01-01/user-data > /root/user-data || true + key="$(sed 's/|/\n/g; s/SSH_HOST_DSA_KEY://; t; d' /root/user-data)" + key_pub="$(sed 's/SSH_HOST_DSA_KEY_PUB://; t; d' /root/user-data)" + if [ -n "$key" -a -n "$key_pub" -a ! -e /etc/ssh/ssh_host_dsa_key ]; then + mkdir -m 0755 -p /etc/ssh + (umask 077; echo "$key" > /etc/ssh/ssh_host_dsa_key) + echo "$key_pub" > /etc/ssh/ssh_host_dsa_key.pub + fi ''; }; @@ -57,4 +71,8 @@ with pkgs.lib; ''; }; + # Only start sshd after we've obtained the host key (if given in the + # user data), otherwise the sshd job will generate one itself. + jobs.sshd.startOn = mkOverride 90 "stopped fetch-ec2-data"; + }