Working backplane dns client/server

static/backplane-dns-client/dns-client.rb

@@ -42,6 +42,11 @@ OptionParser.new do |opts|
           "Check for a public IPv6 and register with the backplane.") do
     options[:ipv6] = true
   end
+
+  opts.on("-f", "--sshfp",
+          "Register host SSH key fingerprints with the backplane.") do
+    options[:sshfp] = true
+  end
 end.parse!
 
 def error(msg)
@@ -98,10 +103,12 @@ class XMPPClient
   def send(msg_content)
     msg_id = SecureRandom::uuid
     encoded_payload = payload(msg_content, msg_id).to_json
+    puts "payload: #{encoded_payload}"
     msg = Jabber::Message.new(@service_jid, encoded_payload)
     msg.type = :chat
     @client.send(msg)
     response = receive_response(msg_id)
+    puts "response: #{response}"
     response and response["status"] == "OK"
   end
 
@@ -109,6 +116,10 @@ class XMPPClient
     send(ip_payload(ip))
   end
 
+  def send_sshfp(fps)
+    send(sshfp_payload(fps))
+  end
+
   def payload(req, msg_id)
     {
       version: 1,
@@ -126,6 +137,14 @@ class XMPPClient
     }
   end
 
+  def sshfp_payload(fp)
+    {
+      request: :change_sshfp,
+      domain:  @domain,
+      sshfp:   fp
+    }
+  end
+
   def register_response_callback
     @client.add_message_callback do |msg|
       enqueue_message(JSON.parse(msg.body))
@@ -198,6 +217,13 @@ def interface_addresses(interface)
   end
 end
 
+def host_sshfp
+  keys = `ssh-keygen -r hostname`.split("\n").map do |k|
+    k.match(/[0-9] [0-9] [a-fA-F0-9]{32,64}$/)[0]
+  end
+  keys.compact
+end
+
 client = XMPPClient::new(options[:domain],
                          Socket::gethostname,
                          options[:server],
@@ -243,6 +269,21 @@ begin
       puts "#{options[:server]}: no valid public IPv6 found on the local host"
     end
   end
+
+  if options[:sshfp]
+    fps = host_sshfp
+    if not fps.empty?
+      puts "#{options[:server]}: #{Socket::gethostname}.#{options[:domain]} IN SSHFP => #{fps}"
+      if client.send_sshfp(fps)
+        puts "OK"
+      else
+        puts "ERROR"
+        success = false
+      end
+    else
+      puts "#{options[:server]}: no valid sshfps found"
+    end
+  end
 ensure
   client.disconnect
 end