Merge pull request #20 from inkblot/auto-generating-keys

Auto generating keys

README.md

@@ -55,12 +55,18 @@ Puppet will manage the entire `named.conf` file and its includes.  Most paramete
 Creates a TSIG key file.  Only the `secret` parameter is required, but it is recommended to explicitly supply the `algorithm` as well.  The key file will be stored in `${::bind::confdir}/keys` with a filename derived from the title of the `bind::key` declaration.
 
     bind::key { 'local-update':
-        algorithm => 'hmac-sha256',
+        algorithm => 'hmac-sha256', # default: 'hmac-sha256'
         secret    => '012345678901345678901234567890123456789=',
         owner     => 'root',
         group     => 'bind',
     }
 
+If no secret is specified, the bind::key define will generate one. The secret_bits parameter controls the size of the secret.
+
+    bind::key { 'local-update':
+        secret_bits => 512, # default: 256
+    }
+
 ###bind::acl
 
 Declares an acl in the server's configuration.  The acl's name is the title of the `bind::acl` declaration.

lib/puppet/parser/functions/hmac_secret.rb

@@ -0,0 +1,9 @@
+# ex: syntax=ruby si sw=2 ts=2 et
+require 'securerandom'
+
+module Puppet::Parser::Functions
+  newfunction(:hmac_secret, :type => :rvalue) do |args|
+    bits = args[0].to_i
+    SecureRandom.base64(bits / 8)
+  end
+end

manifests/key.pp

@@ -1,28 +1,50 @@
 # ex: syntax=puppet si ts=4 sw=4 et
 
 define bind::key (
-    $secret,
+    $secret      = undef,
+    $secret_bits = 256,
     $algorithm   = 'hmac-sha256',
     $owner       = 'root',
     $group       = $bind::params::bind_group,
+    $keydir      = $::bind::keydir::keydir,
+    $keyfile     = undef,
+    $include     = true,
 ) {
-    $keydir = $::bind::keydir::keydir
 
-    file { "${keydir}/${name}":
+    # Generate a key of size $secret_bits if no $secret
+    $secret_actual = $secret ? {
+        undef   => hmac_secret($secret_bits),
+        default => $secret,
+    }
+
+    # Keep existing key if the module is generating a key
+    $replace = $secret ? {
+        undef   => false,
+        default => true,
+    }
+
+    # Use key name as key file name if none is supplied
+    $key_file_name = $keyfile ? {
+        undef   => $name,
+        default => $keyfile,
+    }
+
+    file { "${keydir}/${key_file_name}":
         ensure  => present,
         owner   => $owner,
         group   => $group,
         mode    => '0640',
+        replace => $replace,
         content => template('bind/key.conf.erb'),
     }
 
-    if (defined(Class['bind'])) {
+    if $include and defined(Class['bind']) {
-        Package['bind'] -> File["${keydir}/${name}"] ~> Service['bind']
+        Package['bind'] -> File["${keydir}/${key_file_name}"] ~> Service['bind']
 
         concat::fragment { "bind-key-${name}":
             order   => '10',
             target  => "${bind::confdir}/keys.conf",
-            content => "include \"${bind::confdir}/keys/${name}\";\n",
+            content => "include \"${keydir}/${key_file_name}\";\n",
         }
     }
 }

templates/key.conf.erb

@@ -1,5 +1,5 @@
 
 key <%= @name %> {
 	algorithm <%= @algorithm %>;
-	secret "<%= @secret %>";
+	secret "<%= @secret_actual %>";
 };