From d63e6e2745e70150af2c3cad0efd09b126f4cfc2 Mon Sep 17 00:00:00 2001
From: Tom Hughes <tom@compton.nu>
Date: Sun, 1 Mar 2020 17:11:22 +0000
Subject: [PATCH] Enable DKIM signing of subdomains

---
 cookbooks/exim/recipes/default.rb                 | 7 +++++++
 cookbooks/exim/templates/default/dkim-domains.erb | 3 +++
 cookbooks/exim/templates/default/exim4.conf.erb   | 2 +-
 3 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 cookbooks/exim/templates/default/dkim-domains.erb

diff --git a/cookbooks/exim/recipes/default.rb b/cookbooks/exim/recipes/default.rb
index 11865f6b6..a9f6472e6 100644
--- a/cookbooks/exim/recipes/default.rb
+++ b/cookbooks/exim/recipes/default.rb
@@ -120,6 +120,13 @@ end
 if node[:exim][:dkim_selectors]
   keys = data_bag_item("exim", "dkim")
 
+  template "/etc/exim4/dkim-domains" do
+    owner "root"
+    source "dkim-domains.erb"
+    group "Debian-exim"
+    mode 0o644
+  end
+
   template "/etc/exim4/dkim-selectors" do
     owner "root"
     source "dkim-selectors.erb"
diff --git a/cookbooks/exim/templates/default/dkim-domains.erb b/cookbooks/exim/templates/default/dkim-domains.erb
new file mode 100644
index 000000000..992ac39c7
--- /dev/null
+++ b/cookbooks/exim/templates/default/dkim-domains.erb
@@ -0,0 +1,3 @@
+<% node[:exim][:dkim_selectors].each do |domain, _selector| -%>
+*.<%= domain %>: <%= domain %>
+<% end -%>
diff --git a/cookbooks/exim/templates/default/exim4.conf.erb b/cookbooks/exim/templates/default/exim4.conf.erb
index ab832999d..3c4ebd4aa 100644
--- a/cookbooks/exim/templates/default/exim4.conf.erb
+++ b/cookbooks/exim/templates/default/exim4.conf.erb
@@ -710,7 +710,7 @@ remote_smtp:
 
 signed_smtp:
   driver = smtp
-  dkim_domain = ${lc:${domain:$h_from:}}
+  dkim_domain = ${lookup{${domain:$h_from:}}partial-lsearch{/etc/exim4/dkim-domains}{$value}}
   dkim_selector = ${lookup{$dkim_domain}lsearch{/etc/exim4/dkim-selectors}{$value}}
   dkim_private_key = /etc/exim4/dkim-keys/${dkim_domain}
   dkim_identity = ${lc:${address:$h_from:}}
-- 
2.39.5