From c5c1378f59bd81bbc9638c1862e5c81ebf02d23d Mon Sep 17 00:00:00 2001
From: Colin <colin@uninsane.org>
Date: Tue, 14 Mar 2023 11:34:48 +0000
Subject: [PATCH] trust-dns: properly quote TXT records

---
 modules/services/trust-dns.nix | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/modules/services/trust-dns.nix b/modules/services/trust-dns.nix
index 8212ec65..3919951d 100644
--- a/modules/services/trust-dns.nix
+++ b/modules/services/trust-dns.nix
@@ -7,7 +7,20 @@ with lib;
 let
   cfg = config.sane.services.trust-dns;
   toml = pkgs.formats.toml { };
-  fmtRecord = proto: rrtype: name: value: "${name}\t${proto}\t${rrtype}\t${value}";
+  recordFormatters = {
+    # quote rules for zone files:
+    # - any character may be encoded by `\DDD`, where `DDD` represents its ascii value in base 8.
+    # - any non-digit `X` may be encoded by `\X`.
+    # - stated in: <https://www.ietf.org/rfc/rfc1035.txt>: 5.1 Format
+    # - visible in <trust-dns:crates/proto/src/serialize/txt/zone_lex.rs:escape_seq>
+    # for us, we can just replace `\` => `\\ and `"` -> `\"`
+    TXT = value: "\"" + (lib.escape [ "\\" "\"" ] value) + "\"";
+  };
+  fmtRecord = proto: rrtype: name: value:
+    let
+      formatter = recordFormatters."${rrtype}" or lib.id;
+    in
+      "${name}\t${proto}\t${rrtype}\t${formatter value}";
   fmtRecordList = proto: rrtype: name: values: concatStringsSep
     "\n"
     (map (fmtRecord proto rrtype name) values)