From 289934f3d16405c6aa791d2b0702c2f893045e0e Mon Sep 17 00:00:00 2001
From: Bas Westerbaan <bas@westerbaan.name>
Date: Wed, 11 Oct 2023 21:45:37 +0200
Subject: [PATCH] tls: Add X25519Kyber768Draft00 PQ "curve" behind build tag
 (#5852)
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… when compiled with cfgo (https://github.com/cloudflare/go).
---
 modules/caddytls/cf.go | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 modules/caddytls/cf.go

diff --git a/modules/caddytls/cf.go b/modules/caddytls/cf.go
new file mode 100644
index 00000000..e61a59c0
--- /dev/null
+++ b/modules/caddytls/cf.go
@@ -0,0 +1,24 @@
+//go:build cfgo
+
+package caddytls
+
+// This file adds support for X25519Kyber768Draft00, a post-quantum
+// key agreement that is currently being rolled out by Chrome [1]
+// and Cloudflare [2,3]. For more context, see the PR [4].
+//
+// [1] https://blog.chromium.org/2023/08/protecting-chrome-traffic-with-hybrid.html
+// [2] https://blog.cloudflare.com/post-quantum-for-all/
+// [3] https://blog.cloudflare.com/post-quantum-to-origins/
+// [4] https://github.com/caddyserver/caddy/pull/5852
+
+import (
+	"crypto/tls"
+)
+
+func init() {
+	SupportedCurves["X25519Kyber768Draft00"] = tls.X25519Kyber768Draft00
+	defaultCurves = append(
+		[]tls.CurveID{tls.X25519Kyber768Draft00},
+		defaultCurves...,
+	)
+}