DOC: Be a bit more explicit about allow-0rtt security implications.
Document a bit better than allow-0rtt can trivially be used for replay attacks,
and so should only be used when it's safe to replay a request.
This should probably be backported to 1.8 and 1.9.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 2447254..888515f 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -10768,7 +10768,10 @@
allow-0rtt
Allow receiving early data when using TLSv1.3. This is disabled by default,
- due to security considerations.
+ due to security considerations. Because it is vulnerable to replay attacks,
+ you should only allow if for requests that are safe to replay, ie requests
+ that are idempotent. You can use the "wait-for-handshake" action for any
+ request that wouldn't be safe with early data.
alpn <protocols>
This enables the TLS ALPN extension and advertises the specified protocol