RFC 9440 · INFORMATIONAL · 2023
SUN · 14 JUN 2026
Client-Cert HTTP Header Field
Overview
RFC 9440, “Client-Cert HTTP Header Field”, is an Informational document published in July 2023 by B. Campbell, M. Bishop. The canonical text is published by the RFC Editor.
Abstract
This document describes HTTP extension header fields that allow a TLS terminating reverse proxy (TTRP) to convey the client certificate information of a mutually authenticated TLS connection to the origin server in a common and predictable manner.
What “Informational” means
Published for the general information of the community. It does not define an IETF standard and carries no standards-track status.
Read this RFC
The canonical text of RFC 9440 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.
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