---
title: cf.tls_client_auth.cert_chain_rfc9440_too_large
description: Returns `true` when the RFC 9440 encoded client certificate chain exceeds the 16 KiB size limit.
image: https://developers.cloudflare.com/core-services-preview.png
---

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#  cf.tls\_client\_auth.cert\_chain\_rfc9440\_too\_large 

`cf.tls_client_auth.cert_chain_rfc9440_too_large` ` Boolean ` 

Returns `true` when the RFC 9440 encoded client certificate chain exceeds the 16 KiB size limit.

When `true`, [cf.tls\_client\_auth.cert\_chain\_rfc9440](https://developers.cloudflare.com/ruleset-engine/rules-language/fields/reference/cf.tls%5Fclient%5Fauth.cert%5Fchain%5Frfc9440/) contains an empty string instead of the encoded certificate chain.

This field defaults to `false` if the connection does not use [mTLS authentication](https://developers.cloudflare.com/ssl/client-certificates/enable-mtls/).

Categories: 
* Request
* mTLS

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