---
title: tls.client.tlsexts_sha
summary: null
url: >-
  https://www.fastly.com/documentation/reference/vcl/variables/client-connection/tls-client-tlsexts-sha
---

**Type:** STRING  
**Access:** read-only

**Available in:** recv, hash, deliver, log

A SHA-1 hash of the TLS extension identifiers sent from the client as part of
the TLS handshake, represented in Base64.