---
title: cf.tls_client_extensions_sha1_le · Cloudflare Ruleset Engine docs
description: The SHA-1 fingerprint of TLS client extensions, encoded in Base64 using little-endian format.
source_url:
  html: https://zt-dark-mode-changelog.preview.developers.cloudflare.com/ruleset-engine/rules-language/fields/reference/cf.tls_client_extensions_sha1_le/index.md
  md: https://zt-dark-mode-changelog.preview.developers.cloudflare.com/ruleset-engine/rules-language/fields/reference/cf.tls_client_extensions_sha1_le/
---

# cf.tls\_client\_extensions\_sha1\_le

`cf.tls_client_extensions_sha1_le` String

The SHA-1 fingerprint of TLS client extensions, encoded in Base64 using little-endian format.

For the big-endian version of this field, refer to [`cf.tls_client_extensions_sha1`](https://developers.cloudflare.com/ruleset-engine/rules-language/fields/reference/cf.tls_client_extensions_sha1/).

Example value:

```txt
"7zIpdDU5pvFPPBI2/PCzqbaXnRA="
```

Categories:

* Request
* SSL/TLS
