---
sidebar_label: filesha1
description: |-
  The filesha1 function computes the SHA1 hash of the contents of
  a given file and encodes it as hex.
---

# `filesha1` Function

`filesha1` is a variant of [`sha1`](../../language/functions/sha1.mdx)
that hashes the contents of a given file rather than a literal string.

This is similar to `sha1(file(filename))`, but
because [`file`](../../language/functions/file.mdx) accepts only UTF-8 text it cannot be used to
create hashes for binary files.

Collision attacks have been successfully performed against this hashing
function. Before using this function for anything security-sensitive, review
relevant literature to understand the security implications.