---
title: crypto.HMAC
linkTitle: hmac
description: Returns a cryptographic hash that uses a key to sign a message.
categories: [functions]
keywords: []
menu:
  docs:
    parent: functions
function:
  aliases: [hmac]
  returnType: string
  signatures: ['crypto.HMAC HASH_TYPE KEY MESSAGE [ENCODING]']
relatedFunctions:
  - crypto.FNV32a
  - crypto.HMAC
  - crypto.MD5
  - crypto.SHA1
  - crypto.SHA256
aliases: [/functions/hmac]
---

Set the `HASH_TYPE` argument to `md5`, `sha1`, `sha256`, or `sha512`.

Set the optional `ENCODING` argument to either `hex` (default) or `binary`.

```go-html-template
{{ hmac "sha256" "Secret key" "Secret message" }}
5cceb491f45f8b154e20f3b0a30ed3a6ff3027d373f85c78ffe8983180b03c84

{{ hmac "sha256" "Secret key" "Secret message" "hex" }}
5cceb491f45f8b154e20f3b0a30ed3a6ff3027d373f85c78ffe8983180b03c84

{{ hmac "sha256" "Secret key" "Secret message" "binary" | base64Encode }}
XM60kfRfixVOIPOwow7Tpv8wJ9Nz+Fx4/+iYMYCwPIQ=
```