---
title: Calling hmac.New with unchanging hash.New
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Static Code Analysis (SAST) > SAST
  Rules > Calling hmac.New with unchanging hash.New
---

# Calling hmac.New with unchanging hash.New

{% callout %}
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{% alert level="danger" %}
This product is not supported for your selected [Datadog site](https://docs.datadoghq.com/getting_started/site). ().
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{% /callout %}

## Metadata{% #metadata %}

**ID:** `go-security/hmac-needs-new`

**Language:** Go

**Severity:** Error

**Category:** Security

**CWE**: [323](https://cwe.mitre.org/data/definitions/323.html)

## Description{% #description %}

No description found

## Non-Compliant Code Examples{% #non-compliant-code-examples %}

```go
func main() {
    hmacKey := []byte("secret")

    h := sha256.New()
    hmacInstance := hmac.New(func() hash.Hash { return h }, hmacKey)

    var h2 hash.Hash
    hmacInstance2 := hmac.New(func() hash.Hash { return h2 }, hmacKey)

    h3 := sha512.New()
    f := func() hash.Hash { return h3 }
    hmacInstance3 := hmac.New(f, hmacKey)
}
```

## Compliant Code Examples{% #compliant-code-examples %}

```go
func main() {
    hmacKey := []byte("secret")
    h := hmac.New(func() hash.Hash { return sha256.New() }, hmacKey)
}
```
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