---
title: Avoid weak hash algorithms.
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Static Code Analysis (SAST) > SAST
  Rules > Avoid weak hash algorithms.
---

# Avoid weak hash algorithms.

{% callout %}
# Important note for users on the following Datadog sites: app.ddog-gov.com

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

{% /callout %}

## Metadata{% #metadata %}

**ID:** `elixir-security/weak-hash-algorithms`

**Language:** Elixir

**Severity:** Error

**Category:** Security

**CWE**: [328](https://cwe.mitre.org/data/definitions/328.html)

**Related CWEs**:

- [916](https://cwe.mitre.org/data/definitions/916.html)

## Description{% #description %}

Avoid unsecured hash algorithms, as they may lead to data leaks. Use safe and proven hash algorithms.

#### Learn More{% #learn-more %}

- [Wikipedia - Secure Hash Algorithms](https://en.wikipedia.org/wiki/Secure_Hash_Algorithms)

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

```elixir
# The hash functions with md5, sha1, ripemd (128-bit), and sha should be highlighted,
# as they are cryptographically weak and can be easily broken.
defmodule InsecureHashExample do
  # Insecure hash function using MD5
  defp insecure_hash_one(data) do
  # check this
    :cr.hash(data, :md5) |> Base.encode16(case: :lower)
  end
  # Insecure hash function using sha1
  defp insecure_hash_one(data) do
    # validate spacing 
    :crypto.hash(data, :sha1) |> Base.encode16(case: :lower)
  end

# Spacing does not matter
:crypto. hash(:md5, data)

hex = Base.encode16(:crypto. hash(:ripemd160, data))
```

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

```elixir
# The hash functions other than md5, sha1, ripemd (128-bit), and sha are not highlighted
# as they are cryptographically strong and cannot be broken via standard hardware.
defmodule PasswordCompare do
  def option_one(password, md5_hash) do
    case :crypto.hash(:sha2, password) == md5_hash do
      true -> :entry_granted_op1
      false -> :entry_denied_op1
    end
  end
end
a = :crypto.hash(:sha3, something)
```
  Seamless integrations. Try Datadog Code SecurityDatadog Code Security 
{% icon name="icon-external-link" /%}