# Usage of Weak Hashing library (MD5)

## Overview

* **Rule ID**: `java_lang_weak_hash_md5`
* **Applicable Languages**: Java
* **Weakness ID**: CWE-328

## Description

Using a weak hashing algorithm such as MD5 heightens the risk of data breaches. MD5 is susceptible to collision attacks, where different inputs generate the same hash, undermining data integrity and security.

## Remediation Guidelines

* **Do not** use MD5 for hashing purposes. This algorithm is no longer considered secure and can compromise data integrity.

  ```java
  MessageDigest md = MessageDigest.getInstance("MD5"); // unsafe

  ```
* **Do opt** for stronger hashing algorithms like SHA-256 to ensure data security.

  ```java
  MessageDigest md = MessageDigest.getInstance("SHA-256");
  ```

## References

* [**Java MessageDigest class**](https://docs.oracle.com/en/java/javase/20/docs/api/java.base/java/security/MessageDigest.html)
* [**CWE-328: Use of Weak Hashtion**](https://cwe.mitre.org/data/definitions/328.html)
* [**OWASP Top 10: A02:2021 - Cryptographic Failures**](https://owasp.org/Top10/A02_2021-Cryptographic_Failures/)

## Configuration

To omit this rule during a scan, and to provide you with continuous 24/7 code-level scanning, you can employ our [**SAST TOOL**](https://scopy.sec1.io/login)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.sec1.io/user-docs/4-sast/2-java/usage-of-weak-hashing-library.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.