# getHash

## `getHash` Function

The `getHash` function generates a **hashed string** from a given input using the [Node.js `crypto`](https://nodejs.org/api/crypto.html#cryptocreatehashalgorithm-options) library. It supports configurable **hashing algorithms** and **output encodings**.

***

### Purpose

Use this function to:

* Create hashed versions of identifiers or tokens
* Generate consistent anonymized values (e.g., hashed IPs, emails)
* Integrate hash-based logic into tracking or enrichment flows

***

### Function Definition

| Property          | Description                              |
| ----------------- | ---------------------------------------- |
| **Function Name** | `this.getHash`                           |
| **Type**          | `function`                               |
| **Available In**  | Server-Side Variables                    |
| **Returns**       | `string` (the hashed value of the input) |

***

### Parameters

| Parameter   | Description                                                    | Type     | Required                                      | Example    |
| ----------- | -------------------------------------------------------------- | -------- | --------------------------------------------- | ---------- |
| `input`     | The input string to be hashed                                  | `string` | <i class="fa-square-check">:square-check:</i> | `"secret"` |
| `algorithm` | The hashing algorithm to use (e.g., `"sha256"`, `"md5"`, etc.) | `string` | <i class="fa-square-check">:square-check:</i> | `"sha256"` |
| `encoding`  | The output format of the hash (`"hex"`, `"base64"`, etc.)      | `string` |                                               | `"hex"`    |

> **Default Encoding:** `"hex"` if not specified

***

### Supported Algorithms & Encodings

See the official [Node.js Crypto documentation](https://nodejs.org/api/crypto.html#cryptocreatehashalgorithm-options) for a full list of supported algorithms and encodings.

Common choices:

* **Algorithms:** `sha256`, `sha1`, `md5`, `sha512`
* **Encodings:** `hex`, `base64`, `latin1`

***

### Example Usage

```js
async function() {
    let x = this.getHash("secret", "sha256", "hex");
    return x;
}
```

This example returns a SHA-256 hash of the string `"secret"` encoded in hexadecimal.

***

### Use Cases

* Generate anonymized keys (e.g., hashed IP or user ID)
* Create checksum or verification values
* Store secure reference identifiers without exposing raw input
* Match identifiers across systems using shared hashing rules

***

### Notes

* This function uses Node.js' built-in `crypto.createHash` behind the scenes.
* Output is deterministic: same input → same hash.
* Make sure the chosen algorithm and encoding match your system requirements.
* Do **not** use `md5` or `sha1` for security-critical applications — these are considered weak.

***

### Summary

`this.getHash` is a flexible and secure way to generate hashed values in JENTIS server-side variables. Whether you’re anonymizing personal data or aligning IDs across systems, this function allows full control over the hashing algorithm and encoding.