The problem statement!

Most of the people save data into local storage, Is this a safe method to store ? No! Local storage writes the data as a plan string and any one who has the access to the device can read this data and manipulate.

Most of the people thinks that we can encrypt the data and save it on local storage, But in this case, you need to have a secure key to decrypt this data,

Let's consider this Scenario, You have encrypted the user login information and saved on local storage, When the platform reload, You are decrypting the data which is written on local storage and marking the user as logged or logged out, Here your website share a common secure key to encrypt and decrypt, which means only your website knows how to decrypt,

In this case, if someone copies the data from local storage and past on a different browser, then load your website, Your website will authenticate the user, Why ? because your website knows how to decrypt the data!

This is the problem when you have a single secure key! Then how do we solve this issue ?

Why React Secure Storage ?

React secure storage is created to securely write the data to local storage ( Basically its a wrapper written on top of default localStorage to write the data securely to the localStorage ), here secure storage library generate a secure key for every browser and encrypt the data using this key, which means only the browser which encrypted the data can decrypt it,

Additionally react secure storage preserve the data format for every data type, As out of the box it supports the following data types

String | Object | Number | Boolean

Which means you don't need to explicitly convert every data to string

How does it work ?

React secure storage is written in Singleton design pattern, and when the library initialized it reads all the data from local storage and decrypt all the data which is written using react-secure-storage and keeps on the memory, This ensure faster reading of all the data,

The key is generated using browser fingerprint, which is generated using 10+ browser key identifiers and user input secure key,

The user specific Secure key can be configured using .env file as

SECURE_LOCAL_STORAGE_HASH_KEY=xxxxxxxxx

Secure local storage prefix can be configured using .env file as

SECURE_LOCAL_STORAGE_PREFIX=xxxxxxx

Here are the .env prefix lists for the supported languages that are built-in.

Language	Prefix
React	REACT_APP_
Vite	VITE_
Next.Js	NEXT_PUBLIC_

You can always use the environment variables without the prefix as well

How to use

To use the library first you need to install using

yarn add react-secure-storage

or

npm install react-secure-storage

You can use the following methods to read and write items to secure local storage

Function	Usecase	Datatype
setItem(key, value)	To set values to secure storage	Supports 'String - Object - Number - Boolean' as value
getItem(key)	To get values which is saved on secure local storage	Return null if the key does not exits
removeItem(key)	To remove specified key from secure local storage
clear()	Removed all data from secure local storage

How to use with Vite

In the latest version of Vite, process is not defined by default, It uses import.meta.env,

To define the process, You need to add the following code inside vite.config.ts

import { defineConfig } from 'vite'
// ...
export default defineConfig({
  // ...
  define: {
    "process.env": {},
  },
}) 

Here you can pass all the required ENV variables supported by the library inside the process.env object

To disable properties from key generation

If you wish to disable any of the key generation property, You can do it as below

SECURE_LOCAL_STORAGE_DISABLED_KEYS=ScreenPrint|Plugins

or

REACT_APP_SECURE_LOCAL_STORAGE_DISABLED_KEYS=ScreenPrint|Plugins

Here is the list of all the supported values UserAgent|ScreenPrint|Plugins|Fonts|LocalStorage|SessionStorage|TimeZone|Language|SystemLanguage|Cookie|Canvas|Hostname

Here we strongly recommend you to not to disable any of the properties as more properties you have, more unique the browser fingerprint will be!

How to use environment variables for the supported languages.

Language	Key	Usage
Default	SECURE_LOCAL_STORAGE_HASH_KEY	Used to specify the user specific hash key
Default	SECURE_LOCAL_STORAGE_PREFIX	Used to change the local storage prefix where the data will be finally saved
Default	SECURE_LOCAL_STORAGE_DISABLED_KEYS	Used to disable individual property from encryption / fingerprint key generation
React	REACT_APP_SECURE_LOCAL_STORAGE_HASH_KEY	Used to specify the user specific hash key
React	REACT_APP_SECURE_LOCAL_STORAGE_PREFIX	Used to change the local storage prefix where the data will be finally saved
React	REACT_APP_SECURE_LOCAL_STORAGE_DISABLED_KEYS	Used to disable individual property from encryption / fingerprint key generation
Vite	VITE_SECURE_LOCAL_STORAGE_HASH_KEY	Used to specify the user specific hash key
Vite	VITE_SECURE_LOCAL_STORAGE_PREFIX	Used to change the local storage prefix where the data will be finally saved
Vite	VITE_SECURE_LOCAL_STORAGE_DISABLED_KEYS	Used to disable individual property from encryption / fingerprint key generation
Next.Js	NEXT_PUBLIC_SECURE_LOCAL_STORAGE_HASH_KEY	Used to specify the user specific hash key
Next.Js	NEXT_PUBLIC_SECURE_LOCAL_STORAGE_PREFIX	Used to change the local storage prefix where the data will be finally saved
Next.Js	NEXT_PUBLIC_SECURE_LOCAL_STORAGE_DISABLED_KEYS	Used to disable individual property from encryption / fingerprint key generation

Sample Code

import { useEffect } from  "react";
import  secureLocalStorage  from  "react-secure-storage";

  
const App = () => {
    useEffect(() => {
	    secureLocalStorage.setItem("object", {
		    message:  "This is testing of local storage",
	    });
	    secureLocalStorage.setItem("number", 12);
	    secureLocalStorage.setItem("string", "12");
	    secureLocalStorage.setItem("boolean", true);
	    let value = secureLocalStorage.getItem("boolean");
	}, []);

   return (
	    <div>
		    This is a sample code
	    </div>
	);
}

export  default  App;

Build Size ! 7.6KB

Whats new in 1.3.2?

Regular bug fixes and https://github.com/sushinpv/react-secure-storage/issues/39 is resolved

Whats new | Previous?

Added support for Vite and Next.js environment variables

Now you can disable individual fingerprint generation properties, This is discussed in the following enhancement https://github.com/sushinpv/react-secure-storage/issues/14

Secure token returning null when the browser resizes problem was fixed. This was previously included as a security feature, but in the most recent update, it was removed. This was covered in the ensuing issue: https://github.com/sushinpv/react-secure-storage/issues/9

Now that we have included the browser hostname while establishing the secure key, it is more unique. This will guarantee that each website's key is distinct.

Added support for updating Local Storage prefix, Now this can be updated using .env

Resolved https://github.com/sushinpv/react-secure-storage/issues/2

Added support for Cypress

Added proper type definition for the entire package

Added support for older es versions and nextjs

Releasing the first version of react secure local storage, which supports setItem, getItem, removeItem and clear functions

How do I test this library on my local system & How do I contribute ?

For local testing the library make sure you are installing the react-scripts by using npm i react-scripts or yarn add react-scripts. The react-scripts is removed due to vulnerability issue which is highlighted in here : https://github.com/sushinpv/react-secure-storage/issues/3

To contribute on the library, make sure you are creating a development branch for your fix as dev/{feature/fix} and create a PR to master branch.

Before creating the PR, Please make sure to remove the react-scripts from the package.json. and you are creating a production build for the library by running yarn build:lib

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