README.md

NestJS Encryption Module

NestJS Encrytion is a NestJS 9+ module that provides plug-and-play encryption and decryption functionality to your NestJS application.

• Uses aes-256-cbc by default, but supports other ciphers as well.
• Provides a keygen (API and CLI) for generating random and secure encryption keys.
• Thoroughly tested.

Installation

NestJS Encryption can be installed with your favorite package manager.

# NPM
npm install @hedger/nestjs-encryption

# Yarn
yarn add @hedger/nestjs-encryption

# PNPM
pnpm add @hedger/nestjs-encryption

Setup

Setting up the module inside your NestJS application is a matter of registering the module within your AppModule. The module is registered globally by default and can be used anywhere in your application.

You may use either the forRoot or forRootAsync method to register the module in your AppModule.

Using forRoot

The forRoot method is the simplest way to register the module.

import { EncryptionModule, Cipher } from "@hedger/nestjs-encryption";

@Module({
	imports: [
		EncryptionModule.forRoot({
			key: process.env.APP_KEY,
			cipher: Cipher.AES_256_CBC,
		}),
	],
})
export class AppModule {}

Using forRootAsync

The forRootAsync method allows you to register the module asynchronously, optionally resolving the encryption key from a configuration service. Here's an example that uses the ConfigService from @nestjs/config to resolve the encryption key from the APP_KEY environment variable.

import { ConfigModule, ConfigService } from "@nestjs/config";
import { EncryptionModule, Cipher } from "@hedger/nestjs-encryption";

@Module({
	imports: [
		ConfigModule.forRoot({
			isGlobal: true,
		}),
		EncryptionModule.forRootAsync({
			useFactory: (configService: ConfigService) => ({
				key: configService.get<string>("APP_KEY"),
			}),
			inject: [ConfigService],
		}),
	],
	controllers: [AppController],
	providers: [AppService],
})
export class AppModule {}

Usage

Inject the EncryptionService in your service or controller.

import { EncryptionService } from "@hedger/nestjs-encryption";

@Injectable()
export class FooService {
	constructor(private readonly crypto: EncryptionService) {}

	someMethod() {
		const encrypted = this.crypto.encrypt("some value");
		const decrypted = this.crypto.decrypt(encrypted);
	}
}

Encryption key

This package expects the encryption key to be a base64-encoded string of N random bytes, where N is the key length of the cipher you're using. For example, the aes-256-cbc cipher has a key length of 32 bytes, so the encryption key must be a base64-encoded string of 32 random bytes.

Generating a key

This package provides CLI utility for generating random and secure encryption keys.

# Generates a random key for the aes-256-cbc cipher (default)
npm exec nestjs-encryption-keygen

By default, the keygen generates keys for the aes-256-cbc cipher. You may specify a different cipher by passing the --cipher option.

# Generates a random key for the aes-128-cbc cipher
npm exec nestjs-encryption-keygen --cipher aes-128-cbc

See the Supported ciphers section for a list of supported ciphers.

Generating a key programmatically

Random and secure encryption keys may also be generated programmatically by calling the generateKey method on the EncryptionService class.

import { Cipher, EncryptionService } from "@hedger/nestjs-encryption";

// Pass the desired cipher as the first argument.
const key = EncryptionService.generateKey(Cipher.AES_256_CBC);

Supported ciphers

The following ciphers are supported by this package.

• aes-256-cbc (default)
• aes-256-gcm
• aes-128-cbc
• aes-128-gcm

License

Copyright © 2023, Nicolas Hedger. Released under the MIT License.