NestJS guards for Shopify HMAC verification

This module implements Guards which verifies the HMAC signature of incoming requests from Shopify:

• ShopifyAuthGuard - verifies the HMAC signature of incoming Auth requests from Shopify as described in the Shopify documentation and will throw an UnauthorizedException if it is invalid.
• ShopifyWebhookGuard - verifies the HMAC signature of incoming Webhook requests from Shopify as described in the Shopify documentation and will throw an UnauthorizedException if it is invalid.

Basic usage with all default

First install this module:

npm i -P @e-mage/nestjs-shopify-guards

Then import module into your Nestjs application and configure it with your app secret:

import { ShopifyGuardsModule } from '@e-mage/nestjs-shopify-guards';

@Module({
    imports: [
        ShopifyGuardsModule.register({
            apiSecretKey: 'my_client_secret',
        }),
    ],
    controllers: [AppController],
    providers: [AppService],
})
export class AppModule {}

And use the guards in your controller:

import { ShopifyAuthGuard, ShopifyWebhookGuard } from '@e-mage/nestjs-shopify-guards';

@Controller()
@UseGuards(ShopifyAuthGuard)
export class AppController {

    // Guard will verify the HMAC signature of the request
    // and will throw an UnauthorizedException if it is invalid
    @UseGuards(ShopifyAuthGuard)
    @Get('/auth')
    getHello(): string {
      return this.appService.getHello();
    }
    
    // Guard will verify the HMAC signature of the request
    // and will throw an UnauthorizedException if it is invalid
    @UseGuards(ShopifyWebhookGuard)
    @Post('/webhook')
    postHello(): string {
      return this.appService.getHello();
    }
}

You can also use the guards with custom options

You can change the default hmac header name or the default hmac query parameter name:

import { ShopifyGuardsModule } from '@e-mage/nestjs-shopify-guards';

@Module({
    imports: [
        ShopifyGuardsModule.register({
            apiSecretKey: 'my_client_secret',
            hmacHeaderName: 'X-My-Shopify-Hmac-Sha256',
            hmacQueryParameterName: 'my-hmac',
        }),
    ],
    controllers: [AppController],
    providers: [AppService],
})
export class AppModule {}