@nestlab/google-recaptcha

Google recaptcha module

This package provides protection for endpoints using reCAPTCHA for NestJS REST and GraphQL applications. By integrating with reCAPTCHA, this package helps to prevent automated abuse such as spam and bots, improving the security and reliability of your application.

Table of Contents

• Installation
• Changes
• Configuration
  • Options
  • REST application
    • reCAPTCHA v2
    • reCAPTCHA v3
    • reCAPTCHA Enterprise
  • Graphql application
    • reCAPTCHA v2
    • reCAPTCHA v3
    • reCAPTCHA Enterprise
• Usage
  • REST application
  • Graphql application
  • Validate in service
  • Validate in service (Enterprise)
  • Dynamic Recaptcha configuration
  • Error handling
• Contribution
• License

Usage example here

Installation

$ npm i @nestlab/google-recaptcha

Changes

The list of changes made in the project can be found in the CHANGELOG.md file.

Configuration

Options

GoogleRecaptchaModuleOptions

Property	Description
response	Required. Type: (request) => string Function that returns response (recaptcha token) by request
secretKey	Optional. Type: string Google recaptcha secret key. Must be set if you don't use reCAPTCHA Enterprise
debug	Optional. Type: boolean Default: false Enables logging requests, responses, errors and transformed results
logger	Optional. Type: Logger Default: new Logger() Instance of custom logger that extended from Logger (@nestjs/common)
skipIf	Optional. Type: boolean | (request) => boolean | Promise<boolean> Function that returns true if you allow the request to skip the recaptcha verification. Useful for involing other check methods (e.g. custom privileged API key) or for development or testing
enterprise	Optional. Type: GoogleRecaptchaEnterpriseOptions Options for using reCAPTCHA Enterprise API. Cannot be used with secretKey option.
network	Optional. Type: GoogleRecaptchaNetwork | string Default: GoogleRecaptchaNetwork.Google If your server has trouble connecting to https://google.com then you can set networks: GoogleRecaptchaNetwork.Google = 'https://www.google.com/recaptcha/api/siteverify' GoogleRecaptchaNetwork.Recaptcha = 'https://recaptcha.net/recaptcha/api/siteverify' or set any api url
score	Optional. Type: number | (score: number) => boolean Score validator for reCAPTCHA v3 or enterprise. number - minimum available score. (score: number) => boolean - function with custom validation rules.
actions	Optional. Type: string[] Available action list for reCAPTCHA v3 or enterprise. You can make this check stricter by passing the action property parameter to @Recaptcha(...) decorator.
remoteIp	Optional. Type: (request) => string A function that returns a remote IP address from the request
axiosConfig	Optional. Type: AxiosRequestConfig Allows to setup proxy, response timeout, https agent etc...
global	Optional. Type: boolean Default: false Defines a module in the global scope.

GoogleRecaptchaEnterpriseOptions

Property	Description
projectId	Required. Type: string Google Cloud project ID
siteKey	Required. Type: string reCAPTCHA key associated with the site/app.
apiKey	Required. Type: string API key associated with the current project. Must have permission reCAPTCHA Enterprise API. You can manage credentials here.

The module provides two static methods for configuration: forRoot and forRootAsync.

forRoot

forRoot(options: GoogleRecaptchaModuleOptions): DynamicModule

The forRoot method accepts a GoogleRecaptchaModuleOptions object that configures the module. This method should be used in the root AppModule.
Example usage:

@Module({
    imports: [
        GoogleRecaptchaModule.forRoot({
            secretKey: process.env.GOOGLE_RECAPTCHA_SECRET_KEY,
            response: req => req.headers.recaptcha,
        })
    ],
})
export class AppModule {
}

forRootAsync

forRootAsync(options: ModuleAsyncOptions): DynamicModule

The forRootAsync method is similar to forRoot, but allows for asynchronous configuration.
It accepts a GoogleRecaptchaModuleAsyncOptions object that returns a configuration object or a Promise that resolves to a configuration object.
Read more about ConfigService and custom getter function.

Example usage:

@Module({
    imports: [
        GoogleRecaptchaModule.forRootAsync({
            imports: [ConfigModule],
            useFactory: (configService: ConfigService) => configService.googleRecaptchaOptions,
            inject: [ConfigService],
        })
    ],
})
export class AppModule {
}

REST application

REST reCAPTCHA V2

@Module({
    imports: [
        GoogleRecaptchaModule.forRoot({
            secretKey: process.env.GOOGLE_RECAPTCHA_SECRET_KEY,
            response: req => req.headers.recaptcha,
            skipIf: process.env.NODE_ENV !== 'production',
        }),
    ],
})
export class AppModule {
}

Tip: header names transforming to lower case.

For example: If you send 'Recaptcha' header then use (req) => req.headers.recaptcha

REST reCAPTCHA V3

@Module({
    imports: [
        GoogleRecaptchaModule.forRoot({
            secretKey: process.env.GOOGLE_RECAPTCHA_SECRET_KEY,
            response: req => req.headers.recaptcha,
            skipIf: process.env.NODE_ENV !== 'production',
            actions: ['SignUp', 'SignIn'],
            score: 0.8,
        }),
    ],
})
export class AppModule {
}

Tip: header names transforming to lower case.

For example: If you send 'Recaptcha' header then use (req) => req.headers.recaptcha

REST reCAPTCHA Enterprise

@Module({
    imports: [
        GoogleRecaptchaModule.forRoot({
            response: (req) => req.headers.recaptcha,
            skipIf: process.env.NODE_ENV !== 'production',
            actions: ['SignUp', 'SignIn'],
            score: 0.8,
            enterprise: {
                projectId: process.env.RECAPTCHA_ENTERPRISE_PROJECT_ID,
                siteKey: process.env.RECAPTCHA_ENTERPRISE_SITE_KEY,
                apiKey: process.env.RECAPTCHA_ENTERPRISE_API_KEY,
            },
        }),
    ],
})
export class AppModule {
}

Tip: header names transforming to lower case.

For example: If you send 'Recaptcha' header then use (req) => req.headers.recaptcha

Graphql application

Graphql reCAPTCHA V2

@Module({
    imports: [
        GoogleRecaptchaModule.forRoot({
            secretKey: process.env.GOOGLE_RECAPTCHA_SECRET_KEY,
            response: (req: IncomingMessage) => (req.headers.recaptcha || '').toString(),
            skipIf: process.env.NODE_ENV !== 'production',
        }),
    ],
})
export class AppModule {
}

Tip: header names transforming to lower case.

For example: If you send 'Recaptcha' header then use (req: IncomingMessage) => (req.headers.recaptcha || '').toString()

Graphql reCAPTCHA V3

@Module({
    imports: [
        GoogleRecaptchaModule.forRoot({
            secretKey: process.env.GOOGLE_RECAPTCHA_SECRET_KEY,
            response: (req: IncomingMessage) => (req.headers.recaptcha || '').toString(),
            skipIf: process.env.NODE_ENV !== 'production',
            actions: ['SignUp', 'SignIn'],
            score: 0.8,
        }),
    ],
})
export class AppModule {
}

Tip: header names transforming to lower case.

For example: If you send 'Recaptcha' header then use (req: IncomingMessage) => (req.headers.recaptcha || '').toString()

Graphql reCAPTCHA Enterprise

@Module({
    imports: [
        GoogleRecaptchaModule.forRoot({
            response: (req: IncomingMessage) => (req.headers.recaptcha || '').toString(),
            skipIf: process.env.NODE_ENV !== 'production',
            actions: ['SignUp', 'SignIn'],
            score: 0.8,
            enterprise: {
                projectId: process.env.RECAPTCHA_ENTERPRISE_PROJECT_ID,
                siteKey: process.env.RECAPTCHA_ENTERPRISE_SITE_KEY,
                apiKey: process.env.RECAPTCHA_ENTERPRISE_API_KEY,
            },
        }),
    ],
})
export class AppModule {
}

Tip: header names transforming to lower case.

For example: If you send 'Recaptcha' header then use (req) => req.headers.recaptcha

Configuration for reCAPTCHA Enterprise

@Module({
    imports: [
        GoogleRecaptchaModule.forRoot({
            response: (req) => req.headers.recaptcha,
            skipIf: process.env.NODE_ENV !== 'production',
            actions: ['SignUp', 'SignIn'],
            score: 0.8,
            enterprise: { 
                projectId: process.env.RECAPTCHA_ENTERPRISE_PROJECT_ID, 
                siteKey: process.env.RECAPTCHA_ENTERPRISE_SITE_KEY, 
                apiKey: process.env.RECAPTCHA_ENTERPRISE_API_KEY, 
            },
        }),
    ],
})
export class AppModule {
}

Usage

Usage in REST application

To protect your REST endpoints, you can use the @Recaptcha decorator.
Example:

@Controller('feedback')
export class FeedbackController {
    @Recaptcha()
    @Post('send')
    async send(): Promise<any> {
        // TODO: Your implementation.
    }
}

You can also override the default property that contains reCAPTCHA for a specific endpoint.

@Controller('feedback')
export class FeedbackController {
    @Recaptcha({response: req => req.body.recaptha})
    @Post('send')
    async send(): Promise<any> {
        // TODO: Your implementation.
    }
}

Additionally, you can override reCAPTCHA v3 options.

@Controller('feedback')
export class FeedbackController {
    @Recaptcha({response: req => req.body.recaptha, action: 'Send', score: 0.8})
    @Post('send')
    async send(): Promise<any> {
        // TODO: Your implementation.
    }
}

To get the verification result, you can use the @RecaptchaResult() decorator.

@Controller('feedback')
export class FeedbackController {
    @Recaptcha()
    @Post('send')
    async send(@RecaptchaResult() recaptchaResult: RecaptchaVerificationResult): Promise<any> {
        console.log(`Action: ${recaptchaResult.action} Score: ${recaptchaResult.score}`);
        // TODO: Your implementation.
    }
}

If you want to use the Google reCAPTCHA guard in combination with other guards, you can use the @UseGuards decorator.

@Controller('feedback')
export class FeedbackController {
    @SetRecaptchaOptions({action: 'Send', score: 0.8})
    @UseGuards(Guard1, GoogleRecaptchaGuard, Guard2)
    @Post('send')
    async send(): Promise<any> {
        // TODO: Your implementation.
    }
}

You can find a usage example in the following link.

Usage in Graphql application

To protect your resolver, use the @Recaptcha decorator.

@Recaptcha()
@Resolver(of => Recipe)
export class RecipesResolver {
    @Query(returns => Recipe)
    async recipe(@Args('id') id: string): Promise<Recipe> {
        // TODO: Your implementation.
    }
}

Obtain verification result:

@Recaptcha()
@Resolver(of => Recipe)
export class RecipesResolver {
    @Query(returns => Recipe)
    async recipe(@Args('id') id: string,
                 @RecaptchaResult() recaptchaResult: RecaptchaVerificationResult): Promise<Recipe> {
        console.log(`Action: ${recaptchaResult.action} Score: ${recaptchaResult.score}`);
        // TODO: Your implementation.
    }
}

You can override the default recaptcha property for a specific endpoint.

@Recaptcha()
@Resolver(of => Recipe)
export class RecipesResolver {
    @Query(returns => Recipe)
    async recipe(@Args('id') id: string): Promise<Recipe> {
        // TODO: Your implementation.
    }

    // Overridden default header. This query using X-Recaptcha header 
    @Recaptcha({response: (req: IncomingMessage) => (req.headers['x-recaptcha'] || '').toString()})
    @Query(returns => [Recipe])
    recipes(@Args() recipesArgs: RecipesArgs): Promise<Recipe[]> {
        // TODO: Your implementation.
    }
}

Validate in service

@Injectable()
export class SomeService {
    constructor(private readonly recaptchaValidator: GoogleRecaptchaValidator) {
    }

    async someAction(recaptchaToken: string): Promise<void> {
        const result = await this.recaptchaValidator.validate({
            response: recaptchaToken,
            score: 0.8,
            action: 'SomeAction',
        });
        
        if (!result.success) {
            throw new GoogleRecaptchaException(result.errors);
        }
        // TODO: Your implemetation
    }
}

Validate in service (Enterprise)

@Injectable()
export class SomeService {
    constructor(private readonly recaptchaEnterpriseValidator: GoogleRecaptchaEnterpriseValidator) {
    }

    async someAction(recaptchaToken: string): Promise<void> {
        const result = await this.recaptchaEnterpriseValidator.validate({
            response: recaptchaToken,
            score: 0.8,
            action: 'SomeAction',
        });
        
        if (!result.success) {
            throw new GoogleRecaptchaException(result.errors);
        }
        
        const riskAnalytics = result.getEnterpriseRiskAnalytics();
        
        // TODO: Your implemetation
    }
}

Dynamic Recaptcha configuration

The RecaptchaConfigRef class provides a convenient way to modify Recaptcha validation parameters within your application. This can be particularly useful in scenarios where the administration of Recaptcha is managed dynamically, such as by an administrator. The class exposes methods that allow the customization of various Recaptcha options.

RecaptchaConfigRef API:

@Injectable()
class RecaptchaConfigRef {
  // Sets the secret key for Recaptcha validation.
  setSecretKey(secretKey: string): this;

  // Sets enterprise-specific options for Recaptcha validation
  setEnterpriseOptions(options: GoogleRecaptchaEnterpriseOptions): this;

  // Sets the score threshold for Recaptcha validation.
  setScore(score: ScoreValidator): this;

  // Sets conditions under which Recaptcha validation should be skipped.
  setSkipIf(skipIf: SkipIfValue): this;
}

Usage example:

@Injectable()
export class RecaptchaAdminService implements OnApplicationBootstrap {
	constructor(private readonly recaptchaConfigRef: RecaptchaConfigRef) {
	}

	async onApplicationBootstrap(): Promise<void> {
		// TODO: Pull recaptcha configs from your database 

		this.recaptchaConfigRef
			.setSecretKey('SECRET_KEY_VALUE')
			.setScore(0.3);
	}

	async updateSecretKey(secretKey: string): Promise<void> {
		// TODO: Save new secret key to your database

		this.recaptchaConfigRef.setSecretKey(secretKey);
	}
}

After call this.recaptchaConfigRef.setSecretKey(...) - @Recaptcha guard and GoogleRecaptchaValidator will use new secret key.

Error handling

GoogleRecaptchaException

GoogleRecaptchaException extends HttpException extends Error.

The GoogleRecaptchaException is an exception that can be thrown by the GoogleRecaptchaGuard when an error occurs. It extends the HttpException class provided by NestJS, which means that it can be caught by an ExceptionFilter in the same way as any other HTTP exception.

One important feature of the GoogleRecaptchaException is that it contains an array of Error Code values in the errorCodes property. These values can be used to diagnose and handle the error.

Error code	Description	Status code
ErrorCode.MissingInputSecret	The secret parameter is missing. (Throws from reCAPTCHA api).	500
ErrorCode.InvalidInputSecret	The secret parameter is invalid or malformed. (Throws from reCAPTCHA api).	500
ErrorCode.MissingInputResponse	The response parameter is missing. (Throws from reCAPTCHA api).	400
ErrorCode.InvalidInputResponse	The response parameter is invalid or malformed. (Throws from reCAPTCHA api).	400
ErrorCode.BadRequest	The request is invalid or malformed. (Throws from reCAPTCHA api).	500
ErrorCode.TimeoutOrDuplicate	The response is no longer valid: either is too old or has been used previously. (Throws from reCAPTCHA api).	400
ErrorCode.UnknownError	Unknown error. (Throws from reCAPTCHA api).	500
ErrorCode.ForbiddenAction	Forbidden action. (Throws from guard when expected action not equals to received).	400
ErrorCode.LowScore	Low score (Throws from guard when expected score less than received).	400
ErrorCode.InvalidKeys	keys were copied incorrectly, the wrong keys were used for the environment (e.g. development vs production), or if the keys were revoked or deleted from the Google reCAPTCHA admin console.. (Throws from reCAPTCHA api).	400
ErrorCode.NetworkError	Network error (like ECONNRESET, ECONNREFUSED...).	500
ErrorCode.SiteMismatch	Site mismatch (Throws from reCAPTCHA Enterprise api only).	400
ErrorCode.BrowserError	Browser error (Throws from reCAPTCHA Enterprise api only).	400

GoogleRecaptchaNetworkException

The GoogleRecaptchaNetworkException is an exception that extends the GoogleRecaptchaException class and is thrown in the case of a network error.
It contains a networkErrorCode property, which contains the error code of the network error, retrieved from the code property of the AxiosError object.

You can handle it via ExceptionFilter.

Example exception filter implementation.

@Catch(GoogleRecaptchaException)
export class GoogleRecaptchaFilter implements ExceptionFilter {
    catch(exception: GoogleRecaptchaException, host: ArgumentsHost): any {
        // TODO: Your exception filter implementation
    }
}

And add your filter to application

async function bootstrap() {
    const app = await NestFactory.create(AppModule);
    app.useGlobalFilters(new ErrorFilter(), new GoogleRecaptchaFilter());
    await app.listen(3000);
}
bootstrap();

Contribution

We welcome any contributions to improve our package! If you find a bug, have a feature request, or want to suggest an improvement, feel free to submit an issue on our GitHub repository.

If you want to contribute to the codebase directly, please follow our contributing guidelines outlined in the CONTRIBUTING.md file in the repository.

We value the contributions of our community and appreciate all efforts to make this package better for everyone. Thank you for your support!

License

This project is licensed under the MIT License - see the LICENSE.md file for details.