OTP & CAPTCHA Generator

A simple utility for generating OTPs (One-Time Passwords) and CAPTCHAs (both text-based and math-based). This library provides flexibility in character sets and customization options, making it easy to integrate into your applications.

Features

• Generate OTPs with digits, upper case, lower case, and special characters.
• Generate text-based CAPTCHA with noise and distortion for security.
• Generate math-based CAPTCHA for different difficulty levels.
• Outputs CAPTCHA as an image saved in PNG format.

Installation

Install the package using npm:

1npm install otp-captcha-generator;
2npm install canvas;

Usage

learn How to use this package.

1. OTP Generation

You can generate OTPs of any length with customizable options such as digits, upper case, lower case, and special characters.

1const { generateOTP } = require('otp-captcha-generator');
2
3// Generate a 6-digit OTP (default)
4const otp = generateOTP();
5console.log(otp);  // Example output: '123456'
6
7// Generate an OTP with custom options
8const customOtp = generateOTP(8, { upperCase: true, lowerCase: true, specialCase: true });
9console.log(customOtp);  // Example output: 'Ab!3$Cd2'

OTP Options

Option	Type	Default	Description
length	Number	6	Length of the OTP
digits	Boolean	true	Include digits in the OTP
upperCase	Boolean	false	Include uppercase letters in the OTP
lowerCase	Boolean	false	Include lowercase letters in the OTP
specialCase	Boolean	false	Include special characters in the OTP

2. CAPTCHA Generation

You can generate two types of CAPTCHA: simple text-based CAPTCHA and math-based CAPTCHA. Both are saved as images in the root directory.

Text-Based CAPTCHA

1const { generateCaptcha } = require('otp-captcha-generator');
2
3// Generate a simple text-based CAPTCHA with default options
4const simpleCaptcha = generateCaptcha('simple');
5console.log(simpleCaptcha.captchaText);  // Example output: 'A1B2C3'
6console.log(simpleCaptcha.imagePath);    // Path to the generated image
7
8// Generate a text-based CAPTCHA with custom options
9const customCaptcha = generateCaptcha('simple', { length: 8, digits: true, upperCase: true, lowerCase: true });
10console.log(customCaptcha.captchaText);  // Example output: 'A1bC2dE3'
11console.log(customCaptcha.imagePath);    // Path to the generated image

Text-Based CAPTCHA Options

Option	Type	Default	Description
length	Number	6	Length of the CAPTCHA text (for text-based CAPTCHA)
digits	Boolean	true	Include digits in the CAPTCHA text (for text-based CAPTCHA)
upperCase	Boolean	false	Include uppercase letters in the CAPTCHA text (for text-based CAPTCHA)
lowerCase	Boolean	false	Include lowercase letters in the CAPTCHA text (for text-based CAPTCHA)

Math-Based CAPTCHA

1const { generateCaptcha } = require('otp-captcha-generator');
2
3// Generate a math-based CAPTCHA with default difficulty (low)
4const mathCaptcha = generateCaptcha('math');
5console.log(mathCaptcha.captchaText);  // Example output: '5 + 3 = ?'
6console.log(mathCaptcha.answer);       // Example output: 8
7console.log(mathCaptcha.imagePath);   // Path to the generated image
8
9// Generate a math-based CAPTCHA with medium difficulty
10const mediumMathCaptcha = generateCaptcha('math', { difficulty: 'medium' });
11console.log(mediumMathCaptcha.captchaText);  // Example output: '12 * 4 = ?'
12console.log(mediumMathCaptcha.answer);       // Example output: 48
13console.log(mediumMathCaptcha.imagePath);   // Path to the generated image
14
15// Generate a math-based CAPTCHA with high difficulty
16const highMathCaptcha = generateCaptcha('math', { difficulty: 'high' });
17console.log(highMathCaptcha.captchaText);  // Example output: '78 / 39 = ?'
18console.log(highMathCaptcha.answer);       // Example output: 2
19console.log(highMathCaptcha.imagePath);   // Path to the generated image

Math CAPTCHA Options

Option	Type	Default	Description
difficulty	String	low	Difficulty level for math CAPTCHA (low, medium, high)

Functions

generateOTP(length, options)

Generates an OTP based on the provided length and options.

Parameters:

• length (Number): The length of the OTP. Default is 6.
• options (Object): Optional settings for OTP generation. Includes:
  • digits (Boolean): Include digits in the OTP (default is true).
  • upperCase (Boolean): Include uppercase letters in the OTP (default is false).
  • lowerCase (Boolean): Include lowercase letters in the OTP (default is false).
  • specialCase (Boolean): Include special characters in the OTP (default is false).

Returns:

• String: The generated OTP.

generateCaptcha(type, options)

Generates a CAPTCHA image based on the provided type and options.

Parameters:

• type (String): Type of CAPTCHA to generate. Can be either "simple" or "math".
• options (Object): Optional settings for CAPTCHA generation. Includes:
  • For Simple CAPTCHA:
    • length (Number): Length of the CAPTCHA text (default is 6).
    • digits (Boolean): Include digits (default is true).
    • upperCase (Boolean): Include uppercase letters (default is false).
    • lowerCase (Boolean): Include lowercase letters (default is false).
  • For Math CAPTCHA:
    • difficulty (String): Difficulty level ("low", "medium", or "high").

Returns:

• Object: Contains the following properties:
  • captchaText (String): The text of the CAPTCHA.
  • answer (String): The answer to the CAPTCHA (only for math CAPTCHA).
  • imagePath (String): Path to the generated CAPTCHA image.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Contributing

Feel free to contribute by submitting issues, pull requests, or feature requests. Your feedback and improvements are welcome!

Contact

For any questions or support, please contact dg0883015@gmail.com.

This README.md file provides comprehensive instructions and code snippets for using the OTP and CAPTCHA generation functionalities, including all options and use cases.