@nithin-sivakumar/genotp

A lightweight and secure OTP (One-Time Password) generator for JavaScript with customizable features like length, character set, prefix, suffix, and base64 encoding.

Features

• Secure OTP Generation: Uses crypto module for secure, random OTP generation.
• Customizable Length: Generate OTPs of any length.
• Multiple Character Sets:
  • Numeric: 0123456789
  • Alphanumeric: ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789
  • Custom: Use a custom character set of your choice.
• Prefix and Suffix: Optionally add a prefix or suffix to your OTP.
• Base64 Encoding: Optionally return the OTP as a base64-encoded string.
• No Expiry Handling: This package only focuses on OTP generation; expiry is left to the user.

Installation

To install the package, run:

npm install @nithin-sivakumar/genotp

Usage

Generate OTP

To generate an OTP, use the generate function with the following options:

import { generate } from "@nithin-sivakumar/genotp";

// Generate Numeric OTP of length 6
const otp = generate(6, "numeric");
console.log("Generated Numeric OTP:", otp);

// Generate Alphanumeric OTP with a prefix
const otpWithPrefix = generate(8, "alphanumeric", "", "OTP-", "");
console.log("Generated OTP with Prefix:", otpWithPrefix);

// Generate OTP with a custom character set
const customCharSet =
  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#";
const otpWithCustomCharSet = generate(10, "custom", customCharSet);
console.log("Generated OTP with Custom Character Set:", otpWithCustomCharSet);

// Generate Base64-encoded OTP
const base64Otp = generate(10, "alphanumeric", "", "", "", true);
console.log("Base64 Encoded OTP:", base64Otp);

Options for generate function:

• length (number): The length of the OTP. Default is 6.
• mode (string): The mode of OTP generation:
  • 'numeric': OTP contains only numbers.
  • 'alphanumeric': OTP contains numbers and letters (both uppercase).
  • 'custom': OTP uses a custom character set. Default is 'numeric'.
• charSet (string): Custom characters to use for OTP generation (only for custom mode). Default is empty.
• prefix (string): Optional prefix to be added to the OTP. Default is "".
• suffix (string): Optional suffix to be added to the OTP. Default is "".
• base64Encode (boolean): Whether to return the OTP as a base64-encoded string. Default is false.

Example

import { generate } from "@nithin-sivakumar/genotp";

// Generate OTP of length 6 using numeric characters
const otp = generate(6, "numeric");
console.log(otp); // Example: 123456

// Generate OTP of length 8 using alphanumeric characters
const otpAlphanumeric = generate(8, "alphanumeric");
console.log(otpAlphanumeric); // Example: A1B2C3D4

// Generate OTP with custom character set
const customOtp = generate(
  10,
  "custom",
  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#"
);
console.log(customOtp); // Example: aB1!jK8@

Error Handling

The package throws the following errors:

• Invalid Mode or Character Set: If the mode or character set is invalid, an error will be thrown.
• Invalid Length: If the length is less than or equal to 0, an error will be thrown.

License

MIT License. See LICENSE for more information.