@lowlighter/crypto

🧮 Cryptographic utilities

🔑 Time-based One-Time Password (TOTP)

Issue a new TOTP secret with metadata (issuer, account, image, etc.).

• 🦕 Playground
• 📚 Documentation

📑 Examples

import { otpauth, otpsecret, verify } from "./totp.ts"
import { qrcode } from "jsr:@libs/qrcode"

// Issue a new TOTP secret
const secret = otpsecret()
const url = otpauth({ issuer: "example.com", account: "alice", secret })
console.log(`Please scan the following QR Code:`)
qrcode(url.href, { output: "console" })

// Verify a TOTP token
const token = prompt("Please enter the token generated by your app:")!
console.assert(await verify({ token, secret }))

✨ Features

• Has no external dependencies.
• Is lightweight.

This library is based on the well-written article of @rajat-sr How To Implement Google Authenticator Two Factor Auth in JavaScript

🔐 Symmetric encryption (using AES-GCM 256 with a PBKDF2 derived key)

• 🦕 Playground
• 📚 Documentation

📑 Examples

import { decrypt, encrypt, exportKey, importKey } from "./encryption.ts"

// Generate a key. Same seed and salt combination will always yield the same key
const key = await exportKey({ seed: "hello", salt: "world" })
console.assert(key === "664d43091e7905723fc92a4c38f58e9aeff6d822488eb07d6b11bcfc2468f48a")

// Encrypt a message
const message = "🍱 bento"
const secret = await encrypt(message, { key, length: 512 })
console.assert(secret !== message)

// Encrypted messages are different each time and can also obfuscate the original message size
console.assert(secret !== await encrypt(message, { key, length: 512 }))
console.assert(secret.length === 512)

// Decrypt a message
const decrypted = await decrypt(secret, { key })
console.assert(decrypted === message)

✨ Features

• Use the native Web Crypto APIs.
• Uses a AES-GCM 256-bits with PBKDF2-derived key to encrypt and decrypt messages.
  • Encrypted messages are different each time thanks to an initialization vector.
  • The derived keys from a given seed/password are always the same.
• Includes functionalities to introduce additional entropy:
  • Support for SHA-256 to guarantee integrity.
  • Support for retaining the stored size to help verify integrity (for messages with length < 255)
  • Support for adding padding to force length be 256 or 512 bytes and obfuscate the original size (can be disabled using 0 as value)

📜 License and credits

Copyright (c) Simon Lecoq <@lowlighter>. (MIT License)
https://github.com/lowlighter/libs/blob/main/LICENSE

[!CAUTION]

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND

The author is not responsible for any damage that could be caused by the use of this library. It is your responsibility to use it properly and to understand the security implications of the choices you make.