🧮 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