Hey there! I’ve got you covered for your Cordova Windows app encryption/storage needs since the simple-crypto plugin doesn’t support Windows. Here are a few solid alternatives and implementation steps:

1. Use the Web Crypto API (No Extra Plugins Needed) #

Windows Cordova apps run on Edge WebView, which fully supports the native Web Crypto API. This is a lightweight, native alternative that avoids third-party plugin dependencies.

Key Steps: #

• Generate an AES-GCM encryption key (ideal for symmetric encryption of form data)
• Convert form data to a usable format and encrypt it
• Decrypt stored data back to plaintext
• Use cordova-plugin-file to save/retrieve encrypted data to a private local file

Example Code: #

Generate Encryption Key

async function generateEncryptionKey() {
  const key = await window.crypto.subtle.generateKey(
    { name: "AES-GCM", length: 256 },
    true, // Allow key extraction for storage if needed
    ["encrypt", "decrypt"]
  );
  return key;
}

Encrypt Form Data

async function encryptFormData(plaintext, key) {
  const encoder = new TextEncoder();
  const data = encoder.encode(plaintext);
  const iv = window.crypto.getRandomValues(new Uint8Array(12)); // GCM's recommended IV length
  const encryptedBuffer = await window.crypto.subtle.encrypt(
    { name: "AES-GCM", iv: iv },
    key,
    data
  );
  // Combine IV and encrypted data (we need the IV to decrypt later)
  return new Uint8Array([...iv, ...new Uint8Array(encryptedBuffer)]);
}

Decrypt Stored Data

async function decryptStoredData(encryptedData, key) {
  // Split IV (first 12 bytes) from the encrypted content
  const iv = encryptedData.slice(0, 12);
  const encryptedContent = encryptedData.slice(12);
  const decryptedBuffer = await window.crypto.subtle.decrypt(
    { name: "AES-GCM", iv: iv },
    key,
    encryptedContent
  );
  const decoder = new TextDecoder();
  return decoder.decode(decryptedBuffer);
}

Save Encrypted Data to Local File

// First install the file plugin: `cordova plugin add cordova-plugin-file`

async function saveEncryptedFile(encryptedData) {
  const appDir = await window.resolveLocalFileSystemURL(cordova.file.dataDirectory);
  const file = await appDir.getFile("encrypted-form-data.bin", { create: true, exclusive: false });
  const writer = await file.createWriter();
  writer.write(new Blob([encryptedData]));
  console.log("Form data saved securely!");
}

Retrieve & Decrypt Data from File

async function loadAndDecryptFile(key) {
  const filePath = cordova.file.dataDirectory + "encrypted-form-data.bin";
  const fileEntry = await window.resolveLocalFileSystemURL(filePath);
  const file = await fileEntry.file();
  const reader = new FileReader();
  
  return new Promise((resolve, reject) => {
    reader.onload = async () => {
      const encryptedData = new Uint8Array(reader.result);
      const plaintextData = await decryptStoredData(encryptedData, key);
      resolve(plaintextData);
    };
    reader.onerror = reject;
    reader.readAsArrayBuffer(file);
  });
}

2. Use CryptoJS with cordova-plugin-file #

If you prefer a more straightforward, plugin-like API (similar to simple-crypto), CryptoJS is a popular JavaScript encryption library that works seamlessly in Cordova Windows apps.

Setup: #

1. Download CryptoJS and include it in your project (avoid CDNs for offline support)
2. Install cordova-plugin-file as before

Example Code: #

Encrypt & Save Data

// Assume CryptoJS is loaded via <script src="js/crypto-js.min.js"></script>

function encryptWithCryptoJS(plaintext, secretKey) {
  const iv = CryptoJS.lib.WordArray.random(12);
  const encrypted = CryptoJS.AES.encrypt(plaintext, secretKey, { iv: iv });
  // Return IV and encrypted data as a delimited base64 string
  return iv.toString(CryptoJS.enc.Base64) + ":" + encrypted.toString();
}

async function saveCryptoJSData(encryptedString) {
  const appDir = await window.resolveLocalFileSystemURL(cordova.file.dataDirectory);
  const file = await appDir.getFile("form-data.txt", { create: true, exclusive: false });
  const writer = await file.createWriter();
  writer.write(encryptedString);
}

Retrieve & Decrypt Data

function decryptWithCryptoJS(encryptedString, secretKey) {
  const [ivBase64, encryptedBase64] = encryptedString.split(":");
  const iv = CryptoJS.enc.Base64.parse(ivBase64);
  const decrypted = CryptoJS.AES.decrypt(encryptedBase64, secretKey, { iv: iv });
  return decrypted.toString(CryptoJS.enc.Utf8);
}

async function loadAndDecryptCryptoJSData(secretKey) {
  const filePath = cordova.file.dataDirectory + "form-data.txt";
  const fileEntry = await window.resolveLocalFileSystemURL(filePath);
  const file = await fileEntry.file();
  const reader = new FileReader();
  
  return new Promise((resolve, reject) => {
    reader.onload = () => {
      const plaintextData = decryptWithCryptoJS(reader.result, secretKey);
      resolve(plaintextData);
    };
    reader.onerror = reject;
    reader.readAsText(file);
  });
}

Critical Notes: #

• Key Management: Never hardcode encryption keys in your app! Use Windows' built-in credential storage (via cordova-plugin-windows-credentials or direct Windows Runtime API calls) to store keys securely.
• File Storage: Always use cordova.file.dataDirectory—this is a private directory only accessible to your app, preventing unauthorized access.
• Testing: Test encryption/decryption flows on physical Windows devices (not just emulators) to ensure full compatibility.

内容的提问来源于stack exchange，提问作者Ronit Roy