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SCEE-Node.js
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SCEE-Node.js
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const crypto = require("crypto");
const ALGORITHM_NAME = "aes-128-gcm";
const ALGORITHM_NONCE_SIZE = 12;
const ALGORITHM_TAG_SIZE = 16;
const ALGORITHM_KEY_SIZE = 16;
const PBKDF2_NAME = "sha256";
const PBKDF2_SALT_SIZE = 16;
const PBKDF2_ITERATIONS = 32767;
function encryptString(plaintext, password) {
// Generate a 128-bit salt using a CSPRNG.
let salt = crypto.randomBytes(PBKDF2_SALT_SIZE);
// Derive a key using PBKDF2.
let key = crypto.pbkdf2Sync(Buffer.from(password, "utf8"), salt, PBKDF2_ITERATIONS, ALGORITHM_KEY_SIZE, PBKDF2_NAME);
// Encrypt and prepend salt.
let ciphertextAndNonceAndSalt = Buffer.concat([ salt, encrypt(Buffer.from(plaintext, "utf8"), key) ]);
// Return as base64 string.
return ciphertextAndNonceAndSalt.toString("base64");
}
function decryptString(base64CiphertextAndNonceAndSalt, password) {
// Decode the base64.
let ciphertextAndNonceAndSalt = Buffer.from(base64CiphertextAndNonceAndSalt, "base64");
// Create buffers of salt and ciphertextAndNonce.
let salt = ciphertextAndNonceAndSalt.slice(0, PBKDF2_SALT_SIZE);
let ciphertextAndNonce = ciphertextAndNonceAndSalt.slice(PBKDF2_SALT_SIZE);
// Derive the key using PBKDF2.
let key = crypto.pbkdf2Sync(Buffer.from(password, "utf8"), salt, PBKDF2_ITERATIONS, ALGORITHM_KEY_SIZE, PBKDF2_NAME);
// Decrypt and return result.
return decrypt(ciphertextAndNonce, key).toString("utf8");
}
function encrypt(plaintext, key) {
// Generate a 96-bit nonce using a CSPRNG.
let nonce = crypto.randomBytes(ALGORITHM_NONCE_SIZE);
// Create the cipher instance.
let cipher = crypto.createCipheriv(ALGORITHM_NAME, key, nonce);
// Encrypt and prepend nonce.
let ciphertext = Buffer.concat([ cipher.update(plaintext), cipher.final() ]);
return Buffer.concat([ nonce, ciphertext, cipher.getAuthTag() ]);
}
function decrypt(ciphertextAndNonce, key) {
// Create buffers of nonce, ciphertext and tag.
let nonce = ciphertextAndNonce.slice(0, ALGORITHM_NONCE_SIZE);
let ciphertext = ciphertextAndNonce.slice(ALGORITHM_NONCE_SIZE, ciphertextAndNonce.length - ALGORITHM_TAG_SIZE);
let tag = ciphertextAndNonce.slice(ciphertext.length + ALGORITHM_NONCE_SIZE);
// Create the cipher instance.
let cipher = crypto.createDecipheriv(ALGORITHM_NAME, key, nonce);
// Decrypt and return result.
cipher.setAuthTag(tag);
return Buffer.concat([ cipher.update(ciphertext), cipher.final() ]);
}