persistent-storage/dist/crypto.js

Abstracts access to any storage object implementing the webstorage Storage interface, offering optional compression using lz-string and optional encryption using crypto

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var crypto = require('crypto');
function generateSalt(lengthBytes) {
    return crypto.randomBytes(lengthBytes).toString('hex');
}
exports.generateSalt = generateSalt;
function generateIV(lengthBytes) {
    return crypto.randomBytes(lengthBytes);
}
exports.generateIV = generateIV;
var KeyDerivationOptions = (function () {
    function KeyDerivationOptions(opts) {
        this.salt = '';
        this.iterations = 10;
        this.derivedKeyLength = 16;
        this.digest = 'sha512';
        this.password = opts.password;
        this.salt = opts.salt || this.salt;
        this.iterations = opts.iterations || this.iterations;
        this.derivedKeyLength = opts.derivedKeyLength || this.derivedKeyLength;
        this.digest = opts.digest || this.digest;
    }
    return KeyDerivationOptions;
}());
exports.KeyDerivationOptions = KeyDerivationOptions;
function deriveEncryptionKey(options) {
    return crypto.pbkdf2Sync(options.password, options.salt, options.iterations, options.derivedKeyLength, options.digest).toString('hex');
}
exports.deriveEncryptionKey = deriveEncryptionKey;
function encryptUtf8(str, options) {
    return encrypt(str, 'utf8', options);
}
exports.encryptUtf8 = encryptUtf8;
function encryptUcs2(str, options) {
    return encrypt(str, 'ucs2', options);
}
exports.encryptUcs2 = encryptUcs2;
function decryptUtf8(str, options) {
    return decrypt(str, 'utf8', options);
}
exports.decryptUtf8 = decryptUtf8;
function decryptUcs2(str, options) {
    return decrypt(str, 'ucs2', options);
}
exports.decryptUcs2 = decryptUcs2;
var MIN_CHUNK_SIZE = 32;
var chunkSize = 512;
function encrypt(str, srcEncoding, options) {
    var cipher = crypto.createCipheriv(options.algorithm, options.key, options.iv);
    var result = '', elapsed = 0, chunkStart = 0, chunk;
    while (str.length > 0) {
        if (chunkStart) {
            //only want to adapt the chunkSize if we are processing something bigger than a single chunk
            if (elapsed > 5 && chunkSize > MIN_CHUNK_SIZE) {
                chunkSize /= 2;
            }
            else if (elapsed === 0) {
                chunkSize *= 2;
            }
        }
        chunkStart = Date.now();
        chunk = str.slice(0, chunkSize);
        str = str.slice(chunkSize);
        result += cipher.update(chunk, srcEncoding).toString('ucs2');
        elapsed = Date.now() - chunkStart;
    }
    return result + cipher.final().toString('ucs2');
}
function decrypt(str, destEncoding, options) {
    var decipher = crypto.createDecipheriv(options.algorithm, options.key, options.iv);
    var result = '', elapsed = 0, chunkStart = 0, chunk;
    while (str.length > 0) {
        if (chunkStart) {
            //only want to adapt the chunkSize if we are processing something bigger than a single chunk
            if (elapsed > 5 && chunkSize > MIN_CHUNK_SIZE) {
                chunkSize /= 2;
            }
            else if (elapsed === 0) {
                chunkSize *= 2;
            }
        }
        chunkStart = Date.now();
        chunk = str.slice(0, chunkSize);
        str = str.slice(chunkSize);
        result += decipher.update(chunk, 'ucs2', destEncoding);
        elapsed = Date.now() - chunkStart;
    }
    return result + decipher.final(destEncoding);
}
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