freehold
Version:
App data encryption for web3
250 lines (249 loc) • 14.9 kB
JavaScript
"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
var __generator = (this && this.__generator) || function (thisArg, body) {
var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
function verb(n) { return function (v) { return step([n, v]); }; }
function step(op) {
if (f) throw new TypeError("Generator is already executing.");
while (_) try {
if (f = 1, y && (t = op[0] & 2 ? y["return"] : op[0] ? y["throw"] || ((t = y["return"]) && t.call(y), 0) : y.next) && !(t = t.call(y, op[1])).done) return t;
if (y = 0, t) op = [op[0] & 2, t.value];
switch (op[0]) {
case 0: case 1: t = op; break;
case 4: _.label++; return { value: op[1], done: false };
case 5: _.label++; y = op[1]; op = [0]; continue;
case 7: op = _.ops.pop(); _.trys.pop(); continue;
default:
if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
if (t[2]) _.ops.pop();
_.trys.pop(); continue;
}
op = body.call(thisArg, _);
} catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
}
};
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
var bytes_1 = require("@ethersproject/bytes");
var strings_1 = require("@ethersproject/strings");
var webcrypto_liner_1 = __importDefault(require("webcrypto-liner"));
var crypto;
if (typeof webcrypto_liner_1.default === "undefined") {
crypto = require("crypto").webcrypto;
}
var FreeholdSigner = /** @class */ (function () {
function FreeholdSigner(encrypt, decrypt) {
this._encrypt = encrypt;
this._decrypt = decrypt;
}
FreeholdSigner.prototype.encrypt = function (plaintext) {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
return [2 /*return*/, this._encrypt(plaintext)];
});
});
};
FreeholdSigner.prototype.decrypt = function (cipherText) {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
return [2 /*return*/, this._decrypt(cipherText)];
});
});
};
return FreeholdSigner;
}());
function __createSignerObject(secretKey) {
return __awaiter(this, void 0, void 0, function () {
var enc, seed, masterKey;
var _this = this;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
enc = new TextEncoder();
seed = Buffer.concat([
enc.encode(secretKey),
//crypto.getRandomValues(new Uint8Array(16))
]);
return [4 /*yield*/, crypto.subtle.importKey("raw", seed, "PBKDF2", false, ["deriveBits", "deriveKey"])
// Just for good measure. Keep the raw data out of scope.
];
case 1:
masterKey = _a.sent();
// Just for good measure. Keep the raw data out of scope.
secretKey = undefined;
return [2 /*return*/, new FreeholdSigner(function (plaintext) { return __awaiter(_this, void 0, void 0, function () {
var iv, salt, key, ct, ctBuffer;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
iv = crypto.getRandomValues(new Uint8Array(12));
salt = crypto.getRandomValues(new Uint8Array(16));
return [4 /*yield*/, crypto.subtle.deriveKey({
name: "PBKDF2",
salt: salt,
iterations: 100000,
hash: "SHA-256"
}, masterKey, { name: "AES-GCM", length: 256 }, false, ["encrypt"])
// Encrypt the plaintext via AES using the key and the iv
];
case 1:
key = _a.sent();
return [4 /*yield*/, crypto.subtle.encrypt({
name: "AES-GCM",
iv: iv
}, key, enc.encode(plaintext))
// Convert result to buffer
];
case 2:
ct = _a.sent();
ctBuffer = Buffer.from(ct);
// Return a base64url encoded string that includes both the iv, salt, and
// cipher text. This makes the data easy to store and pass around.
return [2 /*return*/, Buffer.concat([
iv,
salt,
ctBuffer
]).toString("base64url")];
}
});
}); }, function (cipherText) { return __awaiter(_this, void 0, void 0, function () {
var data, iv, salt, key, ciphertext, plainBuffer, e_1;
return __generator(this, function (_a) {
switch (_a.label) {
case 0:
data = Buffer.from(cipherText, "base64url");
iv = data.subarray(0, 12);
salt = data.subarray(12, 28);
return [4 /*yield*/, crypto.subtle.deriveKey({
name: "PBKDF2",
salt: salt,
iterations: 100000,
hash: "SHA-256"
}, masterKey, { name: "AES-GCM", length: 256 }, false, ["decrypt"])
// Get the remaining bytes of the cipher text as the encrypted data
];
case 1:
key = _a.sent();
ciphertext = data.subarray(28);
_a.label = 2;
case 2:
_a.trys.push([2, 4, , 5]);
return [4 /*yield*/, crypto.subtle.decrypt({ name: 'AES-GCM', iv: iv }, key, ciphertext)
// And convert back to string.
];
case 3:
plainBuffer = _a.sent();
// And convert back to string.
return [2 /*return*/, new TextDecoder().decode(plainBuffer)];
case 4:
e_1 = _a.sent();
throw new Error('Decrypt failed: ' + typeof e_1.message !== "undefined" ? e_1.message : e_1);
case 5: return [2 /*return*/];
}
});
}); })];
}
});
});
}
function __createSigner(provider, address, fragmentData) {
return __awaiter(this, void 0, void 0, function () {
var _this = this;
return __generator(this, function (_a) {
return [2 /*return*/, (function () { return __awaiter(_this, void 0, void 0, function () {
var toSign, _i, toSign_1, fragment, _a, _b, _c, _d;
var _this = this;
return __generator(this, function (_e) {
switch (_e.label) {
case 0:
toSign = JSON.parse(fragmentData);
// Make sure it's an array
if (!Array.isArray(toSign)) {
toSign = [toSign];
}
_i = 0, toSign_1 = toSign;
_e.label = 1;
case 1:
if (!(_i < toSign_1.length)) return [3 /*break*/, 4];
fragment = toSign_1[_i];
if (!(fragment.type == "password")) return [3 /*break*/, 3];
_a = fragment;
_c = (_b = Buffer).from;
return [4 /*yield*/, crypto.subtle.digest('SHA-256', new TextEncoder().encode(fragment.data))];
case 2:
_a.data = _c.apply(_b, [_e.sent()]).toString("hex");
_e.label = 3;
case 3:
_i++;
return [3 /*break*/, 1];
case 4:
_d = __createSignerObject;
return [4 /*yield*/, toSign.map(function (fragment) { return __awaiter(_this, void 0, void 0, function () {
var _a;
return __generator(this, function (_b) {
switch (_b.label) {
case 0:
_a = [fragment];
return [4 /*yield*/, provider.send('personal_sign', [
(0, bytes_1.hexlify)((0, strings_1.toUtf8Bytes)(fragment.data)),
address
])];
case 1: return [2 /*return*/, _a.concat([
(_b.sent()).replace("0x", "")
])];
}
});
}); }).reduce(function (key, tuple) { return __awaiter(_this, void 0, void 0, function () {
var _a, _b;
return __generator(this, function (_c) {
switch (_c.label) {
case 0: return [4 /*yield*/, key];
case 1:
_a = (_c.sent());
return [4 /*yield*/, tuple];
case 2:
_b = _a + (_c.sent())[1];
return [4 /*yield*/, tuple];
case 3:
// Add on the unsigned data + signature for this fragment.
return [2 /*return*/, _b + (_c.sent())[0].data];
}
});
}); }, Promise.resolve(""))];
case 5:
// We try really hard to leave as little data at rest as possible
// e.g., we don't store signed messages in memory for very long
return [2 /*return*/, _d.apply(void 0, [_e.sent()])];
}
});
}); })()];
});
});
}
;
function freehold(provider, address, toSign) {
return __awaiter(this, void 0, void 0, function () {
return __generator(this, function (_a) {
// We call a private signer just to be extra careful.
// We stringify the input becasue we don't want to hold a
// a reference to the original data.
return [2 /*return*/, __createSigner(provider, address, JSON.stringify(toSign))];
});
});
}
exports.default = freehold;