const crypto = require('crypto');
const zlib = require('zlib');
const { promisify } = require('util');
-const common = require('./common');
+const { MysteryBoxError } = require('./errors');
const allVersions = require('./version-parameters');
const { performance } = require('perf_hooks');
const { name: packageName, version: packageVersion } = require('../package.json');
const deflateRawAsync = promisify(zlib.deflateRaw);
const inflateRawAsync = promisify(zlib.inflateRaw);
const scryptAsync = promisify(crypto.scrypt);
+const randomBytesAsync = promisify(crypto.randomBytes);
/**
* Only you will know what's inside your...
const payloadFlagsMask = (availableFlags.BufferPayload);
const payloadFlagsShift = 7;
-
class MysteryBox extends EventEmitter {
/**
- * @param {Object} options
- * @param {String|String[]} options.encryptionSecret - if an array, will always encrypt with first secret, will attempt to decrypt with all; useful for rolling secrets
- * @param {Number=} options.defaultFlags
+ * @param {object} options options
+ * @param {string|string[]} options.encryptionSecret if an array, will always encrypt with first secret, will attempt to decrypt with all; useful for rolling secrets
+ * @param {number=} options.defaultFlags default flags to use when packing boxes
+ * @param {any[]} args passed on to EventEmitter constructor
*/
constructor(options = {}, ...args) {
super(...args);
- this.secrets = common.ensureArray(options.encryptionSecret);
+ this.secrets = MysteryBox._ensureArray(options.encryptionSecret);
if (!this.secrets.length) {
- throw new Error('missing encryption secret');
+ throw new MysteryBoxError('missing encryption secret');
}
// Filter any unavailable algorithms
// Default to highest
this.bestVersion = Number(Object.keys(this.versionParameters).sort().pop());
if (Number.isNaN(this.bestVersion)) {
- throw new Error('no supported versions available');
+ throw new MysteryBoxError('no supported versions available');
}
this.Flags = availableFlags;
this.defaultFlags = 'defaultFlags' in options ? options.defaultFlags : availableFlags.Flate;
if (this.defaultFlags < 0 || this.defaultFlags > 255) {
- throw new RangeError('Invalid default flag value');
+ throw new MysteryBoxError('Invalid default flag value');
+ }
+ }
+
+
+ /**
+ * Return an array containing x if x is something and not an array
+ * @param {*} x thing to ensure is an array
+ * @returns {any[]} thing array or thing in an array
+ */
+ static _ensureArray(x) {
+ if (x === undefined) {
+ return [];
+ }
+ if (!Array.isArray(x)) {
+ return Array(x);
}
+ return x;
}
/**
* Parse the bits out of the flags.
+ * @param {number} flags flags
+ * @returns {object} decoded flags
*/
static _decodeFlags(flags) {
return {
/**
* Generate key data.
+ * @param {string} deriver key deriver enum
+ * @param {Buffer} secret secret
+ * @param {Buffer} salt salt
+ * @param {number} keyBytes bytes in key
+ * @returns {Promise<Buffer>} key
*/
static async _keyFromSecret(deriver, secret, salt, keyBytes) {
switch (deriver) {
return scryptAsync(secret, salt, keyBytes);
default:
- throw new RangeError('unsupported key deriver');
+ throw new MysteryBoxError('unsupported key deriver');
}
}
/**
* Return bits and bit mask for given number of encoded bytes.
- * @param {Number} numBytes
- * @returns {Object}
+ * @param {number} numBytes number of bytes
+ * @returns {object} bits value and mask
*/
static _versionHeaderBits(numBytes) {
// Round up to 8 bits in result, just to be proper.
* Number of packed bytes is indicated by location of first leading 0 bit.
* Support for numbers larger than 127 is of dubious practicality, but here
* it is anyhow.
- * @param {Number} firstByte
- * @returns {Object}
+ * @param {number} firstByte first byte contains encoded byte length
+ * @returns {object} number of bytes and masked first byte
*/
static _versionHeaderDecode(firstByte) {
for (let numBytes = 1; numBytes <= 8; numBytes++) {
}
}
// Nine bytes would be an extravagence.
- throw new RangeError(`unsupported version header (0x${firstByte.toString(16)})`);
+ throw new MysteryBoxError(`unsupported version header (0x${firstByte.toString(16)})`);
}
* many total bytes comprise the version, in big-endian encoding.
* Returns decoded version and number of bytes used to decode.
* Only supports up to 6-byte numbers, and of those, only up to 4398046511103.
- * @param {Buffer} buf - N.B. will be mogrified
- * @returns {Object}
+ * @param {Buffer} buf N.B. will be mogrified
+ * @returns {object} decoded version and version byte length
*/
static _versionDecode(buf) {
const headerByte = buf.readUInt8(0);
}
if (versionBytes > 6) {
- throw new RangeError(`unsupported version (${versionBytes} bytes)`);
+ throw new MysteryBoxError(`unsupported version (${versionBytes} bytes)`);
}
// Otherwise, update the masked first byte and parse the rest of the buffer.
/**
* Encode a version identifier into a buffer of a variable number of bytes.
- * @param {Number} version
- * @returns {Object}
+ * @param {number} version version number to encode
+ * @returns {object} encoded version buffer and number of bytes
*/
static _versionEncode(version) {
let versionBytes = 0;
} else if (version <= 0x03ffffffffff) { // 34359738368-4398046511103
versionBytes = 6;
} else {
- throw new RangeError('version too large to encode');
+ throw new MysteryBoxError(`version too large to encode (${version})`);
}
const buffer = Buffer.alloc(versionBytes);
/**
* Stats tracked when packing/unpacking boxes.
- * @returns {Object}
+ * @param {string} method method name generating stats
+ * @returns {object} stats and timings
*/
static _newStats(method) {
return {
/**
* Put contents into a mysterious box.
- * @param {Object|Buffer} contents
- * @param {Number=} version
- * @param {Number=} flags
- * @returns {String}
+ * @param {object|Buffer} contents object or buffer
+ * @param {number=} version version
+ * @param {number=} flags flags
+ * @returns {Promise<string>} encoded contents
*/
async pack(contents, version = this.bestVersion, flags = this.defaultFlags) {
const { stats, timingsMs } = MysteryBox._newStats('pack');
if (!(version in this.versionParameters)) {
- throw new RangeError(`MysteryBox format version ${version} not supported`);
+ throw new MysteryBoxError(`MysteryBox format version ${version} not supported`);
}
// eslint-disable-next-line security/detect-object-injection
const v = this.versionParameters[version];
const { buffer: versionBuffer, versionBytes } = MysteryBox._versionEncode(v.version);
if (versionBytes !== v.versionBytes) {
- throw new Error('internal inconsistency, mismatched version byte length');
+ throw new MysteryBoxError('internal inconsistency, mismatched version byte length');
}
const [iv, salt] = await Promise.all([
v.ivBytes,
v.saltBytes,
- ].map((b) => common.randomBytesAsync(b)));
+ ].map((b) => randomBytesAsync(b)));
timingsMs.preCompress = performance.now();
let compressedContents;
break;
}
stats.compressedBytes = Buffer.byteLength(compressedContents);
- // const compressionRatio = stats.compressedBytes / stats.serializedBytes;
timingsMs.postCompress = timingsMs.preCrypt = performance.now();
let payload;
/**
* Take contents out of a mysterious box.
- * @param {String} box - Base64URL encoded payload
- * @returns {Object}
+ * @param {string} box - Base64URL encoded payload
+ * @returns {Promise<object|Buffer>} decoded contents
*/
async unpack(box) {
const { stats, timingsMs } = MysteryBox._newStats('unpack');
if (!box) {
- throw new RangeError('nothing to unpack');
+ throw new MysteryBoxError('nothing to unpack');
}
const raw = Buffer.from(box, 'base64url');
const { version, versionBytes } = MysteryBox._versionDecode(raw);
if (!(version in this.versionParameters)) {
- throw new RangeError('unsupported version');
+ throw new MysteryBoxError(`unsupported version (${version})`);
}
// eslint-disable-next-line security/detect-object-injection
const v = this.versionParameters[version];
if (v.versionBytes !== versionBytes) {
- throw new Error('internal inconsistency, mismatched version byte length');
+ throw new MysteryBoxError('internal inconsistency, mismatched version byte length');
}
offset += v.versionBytes;
stats.version = version;
const minBytes = v.versionBytes + v.flagsBytes + v.ivBytes + v.saltBytes + v.tagBytes;
if (raw.length < minBytes) {
- throw new RangeError('not enough to unpack');
+ throw new MysteryBoxError('not enough to unpack');
}
const flags = raw.subarray(offset, offset + v.flagsBytes).readUInt8(0);
/**
* Pretty-print flag values
- * @param {Number} flags
- * @returns {String}
+ * @param {number} flags flags
+ * @returns {string} pretty flags
*/
_prettyFlags(flags) {
const flagNames = Object.entries(this.Flags).reduce((acc, cur) => {
/**
* Everyone loves numbers.
- * @param {Object} timingsMs
- * @returns
+ * @param {object} timingsMs raw timings
+ * @param {number} timingsMs.start start
+ * @param {number} timingsMs.preCompress checkpoint
+ * @param {number} timingsMs.postCompress checkpoint
+ * @param {number} timingsMs.preCrypt checkpoint
+ * @param {number} timingsMs.postCrypt checkpoint
+ * @param {number} timingsMs.end checkpoint
+ * @returns {object} computed timings
*/
static _timingsLog({ start, preCompress, postCompress, preCrypt, postCrypt, end }) {
return {
}
-module.exports = MysteryBox;
\ No newline at end of file
+module.exports = MysteryBox;
projects / squeep-mystery-box / blobdiff