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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 290x 289x 288x 288x 288x 288x 287x 286x 286x 285x 284x 284x 284x 283x 282x 281x 281x 281x 280x 280x 280x 518x 517x 516x 515x 514x 513x 512x 511x 273x 272x 272x 272x 272x 272x 272x 272x 272x 509x 509x 509x 509x 509x 509x 509x 509x 509x 272x 272x 424x 272x 424x 272x 272x 1x | /** * @file Multi-factor Derived Key Setup * @copyright Multifactor 2022 All Rights Reserved * * @description * Validate and setup a configuration for a multi-factor derived key * * @author Vivek Nair (https://nair.me) <[email protected]> */ const defaults = require('../defaults') const kdfSetup = require('./kdf').kdf const kdf = require('../kdf').kdf const crypto = require('crypto') const { v4: uuidv4 } = require('uuid') const { hkdf } = require('@panva/hkdf') const share = require('../secrets/share').share const xor = require('buffer-xor') const MFKDFDerivedKey = require('../classes/MFKDFDerivedKey') /** * Validate and setup a configuration for a multi-factor derived key * * @example * // setup 16 byte 2-of-3-factor multi-factor derived key with a password, HOTP code, and UUID recovery code * const setup = await mfkdf.setup.key([ * await mfkdf.setup.factors.password('password'), * await mfkdf.setup.factors.hotp({ secret: Buffer.from('hello world') }), * await mfkdf.setup.factors.uuid({ id: 'recovery', uuid: '9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d' }) * ], {threshold: 2, size: 16}) * * // derive key using 2 of the 3 factors * const derive = await mfkdf.derive.key(setup.policy, { * password: mfkdf.derive.factors.password('password'), * hotp: mfkdf.derive.factors.hotp(365287) * }) * * setup.key.toString('hex') // -> 34d20ced439ec2f871c96ca377f25771 * derive.key.toString('hex') // -> 34d20ced439ec2f871c96ca377f25771 * * @param {Array.<MFKDFFactor>} factors - Array of factors used to derive this key * @param {Object} [options] - Configuration options * @param {string} [options.id] - Unique identifier for this key; random UUIDv4 generated by default * @param {number} [options.size=32] - Size of derived key, in bytes * @param {number} [options.threshold] - Number of factors required to derive key; factors.length by default (all required) * @param {Buffer} [options.salt] - Cryptographic salt; generated via secure PRG by default (recommended) * @param {string} [options.kdf='argon2id'] - KDF algorithm to use; hkdf, pbkdf2, bcrypt, scrypt, argon2i, argon2d, or argon2id * @param {string} [options.hkdfdigest='sha256'] - Hash function to use if using hkdf; one of sha1, sha256, sha384, or sha512 * @param {number} [options.pbkdf2rounds=310000] - Number of rounds to use if using pbkdf2 * @param {string} [options.pbkdf2digest='sha256'] - Hash function to use if using pbkdf2; one of sha1, sha256, sha384, or sha512 * @param {number} [options.bcryptrounds=10] - Number of rounds to use if using bcrypt * @param {number} [options.scryptcost=16384] - Iterations count (N) to use if using scrypt * @param {number} [options.scryptblocksize=8] - Block size (r) to use if using scrypt * @param {number} [options.scryptparallelism=1] - Parallelism factor (p) to use if using scrypt * @param {number} [options.argon2time=2] - Iterations to use if using argon2 * @param {number} [options.argon2mem=24576] - Memory to use if using argon2 * @param {number} [options.argon2parallelism=1] - Parallelism to use if using argon2 * @returns {MFKDFDerivedKey} A multi-factor derived key object * @author Vivek Nair (https://nair.me) <[email protected]> * @since 0.8.0 * @async * @memberOf setup */ async function key (factors, options) { if (!Array.isArray(factors)) throw new TypeError('factors must be an array') if (factors.length === 0) throw new RangeError('factors must not be empty') options = Object.assign(Object.assign({}, defaults.key), options) const policy = { $schema: 'https://mfkdf.com/schema/v1.0.0/policy.json' } // id if (options.id === undefined) options.id = uuidv4() if (typeof options.id !== 'string') throw new TypeError('id must be a string') if (options.id.length === 0) throw new RangeError('id must not be empty') policy.$id = options.id // size if (!Number.isInteger(options.size)) throw new TypeError('key size must be an integer') if (!(options.size > 0)) throw new RangeError('key size must be positive') policy.size = options.size // threshold if (options.threshold === undefined) options.threshold = factors.length if (!Number.isInteger(options.threshold)) throw new TypeError('threshold must be an integer') if (!(options.threshold > 0)) throw new RangeError('threshold must be positive') if (!(options.threshold <= factors.length)) throw new RangeError('threshold cannot be greater than number of factors') policy.threshold = options.threshold // salt if (options.salt === undefined) options.salt = crypto.randomBytes(policy.size) if (!(Buffer.isBuffer(options.salt))) throw new TypeError('salt must be a buffer') policy.salt = options.salt.toString('base64') // kdf policy.kdf = kdfSetup(options) // check factor correctness for (const factor of factors) { // type if (typeof factor.type !== 'string') throw new TypeError('factor type must be a string') if (factor.type.length === 0) throw new RangeError('factor type must not be empty') // id if (typeof factor.id !== 'string') throw new TypeError('factor id must be a string') if (factor.id.length === 0) throw new RangeError('factor id must not be empty') // data if (!Buffer.isBuffer(factor.data)) throw new TypeError('factor data must be a buffer') if (factor.data.length === 0) throw new RangeError('factor data must not be empty') // params if (typeof factor.params !== 'function') throw new TypeError('factor params must be a function') } // id uniqueness const ids = factors.map(factor => factor.id) if ((new Set(ids)).size !== ids.length) throw new RangeError('factor ids must be unique') // generate secret key material const secret = crypto.randomBytes(policy.size) const key = await kdf(secret, Buffer.from(policy.salt, 'base64'), policy.size, policy.kdf) const shares = share(secret, policy.threshold, factors.length) // process factors policy.factors = [] const outputs = {} const theoreticalEntropy = [] const realEntropy = [] for (const [index, factor] of factors.entries()) { // stretch to key length via HKDF/SHA-512 const share = shares[index] theoreticalEntropy.push(factor.data.byteLength * 8) realEntropy.push(factor.entropy) let stretched = Buffer.from(await hkdf('sha512', factor.data, '', '', policy.size)) if (Buffer.byteLength(share) > policy.size) stretched = Buffer.concat([Buffer.alloc(Buffer.byteLength(share) - policy.size), stretched]) const pad = xor(share, stretched) const params = await factor.params({ key }) outputs[factor.id] = await factor.output() policy.factors.push({ id: factor.id, type: factor.type, pad: pad.toString('base64'), params }) } const result = new MFKDFDerivedKey(policy, key, secret, shares, outputs) theoreticalEntropy.sort((a, b) => a - b) const theoretical = theoreticalEntropy.slice(0, policy.threshold).reduce((a, b) => a + b, 0) realEntropy.sort((a, b) => a - b) const real = realEntropy.slice(0, policy.threshold).reduce((a, b) => a + b, 0) result.entropyBits = { theoretical: Math.min(policy.size * 8, theoretical), real: Math.min(policy.size * 8, real) } return result } module.exports.key = key |