micro-key-producer

Produces secure passwords & keys for WebCrypto, SSH, PGP, SLIP10, OTP and many others.

• 🔓 Secure: audited noble cryptography
• 🔻 Tree-shakeable: unused code is excluded from your builds
• 🎲 Create deterministic (known) or random keys
• 🔑 SSH, PGP, TOR, IPNS, SLIP10, BLS12-381 ETH keys
• 💾 WebCrypto-compatible JWK, DER, PKCS#8, SPKI converter
• 🔗 gpgkp(1): Sign git commits without gnupg
• 📟 Generate secure passwords & OTP 2FA codes

Used in: terminal7 WebRTC terminal multiplexer.

Usage

npm install micro-key-producer

jsr add jsr:@paulmillr/micro-key-producer

import ssh from 'micro-key-producer/ssh.js';
import pgp from 'micro-key-producer/pgp.js';
import slip10 from 'micro-key-producer/slip10.js';
import * as webconv from 'micro-key-producer/convert.js';
import ipns from 'micro-key-producer/ipns.js';
import tor from 'micro-key-producer/tor.js';
import { createDerivedEIP2334Keystores } from 'micro-key-producer/bls.js';
import { secureMask } from 'micro-key-producer/password.js';
import { hotp, totp } from 'micro-key-producer/otp.js';

import { randomBytes } from 'micro-key-producer/utils.js';

• Usage
  • Key generation: deterministic vs random seeds
  • ssh: ed25519 keys
  • pgp: ed25519 keys
    • gpgkp(1): Sign git commits without gnupg
  • slip10: bip32-like ed25519 keys
  • convert: key converter for JWK, DER, PKCS, SPKI
  • tor: keys and addresses
  • ipns: addresses
  • bls: keys for ETH validators
  • password: secure passwords with masks
  • otp: 2FA HOTP and TOTP codes
• Internals
  • PGP key generation
  • Password generation
    • Bruteforce estimation and ZXCVBN score
    • Mask control characters
    • Design rationale
    • What do we want from passwords?
  • SLIP10 API
• License

Key generation: deterministic vs random seeds

Every method takes a seed (key), from which the formatted result is produced.

A seed can be deterministic (a.k.a. known - it will always produce the same result), or random.

// known: (deterministic) Uses known mnemonic (handled in separate package)
import { mnemonicToSeedSync } from '@scure/bip39';
const mnemonic = 'letter advice cage absurd amount doctor acoustic avoid letter advice cage above';
const knownSeed = mnemonicToSeedSync(mnemonic, '');

// random: Uses system's CSPRNG to produce new random seed
import { randomBytes } from 'micro-key-producer/utils.js';
const randSeed = randomBytes(32);

ssh: ed25519 keys

import ssh from 'micro-key-producer/ssh.js';
import { randomBytes } from 'micro-key-producer/utils.js';

const seed = randomBytes(32);
const key = ssh(seed, '[email protected]');
console.log(key.fingerprint, key.privateKey, key.publicKey);
// SHA256:3M832z6j5R6mQh4TTzVG5KVs2Ibvy...
// -----BEGIN OPENSSH PRIVATE KEY----- ...
// ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAA...

pgp: ed25519 keys

import pgp, { getKeyId } from 'micro-key-producer/pgp.js';
import { randomBytes } from 'micro-key-producer/utils.js';

const seed = randomBytes(32);
const email = '[email protected]';
const pass = 'password';
const createdAt = Date.now(); // optional; timestamp >= 0. 0 is 1970-01-01 00:00:00

const keyId = getKeyId(seed);
const key = pgp(seed, email, pass, createdAt);
console.log(key.fingerprint, key.privateKey, key.publicKey);
// ca88e2a8afd9cdb8
// -----BEGIN PGP PRIVATE KEY BLOCK-----...
// -----BEGIN PGP PUBLIC KEY BLOCK-----...

The PGP (GPG) keys conform to RFC 4880 & RFC 6637. Only ed25519 algorithm is currently supported.

gpgkp(1): Sign git commits without gnupg

git config commit.gpgsign true
git config user.signingkey <KEY_ID>
git config gpg.program <PATH_TO_KEY_PRODUCER>/bin/gpgkp.js

gpgkp binary is installed by the package. You can use it to sign and verify git commits.

slip10: bip32-like ed25519 keys

import slip10 from 'micro-key-producer/slip10.js';
import { randomBytes } from 'micro-key-producer/utils.js';

const seed = randomBytes(32);
const hdkey1 = slip10.fromMasterSeed(seed);

// props
[hdkey1.depth, hdkey1.index, hdkey1.chainCode];
console.log(hdkey2.privateKey, hdkey2.publicKey);
console.log(hdkey3.derive("m/0/2147483647'/1'"));
const sig = hdkey3.sign(hash);
hdkey3.verify(hash, sig);

SLIP10 (ed25519 BIP32) HDKey implementation has been funded by the Kin Foundation for Kinetic.

convert: key converter for JWK, DER, PKCS, SPKI

import { p256 } from '@noble/curves/nist.js';
import { p256_der, p256_jwk, p256_jwk_ecdh } from 'micro-key-producer/convert.js';
const { publicKey, secretKey } = p256.keygen();
console.log(
  secretKey,
  p256_der.secretKey.encode(secretKey),
  p256_der.secretKey.decode(p256_der.secretKey.encode(secretKey)),
  p256_jwk.secretKey.encode(secretKey),
  p256_jwk_ecdh.secretKey.encode(secretKey)
)

The module allows to convert between "raw" noble-curves format and WebCrypto formats (JWK, DER, PKCS, SPKI).

tor: keys and addresses

import tor from 'micro-key-producer/tor.js';
import { randomBytes } from 'micro-key-producer/utils.js';
const seed = randomBytes(32);
const key = tor(seed);
console.log(key.privateKey, key.publicKey);
// ED25519-V3:EOl78M2gA...
// rx724x3oambzxr46pkbd... .onion

ipns: addresses

import ipns from 'micro-key-producer/ipns.js';
import { randomBytes } from 'micro-key-producer/utils.js';
const seed = randomBytes(32);
const k = ipns(seed);
console.log(k.privateKey, k.publicKey, k.base16, k.base32, k.base36, k.contenthash);
// 0x080112400681d6420abb1b...
// 0x017200240801122012c829...
// ipns://f0172002408011220...
// ipns://bafzaajaiaejcaewi...
// ipns://k51qzi5uqu5dgnfwb...
// 0xe501017200240801122012...

bls: EIP-2333 keys for ETH validators

import { mnemonicToSeedSync } from '@scure/bip39';
import { createDerivedEIP2334Keystores } from 'micro-key-producer/bls.js';

const password = 'my_password';
const mnemonic = 'letter advice cage absurd amount doctor acoustic avoid letter advice cage above';
const keyType = 'signing'; // or 'withdrawal'
const indexes = [0, 1, 2, 3]; // create 4 keys

const keystores = createDerivedEIP2334Keystores(
  password
  'scrypt',
  mnemonicToSeedSync(mnemonic, ''),
  keyType,
  indexes
);

Conforms to EIP-2333 / EIP-2334 / EIP-2335. Online demo: eip2333-tool

password: secure passwords with masks

import { mask, secureMask } from 'micro-key-producer/password.js';
import { randomBytes } from '@noble/hashes/utils.js';

const seed = randomBytes(32);
const pass = secureMask.apply(seed).password;
// wivfi1-Zykrap-fohcij, will change on each run
// secureMask is format from iOS keychain, see "Detailed API" section

Supports iOS / macOS Safari Secure Password from Keychain. Optional zxcvbn score for password bruteforce estimation

otp: 2FA HOTP and TOTP codes

import { hotp, totp, parse } from 'micro-key-producer/otp.js';
hotp(parse('ZYTYYE5FOAGW5ML7LRWUL4WTZLNJAMZS'), 0n); // 549419
totp(parse('ZYTYYE5FOAGW5ML7LRWUL4WTZLNJAMZS'), 0); // 549419

Conforms to RFC 6238.

Internals

PGP key generation

1. Generated private and public keys would have different representation, however, their fingerprints would be the same. This is because AES encryption is used to hide the keys, and AES requires different IV / salt.
2. The function is slow (400ms on Apple M4), because it uses S2K to derive keys.
3. "warning: lower 3 bits of the secret key are not cleared" happens even for keys generated with GnuPG 2.3.6, because check looks at item as Opaque MPI, when it is just MPI: see bugtracker URL.

import * as pgp from 'micro-key-producer/pgp';
import { randomBytes } from 'micro-key-producer/utils';
const pseed = randomBytes(32);
pgp.getKeyId(pseed); // fast
const pkeys = pgp.getKeys(pseed, '[email protected]', 'password');
console.log(pkeys.keyId);
console.log(pkeys.privateKey);
console.log(pkeys.publicKey);

// Also, you can explore existing keys internal structure
console.log(pgp.pubArmor.decode(keys.publicKey));
const privDecoded = pgp.privArmor.decode(keys.privateKey);
console.log(privDecoded);
// And receive raw private keys as bigint
console.log({
  ed25519: pgp.decodeSecretKey('password', privDecoded[0].data),
  cv25519: pgp.decodeSecretKey('password', privDecoded[3].data),
});

Password generation

Bruteforce estimation and ZXCVBN score

import { secureMask, mask } from 'micro-key-producer/password.js';
console.log(pwd.secureMask.estimate);

// Output
{
  score: 'somewhat guessable', // ZXCVBN Score
  // Guess times
  guesses: {
    online_throttling: '1y 115mo', // Throttled online attack
    online: '1mo 10d', // Online attack
    // Offline attack (salte, slow hash function like bcrypt, scrypt, PBKDF2, argon, etc)
    slow: '57min 36sec',
    fast: '0 sec' // Offline attack
  },
  // Estimated attack costs (in $)
  costs: {
    luks: 1.536122841572242, // LUKS (Linux FDE)
    filevault2: 0.2308740987992559, // FileVault 2 (macOS FDE)
    macos: 0.03341598798410283, // MaccOS v10.8+ passwords
    pbkdf2: 0.011138662661367609 // PBKDF2 (PBKDF2-HMAC-SHA256)
  }
}

Mask control characters

Mask	Description	Example
1	digits	4, 7, 5, 0
@	symbols	!, @, %, ^
v	vowels	a, e, i
c	consonant	b, c, d
a	letter (vowel or consonant)	a, b, e, c
V	uppercase vowel	A, E, I
C	uppercase consonant	B, C, D
A	uppercase letter	A, B, E, C
l	lower and upper case letters	A, b, C
n	same as 'l', but also digits	A, 1, b, 2, C
*	same as 'n', but also symbols	A, 1, !, b, @
s	syllable (same as 'cv')	ca, re, do
S	Capitalized syllable (same as 'Cv)	Ca, Ti, Je
	All other characters used as is

Examples:

• Mask: Cvccvc-cvccvc-cvccv1 will generate Mavmuq-xadgys-poqsa5
• Mask @Ss-ss-ss will generate: *Tavy-qyjy-vemo

Design rationale

Most strict password rules (so password will be accepted everywhere):

• at least one upper-case character
• at least one lower-case character
• at least one symbol
• at least one digit
• length greater or equal to 8 These rules don't significantly increase password entropy (most humans will use mask like 'Aaaaaa1@' or any other popular mask), but they means that we cannot simple use mask like ********, since it can generate passwords which won't satisfy these rules.

What do we want from passwords?

• length: entering 32 character password for FDE via IPMI java applet on remote server is pretty painful. -> 12-16 probably ok, anything with more characters has chance to be truncated by service.
• readability: entering '!#%!$#Y^&*#%@#!!1' from air-gapped pc is hard.
• entropy:
  • 32 bit is likely to be brutforced via network
  • 64 bit: 22 days && 1.6k$ at 4x V100: https://blog.trailofbits.com/2019/11/27/64-bits-ought-to-be-enough-for-anybody/ but it is simple loop, if there is something like pbkdf before password, it will significantly slowdown everything
  • 80 bits is probably outside of budget for most attackers (btc hash rate) even if there is major speedup for specific algorithm
  • For websites and services we don't care much about entropy, since passwords are unique and there is no re-usage, however for FDE / server password entropy is pretty important
• no fancy and unique mask by default: we don't want to fingeprint users
• any mask will leak eventually (even if user choices personal mask, there will be password leaks from websites), so we cannot calculate entropy by ****** mask, we need to calculate entropy for specific mask (which is smaller).
• Password generator should be reversible, that way we can easily proof entropy/strength of password.

SLIP10 API

SLIP-0010 hierarchical deterministic (HD) wallets for implementation. Based on code from scure-bip32. Check out scure-bip39 if you also need mnemonic phrases.

• SLIP-0010 publicKey is 33 bytes (see this issue), if you want 32-byte publicKey, use .publicKeyRaw getter
• SLIP-0010 vectors fingerprint is actually parentFingerprint
• SLIP-0010 doesn't allow deriving non-hardened keys for Ed25519, however some other libraries treat non-hardened keys (m/0/1) as hardened (m/0'/1'). If you want this behaviour, there is a flag forceHardened in derive method

Note: chainCode property is essentially a private part of a secret "master" key, it should be guarded from unauthorized access.

The full API is:

class HDKey {
  public static HARDENED_OFFSET: number;
  public static fromMasterSeed(seed: Uint8Array | string): HDKey;

  readonly depth: number = 0;
  readonly index: number = 0;
  readonly chainCode: Uint8Array | null = null;
  readonly parentFingerprint: number = 0;
  public readonly privateKey: Uint8Array;

  get fingerprint(): number;
  get fingerprintHex(): string;
  get parentFingerprintHex(): string;
  get pubKeyHash(): Uint8Array;
  get publicKey(): Uint8Array;
  get publicKeyRaw(): Uint8Array;

  derive(path: string, forceHardened = false): HDKey;
  deriveChild(index: number): HDKey;
  sign(hash: Uint8Array): Uint8Array;
  verify(hash: Uint8Array, signature: Uint8Array): boolean;
}

License

MIT (c) Paul Miller (https://paulmillr.com), see LICENSE file.