Implementation for generating short, human-readable and pronounceable random strings from integers, and back again.

proquint.ts

// Proquint implementation based on https://arxiv.org/html/0901.4016

const uint2consonant: string[] = [
  'b',
  'd',
  'f',
  'g',
  'h',
  'j',
  'k',
  'l',
  'm',
  'n',
  'p',
  'r',
  's',
  't',
  'v',
  'z',
];

const uint2vowel: string[] = ['a', 'i', 'o', 'u'];

const MASK_FIRST4 = 0xf0000000;
const MASK_FIRST2 = 0xc0000000;

function quint2hex(inp: string): string {
  let ret = 'x';
  let remaining = inp;
  while (remaining.length > 0) {
    let current = remaining.substring(0, 11);
    if (
      !current.match(/^[bdfghjklmnprstvzaiou]{5}-[bdfghjklmnprstvzaiou]{5}$/)
    ) {
      console.error(
        'bad quint format detected. expected format cvcvc-cvcvc - found: ' +
          current
      );
      throw 'bad quint format for: ' + inp;
    }
    if (remaining.length > 12) remaining = remaining.substring(12);
    else remaining = remaining.substring(11);
    let currentHex = quint2uint(current).toString(16);
    while (currentHex.length < 8) currentHex = '0' + currentHex;
    ret += currentHex;
  }
  return ret;
}

function hex2quint(hex: string): string {
  let sep = '-';
  let ret = '';
  if (!hex.match(/^x(([0-9a-f]{2}){2})+$/)) {
    console.error('Bad hex length: ' + hex.length);
    throw 'Bad hex length: ' + hex.length;
  }
  let remaining = hex.substring(1); //skip x
  while (remaining.length > 0) {
    if (remaining.length < 8 && remaining.length % 8 != 0) {
      console.error('Bad hex length: ' + remaining.length);
      throw 'Bad hex length: ' + hex;
    }
    let current = remaining.substring(0, 8);
    remaining = remaining.substring(8);
    let currentQuint = uint2quint(parseInt(current, 16) >> 0);
    ret += currentQuint;
    if (sep) ret += sep;
  }
  if (ret.endsWith(sep)) ret = ret.substring(0, ret.length - sep.length);
  return ret;
}

var crypto = require('crypto');
export function getRandom32UInt() {
  return crypto.randomBytes(4).readUInt32BE(0, true);
}

// 32 bits of entropy, add more quints to get to more
export function uint2quint(i: number): string {
  let j: number;
  let quint = '';

  j = i & MASK_FIRST4;
  i <<= 4;
  j >>>= 28;
  quint += uint2consonant[j];
  j = i & MASK_FIRST2;
  i <<= 2;
  j >>>= 30;
  quint += uint2vowel[j];
  j = i & MASK_FIRST4;
  i <<= 4;
  j >>>= 28;
  quint += uint2consonant[j];
  j = i & MASK_FIRST2;
  i <<= 2;
  j >>>= 30;
  quint += uint2vowel[j];
  j = i & MASK_FIRST4;
  i <<= 4;
  j >>>= 28;
  quint += uint2consonant[j];

  quint += '-';

  j = i & MASK_FIRST4;
  i <<= 4;
  j >>>= 28;
  quint += uint2consonant[j];
  j = i & MASK_FIRST2;
  i <<= 2;
  j >>>= 30;
  quint += uint2vowel[j];
  j = i & MASK_FIRST4;
  i <<= 4;
  j >>>= 28;
  quint += uint2consonant[j];
  j = i & MASK_FIRST2;
  i <<= 2;
  j >>>= 30;
  quint += uint2vowel[j];
  j = i & MASK_FIRST4;
  i <<= 4;
  j >>>= 28;
  quint += uint2consonant[j];
  return quint;
}

export function quint2uint(quint: string): number {
  let res = 0;
  let remaining = quint.length;
  let i = 0;
  while (remaining > 0) {
    let c = quint[i++];
    remaining--;
    switch (c) {
      /* consonants */
      case 'b':
        res <<= 4;
        res += 0;
        break;
      case 'd':
        res <<= 4;
        res += 1;
        break;
      case 'f':
        res <<= 4;
        res += 2;
        break;
      case 'g':
        res <<= 4;
        res += 3;
        break;

      case 'h':
        res <<= 4;
        res += 4;
        break;
      case 'j':
        res <<= 4;
        res += 5;
        break;
      case 'k':
        res <<= 4;
        res += 6;
        break;
      case 'l':
        res <<= 4;
        res += 7;
        break;

      case 'm':
        res <<= 4;
        res += 8;
        break;
      case 'n':
        res <<= 4;
        res += 9;
        break;
      case 'p':
        res <<= 4;
        res += 10;
        break;
      case 'r':
        res <<= 4;
        res += 11;
        break;

      case 's':
        res <<= 4;
        res += 12;
        break;
      case 't':
        res <<= 4;
        res += 13;
        break;
      case 'v':
        res <<= 4;
        res += 14;
        break;
      case 'z':
        res <<= 4;
        res += 15;
        break;

      /* vowels */
      case 'a':
        res <<= 2;
        res += 0;
        break;
      case 'i':
        res <<= 2;
        res += 1;
        break;
      case 'o':
        res <<= 2;
        res += 2;
        break;
      case 'u':
        res <<= 2;
        res += 3;
        break;

      /* separators */
      default:
        break;
    }
  }
  return res >>> 0; //the unsigned right shift fixes signed int issue - http://stackoverflow.com/a/17106974/1777150
}