crypto-keygen-suite/keyGen/keygenerators/xptag.js

Key generation utilities for cryptographic operations. YES I RENAMED IT. SIX STATE PROTOCOL!!! See its folder for all <3

#!/usr/bin/env node
import yargs from 'yargs';
import { hideBin } from 'yargs/helpers';

function uid(length) {
  const HEX = Array.from({ length: 36 }, (_, i) => i.toString(36)).join('');
  let result = '';
  for (let i = 0; i < (length || 11); i++) {
    result += HEX[Math.floor(Math.random() * 36)];
  }
  return result;
}

const xptagPrefix = () => uid(9);

const xptagPrivate = (t, a) => xptag(t, a, true);

function xptag(t, a, r) {
  const e = a || uid(9);
  const i = uid(16);
  let x = r ? 3 : 1;
  let o = '';

  if (t) {
    let a;
    if (x | 4) {
      x |= 4;
    }
    if (t < 0) {
      x |= 8;
      a = Math.ceil(-t / 5);
    } else {
      a = Math.ceil(Date.now() / 1000 / 60 / 5) + Math.ceil(t / 5);
    }
    o = a.toString(16);
  }

  return e + i + x.toString(16) + o;
}

function xptagDecode(tag) {
  if (typeof tag !== 'string' || tag.length < 26) {
    throw new Error('Invalid xptag string');
  }

  const prefix = tag.slice(0, 9);
  const id = tag.slice(9, 25);
  const flagHex = tag.slice(25, 26);
  const flags = parseInt(flagHex, 16);

  const timestampHex = tag.slice(26);
  let timestamp = null;
  let timestampReadable = null;

  const isPrivate = (flags & 0x3) === 3;
  const bit4Set = (flags & 0x4) !== 0;
  const bit8Set = (flags & 0x8) !== 0;

  if (timestampHex) {
    const timeValue = parseInt(timestampHex, 16);
    if (!isNaN(timeValue)) {
      if (bit8Set) {
        timestamp = -timeValue * 5;
        timestampReadable = `Negative offset: ${timestamp} (units of 5 minutes)`;
      } else {
        timestamp = timeValue * 5 * 60 * 1000;
        timestampReadable = new Date(timestamp).toISOString();
      }
    }
  }

  return {
    prefix,
    id,
    flags,
    isPrivate,
    bit4Set,
    bit8Set,
    timestampHex: timestampHex || null,
    timestamp,
    timestampReadable,
  };
}

// CLI using yargs
yargs(hideBin(process.argv))
  .scriptName('xptag-cli')
  .usage('$0 <cmd> [args]')
  .command(
    'generate',
    'Generate a new xptag',
    (y) =>
      y
        .option('time', {
          alias: 't',
          describe: 'Time offset in minutes (positive or negative)',
          type: 'number',
          default: 0,
        })
        .option('private', {
          alias: 'p',
          describe: 'Generate a private xptag',
          type: 'boolean',
          default: false,
        }),
    (argv) => {
      let offset = argv.time;
      if (offset !== 0) offset = Math.ceil(offset / 5) * 5; // normalize to 5 min units
      const tag = xptag(offset, undefined, argv.private);
      console.log(tag);
    }
  )
  .command(
    'decode <tag>',
    'Decode an xptag string',
    (y) =>
      y.positional('tag', {
        describe: 'xptag string to decode',
        type: 'string',
      }),
    (argv) => {
      try {
        const decoded = xptagDecode(argv.tag);
        console.log(JSON.stringify(decoded, null, 2));
      } catch (e) {
        console.error('Error:', e.message);
      }
    }
  )
  .demandCommand(1, 'You need to specify a command')
  .help()
  .parse();