Generate random token base 56 which is alphanumeric upper and lower omitting letters 0 and I and digits zero and one
npm install secret-base56Randomly generate a secret token using base56 charset i.e. alphanumeric upper and lower omitting letters I and O and digits zero and one.
We omit those characters to avoid potential confusion if transcribed by humans e.g. for hand-written backup.
This is suitable for secret URLs, whereas base64 includes slash in its charset.
Incidently, my personal use case is for Telegram.org webhook secrets - see https://github.com/evanx/webhook-publish
You can test my image on DockerHub:
``
docker run evanxsummers/secret-base56
It should output a random base56 string e.g.
It is implemented as follows:
`javascript`
const assert = require('assert');
const crypto = require('crypto');
const letters24 = 'ABCDEFGHJKLMNPQRSTUVWXYZ'; // exclude I and O since too similar to 0 and 1
const digits8 = '23456789'; // omit 0 and 1 to avoid potential confusion with O and I (and perhaps 'l')
const charset = [digits8, letters24, letters24.toLowerCase()].join('');
assert.equal(charset.length, 56);
const length = parseInt(process.env.length || '16');
const string = crypto.randomBytes(length)
.map(value => charset.charCodeAt(Math.floor(value*charset.length/256)))
.toString();
console.log(string);
where we generate an array of random bytes (values 0 to 255 inclusive) of the desired and then map each into our charset:`
23456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghjklmnpqrstuvwxyz
We can build using its Dockerfile as follows:`
docker build -t secret-base56 https://github.com/evanx/secret-base56.git
where we tag the image so we can run by tag name:
docker run -t secret-base56
which gives random output e.g.
Use length envar to change from default 16
docker run -e length=32 secret-base56
which outputs length token e.g. CMZRUgDU5RxwzhDFh7fV5EKAKz6HmXdb`
You can then use this for a secret URL e.g. for a Telegram Bot webhook, or some other purpose.
See the following related project which is case-insensitive base32.
https://github.com/evanx/secret-base32
Base32 is better for hand-written backups since some letters have similar shapes in lowercase e.g. c, s, u, v