This project provides a small utility for numerical ID obscuration for public display or referencing. It converts a number like 19 to a string like ivUVjy0Q, and a given string ("public ID") can be converted back to the original number.
One special feature of this function is, that a number can be converted to several, various string values depending on random values, but each possible string can be mapped to exactly one number.
const publicId = require('public-id');
publicId(19).then(generatedId => {
console.log('public id:', generatedId);
publicId('ivUVjy0Q').then(id => {
console.log('id:', id);
});
});Using a generator instance:
const {PublicIdGenerator} = require('public-id');
const generator = new PublicIdGenerator();
generator.generate(19).then(generatedId => {
console.log('public id:', generatedId);
generator.decode('ivUVjy0Q').then(id => {
console.log('id:', id);
});
});| Platform | Support |
|---|---|
| Node.js | 7.10.1+, 8.x and up |
| Chrome | 55+ |
| Edge | Yes |
| Firefox | 52+ |
| IE | No |
| Opera | 42+ |
| Safari | 10.1+ |
Use npm to install the package:
$ npm install --save public-idNow require that package in your code:
const publicId = require('public-id');
const {PublicIdGenerator} = require('public-id');
async main() {
console.log(await publicId(12));
const generator = new PublicIdGenerator();
console.log(await generator.generate(12));
}
main();Just download the index.js, rename it to public-id.js or whatever you like
and include it in your HTML file:
<script src="public-id.js"></script>
<script>
async main() {
console.log(await publicId(12));
const {PublicIdGenerator} = publicId;
const generator = new PublicIdGenerator();
console.log(await generator.generate(12));
}
</script>If you're using AMD, publicId is not exported globally. You can access it like
this:
define(['public-id'], async (publicId) => {
console.log(await publicId(12));
const {PublicIdGenerator} = publicId;
const generator = new PublicIdGenerator();
console.log(await generator.generate(12));
});- id: the numerical ID to be encoded; must be >= 1
- length: desired length of output string
- random: either an array of numbers between 0 (inclusive) and 1 (exclusive), or a function that returns a Promise that is resolved to such a number
- returns:
Promise<string>
Generate an obscured public id from a number.
- returns:
Promise<number>
Convert a public ID back to number.
Change the configuration. Only changes options, that are specified in the parameter object.
publicId.configure({
key: 'awesome',
index: 'abcdefghijklmnopqrstuvwxyz',
defaultIdLength: 10
});See Options below for more details.
Reset options to the initial values.
Constructor for a new PublicIdGenerator. See Options below for possible options.
const generator = new PublicIdGenerator(options);- id: the numerical ID to be encoded; must be >= 1
- length: desired length of output string
- random: either an array of numbers between 0 (inclusive) and 1 (exclusive), or a function that returns a Promise that is resolved to such a number
- returns:
Promise<string>
Generate an obscured public id from a number.
- alias:
generate(),encode()
- returns:
Promise<number>
Convert a public ID back to number.
- alias:
decode()
Change some configurations.
generator.configure({
key: 'awesome',
index: 'abcdefghijklmnopqrstuvwxyz',
defaultIdLength: 10
});See Options below for more details.
Reset options to the initial values.
- key: (string) the key, that is used to encode and decode the IDs. If you change your key, all your generated public IDs become invalid.
- index: (string) possible characters, that are used in the public IDs. If you change your index or change the order of the characters, all your generated public IDs become invalid.
- defaultIdLength: (number, default 8) the output length of generated public IDs, if no other length is specified by parameter.
- signatureLength: (number, default 2) number of characters within the generated public ID, which indicates the random value of the output. If set to 0, every numerical ID corresponds to exactly one possible public ID. If you change this value, all your generated public IDs become invalid.
- randomFunction: (function) a custom random number generator. Must return a Promise, which resolves to a number between 0 (inclusive) and 1 (exclusive).
By default, Math.random() is used to generate random values. If you need more
security, you can use a more secure random function like
crypto.getRandomValues() in the browser or the crypto module in Node.js.
// in the browser
publicId.configure({
async randomFunction() {
const array = new Uint32Array(1);
window.crypto.getRandomValues(array);
return array[0] / (256 ** 4);
}
});// in Node.js
const crypto = require('crypto');
publicId.configure({
randomFunction() {
return new Promise((resolve, reject) => {
crypto.randomBytes(1, (error, buffer) => {
if(error) {
return reject(error);
}
resolve(buffer[0] / 256);
});
});
}
});Depending on the raw output length (i.e. the total length minus the signature length) and the number of characters available there's a limit for the maximum numerical ID that can be encoded. The following tables shows some sample configurations and the maximum IDs:
| Signature | Length | Raw Length | Index | Min ID | Max ID | Fits in |
|---|---|---|---|---|---|---|
| 2 | 8 | 6 | 62 (A-Z, a-z, 0-9) | 1 | 56800235584 | 5 bytes |
| 2 | 8 | 6 | 26 (a-z) | 1 | 308915776 | 4 bytes |
| 1 | 8 | 7 | 62 (A-Z, a-z, 0-9) | 1 | 3521614606208 | 6 bytes |
| 4 | 12 | 8 | 62 (A-Z, a-z, 0-9) | 1 | 218340105584896 | 6 bytes |
| 2 | 12 | 10 | 62 (A-Z, a-z, 0-9) | 1 | 839299365868340200 | 8 bytes |
You can use the maxId() method to get the maximum ID possible using the
current configuration.
public-id is licensed under the MIT License.