88 lines
3.3 KiB
Handlebars
88 lines
3.3 KiB
Handlebars
|
# bigint-utils
|
||
|
|
|
||
|
|
Some extra functions to work with modular arithmetics along with secure random numbers and probable prime (Miller-Rabin primality test) generation/testing using native JS (stage 3) implementation of BigInt. It can be used with Node.js (>=10.4.0) and [Web Browsers supporting BigInt](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt#Browser_compatibility).
|
||
|
|
|
||
|
|
_The operations supported on BigInts are not constant time. BigInt can be therefore **[unsuitable for use in cryptography](https://www.chosenplaintext.ca/articles/beginners-guide-constant-time-cryptography.html)**_
|
||
|
|
|
||
|
|
Many platforms provide native support for cryptography, such as [webcrypto](https://w3c.github.io/webcrypto/Overview.html) or [node crypto](https://nodejs.org/dist/latest/docs/api/crypto.html).
|
||
|
|
|
||
|
|
## Installation
|
||
|
|
bigint-utils is distributed as both an ES6 and a CJS module.
|
||
|
|
|
||
|
|
The ES6 module is built for any [web browser supporting BigInt](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt#Browser_compatibility). The module only uses native javascript implementations and no polyfills had been applied.
|
||
|
|
|
||
|
|
The CJS module is built as a standard node module.
|
||
|
|
|
||
|
|
bigint-utils can be imported to your project with `npm`:
|
||
|
|
```bash
|
||
|
|
npm install bigint-utils
|
||
|
|
```
|
||
|
|
|
||
|
|
For web browsers, you can also [download the bundle from GitHub](https://raw.githubusercontent.com/juanelas/bigint-utils/master/dist/bigint-utils-latest.browser.mod.min.js).
|
||
|
|
|
||
|
|
## Usage example
|
||
|
|
|
||
|
|
With node js:
|
||
|
|
```javascript
|
||
|
|
const bigintUtils = require('bigint-utils');
|
||
|
|
|
||
|
|
// Stage 3 BigInts with value 666 can be declared as BigInt('666')
|
||
|
|
// or the shorter new no-so-linter-friendly syntax 666n
|
||
|
|
let a = BigInt('5');
|
||
|
|
let b = BigInt('2');
|
||
|
|
let n = BigInt('19');
|
||
|
|
|
||
|
|
console.log(bigintModArith.modPow(a, b, n)); // prints 6
|
||
|
|
|
||
|
|
console.log(bigintModArith.modInv(BigInt('2'), BigInt('5'))); // prints 3
|
||
|
|
|
||
|
|
console.log(bigintModArith.modInv(BigInt('3'), BigInt('5'))); // prints 2
|
||
|
|
|
||
|
|
// Generation of a probable prime of 2048 bits
|
||
|
|
const prime = await bigintUtils.prime(2048);
|
||
|
|
|
||
|
|
// Testing if a prime is a probable prime (Miller-Rabin)
|
||
|
|
if ( await bigintUtils.isProbablyPrime(prime) )
|
||
|
|
// code if is prime
|
||
|
|
|
||
|
|
// Get a cryptographically secure random number between 1 and 2**256 bits.
|
||
|
|
const rnd = bigintUtils.randBetween(BigInt(2)**256);
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
From a browser, you can just load the module in a html page as:
|
||
|
|
```html
|
||
|
|
<script type="module">
|
||
|
|
import * as bigintUtils from 'bigint-utils-latest.browser.mod.min.js';
|
||
|
|
|
||
|
|
let a = BigInt('5');
|
||
|
|
let b = BigInt('2');
|
||
|
|
let n = BigInt('19');
|
||
|
|
|
||
|
|
console.log(bigintModArith.modPow(a, b, n)); // prints 6
|
||
|
|
|
||
|
|
console.log(bigintModArith.modInv(BigInt('2'), BigInt('5'))); // prints 3
|
||
|
|
|
||
|
|
console.log(bigintModArith.modInv(BigInt('3'), BigInt('5'))); // prints 2
|
||
|
|
|
||
|
|
(async function () {
|
||
|
|
// Generation of a probable prime of 2018 bits
|
||
|
|
const p = await bigintSecrets.prime(2048);
|
||
|
|
|
||
|
|
// Testing if a prime is a probable prime (Miller-Rabin)
|
||
|
|
const isPrime = await bigintSecrets.isProbablyPrime(p);
|
||
|
|
alert(p.toString() + '\nIs prime?\n' + isPrime);
|
||
|
|
|
||
|
|
// Get a cryptographically secure random number between 1 and 2**256 bits.
|
||
|
|
const rnd = await bigintSecrets.randBetween(BigInt(2)**256);
|
||
|
|
alert(rnd);
|
||
|
|
})();
|
||
|
|
</script>
|
||
|
|
```
|
||
|
|
|
||
|
|
# bigint-utils JS Doc
|
||
|
|
|
||
|
|
{{>main}}
|
||
|
|
|
||
|
|
* * *
|