browser-canvas-fingerprinting/src/util.js

A simple canvas fingerprinting implementation in browser with specific information used to generate fingerprint

export function keyCount(obj) {
    if (!obj) return 0;
    const visited = new WeakSet();

    function countKeys(currentObj) {
        if (currentObj === null || typeof currentObj !== 'object') {
            return 0;
        }

        if (visited.has(currentObj)) {
            return 0;
        }
        visited.add(currentObj);

        let count = Reflect.ownKeys(currentObj).length;

        const proto = Object.getPrototypeOf(currentObj);
        if (proto !== null) {
            count += countKeys(proto);
        }

        return count;
    }

    return countKeys(obj);
}

export function urand(bits) {
    if (bits <= 0 || !Number.isInteger(bits)) {
        throw new Error('bits must be a positive integer');
    }
    
    const bytesNeeded = Math.ceil(bits / 8);
    const byteArray = new Uint8Array(bytesNeeded);
    crypto.getRandomValues(byteArray);
    
    let result = 0n;
    for (let i = 0; i < bytesNeeded; i++) {
        result = (result << 8n) | BigInt(byteArray[i]);
    }
    
    return result & ((1n << BigInt(bits)) - 1n);
}