jose/dist/browser/runtime/check_key_length.js

export default (alg, key) => {
    if (alg.startsWith('RS') || alg.startsWith('PS')) {
        const { modulusLength } = key.algorithm;
        if (typeof modulusLength !== 'number' || modulusLength < 2048) {
            throw new TypeError(`${alg} requires key modulusLength to be 2048 bits or larger`);
        }
    }
};