metadata-based-explorer1
Version:
Box UI Elements
59 lines (49 loc) • 1.63 kB
JavaScript
/**
* @flow
* @file Wrapper to provide a consistent interface for the webcrypto API
* @author Box
*/
/**
* Returns the correct crypto library based on browser implementation
*
* @return {Object}
*/
function getCrypto(): Object {
return window.crypto || window.msCrypto;
}
/**
* Returns a Promise of a digest generated from the
* hash function and text given as parameters
*
* @param {string} algorithm
* @param {ArrayBuffer} buffer
* @return {Promise} Promise - resolves with an ArrayBuffer containing the digest result
*/
function digest(algorithm: string, buffer: ArrayBuffer): Promise<ArrayBuffer> {
const cryptoRef = getCrypto();
if (cryptoRef !== window.msCrypto) {
return cryptoRef.subtle.digest(algorithm, buffer);
}
// IE11 implements an early version of the SubtleCrypto interface which doesn't use Promises
// See http://web-developer-articles.blogspot.com/2015/05/web-cryptography-api.html
return new Promise((resolve, reject) => {
const cryptoOperation = cryptoRef.subtle.digest({ name: algorithm }, buffer);
cryptoOperation.oncomplete = event => {
resolve(event.target.result);
};
cryptoOperation.onerror = reject;
});
}
/**
* Given a buffer/byteArray fills it with random values and returns the same array
*
* @param {Uint8Array} buffer
* @return {Uint8Array}
*/
function getRandomValues(buffer: Uint8Array): Uint8Array {
const cryptoRef = getCrypto();
const copy = new Uint8Array(buffer);
cryptoRef.getRandomValues(copy);
return copy;
}
export { getCrypto, digest, getRandomValues };