Current method of signing S3 upload URL

snippet.js

// tools.generateId
function generateId(size){
  var text = [];
  var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

  for( var i=0; i < size; i++ )
    text.push(possible.charAt(Math.floor(Math.random() * possible.length)));

  return text.join('');
}

// main signing function

export function getSignedRequest(file) {
  return new Promise((resolve, reject) => {
    getJWT()
    .then((jwt) => {
      request
      .get(getURL() + "sign_s3?file_name=" + tools.generateId(64) + "&file_type="+file.type)
      .set(headersConstructor(jwt))
      .end(function(err, res){
        if(err){
          console.log('ERROR ON GET SIGNED REQUEST');
          console.log(err);
          reject(err);
        }
        resolve(res);
      });
    })
    .catch((err) => {
      console.log(err);
      reject(err);
    });
  });
}

export function uploadFile(file, signed_request, url){
  return new Promise((resolve, reject) => {
    let xhr = new XMLHttpRequest();
    xhr.open("PUT", signed_request);
    xhr.setRequestHeader('x-amz-acl', 'public-read');
    xhr.onload = function() {
      if (xhr.status === 200) {
        resolve(url);
      }
    };
    xhr.onerror = function() {
      console.log("Could not upload file.");
      reject();
    };
    xhr.send(file);
  });
}