random.js

// NOTICE: the code in this file originally developed by Microsoft
// original source: https://github.com/AzureAD/azure-activedirectory-library-for-js/blob/master/lib/adal.js#L1029
//----------------------------------------------------------------------
// AdalJS v1.0.8
// @preserve Copyright (c) Microsoft Open Technologies, Inc.
// All Rights Reserved
// Apache License 2.0
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//----------------------------------------------------------------------

export default function random() {
    var guidHolder = 'xxxxxxxxxxxx4xxxyxxxxxxxxxxxxxxx';
    var hex = '0123456789abcdef';
    var r = 0;
    var guidResponse = "";
    for (var i = 0; i < guidHolder.length; i++) {
        if (guidHolder[i] !== '-' && guidHolder[i] !== '4') {
            // each x and y needs to be random
            r = Math.random() * 16 | 0;
        }

        if (guidHolder[i] === 'x') {
            guidResponse += hex[r];
        } else if (guidHolder[i] === 'y') {
            // clock-seq-and-reserved first hex is filtered and remaining hex values are random
            r &= 0x3; // bit and with 0011 to set pos 2 to zero ?0??
            r |= 0x8; // set pos 3 to 1 as 1???
            guidResponse += hex[r];
        } else {
            guidResponse += guidHolder[i];
        }
    }
    return guidResponse;
}