@okta-dfuhriman/okta-auth-js/lib/crypto/base64.ts

The Okta Auth SDK

/*!
 * Copyright (c) 2015-present, Okta, Inc. and/or its affiliates. All rights reserved.
 * The Okta software accompanied by this notice is provided pursuant to the Apache License, Version 2.0 (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.
 */

import { AuthSdkError } from '../errors';
import { atob, btoa } from './webcrypto';

// converts a string to base64 (url/filename safe variant)
export function stringToBase64Url(str) {
  var b64 = btoa(str);
  return base64ToBase64Url(b64);
}

// converts a standard base64-encoded string to a "url/filename safe" variant
export function base64ToBase64Url(b64) {
  return b64.replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');
}

// converts a "url/filename safe" base64 string to a "standard" base64 string
export function base64UrlToBase64(b64u) {
  return b64u.replace(/-/g, '+').replace(/_/g, '/');
}

export function base64UrlToString(b64u) {
  var b64 = base64UrlToBase64(b64u);
  switch (b64.length % 4) {
    case 0:
      break;
    case 2:
      b64 += '==';
      break;
    case 3:
      b64 += '=';
      break;
    default:
      throw new AuthSdkError('Not a valid Base64Url');
  }
  var utf8 = atob(b64);
  try {
    return decodeURIComponent(escape(utf8));
  } catch (e) {
    return utf8;
  }
}

export function stringToBuffer(str) {
  var buffer = new Uint8Array(str.length);
  for (var i = 0; i < str.length; i++) {
    buffer[i] = str.charCodeAt(i);
  }
  return buffer;
}

export function base64UrlDecode(str) {
  return atob(base64UrlToBase64(str));
}

// Converts base64 string to binary data view
export function base64UrlToBuffer(b64u) {
  return Uint8Array.from(base64UrlDecode(b64u), (c: string) => c.charCodeAt(0));
}

// Converts an ArrayBuffer object that contains binary data to base64 encoded string
export function bufferToBase64Url(bin) {
  return btoa(new Uint8Array(bin).reduce((s, byte) => s + String.fromCharCode(byte), ''));
}