/*
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* Copyright (c) Microsoft Corporation. All rights reserved.
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* Licensed under the MIT License.
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*/
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import {
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BrowserAuthErrorCodes,
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createBrowserAuthError,
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} from "../error/BrowserAuthError.js";
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/**
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* Class which exposes APIs to decode base64 strings to plaintext. See here for implementation details:
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* https://developer.mozilla.org/en-US/docs/Glossary/Base64#the_unicode_problem
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*/
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/**
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* Returns a URL-safe plaintext decoded string from b64 encoded input.
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* @param input
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*/
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export function base64Decode(input: string): string {
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return new TextDecoder().decode(base64DecToArr(input));
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}
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/**
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* Decodes base64 into Uint8Array
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* @param base64String
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*/
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export function base64DecToArr(base64String: string): Uint8Array {
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let encodedString = base64String.replace(/-/g, "+").replace(/_/g, "/");
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switch (encodedString.length % 4) {
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case 0:
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break;
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case 2:
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encodedString += "==";
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break;
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case 3:
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encodedString += "=";
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break;
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default:
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throw createBrowserAuthError(
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BrowserAuthErrorCodes.invalidBase64String
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);
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}
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const binString = atob(encodedString);
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return Uint8Array.from(binString, (m) => m.codePointAt(0) || 0);
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}
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