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std/encoding/base64url.ts

The Deno Standard Library
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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
/** * Utilities for * {@link https://datatracker.ietf.org/doc/html/rfc4648#section-5 | base64url} * encoding and decoding. * * This module is browser compatible. * * @module */
import * as base64 from "./base64.ts";
/** * Some variants allow or require omitting the padding '=' signs: * https://en.wikipedia.org/wiki/Base64#The_URL_applications * * @param base64url */function addPaddingToBase64url(base64url: string): string { if (base64url.length % 4 === 2) return base64url + "=="; if (base64url.length % 4 === 3) return base64url + "="; if (base64url.length % 4 === 1) { throw new TypeError("Illegal base64url string!"); } return base64url;}
function convertBase64urlToBase64(b64url: string): string { if (!/^[-_A-Z0-9]*?={0,2}$/i.test(b64url)) { // Contains characters not part of base64url spec. throw new TypeError("Failed to decode base64url: invalid character"); } return addPaddingToBase64url(b64url).replace(/\-/g, "+").replace(/_/g, "/");}
function convertBase64ToBase64url(b64: string) { return b64.endsWith("=") ? b64.endsWith("==") ? b64.replace(/\+/g, "-").replace(/\//g, "_").slice(0, -2) : b64.replace(/\+/g, "-").replace(/\//g, "_").slice(0, -1) : b64.replace(/\+/g, "-").replace(/\//g, "_");}
/** * Convert data into a base64url-encoded string. * * @see {@link https://datatracker.ietf.org/doc/html/rfc4648#section-5} * * @param data The data to encode. * @returns The base64url-encoded string. * * @example * ```ts * import { encodeBase64Url } from "https://deno.land/std@$STD_VERSION/encoding/base64url.ts"; * * encodeBase64Url("foobar"); // "Zm9vYmFy" * ``` */export function encodeBase64Url( data: ArrayBuffer | Uint8Array | string,): string { return convertBase64ToBase64url(base64.encodeBase64(data));}
/** * Decodes a given base64url-encoded string. * * @see {@link https://datatracker.ietf.org/doc/html/rfc4648#section-5} * * @param b64url The base64url-encoded string to decode. * @returns The decoded data. * * @example * ```ts * import { decodeBase64Url } from "https://deno.land/std@$STD_VERSION/encoding/base64url.ts"; * * decodeBase64Url("Zm9vYmFy"); // Uint8Array(6) [ 102, 111, 111, 98, 97, 114 ] * ``` */export function decodeBase64Url(b64url: string): Uint8Array { return base64.decodeBase64(convertBase64urlToBase64(b64url));}