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std/encoding/base64.ts

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-4 | base64} * encoding and decoding. * * This module is browser compatible. * * @module */
import { validateBinaryLike } from "./_util.ts";
const base64abc = [ "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "+", "/",];
/** * Converts data into a base64-encoded string. * * @see {@link https://datatracker.ietf.org/doc/html/rfc4648#section-4} * * @example * ```ts * import { encodeBase64 } from "https://deno.land/std@$STD_VERSION/encoding/base64.ts"; * * encodeBase64("foobar"); // "Zm9vYmFy" * ``` */export function encodeBase64(data: ArrayBuffer | Uint8Array | string): string { // CREDIT: https://gist.github.com/enepomnyaschih/72c423f727d395eeaa09697058238727 const uint8 = validateBinaryLike(data); let result = "", i; const l = uint8.length; for (i = 2; i < l; i += 3) { result += base64abc[(uint8[i - 2]!) >> 2]; result += base64abc[ (((uint8[i - 2]!) & 0x03) << 4) | ((uint8[i - 1]!) >> 4) ]; result += base64abc[ (((uint8[i - 1]!) & 0x0f) << 2) | ((uint8[i]!) >> 6) ]; result += base64abc[(uint8[i]!) & 0x3f]; } if (i === l + 1) { // 1 octet yet to write result += base64abc[(uint8[i - 2]!) >> 2]; result += base64abc[((uint8[i - 2]!) & 0x03) << 4]; result += "=="; } if (i === l) { // 2 octets yet to write result += base64abc[(uint8[i - 2]!) >> 2]; result += base64abc[ (((uint8[i - 2]!) & 0x03) << 4) | ((uint8[i - 1]!) >> 4) ]; result += base64abc[((uint8[i - 1]!) & 0x0f) << 2]; result += "="; } return result;}
/** * Decodes a base64-encoded string. * * @see {@link https://datatracker.ietf.org/doc/html/rfc4648#section-4} * * @example * ```ts * import { encodeBase64 } from "https://deno.land/std@$STD_VERSION/encoding/base64.ts"; * * encodeBase64("foobar"); // "Zm9vYmFy" * ``` */export function decodeBase64(b64: string): Uint8Array { const binString = atob(b64); const size = binString.length; const bytes = new Uint8Array(size); for (let i = 0; i < size; i++) { bytes[i] = binString.charCodeAt(i); } return bytes;}