mirror of
https://github.com/denoland/deno.git
synced 2024-11-22 15:06:54 -05:00
59 lines
1.9 KiB
TypeScript
59 lines
1.9 KiB
TypeScript
// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
|
|
|
|
// deno-fmt-ignore
|
|
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", "+", "/"];
|
|
|
|
/**
|
|
* CREDIT: https://gist.github.com/enepomnyaschih/72c423f727d395eeaa09697058238727
|
|
* Encodes a given Uint8Array, ArrayBuffer or string into RFC4648 base64 representation
|
|
* @param data
|
|
*/
|
|
export function encode(data: ArrayBuffer | string): string {
|
|
const uint8 =
|
|
typeof data === "string"
|
|
? new TextEncoder().encode(data)
|
|
: data instanceof Uint8Array
|
|
? data
|
|
: new Uint8Array(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 given RFC4648 base64 encoded string
|
|
* @param b64
|
|
*/
|
|
export function decode(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;
|
|
}
|