TOTPFit/lib/totp-quickjs/base32decoder.js

54 lines
1.3 KiB
JavaScript

export function decode(base32) {
for (
var base32chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567",
bits = "",
hex = "",
i = 0;
i < base32.length;
i++
) {
var val = base32chars.indexOf(base32.charAt(i).toUpperCase());
bits += leftpad(val.toString(2), 5, "0");
}
for (i = 0; i + 4 <= bits.length; i += 4) {
var chunk = bits.substr(i, 4);
hex += parseInt(chunk, 2).toString(16);
}
return hex;
}
function leftpad(str, len, pad) {
return (
len + 1 >= str.length &&
(str = new Array(len + 1 - str.length).join(pad) + str),
str
);
}
export function base64decode(base64) {
const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
let result = [];
let i = 0, j = 0;
let b1, b2, b3, b4;
while (i < base64.length) {
b1 = chars.indexOf(base64.charAt(i++));
b2 = chars.indexOf(base64.charAt(i++));
b3 = chars.indexOf(base64.charAt(i++));
b4 = chars.indexOf(base64.charAt(i++));
if (b1 === -1 || b2 === -1) break;
result[j++] = (b1 << 2) | (b2 >> 4);
if (b3 !== -1) {
result[j++] = ((b2 & 15) << 4) | (b3 >> 2);
}
if (b4 !== -1) {
result[j++] = ((b3 & 3) << 6) | b4;
}
}
return result.slice(0, j);
}