1
export const timingSafeEqual = (left: Uint8Array, right: Uint8Array): boolean => {
2
  const lengthsMatch = left.byteLength === right.byteLength;
3
  // subtle.timingSafeEqual throws when inputs differ in length.
4
  // Compare left against itself to keep execution time constant, then
5
  // negate to produce the expected false for mismatched lengths.
6
  return lengthsMatch ? crypto.subtle.timingSafeEqual(left, right) : !crypto.subtle.timingSafeEqual(left, left);
7
};
8
 
9
export const encodeHex = (value: Uint8Array): string =>
10
  Array.from(value, (byte) => byte.toString(16).padStart(2, "0")).join("");
11
 
12
export const encodeBase64 = (value: Uint8Array): string => {
13
  let binary = "";
14
  for (const byte of value) {
15
    binary += String.fromCharCode(byte);
16
  }
17
 
18
  return btoa(binary);
19
};
20
 
21
export const decodeBase64 = (value: string): Uint8Array => {
22
  let normalized = value.trim().replace(/-/gu, "+").replace(/_/gu, "/");
23
  const remainder = normalized.length % 4;
24
  if (remainder > 0) {
25
    normalized = normalized.padEnd(normalized.length + (4 - remainder), "=");
26
  }
27
 
28
  const binary = atob(normalized);
29
  const output = new Uint8Array(binary.length);
30
  for (let index = 0; index < binary.length; index += 1) {
31
    output[index] = binary.charCodeAt(index);
32
  }
33
 
34
  return output;
35
};
36
 
37
export const encodeBase64Url = (value: Uint8Array): string =>
38
  encodeBase64(value).replace(/\+/gu, "-").replace(/\//gu, "_").replace(/=+$/u, "");
39
 
40
export const decodeBase64Url = (value: string): Uint8Array => decodeBase64(value);
41
 
42
export const toArrayBuffer = (value: Uint8Array): ArrayBuffer =>
43
  value.buffer.slice(value.byteOffset, value.byteOffset + value.byteLength) as ArrayBuffer;