export const decodeBase64Url = (str: string): Uint8Array => { return decodeBase64(str.replace(/_|-/g, (m) => ({ _: '/', '-': '+' }[m] ?? m))) } export const encodeBase64Url = (buf: ArrayBufferLike): string => encodeBase64(buf).replace(/\/|\+/g, (m) => ({ '/': '_', '+': '-' }[m] ?? m)) // This approach is written in MDN. // btoa does not support utf-8 characters. So we need a little bit hack. export const encodeBase64 = (buf: ArrayBufferLike): string => { const binary = String.fromCharCode(...new Uint8Array(buf)) return btoa(binary) } // atob does not support utf-8 characters. So we need a little bit hack. export const decodeBase64 = (str: string): Uint8Array => { const binary = atob(str) const bytes = new Uint8Array(new ArrayBuffer(binary.length)) const half = binary.length / 2 for (let i = 0, j = binary.length - 1; i <= half; i++, j--) { bytes[i] = binary.charCodeAt(i) bytes[j] = binary.charCodeAt(j) } return bytes }