utils.ts

/********************************
     Encoding/Decoding Utils
********************************/

/*
let webCrypto :any = null

export async function getCrypto() {
    if(!webCrypto) {
        console.log(window?.crypto)
        webCrypto = window?.crypto ?? (await import("crypto")).webcrypto
        console.log(webCrypto)
    }
    return webCrypto
}
*/


export function randomChallenge() {
    return crypto.randomUUID()
}


export function toBuffer(txt :string) :ArrayBuffer {
    return Uint8Array.from(txt, c => c.charCodeAt(0)).buffer
}

export function parseBuffer(buffer :ArrayBuffer) :string {
    return String.fromCharCode(...new Uint8Array(buffer))
}


export function isBase64url(txt :string) :boolean {
    return txt.match(/^[a-zA-Z0-9\-_]+=*$/) !== null
}

export function toBase64url(buffer :ArrayBuffer) :string {
    const txt = btoa(parseBuffer(buffer)) // base64
    return txt.replaceAll('+', '-').replaceAll('/', '_')
}

export function parseBase64url(txt :string) :ArrayBuffer {
    txt = txt.replaceAll('-', '+').replaceAll('_', '/') // base64url -> base64
    return toBuffer(atob(txt))
}


export async function sha256(buffer :ArrayBuffer) :Promise<ArrayBuffer> {
    return await crypto.subtle.digest('SHA-256', buffer)
}

export function bufferToHex (buffer :ArrayBuffer) :string {
    return [...new Uint8Array (buffer)]
        .map (b => b.toString (16).padStart (2, "0"))
        .join ("");
}


export function concatenateBuffers(buffer1 :ArrayBuffer, buffer2  :ArrayBuffer) {
    var tmp = new Uint8Array(buffer1.byteLength + buffer2.byteLength);
    tmp.set(new Uint8Array(buffer1), 0);
    tmp.set(new Uint8Array(buffer2), buffer1.byteLength);
    return tmp;
  };