Simplified the code and removed IE support for new SMART V2 features …

…like PKCE and asymmetric authentication.

src/security/browser.ts

@@ -32,7 +32,7 @@ export function randomBytes(count: number): Uint8Array {
 }
 
 export async function digestSha256(payload: string): Promise<Uint8Array> {
-    const prepared: ArrayBuffer = new Uint8Array(s2b(payload));
+    const prepared = new TextEncoder().encode(payload);
     const hash = await subtle.digest('SHA-256', prepared);
     return new Uint8Array(hash);
 }
@@ -85,27 +85,8 @@ export async function signCompactJws(alg: keyof typeof ALGS, privateKey: CryptoK
     const signature = await subtle.sign(
         { ...privateKey.algorithm, hash: 'SHA-384' },
         privateKey,
-        s2b(jwtAuthenticatedContent)
+        new TextEncoder().encode(jwtAuthenticatedContent)
     );
 
     return `${jwtAuthenticatedContent}.${fromUint8Array(new Uint8Array(signature), true)}`
 }
-
-function s2b ( s: string ) {
-    const b = new Uint8Array(s.length);
-    const bs = utf8ToBinaryString(s)
-    for ( var i = 0; i < bs.length; i++ ) b[i] = bs.charCodeAt(i);
-    return b;
-}
-
-// UTF-8 to Binary String
-// Source: https://coolaj86.com/articles/sign-jwt-webcrypto-vanilla-js/
-// Because JavaScript has a strange relationship with strings
-// https://coolaj86.com/articles/base64-unicode-utf-8-javascript-and-you/
-function utf8ToBinaryString(str: string) {
-    // replaces any uri escape sequence, such as %0A, with binary escape, such as 0x0A
-    return encodeURIComponent(str).replace(/%([0-9A-F]{2})/g, function(_, p1) {
-        return String.fromCharCode(parseInt(p1, 16));
-    });
-}
-

src/smart.ts

@@ -328,8 +328,8 @@ export async function authorize(
     if (shouldIncludeChallenge(extensions.codeChallengeMethods.includes('S256'), pkceMode)) {
         let codes = await env.security.generatePKCEChallenge()
         Object.assign(state, codes);
-        await storage.set(stateKey, state); // note that the challenge is ALREADY encoded properly  
-        redirectParams.push("code_challenge=" + state.codeChallenge);
+        await storage.set(stateKey, state);
+        redirectParams.push("code_challenge=" + state.codeChallenge);// note that the challenge is ALREADY encoded properly
         redirectParams.push("code_challenge_method=S256");
     }
 
@@ -438,7 +438,8 @@ export function onMessage(e: MessageEvent) {
 /**
  * The ready function should only be called on the page that represents
  * the redirectUri. We typically land there after a redirect from the
- * authorization server..
+ * authorization server, but this code will also be executed upon subsequent
+ * navigation or page refresh.
  */
 export async function ready(env: fhirclient.Adapter, options: fhirclient.ReadyOptions = {}): Promise<Client>
 {