feat: implement end-to-end encryption for relay connections

packages/app/src/polyfills/crypto.ts

@@ -7,16 +7,44 @@ declare global {
 }
 
 export function polyfillCrypto(): void {
-  if (typeof globalThis.crypto === "undefined") {
-    (globalThis as any).crypto = {};
+  let webcrypto: Crypto | null = null;
+  try {
+    // Prefer the React Native entrypoint to avoid the browser shim.
+    // eslint-disable-next-line @typescript-eslint/no-var-requires
+    const rnModule = require("@sphereon/isomorphic-webcrypto/src/react-native");
+    webcrypto = (rnModule?.default ?? rnModule) as Crypto;
+  } catch {
+    // eslint-disable-next-line @typescript-eslint/no-var-requires
+    const fallbackModule = require("@sphereon/isomorphic-webcrypto");
+    webcrypto = (fallbackModule?.default ?? fallbackModule) as Crypto;
   }
 
-  if (typeof globalThis.crypto.randomUUID !== "function") {
+  const existing = (globalThis as any).crypto as Crypto | null | undefined;
+  let target = existing;
+  if (!target || typeof (target as Crypto).subtle === "undefined") {
+    target = (webcrypto && typeof webcrypto === "object" ? (webcrypto as Crypto) : undefined) ?? ({} as Crypto);
+    (globalThis as any).crypto = target;
+  }
+
+  const ensureSecure = (globalThis as any).crypto?.ensureSecure as
+    | (() => Promise<void>)
+    | undefined;
+  if (typeof ensureSecure === "function") {
+    void ensureSecure();
+  }
+
+  if (typeof (globalThis as any).crypto?.randomUUID !== "function") {
+    if (!globalThis.crypto) {
+      (globalThis as any).crypto = {} as Crypto;
+    }
     globalThis.crypto.randomUUID = () =>
       ExpoCrypto.randomUUID() as `${string}-${string}-${string}-${string}-${string}`;
   }
 
-  if (typeof globalThis.crypto.getRandomValues !== "function") {
+  if (typeof (globalThis as any).crypto?.getRandomValues !== "function") {
+    if (!globalThis.crypto) {
+      (globalThis as any).crypto = {} as Crypto;
+    }
     globalThis.crypto.getRandomValues = <T extends ArrayBufferView>(array: T): T => {
       return ExpoCrypto.getRandomValues(array as any) as T;
     };