Fix crypto polyfill (#627)

extension/src/crypto-polyfill.ts

@@ -1,21 +1,7 @@
 import * as crypto from 'crypto'
 
-globalThis.crypto = {
-  getRandomValues: (buffer: Buffer) => {
-    const buf = new Uint8Array(buffer.buffer, buffer.byteOffset, buffer.byteLength)
-    if (!(buf instanceof Uint8Array)) {
-      throw new TypeError('expected Uint8Array')
-    }
-    if (buf.length > 65536) {
-      const e = new Error()
-      // @ts-expect-error
-      e.code = 22
-      e.message = `Failed to execute 'getRandomValues' on 'Crypto': The 'ArrayBufferView's byte length (${buf.length}) exceeds the number of bytes of entropy available via this API (65536).`
-      e.name = 'QuotaExceededError'
-      throw e
-    }
-    const bytes = crypto.randomBytes(buf.length)
-    buf.set(bytes)
-    return buf
-  }
-} as any
+if (globalThis.crypto == null) {
+  Object.defineProperty(globalThis, 'crypto', {
+    value: crypto
+  })
+}