From ecceb6a87f015f1e1eae5a0d775069672be5e3d4 Mon Sep 17 00:00:00 2001
From: Alberto Ricart <alberto@synadia.com>
Date: Wed, 10 Aug 2022 14:51:47 -0500
Subject: [PATCH] [FIX] simplified the nuid "shim" for getRandomValues [FIX]
 put an assertion for crypto.subtle on the objectstore create, as this is
 required

---
 nats-base-client/nuid.ts        | 32 +++++++++++---------------------
 nats-base-client/objectstore.ts | 15 +++++++++------
 2 files changed, 20 insertions(+), 27 deletions(-)

diff --git a/nats-base-client/nuid.ts b/nats-base-client/nuid.ts
index d62e9767..36570f90 100644
--- a/nats-base-client/nuid.ts
+++ b/nats-base-client/nuid.ts
@@ -24,28 +24,18 @@ const minInc = 33;
 const maxInc = 333;
 const totalLen = preLen + seqLen;
 
-const cryptoObj = initCrypto();
-
-function initCrypto() {
-  let cryptoObj = null;
-  if (typeof globalThis !== "undefined") {
-    if (
-      "crypto" in globalThis && globalThis.crypto.getRandomValues !== undefined
-    ) {
-      cryptoObj = globalThis.crypto;
-    }
+function _getRandomValues(a: Uint8Array) {
+  for (let i = 0; i < a.length; i++) {
+    a[i] = Math.floor(Math.random() * 255);
   }
-  if (!cryptoObj) {
-    // shim it
-    cryptoObj = {
-      getRandomValues: function (array: Uint8Array) {
-        for (let i = 0; i < array.length; i++) {
-          array[i] = Math.floor(Math.random() * 255);
-        }
-      },
-    };
+}
+
+function fillRandom(a: Uint8Array) {
+  if (globalThis?.crypto?.getRandomValues) {
+    globalThis.crypto.getRandomValues(a);
+  } else {
+    _getRandomValues(a);
   }
-  return cryptoObj;
 }
 
 /**
@@ -92,7 +82,7 @@ export class Nuid {
    */
   private setPre() {
     const cbuf = new Uint8Array(preLen);
-    cryptoObj.getRandomValues(cbuf);
+    fillRandom(cbuf);
     for (let i = 0; i < preLen; i++) {
       const di = cbuf[i] % base;
       this.buf[i] = digits.charCodeAt(di);
diff --git a/nats-base-client/objectstore.ts b/nats-base-client/objectstore.ts
index 179fb522..dd1e44c7 100644
--- a/nats-base-client/objectstore.ts
+++ b/nats-base-client/objectstore.ts
@@ -635,12 +635,6 @@ export class ObjectStoreImpl implements ObjectStore {
   }
 
   async init(opts: Partial<ObjectStoreOptions> = {}): Promise<void> {
-    // we may not have support in the environment
-    if (typeof crypto?.subtle?.digest !== "function") {
-      throw new Error(
-        "unable to calculate hashes - crypto.subtle.digest with sha256 support is required",
-      );
-    }
     try {
       this.stream = objectStoreStreamName(this.name);
     } catch (err) {
@@ -669,6 +663,15 @@ export class ObjectStoreImpl implements ObjectStore {
     name: string,
     opts: Partial<ObjectStoreOptions> = {},
   ): Promise<ObjectStore> {
+    // we may not have support in the environment
+    if (typeof crypto?.subtle?.digest !== "function") {
+      return Promise.reject(
+        new Error(
+          "objectstore: unable to calculate hashes - crypto.subtle.digest with sha256 support is required",
+        ),
+      );
+    }
+
     const jsi = js as JetStreamClientImpl;
     let jsopts = jsi.opts || {} as JetStreamOptions;
     const to = jsopts.timeout || 2000;