Add getWebCrypto to isoCrypto

1 files changed, 47 insertions, 0 deletions

diff --git a/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.ts b/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.ts
new file mode 100644
index 0000000..b9c39ca
--- /dev/null
+++ b/packages/server/src/helpers/iso/isoCrypto/getWebCrypto.ts
@@ -0,0 +1,47 @@
+import type { Crypto } from '../../../deps.ts';
+
+let webCrypto: Crypto | undefined = undefined;
+
+/**
+ * Try to get an instance of the Crypto API from the current runtime. Should support Node,
+ * as well as others, like Deno, that implement Web APIs.
+ */
+export async function getWebCrypto(): Promise<Crypto> {
+  if (webCrypto) {
+    return webCrypto;
+  }
+
+  try {
+    /**
+     * Naively attempt a Node import...
+     */
+    // @ts-ignore: We'll handle any errors...
+    // dnt-shim-ignore
+    const _crypto = await require('node:crypto');
+    webCrypto = _crypto as unknown as Crypto;
+  } catch (_err) {
+    /**
+     * Naively attempt to access Crypto as a global object, which popular alternative run-times
+     * support.
+     */
+    // @ts-ignore: ...right here.
+    const _crypto: Crypto = globalThis.crypto;
+
+    if (!_crypto) {
+      // We tried to access it both in Node and
+      throw new MissingWebCrypto();
+    }
+
+    webCrypto = _crypto;
+  }
+
+  return webCrypto;
+}
+
+class MissingWebCrypto extends Error {
+  constructor() {
+    const message = 'An instance of the Crypto API could not be located';
+    super(message);
+    this.name = 'MissingWebCrypto';
+  }
+}