fix: Incorrect usage of ArrayBufferView subarrays #35

src/crypto.ts

@@ -10,7 +10,7 @@ export class Crypto extends core.Crypto {
     if (!ArrayBuffer.isView(array)) {
       throw new TypeError("Failed to execute 'getRandomValues' on 'Crypto': parameter 1 is not of type 'ArrayBufferView'");
     }
-    const buffer = Buffer.from(array.buffer);
+    const buffer = Buffer.from(array.buffer, array.byteOffset, array.byteLength);
     crypto.randomFillSync(buffer);
     return array;
   }

test/crypto.ts

@@ -23,6 +23,16 @@ context("Crypto", () => {
       assert.strictEqual(Buffer.from(array2).equals(array), true);
     });
 
+    it("Uint8Array subarray", () => {
+      const array = new Uint8Array(10);
+      const subarray = array.subarray(0, 5);
+      const array2 = crypto.getRandomValues(subarray);
+
+      assert.notStrictEqual(Buffer.from(array).toString("hex"), "00000000000000000000");
+      assert.strictEqual(subarray, array2);
+      assert.ok(Buffer.from(array).toString("hex").endsWith("0000000000"));
+    });
+
     it("Uint16Array", () => {
       const array = new Uint16Array(5);
       const array2 = crypto.getRandomValues(array);