1 files changed, 90 insertions, 0 deletions
diff --git a/ext/node/polyfills/internal/crypto/_randomFill.mjs b/ext/node/polyfills/internal/crypto/_randomFill.mjs
new file mode 100644
index 000000000..6afc654b4
--- /dev/null
+++ b/ext/node/polyfills/internal/crypto/_randomFill.mjs
@@ -0,0 +1,90 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+// TODO(petamoriken): enable prefer-primordials for node polyfills
+// deno-lint-ignore-file prefer-primordials
+
+import {
+  MAX_SIZE as kMaxUint32,
+} from "ext:deno_node/internal/crypto/_randomBytes.ts";
+import { Buffer } from "node:buffer";
+import { isAnyArrayBuffer, isArrayBufferView } from "node:util/types";
+import { ERR_INVALID_ARG_TYPE } from "ext:deno_node/internal/errors.ts";
+const { core } = globalThis.__bootstrap;
+const { ops } = core;
+
+const kBufferMaxLength = 0x7fffffff;
+
+function assertOffset(offset, length) {
+  if (offset > kMaxUint32 || offset < 0) {
+    throw new TypeError("offset must be a uint32");
+  }
+
+  if (offset > kBufferMaxLength || offset > length) {
+    throw new RangeError("offset out of range");
+  }
+}
+
+function assertSize(size, offset, length) {
+  if (size > kMaxUint32 || size < 0) {
+    throw new TypeError("size must be a uint32");
+  }
+
+  if (size + offset > length || size > kBufferMaxLength) {
+    throw new RangeError("buffer too small");
+  }
+}
+
+export default function randomFill(
+  buf,
+  offset,
+  size,
+  cb,
+) {
+  if (typeof offset === "function") {
+    cb = offset;
+    offset = 0;
+    size = buf.length;
+  } else if (typeof size === "function") {
+    cb = size;
+    size = buf.length - Number(offset);
+  }
+
+  assertOffset(offset, buf.length);
+  assertSize(size, offset, buf.length);
+
+  core.opAsync("op_node_generate_secret_async", Math.floor(size))
+    .then(
+      (randomData) => {
+        const randomBuf = Buffer.from(randomData.buffer);
+        randomBuf.copy(buf, offset, 0, size);
+        cb(null, buf);
+      },
+    );
+}
+
+export function randomFillSync(buf, offset = 0, size) {
+  if (!isAnyArrayBuffer(buf) && !isArrayBufferView(buf)) {
+    throw new ERR_INVALID_ARG_TYPE(
+      "buf",
+      ["ArrayBuffer", "ArrayBufferView"],
+      buf,
+    );
+  }
+
+  assertOffset(offset, buf.byteLength);
+
+  if (size === undefined) {
+    size = buf.byteLength - offset;
+  } else {
+    assertSize(size, offset, buf.byteLength);
+  }
+
+  if (size === 0) {
+    return buf;
+  }
+
+  const bytes = new Uint8Array(buf.buffer ? buf.buffer : buf, offset, size);
+  ops.op_node_generate_secret(bytes);
+
+  return buf;
+}