5 files changed, 156 insertions, 0 deletions
diff --git a/extensions/crypto/01_crypto.js b/extensions/crypto/01_crypto.js
new file mode 100644
index 000000000..dba6b0091
--- /dev/null
+++ b/extensions/crypto/01_crypto.js
@@ -0,0 +1,50 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+"use strict";
+
+((window) => {
+  const core = window.Deno.core;
+
+  function getRandomValues(arrayBufferView) {
+    if (!ArrayBuffer.isView(arrayBufferView)) {
+      throw new TypeError(
+        "Argument 1 does not implement interface ArrayBufferView",
+      );
+    }
+    if (
+      !(
+        arrayBufferView instanceof Int8Array ||
+        arrayBufferView instanceof Uint8Array ||
+        arrayBufferView instanceof Int16Array ||
+        arrayBufferView instanceof Uint16Array ||
+        arrayBufferView instanceof Int32Array ||
+        arrayBufferView instanceof Uint32Array ||
+        arrayBufferView instanceof Uint8ClampedArray
+      )
+    ) {
+      throw new DOMException(
+        "The provided ArrayBufferView is not an integer array type",
+        "TypeMismatchError",
+      );
+    }
+    if (arrayBufferView.byteLength > 65536) {
+      throw new DOMException(
+        `The ArrayBufferView's byte length (${arrayBufferView.byteLength}) exceeds the number of bytes of entropy available via this API (65536)`,
+        "QuotaExceededError",
+      );
+    }
+    const ui8 = new Uint8Array(
+      arrayBufferView.buffer,
+      arrayBufferView.byteOffset,
+      arrayBufferView.byteLength,
+    );
+    core.opSync("op_crypto_get_random_values", null, ui8);
+    return arrayBufferView;
+  }
+
+  window.crypto = {
+    getRandomValues,
+  };
+  window.__bootstrap.crypto = {
+    getRandomValues,
+  };
+})(this);
diff --git a/extensions/crypto/Cargo.toml b/extensions/crypto/Cargo.toml
new file mode 100644
index 000000000..91f60aa9c
--- /dev/null
+++ b/extensions/crypto/Cargo.toml
@@ -0,0 +1,19 @@
+# Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+[package]
+name = "deno_crypto"
+version = "0.19.0"
+edition = "2018"
+description = "Web Cryptography API implementation for Deno"
+authors = ["the Deno authors"]
+license = "MIT"
+readme = "README.md"
+repository = "https://github.com/denoland/deno"
+
+[lib]
+path = "lib.rs"
+
+[dependencies]
+deno_core = { version = "0.86.0", path = "../../core" }
+rand = "0.8.3"
+
diff --git a/extensions/crypto/README.md b/extensions/crypto/README.md
new file mode 100644
index 000000000..be0724458
--- /dev/null
+++ b/extensions/crypto/README.md
@@ -0,0 +1,5 @@
+# deno_crypto
+
+This crate implements the Web Cryptography API.
+
+Spec: https://www.w3.org/TR/WebCryptoAPI/
diff --git a/extensions/crypto/lib.deno_crypto.d.ts b/extensions/crypto/lib.deno_crypto.d.ts
new file mode 100644
index 000000000..a00757e71
--- /dev/null
+++ b/extensions/crypto/lib.deno_crypto.d.ts
@@ -0,0 +1,26 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+/// <reference no-default-lib="true" />
+/// <reference lib="esnext" />
+
+declare var crypto: Crypto;
+
+declare interface Crypto {
+  readonly subtle: null;
+  getRandomValues<
+    T extends
+      | Int8Array
+      | Int16Array
+      | Int32Array
+      | Uint8Array
+      | Uint16Array
+      | Uint32Array
+      | Uint8ClampedArray
+      | Float32Array
+      | Float64Array
+      | DataView
+      | null,
+  >(
+    array: T,
+  ): T;
+}
diff --git a/extensions/crypto/lib.rs b/extensions/crypto/lib.rs
new file mode 100644
index 000000000..45473f4d5
--- /dev/null
+++ b/extensions/crypto/lib.rs
@@ -0,0 +1,56 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+use deno_core::error::null_opbuf;
+use deno_core::error::AnyError;
+use deno_core::include_js_files;
+use deno_core::op_sync;
+use deno_core::Extension;
+use deno_core::OpState;
+use deno_core::ZeroCopyBuf;
+use rand::rngs::StdRng;
+use rand::thread_rng;
+use rand::Rng;
+use rand::SeedableRng;
+use std::path::PathBuf;
+
+pub use rand; // Re-export rand
+
+pub fn init(maybe_seed: Option<u64>) -> Extension {
+  Extension::builder()
+    .js(include_js_files!(
+      prefix "deno:extensions/crypto",
+      "01_crypto.js",
+    ))
+    .ops(vec![(
+      "op_crypto_get_random_values",
+      op_sync(op_crypto_get_random_values),
+    )])
+    .state(move |state| {
+      if let Some(seed) = maybe_seed {
+        state.put(StdRng::seed_from_u64(seed));
+      }
+      Ok(())
+    })
+    .build()
+}
+
+pub fn op_crypto_get_random_values(
+  state: &mut OpState,
+  _args: (),
+  zero_copy: Option<ZeroCopyBuf>,
+) -> Result<(), AnyError> {
+  let mut zero_copy = zero_copy.ok_or_else(null_opbuf)?;
+  let maybe_seeded_rng = state.try_borrow_mut::<StdRng>();
+  if let Some(seeded_rng) = maybe_seeded_rng {
+    seeded_rng.fill(&mut *zero_copy);
+  } else {
+    let mut rng = thread_rng();
+    rng.fill(&mut *zero_copy);
+  }
+
+  Ok(())
+}
+
+pub fn get_declaration() -> PathBuf {
+  PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("lib.deno_crypto.d.ts")
+}