1 files changed, 32 insertions, 0 deletions
diff --git a/dom/crypto/test/browser/browser_WebCrypto_telemetry.js b/dom/crypto/test/browser/browser_WebCrypto_telemetry.js
new file mode 100644
index 0000000000..c18915d6cd
--- /dev/null
+++ b/dom/crypto/test/browser/browser_WebCrypto_telemetry.js
@@ -0,0 +1,32 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global tv */
+
+const WEBCRYPTO_ALG_PROBE = "WEBCRYPTO_ALG";
+
+ChromeUtils.defineESModuleGetters(this, {
+  TelemetryTestUtils: "resource://testing-common/TelemetryTestUtils.sys.mjs",
+});
+
+add_task(async function ecdh_key() {
+  let hist = TelemetryTestUtils.getAndClearHistogram(WEBCRYPTO_ALG_PROBE);
+
+  let alg = { name: "ECDH", namedCurve: "P-256" };
+
+  let x = await crypto.subtle.generateKey(alg, false, [
+    "deriveKey",
+    "deriveBits",
+  ]);
+  let data = await crypto.subtle.deriveBits(
+    { name: "ECDH", public: x.publicKey },
+    x.privateKey,
+    128
+  );
+  is(data.byteLength, 128 / 8, "Should be 16 bytes derived");
+
+  TelemetryTestUtils.assertHistogram(hist, 20, 1);
+});