1 files changed, 110 insertions, 1 deletions
diff --git a/cli/tests/unit/webcrypto_test.ts b/cli/tests/unit/webcrypto_test.ts
index fec412937..c4958fbdf 100644
--- a/cli/tests/unit/webcrypto_test.ts
+++ b/cli/tests/unit/webcrypto_test.ts
@@ -1,4 +1,9 @@
-import { assert, assertEquals, assertRejects } from "./test_util.ts";
+import {
+  assert,
+  assertEquals,
+  assertNotEquals,
+  assertRejects,
+} from "./test_util.ts";
 
 // https://github.com/denoland/deno/issues/11664
 Deno.test(async function testImportArrayBufferKey() {
@@ -608,6 +613,110 @@ Deno.test(async function testAesCbcEncryptDecrypt() {
   assertEquals(new Uint8Array(decrypted), new Uint8Array([1, 2, 3, 4, 5, 6]));
 });
 
+Deno.test(async function testAesCtrEncryptDecrypt() {
+  async function aesCtrRoundTrip(
+    key: CryptoKey,
+    counter: Uint8Array,
+    length: number,
+    plainText: Uint8Array,
+  ) {
+    const cipherText = await crypto.subtle.encrypt(
+      {
+        name: "AES-CTR",
+        counter,
+        length,
+      },
+      key,
+      plainText,
+    );
+
+    assert(cipherText instanceof ArrayBuffer);
+    assertEquals(cipherText.byteLength, plainText.byteLength);
+    assertNotEquals(new Uint8Array(cipherText), plainText);
+
+    const decryptedText = await crypto.subtle.decrypt(
+      {
+        name: "AES-CTR",
+        counter,
+        length,
+      },
+      key,
+      cipherText,
+    );
+
+    assert(decryptedText instanceof ArrayBuffer);
+    assertEquals(decryptedText.byteLength, plainText.byteLength);
+    assertEquals(new Uint8Array(decryptedText), plainText);
+  }
+  for (const keySize of [128, 192, 256]) {
+    const key = await crypto.subtle.generateKey(
+      { name: "AES-CTR", length: keySize },
+      true,
+      ["encrypt", "decrypt"],
+    ) as CryptoKey;
+
+    // test normal operation
+    for (const length of [128 /*, 64, 128 */]) {
+      const counter = await crypto.getRandomValues(new Uint8Array(16));
+
+      await aesCtrRoundTrip(
+        key,
+        counter,
+        length,
+        new Uint8Array([1, 2, 3, 4, 5, 6]),
+      );
+    }
+
+    // test counter-wrapping
+    for (const length of [32, 64, 128]) {
+      const plaintext1 = await crypto.getRandomValues(new Uint8Array(32));
+      const counter = new Uint8Array(16);
+
+      // fixed upper part
+      for (let off = 0; off < 16 - (length / 8); ++off) {
+        counter[off] = off;
+      }
+      const ciphertext1 = await crypto.subtle.encrypt(
+        {
+          name: "AES-CTR",
+          counter,
+          length,
+        },
+        key,
+        plaintext1,
+      );
+
+      // Set lower [length] counter bits to all '1's
+      for (let off = 16 - (length / 8); off < 16; ++off) {
+        counter[off] = 0xff;
+      }
+
+      // = [ 1 block of 0x00 + plaintext1 ]
+      const plaintext2 = new Uint8Array(48);
+      plaintext2.set(plaintext1, 16);
+
+      const ciphertext2 = await crypto.subtle.encrypt(
+        {
+          name: "AES-CTR",
+          counter,
+          length,
+        },
+        key,
+        plaintext2,
+      );
+
+      // If counter wrapped, 2nd block of ciphertext2 should be equal to 1st block of ciphertext1
+      // since ciphertext1 used counter = 0x00...00
+      // and ciphertext2 used counter = 0xFF..FF which should wrap to 0x00..00 without affecting
+      // higher bits
+      assertEquals(
+        new Uint8Array(ciphertext1),
+        new Uint8Array(ciphertext2).slice(16),
+      );
+    }
+  }
+});
+
 // TODO(@littledivy): Enable WPT when we have importKey support
 Deno.test(async function testECDH() {
   const namedCurve = "P-256";