Handling panics in encrypt/decrypt

webcrypto/subtle_crypto.go

@@ -94,7 +94,16 @@ func (sc *SubtleCrypto) Encrypt( //nolint:dupl // we have two similar methods
 
 	callback := sc.vu.RegisterCallback()
 	go func() {
-		result, err := encrypter.Encrypt(plaintext, ck)
+		result, err := func() (result []byte, err error) {
+			defer func() {
+				if r := recover(); r != nil {
+					err = NewError(OperationError, fmt.Sprintf("an unexpected error during encrypting happened: %s", r))
+				}
+			}()
+
+			result, err = encrypter.Encrypt(plaintext, ck)
+			return
+		}()
 
 		callback(func() error {
 			if err != nil {
@@ -186,7 +195,16 @@ func (sc *SubtleCrypto) Decrypt( //nolint:dupl // we have two similar methods
 
 	callback := sc.vu.RegisterCallback()
 	go func() {
-		result, err := decrypter.Decrypt(ciphertext, ck)
+		result, err := func() (result []byte, err error) {
+			defer func() {
+				if r := recover(); r != nil {
+					err = NewError(OperationError, fmt.Sprintf("an unexpected error during decrypting happened: %s", r))
+				}
+			}()
+
+			result, err = decrypter.Decrypt(ciphertext, ck)
+			return
+		}()
 
 		callback(func() error {
 			if err != nil {

webcrypto/tests/cmd_run_test.go

@@ -99,6 +99,25 @@ func TestExamplesInputOutput(t *testing.T) {
 	}
 }
 
+func TestHandlePanic(t *testing.T) {
+	t.Parallel()
+
+	script, err := os.ReadFile("handle-panic.js") //nolint:forbidigo // it's a test case
+	require.NoError(t, err)
+
+	ts := getSingleFileTestState(t, string(script), []string{"-v", "--log-output=stdout"}, 0)
+
+	cmd.ExecuteWithGlobalState(ts.GlobalState)
+
+	stdout := ts.Stdout.String()
+
+	assert.Contains(t, stdout, "1 complete and 0 interrupted iterations")
+	// We expect the panic message to be printed
+	assert.Contains(t, stdout, "Uncaught")
+
+	assert.Empty(t, ts.Stderr.String())
+}
+
 func getFiles(t *testing.T, path string) []string {
 	t.Helper()
 

webcrypto/tests/handle-panic.js

@@ -0,0 +1,40 @@
+// this example demonstrates how to handle panic in the decrypt function
+// we intentionally cut transmittedData from 12 to the end, so it will panic
+// the panic will be caught
+import { crypto } from "k6/experimental/webcrypto";
+
+export default async function () {
+  const keyData = new Uint8Array([
+    7, 152, 164, 45, 255, 169, 164, 66, 164, 163, 20, 197, 194, 223, 48, 213,
+    93, 115, 173, 86, 215, 81, 128, 188, 45, 237, 156, 92, 163, 197, 248, 114,
+  ]);
+
+  const transmittedData = new Uint8Array([
+    167, 9, 89, 202, 97, 13, 137, 77, 223, 24, 226, 161, 225, 228, 121, 248,
+    181, 4, 25, 202, 215, 230, 193, 94, 143, 77, 187, 231, 84, 3, 198, 75, 22,
+    211, 83, 101, 241, 159, 117, 124, 155, 229, 244, 173, 58, 149, 57, 18,
+  ]);
+
+  const iv = new Uint8Array(transmittedData.slice(0, 16));
+
+  // we intentionally cut incorrectly transmittedData from 12 to the end
+  const encryptedData = new Uint8Array(transmittedData.slice(12));
+
+  const importedKey = await crypto.subtle.importKey(
+    "raw",
+    keyData,
+    { name: "AES-CBC", length: "256" },
+    true,
+    ["encrypt", "decrypt"]
+  );
+
+  // if we pass such transmittedData to decrypt function, it will panic
+  await crypto.subtle.decrypt(
+    {
+      name: "AES-CBC",
+      iv: iv,
+    },
+    importedKey,
+    encryptedData
+  );
+}