CryptoKey: type property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is available in Web Workers.

The read-only type property of the CryptoKey interface indicates which kind of key is represented by the object. It can have the following values:

Value

One of the following strings: "secret", "private", or "public".

Examples

This function verifies a message using SubtleCrypto.verify() and a public key given in the parameter. If the key is not a public key, it always returns "invalid", as such verification is fundamentally insecure.

js
async function verifyMessage(publicKey) {
  const signatureValue = document.querySelector(
    ".rsassa-pkcs1 .signature-value",
  );
  signatureValue.classList.remove("valid", "invalid");

  let result = false; // By default, it is invalid

  if (publicKey.type === "public") {
    const encoded = getMessageEncoding();
    result = await window.crypto.subtle.verify(
      "RSASSA-PKCS1-v1_5",
      publicKey,
      signature,
      encoded,
    );
  }

  signatureValue.classList.add(result ? "valid" : "invalid");
}

Specifications

Specification
Web Cryptography API
# dom-cryptokey-type

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
type

Legend

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Full support
Full support