CryptoKey: usages property
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The read-only usages
property of the CryptoKey
interface indicates what can be done with the key.
Value
An Array
of strings from the following list:
"encrypt"
: The key may be used toencrypt
messages."decrypt"
: The key may be used todecrypt
messages."sign"
: The key may be used tosign
messages."verify"
: The key may be used toverify
signatures."deriveKey"
: The key may be used inderiving a new key
."deriveBits"
: The key may be used inderiving bits
."wrapKey"
: The key may be used towrap a key
."unwrapKey"
: The key may be used tounwrap a key
.
Examples
js
const rawKey = window.crypto.getRandomValues(new Uint8Array(16));
// Import an AES secret key from an ArrayBuffer containing the raw bytes.
// Takes an ArrayBuffer string containing the bytes, and returns a Promise
// that will resolve to a CryptoKey representing the secret key.
function importSecretKey(rawKey) {
return window.crypto.subtle.importKey("raw", rawKey, "AES-GCM", true, [
"encrypt",
"decrypt",
]);
}
const key = importSecretKey(rawKey);
console.log(
`The following usages are reported for this key: ${key.usages.toString()}`
);
Specifications
Specification |
---|
Web Cryptography API # dom-cryptokey-usages |
Browser compatibility
BCD tables only load in the browser