Usage in Deno
import { KeyObject } from "node:crypto";
The following are non-functional stubs:
- from
- symmetricKeySize
- equals
- export
Node.js uses a KeyObject
class to represent a symmetric or asymmetric key,
and each kind of key exposes different functions. The createSecretKey, createPublicKey and createPrivateKey methods are used to create KeyObject
instances. KeyObject
objects are not to be created directly using the new
keyword.
Most applications should consider using the new KeyObject
API instead of
passing keys as strings or Buffer
s due to improved security features.
KeyObject
instances can be passed to other threads via postMessage()
.
The receiver obtains a cloned KeyObject
, and the KeyObject
does not need to
be listed in the transferList
argument.
asymmetricKeyDetails: AsymmetricKeyDetails | undefined
This property exists only on asymmetric keys. Depending on the type of the key, this object contains information about the key. None of the information obtained through this property can be used to uniquely identify a key or to compromise the security of the key.
For RSA-PSS keys, if the key material contains a RSASSA-PSS-params
sequence,
the hashAlgorithm
, mgf1HashAlgorithm
, and saltLength
properties will be
set.
Other key details might be exposed via this API using additional attributes.
asymmetricKeySize: number | undefined
For asymmetric keys, this property represents the size of the embedded key in
bytes. This property is undefined
for symmetric keys.
asymmetricKeyType: KeyType | undefined
For asymmetric keys, this property represents the type of the key. Supported key types are:
'rsa'
(OID 1.2.840.113549.1.1.1)'rsa-pss'
(OID 1.2.840.113549.1.1.10)'dsa'
(OID 1.2.840.10040.4.1)'ec'
(OID 1.2.840.10045.2.1)'x25519'
(OID 1.3.101.110)'x448'
(OID 1.3.101.111)'ed25519'
(OID 1.3.101.112)'ed448'
(OID 1.3.101.113)'dh'
(OID 1.2.840.113549.1.3.1)
This property is undefined
for unrecognized KeyObject
types and symmetric
keys.
symmetricKeySize: number | undefined
For secret keys, this property represents the size of the key in bytes. This
property is undefined
for asymmetric keys.
Depending on the type of this KeyObject
, this property is either'secret'
for secret (symmetric) keys, 'public'
for public (asymmetric) keys
or 'private'
for private (asymmetric) keys.
Returns true
or false
depending on whether the keys have exactly the same
type, value, and parameters. This method is not constant time.
export(options: KeyExportOptions<"pem">): string | Buffer
For symmetric keys, the following encoding options can be used:
For public keys, the following encoding options can be used:
For private keys, the following encoding options can be used:
The result type depends on the selected encoding format, when PEM the result is a string, when DER it will be a buffer containing the data encoded as DER, when JWK it will be an object.
When JWK encoding format was selected, all other encoding options are ignored.
PKCS#1, SEC1, and PKCS#8 type keys can be encrypted by using a combination of
the cipher
and format
options. The PKCS#8 type
can be used with anyformat
to encrypt any key algorithm (RSA, EC, or DH) by specifying acipher
. PKCS#1 and SEC1 can only be
encrypted by specifying a cipher
when the PEM format
is used. For maximum compatibility, use PKCS#8 for
encrypted private keys. Since PKCS#8 defines its own
encryption mechanism, PEM-level encryption is not supported when encrypting
a PKCS#8 key. See RFC 5208 for PKCS#8 encryption and RFC 1421 for
PKCS#1 and SEC1 encryption.
export(options?: KeyExportOptions<"der">): Buffer
export(options?: JwkKeyExportOptions): JsonWebKey
from(key: webcrypto.CryptoKey): KeyObject
Example: Converting a CryptoKey
instance to a KeyObject
:
const { KeyObject } = await import('node:crypto');
const { subtle } = globalThis.crypto;
const key = await subtle.generateKey({
name: 'HMAC',
hash: 'SHA-256',
length: 256,
}, true, ['sign', 'verify']);
const keyObject = KeyObject.from(key);
console.log(keyObject.symmetricKeySize);
// Prints: 32 (symmetric key size in bytes)