CryptoKey

The CryptoKey interface of the Web Crypto API represents a cryptographic key obtained from one of the SubtleCrypto methods generateKey(), deriveKey(), importKey(), or unwrapKey().

For security reasons, the CryptoKey interface can only be used in a secure context.

CryptoKey.type

String which may take one of the following values:

• "secret": This key is a secret key for use with a symmetric algorithm.
• "private": This key is the private half of an asymmetric algorithm's CryptoKeyPair.
• "public": This key is the public half of an asymmetric algorithm's CryptoKeyPair.

CryptoKey.extractable

A boolean value indicating whether or not the key may be extracted using SubtleCrypto.exportKey() or SubtleCrypto.wrapKey().

• true: The key may be extracted.
• false The key may not be extracted. exportKey() or wrapKey() will throw an exception if used to extract this key.

CryptoKey.algorithm

An object describing the algorithm for which this key can be used and any associated extra parameters.

• AesKeyGenParams if the algorithm is any of the AES variants.
• RsaHashedKeyGenParams if the algorithm is any of the RSA variants.
• EcKeyGenParams if the algorithm is any of the EC variants.
• HmacKeyGenParams if the algorithm is HMAC.

CryptoKey.usages

An Array of strings, indicating what can be done with the key. Possible values for array elements are:

• "encrypt": The key may be used to encrypt messages.
• "decrypt": The key may be used to decrypt messages.
• "sign": The key may be used to sign messages.
• "verify": The key may be used to verify signatures.
• "deriveKey": The key may be used in deriving a new key.
• "deriveBits": The key may be used in deriving bits.
• "wrapKey": The key may be used to wrap a key.
• "unwrapKey": The key may be used to unwrap a key.

The examples for SubtleCrypto methods often use CryptoKey objects. For example:

• SubtleCrypto.generateKey()
• SubtleCrypto.deriveKey()
• SubtleCrypto.importKey()
• SubtleCrypto.exportKey()
• SubtleCrypto.wrapKey()
• SubtleCrypto.unwrapKey()
• SubtleCrypto.encrypt()
• SubtleCrypto.decrypt()
• SubtleCrypto.sign()
• SubtleCrypto.verify()

• Web Crypto API
• Web security
• Privacy, permissions, and information security
• Crypto and Crypto.subtle.