SubtleCrypto.exportKey

The SubtleCrypto.exportKey() method returns a Promise of the key encrypted in the requested format. If the key is not extractable, that is if CryptoKey.extractable returns false, the promise fails with an InvalidAccessError exception; it the format is unknown, the promive fails with a NotSupported exception.

Syntax

var result = crypto.subtle.exportKey(format, key);

Parameters

• format is an enumerated value describing the data format in which the key has to be exported. It can be one of the following:
  • "raw", the key as an array of bytes, usually a secret key.
  • "pkcs8" a private key, in the IETF Public Key-Cryptographic Standard Encryption #8.
  • "spki", the public key in DER encoding of the SubjectPublicKeyInfo structure from RFC 5280.
  • "jwk", the key in the JSON Web Key format.
• key is the CryptoKey to export.

Return value

• result is a Promise that returns the key in the requested format.

Exceptions

The promise is rejected when one of the following exceptions is encountered:

• InvalidAccessError when trying to export an non-extractable key.
• NotSupported when trying to export in an unknown format.
• TypeError when trying to use an invalid format.

Specifications

Browser compatibility

See also

• Crypto and Crypto.subtle.
• SubtleCrypto, the interface it belongs to.