exportKey

The exportKey() method takes a CryptoKey object as input and exports it in an external, portable format.

Note that for a key to be exportable, it must have been created with the extractable flag set to true.

Usage

exportKey(format, key)

Parameters

Name	Type	Description
`format`	`string`	Defines the data format in which the key should be exported. Depending on the algorithm and key type, the data format could vary. Currently supported formats are `raw`, `jwk`, `spki`, and `pkcs8`.
`key`	CryptoKey	The key to export.

Supported algorithms

AES-CBC	AES-CTR	AES-GCM	AES-KW	ECDH	ECDSA	HMAC	PBKDF2	RSA-OAEP	RSASSA-PKCS1-v1_5	RSA-PSS
✅ AesCbcParams	✅ AesCtrParams	✅ AesGcmParams	❌	✅ EcdhKeyDeriveParams	✅ EcdsaParams	✅ HmacKeyGenParams	✅ Pbkdf2Params	✅ RsaHashedImportParams	✅ RsaHashedImportParams	✅ RsaHashedImportParams

Supported formats

ECDH and ECDSA algorithms have support for pkcs8, spki, raw and jwk formats.
RSA-OAEP, RSASSA-PKCS1-v1_5 and RSA-PSS algorithms have support for pkcs8, spki and jwk formats.
AES-* and HMAC algorithms have currently support for raw and jwk formats.
PBKDF2 algorithm has support for raw format only.

Return Value

A Promise that resolves to a new ArrayBuffer or an JsonWebKey object/dictionary containing the key.

Throws

Type	Description
`InvalidAccessError`	Raised when trying to export a non-extractable key.
`NotSupportedError`	Raised when trying to export in an unknown format.
`TypeError`	Raised when trying to use an invalid format.

Example

export default async function () {
  /**
   * Generate a symmetric key using the AES-CBC algorithm.
   */
  const generatedKey = await crypto.subtle.generateKey(
    {
      name: 'AES-CBC',
      length: '256',
    },
    true,
    ['encrypt', 'decrypt']
  );

  /**
   * Export the key in raw format.
   */
  const exportedKey = await crypto.subtle.exportKey('raw', generatedKey);

  /**
   * Reimport the key in raw format to verify its integrity.
   */
  const importedKey = await crypto.subtle.importKey('raw', exportedKey, 'AES-CBC', true, [
    'encrypt',
    'decrypt',
  ]);

  console.log(JSON.stringify(importedKey));
}