The SubtleCrypto.unwrapKey()
method returns a Promise
of a CryptoKey
corresponding to the wrapped key given in parameter.
Syntax
var result = crypto.unwrapKey(format, wrappedKey, unwrappingKey, unwrapAlgo, unwrappedKeyAlgo, extractable, keyUsages)
;
Parameters
format
is an enumerated value describing the data format of the key to unwrapped. 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"
, usually a public key, in the Simple public key infrastructure standard"jwk"
, the key in the JSON Web Key format.
wrappedKey
is aArrayBuffer
or a ... containing the wrapped key in the given format.unwrappingKey
is theCryptoKey
to use to unwrap.unwrapAlgo
is theDOMString
} representing the algorithm used to perform the unwrapping. It is one of the following:AES-CBC
,AES-CTR
,AES-GCM
,RSA-OAEP
, andAES-KW
.unwrappedKeyAlgo
is theDOMString
} representing the algorithm of the wrapped key.extractable
is aBoolean
indicating if the key can be extracted from theCryptoKey
object at a later stage.keyUsages
is anArray
indicating what can be done with the unwrapped key. Possible values of the array are:"encrypt"
, allowing the key to be used for encrypting messages."decrypt"
, allowing the key to be used for decrypting messages."sign"
, allowing the key to be used for signing messages."verify"
, allowing the key to be used for verifying the signature of messages."deriveKey"
, allowing the key to be used as a base key when deriving a new key."deriveBits"
, allowing the key to be used as a base key when deriving bits of data for use in cryptographic primitives."wrapKey"
, allowing the key to wrap a symmetric key for usage (transfer, storage) in unsecure environments."unwrapKey"
, allowing the key to unwrap a symmetric key for usage (transfer, storage) in unsecure environments.
Return value
Exceptions
The promise is rejected when one of the following exceptions is encountered:
InvalidAccessError
when the unwrapping key is not a key for the requested unwrap algorithm or if theCryptoKey.usages
value of that key doesn't contain"unwrap"
.NotSupported
when trying to use an algorithm that is either unknown or isn't suitable for encryption or wrapping.SyntaxError
whenkeyUsages
is empty but the unwrapped key is of type"secret"
or"private"
.TypeError
when trying to use an invalid format.
Specifications
Specification | Status | Comment |
---|---|---|
Web Cryptography API The definition of 'SubtleCrypto.unwrapKey()' in that specification. |
Candidate Recommendation | Initial definition. |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 37 | (Yes) | 34 (34) | No support | ? | No support |
Feature | Android | Chrome for Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | (Yes) | 37 | (Yes) | 34.0 (34) | No support | ? | No support |
See also
Crypto
andCrypto.subtle
.SubtleCrypto
, the interface it belongs to.