subtle.importKey(format, keyData, algorithm, extractable, keyUsages)

• format：<string> 必须是 'raw'、'pkcs8'、'spki' 或 'jwk' 之一。

  ¥format: <string> Must be one of 'raw', 'pkcs8', 'spki', or 'jwk'.

• keyData：<ArrayBuffer> | <TypedArray> | <DataView> | <Buffer> | <Object>

• algorithm：<string> | <AlgorithmIdentifier> | <RsaHashedImportParams> | <EcKeyImportParams> | <HmacImportParams>

• extractable：<boolean>

• keyUsages：<string[]> 参见 关键用法。

  ¥keyUsages: <string[]> See Key usages.

• 返回：<Promise> 成功后获得 <CryptoKey>。

  ¥Returns: <Promise> Fulfills with a <CryptoKey> upon success.

subtle.importKey() 方法尝试将提供的 keyData 解释为给定的 format，以使用提供的 algorithm、extractable 和 keyUsages 参数创建 <CryptoKey> 实例。如果导入成功，返回的 promise 将使用创建的 <CryptoKey> 进行解析。

¥The subtle.importKey() method attempts to interpret the provided keyData as the given format to create a <CryptoKey> instance using the provided algorithm, extractable, and keyUsages arguments. If the import is successful, the returned promise will be resolved with the created <CryptoKey>.

如果导入 'PBKDF2' 密钥，extractable 必须是 false。

¥If importing a 'PBKDF2' key, extractable must be false.

目前支持的算法包括：

¥The algorithms currently supported include:

支持的密钥算法	'spki'	'pkcs8'	'jwk'	'raw'
'AES-CBC'			✔	✔
'AES-CTR'			✔	✔
'AES-GCM'			✔	✔
'AES-KW'			✔	✔
'ECDH'	✔	✔	✔	✔
'X25519'	✔	✔	✔	✔
'X448' 1	✔	✔	✔	✔
'ECDSA'	✔	✔	✔	✔
'Ed25519'	✔	✔	✔	✔
'Ed448' 1	✔	✔	✔	✔
'HDKF'				✔
'HMAC'			✔	✔
'PBKDF2'				✔
'RSA-OAEP'	✔	✔	✔
'RSA-PSS'	✔	✔	✔
'RSASSA-PKCS1-v1_5'	✔	✔	✔