subtle.importKey(format, keyData, algorithm, extractable, keyUsages)
format: <string> 必须是'raw'、'pkcs8'、'spki'或'jwk'之一。keyData: <ArrayBuffer> | <TypedArray> | <DataView> | <Buffer> | <Object>
algorithm: <AlgorithmIdentifier> | <RsaHashedImportParams> | <EcKeyImportParams> | <HmacImportParams>
extractable: <boolean>keyUsages: <string[]> 参见 主要用途。- 返回：<Promise> 以 <CryptoKey> 完成
subtle.importKey() 方法尝试将提供的 keyData 按给定的 format 进行解析，以使用提供的 algorithm、extractable 和 keyUsages 参数创建一个 <CryptoKey> 实例。如果导入成功，返回的 promise 将会被解析为创建的 <CryptoKey>。
【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 必须为 false。
【If importing a 'PBKDF2' key, extractable must be false.】
目前支持的算法包括：
【The algorithms currently supported include:】
| Key Type | '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' | ✔ | ✔ | ✔ |