subtle.deriveBits(algorithm, baseKey, length)

• algorithm：<AlgorithmIdentifier> | <EcdhKeyDeriveParams> | <HkdfParams> | <Pbkdf2Params>
• baseKey：<CryptoKey>
• length：<number>
• 返回：<Promise> 包含 <ArrayBuffer>

使用 algorithm 中指定的方法和参数以及 baseKey 提供的密钥材料，subtle.deriveBits() 尝试生成 length 位。如果成功，返回的 promise 将会被解析为包含生成数据的 <ArrayBuffer>。Node.js 的实现要求 length 必须是 8 的倍数。

🌐 Using the method and parameters specified in algorithm and the keying material provided by baseKey, subtle.deriveBits() attempts to generate length bits. The Node.js implementation requires that length is a multiple of 8. If successful, the returned promise will be resolved with an <ArrayBuffer> containing the generated data.

目前支持的算法包括：

🌐 The algorithms currently supported include:

• 'ECDH'
• 'HKDF'
• 'PBKDF2'