subtle.deriveBits(algorithm, baseKey[, length])

• algorithm <EcdhKeyDeriveParams> | <HkdfParams> | <Pbkdf2Params>

• baseKey <CryptoKey>

• length <number> | <null> 默认值：null

  ¥length <number> | <null> Default: null

• 返回：<Promise> 成功后使用 <ArrayBuffer> 完成。

  ¥Returns: <Promise> Fulfills with an <ArrayBuffer> upon success.

此方法使用 algorithm 指定的方法和参数以及 baseKey 提供的密钥材料，尝试生成 length 位。

¥Using the method and parameters specified in algorithm and the keying material provided by baseKey, this method attempts to generate length bits.

当未提供 length 或 null 时，将生成给定算法的最大位数。'ECDH'、'X25519' 和 'X448'⁵ 算法允许这样做，对于其他算法，length 必须为数字。

¥When length is not provided or null the maximum number of bits for a given algorithm is generated. This is allowed for the 'ECDH', 'X25519', and 'X448'⁵ algorithms, for other algorithms length is required to be a number.

如果成功，返回的 promise 将使用包含生成数据的 <ArrayBuffer> 进行解析。

¥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:

• 'Argon2d'⁴

• 'Argon2i'⁴

• 'Argon2id'⁴

• 'ECDH'

• 'HKDF'

• 'PBKDF2'

• 'X25519'

• 'X448'⁵