crypto.createHmac(algorithm, key[, options])

• algorithm <string>
• key <string> | <ArrayBuffer> | <Buffer> | <TypedArray> | <DataView> | <KeyObject> | <CryptoKey>
• options <Object> stream.transform 选项
  • encoding <string> 当 key 为字符串时使用的字符串编码。
• 返回: <Hmac>

创建并返回一个使用指定 algorithm 和 key 的 Hmac 对象。可选的 options 参数用于控制流的行为。

【Creates and returns an Hmac object that uses the given algorithm and key. Optional options argument controls stream behavior.】

algorithm 取决于平台上 OpenSSL 版本支持的可用算法。例如 'sha256'、'sha512' 等。在较新的 OpenSSL 版本中，使用 openssl list -digest-algorithms 可以显示可用的摘要算法。

【The algorithm is dependent on the available algorithms supported by the version of OpenSSL on the platform. Examples are 'sha256', 'sha512', etc. On recent releases of OpenSSL, openssl list -digest-algorithms will display the available digest algorithms.】

key 是用于生成加密 HMAC 哈希的 HMAC 密钥。如果它是 KeyObject，则其类型必须为 secret。如果它是一个字符串，请考虑 将字符串用作加密 API 输入时的注意事项。如果它是从密码学安全的熵源获取的，例如 crypto.randomBytes() 或 crypto.generateKey()，其长度不应超过 algorithm 的块大小（例如，对于 SHA-256 为 512 位）。

【The key is the HMAC key used to generate the cryptographic HMAC hash. If it is a KeyObject, its type must be secret. If it is a string, please consider caveats when using strings as inputs to cryptographic APIs. If it was obtained from a cryptographically secure source of entropy, such as crypto.randomBytes() or crypto.generateKey(), its length should not exceed the block size of algorithm (e.g., 512 bits for SHA-256).】

示例：生成文件的 sha256 HMAC

【Example: generating the sha256 HMAC of a file】

import {
  createReadStream,
} from 'node:fs';
import { argv } from 'node:process';
const {
  createHmac,
} = await import('node:crypto');

const filename = argv[2];

const hmac = createHmac('sha256', 'a secret');

const input = createReadStream(filename);
input.on('readable', () => {
  // Only one element is going to be produced by the
  // hash stream.
  const data = input.read();
  if (data)
    hmac.update(data);
  else {
    console.log(`${hmac.digest('hex')} ${filename}`);
  }
});const {
  createReadStream,
} = require('node:fs');
const {
  createHmac,
} = require('node:crypto');
const { argv } = require('node:process');

const filename = argv[2];

const hmac = createHmac('sha256', 'a secret');

const input = createReadStream(filename);
input.on('readable', () => {
  // Only one element is going to be produced by the
  // hash stream.
  const data = input.read();
  if (data)
    hmac.update(data);
  else {
    console.log(`${hmac.digest('hex')} ${filename}`);
  }
});拷贝