Node.js Hmac用法及代碼示例

類：Hmac

• 擴展： <stream.Transform>

Hmac 類是用於創建加密 HMAC 摘要的實用程序。它可以通過以下兩種方式之一使用：

• 作為可讀可寫的stream，其中寫入數據以在可讀端生成計算的HMAC摘要，或
• 使用 hmac.update() 和 hmac.digest() 方法生成計算的 HMAC 摘要。

crypto.createHmac() 方法用於創建Hmac 實例。 Hmac 對象不能直接使用new 關鍵字創建。

示例：使用 Hmac 對象作為流：

const {
  createHmac
} = await import('node:crypto');

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

hmac.on('readable', () => {
  // Only one element is going to be produced by the
  // hash stream.
  const data = hmac.read();
  if (data) {
    console.log(data.toString('hex'));
    // Prints:
    //   7fd04df92f636fd450bc841c9418e5825c17f33ad9c87c518115a45971f7f77e
  }
});

hmac.write('some data to hash');
hmac.end();const {
  createHmac,
} = require('node:crypto');

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

hmac.on('readable', () => {
  // Only one element is going to be produced by the
  // hash stream.
  const data = hmac.read();
  if (data) {
    console.log(data.toString('hex'));
    // Prints:
    //   7fd04df92f636fd450bc841c9418e5825c17f33ad9c87c518115a45971f7f77e
  }
});

hmac.write('some data to hash');
hmac.end();

示例：使用 Hmac 和管道流：

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

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

const input = createReadStream('test.js');
input.pipe(hmac).pipe(stdout);const {
  createReadStream,
} = require('node:fs');
const {
  createHmac,
} = require('node:crypto');
const { stdout } = require('node:process');

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

const input = createReadStream('test.js');
input.pipe(hmac).pipe(stdout);

示例：使用 hmac.update() 和 hmac.digest() 方法：

const {
  createHmac
} = await import('node:crypto');

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

hmac.update('some data to hash');
console.log(hmac.digest('hex'));
// Prints:
//   7fd04df92f636fd450bc841c9418e5825c17f33ad9c87c518115a45971f7f77econst {
  createHmac,
} = require('node:crypto');

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

hmac.update('some data to hash');
console.log(hmac.digest('hex'));
// Prints:
//   7fd04df92f636fd450bc841c9418e5825c17f33ad9c87c518115a45971f7f77e