crypto文档:http://nodejs.org/api/crypto.html

const crypto = require('crypto')

const text = 'I love cupcakes'
const key = 'abcdeg'

crypto.createHmac('sha1', key)
  .update(text)
  .digest('hex')

几年前，有人说update()和digest()是遗留方法，并引入了新的流API方法。现在，文档表明这两种方法都可以使用。例如:

var crypto    = require('crypto');
var text      = 'I love cupcakes';
var secret    = 'abcdeg'; //make this your secret!!
var algorithm = 'sha1';   //consider using sha256
var hash, hmac;

// Method 1 - Writing to a stream
hmac = crypto.createHmac(algorithm, secret);    
hmac.write(text); // write in to the stream
hmac.end();       // can't read from the stream until you call end()
hash = hmac.read().toString('hex');    // read out hmac digest
console.log("Method 1: ", hash);

// Method 2 - Using update and digest:
hmac = crypto.createHmac(algorithm, secret);
hmac.update(text);
hash = hmac.digest('hex');
console.log("Method 2: ", hash);

在节点v6.2.2和v7.7.2上进行了测试

见https://nodejs.org/api/crypto.html # crypto_class_hmac。给出使用流方法的更多示例。

Gwerder的解决方案不会工作，因为hash = hmac.read();在流完成最终确定之前发生。这就是AngraX的问题所在。还有hmac。Write语句在本例中不需要。

而是这样做:

var crypto    = require('crypto');
var hmac;
var algorithm = 'sha1';
var key       = 'abcdeg';
var text      = 'I love cupcakes';
var hash;

hmac = crypto.createHmac(algorithm, key);

// readout format:
hmac.setEncoding('hex');
//or also commonly: hmac.setEncoding('base64');

// callback is attached as listener to stream's finish event:
hmac.end(text, function () {
    hash = hmac.read();
    //...do something with the hash...
});

更正式的说法是，如果你愿意的话

hmac.end(text, function () {

可以写成

hmac.end(text, 'utf8', function () {

因为在这个例子中，text是一个utf字符串

尽管有所有签名和验证哈希算法的示例代码，但我仍然需要进行一些实验和调整才能使其工作。这是我的工作样本，我相信它涵盖了所有的边缘情况。

它是URL安全的(即不需要编码)，它需要一个过期时间，并且不会意外抛出异常。有一个对Day.js的依赖，但是你可以用另一个日期库替换它，或者滚动你自己的日期比较。

用TypeScript编写:

// signature.ts
import * as crypto from 'crypto';
import * as dayjs from 'dayjs';

const key = 'some-random-key-1234567890';

const replaceAll = (
  str: string,
  searchValue: string,
  replaceValue: string,
) => str.split(searchValue).join(replaceValue);

const swap = (str: string, input: string, output: string) => {
  for (let i = 0; i < input.length; i++)
    str = replaceAll(str, input[i], output[i]);

  return str;
};

const createBase64Hmac = (message: string, expiresAt: Date) =>
  swap(
    crypto
      .createHmac('sha1', key)
      .update(`${expiresAt.getTime()}${message}`)
      .digest('hex'),
    '+=/', // Used to avoid characters that aren't safe in URLs
    '-_,',
  );

export const sign = (message: string, expiresAt: Date) =>
  `${expiresAt.getTime()}-${createBase64Hmac(message, expiresAt)}`;

export const verify = (message: string, hash: string) => {
  const matches = hash.match(/(.+?)-(.+)/);
  if (!matches) return false;

  const expires = matches[1];
  const hmac = matches[2];

  if (!/^\d+$/.test(expires)) return false;

  const expiresAt = dayjs(parseInt(expires, 10));
  if (expiresAt.isBefore(dayjs())) return false;

  const expectedHmac = createBase64Hmac(message, expiresAt.toDate());
  // Byte lengths must equal, otherwise crypto.timingSafeEqual will throw an exception
  if (hmac.length !== expectedHmac.length) return false;

  return crypto.timingSafeEqual(
    Buffer.from(hmac),
    Buffer.from(expectedHmac),
  );
};

你可以这样使用它:

import { sign, verify } from './signature';

const message = 'foo-bar';
const expiresAt = dayjs().add(1, 'day').toDate();
const hash = sign(message, expiresAt);

const result = verify(message, hash);

expect(result).toBe(true);