Distributed captcha sending

type

server hook

Supports sending and verifying captcha codes, with cluster-based management of captcha codes

Features

• Easy to use;
• Support single machine, redis and other clusters to manage captcha codes;
• Customize captcha code validity time and resend interval;
• Captcha code anti-overwriting;
• Customize captcha code rules;

Usage

Basic usage

// Create
const { sendCaptcha, verifyCaptcha } = createCaptchaProvider({
  store: RedisAdapter()
});

// Send captcha code
const key = '1234567890';
await sendCaptcha(
  (code, mobile) => alova.Post('/sms/send', { code, mobile }),
  // Mobile phone number as storage key
  { key }
);

// Verify captcha code
const captchaFromUserInput = '1234';
const isValid = await verifyCaptcha(captchaFromUserInput, key);
console.log(isValid ? 'Captcha passed' : 'Captcha code error');

Set the captcha code storage

Before using it, you need to configure the storage of the captcha code through the store configuration. It is the storage adapter of Alova. If it is a single machine, you can use the file storage adapter, and in a distributed cluster, you can use the redis adapter. You can select the appropriate adapter in Storage Adapter, or Custom Storage Adapter.

const redisAdapter = new RedisStorageAdapter({
  host: 'localhost',
  port: '6379',
  username: 'default',
  password: 'my-top-secret',
  db: 0
});

createCaptchaProvider({
  store: redisAdapter
});

Captcha code expiration time

Use expireTime to set the captcha code validity period, in milliseconds, default 300000 (5 minutes).

createCaptchaProvider({
  expireTime: 10 * 60 * 1000
});

Captcha code resend interval

Use resetTime to set the captcha code resend interval, in milliseconds, default 60000 (1 minute).

createCaptchaProvider({
  resetTime: 5 * 60 * 1000
});

Captcha code overwriting prevention

Use resendFormStore to set whether to resend the existing captcha code from the storage to prevent the problem of inconsistent captcha codes caused by users sending multiple times.

createCaptchaProvider({
  // ...
  resendFormStore: true
});

Custom captcha code generation rules

By default, 4 captcha codes consisting of 0 to 9 will be generated. You can set the captcha code generation rules through codeSet configuration. The following three schemes are supported:

Preset character set and length

createCaptchaProvider({
  // ...
  codeSet: ['A', 'B', 'C', 1, 2, 3]
});

You can set the character set and length through codeSet configuration.

createCaptchaProvider({
  // ...
  codeSet: {
    chars: ['A', 'B', 'C', 1, 2, 3], // optional
    length: 6 // Generate 6-digit captcha code, optional
  }
});

Completely customize generation logic

You can also specify codeSet as a function to customize the generation rules.

createCaptchaProvider({
  codeSet: () => {
    // Generate a captcha code containing a check digit
    const baseCode = Math.random().toString().slice(2, 6);
    const checksum = baseCode.split('').reduce((a, b) => a + +b, 0) % 10;
    return baseCode + checksum; // such as "24682"
  }
});

Custom storage key prefix

To prevent conflicts with existing storage keys, you can set the storage key prefix through the keyPrefix configuration, which defaults to alova-captcha

createCaptchaProvider({
  // ...
  keyPrefix: 'payment-system'
});