在 Nestjs 中使用验证码

import { Controller, Get, Query } from '@nestjs/common';
import { ApiTags } from '@nestjs/swagger';

import { CaptchaService } from './captcha.service';

@ApiTags('本地验证码')
@Controller('captcha')
export class CaptchaController {
    constructor(private readonly captchaService: CaptchaService) {}

    @Get('svg')
    createSvg() {
        return this.captchaService.create('svg');
    }

    @Get('math')
    createMath() {
        return this.captchaService.create('math');
    }

    @Get('verify')
    get(@Query('key') key: string, @Query('text') text: string) {
        return this.captchaService.verify(key, text);
    }
}

import { Cache } from '@nestjs/cache-manager';
import { BadRequestException, Injectable } from '@nestjs/common';
import * as svgCaptcha from 'svg-captcha';
import { v4 as uuidv4 } from 'uuid';

import { CacheKeys } from '@/common/enum/cache-keys.enum';

@Injectable()
export class CaptchaService {
    constructor(private readonly cache: Cache) {}

    // 生成验证码，可以选择是否是数学计算
    async create(type: 'math' | 'svg' = 'svg') {
        let captcha: svgCaptcha.CaptchaObj;
        if (type === 'math') {
            captcha = svgCaptcha.createMathExpr({
                mathMin: 0,
                mathMax: 9,
                noise: 1,
                color: true,
            });
        }
        else {
            captcha = svgCaptcha.create({
                ignoreChars: '0o1i',
                noise: 1,
                color: true,
            });
        }

        // 生成一个uuid，调用接口时需要把这个 key 和内容一起传过来，用来校验此次输入是否正确
        const key = uuidv4();
        try {
            // 将生成好的验证码的正确文本缓存起来，后续用来根据 key 做比对
            await this.cache.set(`${CacheKeys.CAPTCHA_CACHE_KEY}:${key}`, captcha.text, 60 * 1000); // 缓存 1 分钟
        }
        catch (error) {
            console.log(error, 'error');
        }

        return {
            key,
            svg: captcha.data,
        };
    }

    // 校验输入的验证码是否正确
    async verify(key: string, text: string) {
        const captchaText = await this.cache.get<string>(`${CacheKeys.CAPTCHA_CACHE_KEY}:${key}`);

        if (captchaText !== text) {
            throw new BadRequestException('验证码错误');
        }

        return true;
    }
}

import { createKeyv } from '@keyv/redis';
import { CacheModule } from '@nestjs/cache-manager';
import { Module } from '@nestjs/common';

import { ConfigModule } from '@/config/config.module';
import { ConfigService } from '@/config/config.service';

import { AppController } from './app.controller';
import { CaptchaModule } from './system/captcha/captcha.module';

@Module({
    imports: [
        CacheModule.registerAsync({
            imports: [ConfigModule],
            inject: [ConfigService],
            isGlobal: true, // 这里有 global 后，别的模块使用时直接 `private readonly cache: Cache` 注入即可
            useFactory(config: ConfigService) {
                return {
                    stores: [
                        createKeyv({
                            url: `redis://${config.cache.redis.host}:${config.cache.redis.port}`,
                            password: config.cache.redis.password,
                        }),
                    ],
                    ttl: config.cache.ttl,
                };
            },
        }),
        CaptchaModule,
    ],
    controllers: [AppController],
    providers: [AppService],
})
export class AppModule {}