session-sms.md

Email captcha base session

0. Install the required nuget package

       Install-Package NCaptcha.AspNetCore.SessionSms
       Install-Package NCaptcha.Targets.Sms.Aliyun

1. Add Options in the appsettings.json file. It depends on which SMS service you choose.

   "CaptchaAliyunSms": {
       "AccountKeyId": "",
       "AccessKeySecret": "",
       "SmsServiceSignName": "",
       "SmsServiceTemplateCode": ""
   }

2. Register in DI

   public void ConfigureServices(IServiceCollection services)
   {
       services.AddSession();
       services.AddSessionBasedSmsCaptcha(builder =>
           builder.UseAliyunSmsCaptcha(Configuration.GetSection("CaptchaAliyunSms").Bind);
       );
   }

3. Configure the session

   public void Configure(IApplicationBuilder app)
   {
       app.UseSession();
   }

4. Add a API for sending captcha code

   public class LoginModel : PageModel
   {
       private readonly ICaptchaGenerator _captchaGenerator;
   
       public LoginModel(ICaptchaGenerator captchaGenerator)
       {
           _captchaGenerator = captchaGenerator;
       }
   
       public async Task OnPostSendCaptchaAsync() => await _captchaGenerator.GenerateCaptchaAsync();
   }

5. Validate the captcha

   public class LoginModel : PageModel
   {
       private readonly ICaptchaValidator _captchaValidator;
   
       public LoginModel(ICaptchaValidator captchaValidator)
       {
           _captchaValidator = captchaValidator;
       }
   
       public async Task<IActionResult> OnPostAsync()
       {
           if (!await _captchaValidator.ValidateAsync(Input.Captcha))
           {
               ModelState.AddModelError(nameof(InputModel.Captcha), "Invalid captcha.");
               return Page();
           }
       }
   }