Feature/captcha

src/Argon.Api/Features/Captcha/CaptchaFeature.cs

@@ -0,0 +1,21 @@
+namespace Argon.Api.Features.Captcha;
+
+using Microsoft.Extensions.Configuration;
+
+public static class CaptchaFeature
+{
+    public static IServiceCollection AddCaptchaFeature(this WebApplicationBuilder builder)
+    {
+        var cfg = builder.Configuration.GetSection("Captcha");
+        builder.Services.Configure<CaptchaOptions>(cfg);
+        var kind = cfg.GetValue<CaptchaKind>("Kind");
+
+        return kind switch
+        {
+            CaptchaKind.NO_CAPTCHA => builder.Services.AddTransient<ICaptchaFeature, NullCaptcha>(),
+            CaptchaKind.CLOUDFLARE => builder.Services.AddTransient<ICaptchaFeature, CloudflareCaptcha>(),
+            CaptchaKind.YANDEX     => builder.Services.AddTransient<ICaptchaFeature, YandexCaptcha>(),
+            _                      => throw new ArgumentOutOfRangeException()
+        };
+    }
+}

src/Argon.Api/Features/Captcha/CaptchaKind.cs

@@ -0,0 +1,8 @@
+namespace Argon.Api.Features.Captcha;
+
+public enum CaptchaKind
+{
+    NO_CAPTCHA,
+    CLOUDFLARE,
+    YANDEX
+}

src/Argon.Api/Features/Captcha/CaptchaOptions.cs

@@ -0,0 +1,9 @@
+namespace Argon.Api.Features.Captcha;
+
+public class CaptchaOptions
+{
+    public string      SiteKey           { get; set; }
+    public string      SiteSecret        { get; set; }
+    public string      ChallengeEndpoint { get; set; }
+    public CaptchaKind Kind              { get; set; }
+}

src/Argon.Api/Features/Captcha/CloudflareCaptcha.cs

@@ -0,0 +1,41 @@
+namespace Argon.Api.Features.Captcha;
+
+using Extensions;
+using Flurl.Http;
+using Microsoft.Extensions.Options;
+
+public class CloudflareCaptcha(HttpContext httpContext, ILogger<ICaptchaFeature> logger, IOptions<CaptchaOptions> options) : ICaptchaFeature
+{
+    public async ValueTask<bool> ValidateAsync(string token)
+    {
+        if (string.IsNullOrEmpty(token))
+            return false;
+        var config   = options.Value;
+        var remoteIp = httpContext.GetIpAddress();
+        try
+        {
+            var response = await config.ChallengeEndpoint
+               .PostMultipartAsync(content => content
+                   .AddString("secret", config.SiteSecret)
+                   .AddString("response", token)
+                   .AddString("remoteip", remoteIp))
+               .ReceiveJson<CloudflareTurnstileResponse>();
+            logger.LogInformation("Success validate captcha token {Challenge_ts} {Hostname}", response.Challenge_ts, response.Hostname);
+            return response?.Success ?? false;
+        }
+        catch (Exception ex)
+        {
+            logger.LogCritical(ex, "failed validate captcha token");
+            return false;
+        }
+    }
+
+    public class CloudflareTurnstileResponse
+    {
+        public bool     Success      { get; set; }
+        public string   Challenge_ts { get; set; }
+        public string   Hostname     { get; set; }
+        public string[] ErrorCodes   { get; set; }
+    }
+
+}

src/Argon.Api/Features/Captcha/ICaptchaFeature.cs

@@ -0,0 +1,6 @@
+namespace Argon.Api.Features.Captcha;
+
+public interface ICaptchaFeature
+{
+    ValueTask<bool> ValidateAsync(string token);
+}

src/Argon.Api/Features/Captcha/NullCaptcha.cs

@@ -0,0 +1,6 @@
+namespace Argon.Api.Features.Captcha;
+
+public class NullCaptcha : ICaptchaFeature
+{
+    public ValueTask<bool> ValidateAsync(string token) => new(true);
+}

src/Argon.Api/Features/Captcha/YandexCaptcha.cs

@@ -0,0 +1,6 @@
+namespace Argon.Api.Features.Captcha;
+
+public class YandexCaptcha : ICaptchaFeature
+{
+    public ValueTask<bool> ValidateAsync(string token) => throw new NotImplementedException();
+}

src/Argon.Api/Program.cs

@@ -5,6 +5,7 @@
 using Argon.Api.Entities;
 using Argon.Api.Extensions;
 using Argon.Api.Features;
+using Argon.Api.Features.Captcha;
 using Argon.Api.Features.EmailForms;
 using Argon.Api.Features.Env;
 using Argon.Api.Features.Jwt;
@@ -43,6 +44,7 @@
 builder.AddOrleans();
 builder.AddEMailForms();
 builder.AddKubeResources();
+builder.AddCaptchaFeature();
 builder.Services.AddDataProtection();
 builder.Services.AddAutoMapper(typeof(User).Assembly); // TODO
 var app = builder.Build();

src/Argon.Api/appsettings.json

@@ -41,5 +41,11 @@
   "Orleans": {
     "ClusterId": "argonapi",
     "ServiceId": "argonapi"
+  },
+  "Captcha": {
+    "SiteKey": "",
+    "SiteSecret": "",
+    "ChallengeEndpoint": "",
+    "Kind": "NO_CAPTCHA"
   }
 }