Add Cap Captcha support

- Add CaptchaCap type constant in types.go
- Add Cap struct with InstanceURL, KeyID, and KeySecret fields
- Add CapCaptcha method in provider.go to return Cap settings
- Add default settings for Cap captcha in setting.go
- Implement Cap captcha verification logic in middleware
- Expose Cap captcha settings in site API

This adds support for Cap captcha service as an alternative
captcha option alongside existing reCAPTCHA, Turnstile and
built-in captcha options.

inventory/setting.go

@@ -143,6 +143,9 @@ var DefaultSettings = map[string]string{
 	"captcha_ReCaptchaSecret":                    "defaultSecret",
 	"captcha_turnstile_site_key":                 "",
 	"captcha_turnstile_site_secret":              "",
+	"captcha_cap_instance_url":                   "",
+	"captcha_cap_key_id":                         "",
+	"captcha_cap_key_secret":                     "",
 	"thumb_width":                                "400",
 	"thumb_height":                               "300",
 	"thumb_entity_suffix":                        "._thumb",

middleware/captcha.go

@@ -38,6 +38,9 @@ type (
 	turnstileResponse struct {
 		Success bool `json:"success"`
 	}
+	capResponse struct {
+		Success bool `json:"success"`
+	}
 )
 
 // CaptchaRequired 验证请求签名
@@ -127,6 +130,61 @@ func CaptchaRequired(enabled func(c *gin.Context) bool) gin.HandlerFunc {
 					return
 				}
 
+				break
+			case setting.CaptchaCap:
+				captchaSetting := settings.CapCaptcha(c)
+				if captchaSetting.InstanceURL == "" || captchaSetting.KeyID == "" || captchaSetting.KeySecret == "" {
+					l.Warning("Cap verification failed: missing configuration")
+					c.JSON(200, serializer.ErrWithDetails(c, serializer.CodeCaptchaError, "Captcha configuration error", nil))
+					c.Abort()
+					return
+				}
+
+				r := dep.RequestClient(
+					request2.WithContext(c),
+					request2.WithLogger(logging.FromContext(c)),
+					request2.WithHeader(http.Header{"Content-Type": []string{"application/json"}}),
+				)
+
+				capEndpoint := strings.TrimSuffix(captchaSetting.InstanceURL, "/") + "/" + captchaSetting.KeyID + "/siteverify"
+				requestBody := map[string]string{
+					"secret":   captchaSetting.KeySecret,
+					"response": service.Ticket,
+				}
+				requestData, err := json.Marshal(requestBody)
+				if err != nil {
+					l.Warning("Cap verification failed: %s", err)
+					c.JSON(200, serializer.ErrWithDetails(c, serializer.CodeCaptchaError, "Captcha validation failed", err))
+					c.Abort()
+					return
+				}
+
+				res, err := r.Request("POST", capEndpoint, strings.NewReader(string(requestData))).
+					CheckHTTPResponse(http.StatusOK).
+					GetResponse()
+				if err != nil {
+					l.Warning("Cap verification failed: %s", err)
+					c.JSON(200, serializer.ErrWithDetails(c, serializer.CodeCaptchaError, "Captcha validation failed", err))
+					c.Abort()
+					return
+				}
+
+				var capRes capResponse
+				err = json.Unmarshal([]byte(res), &capRes)
+				if err != nil {
+					l.Warning("Cap verification failed: %s", err)
+					c.JSON(200, serializer.ErrWithDetails(c, serializer.CodeCaptchaError, "Captcha validation failed", err))
+					c.Abort()
+					return
+				}
+
+				if !capRes.Success {
+					l.Warning("Cap verification failed: validation returned false")
+					c.JSON(200, serializer.ErrWithDetails(c, serializer.CodeCaptchaError, "Captcha validation failed", nil))
+					c.Abort()
+					return
+				}
+
 				break
 			}
 		}

pkg/setting/provider.go

@@ -38,6 +38,8 @@ type (
 		TcCaptcha(ctx context.Context) *TcCaptcha
 		// TurnstileCaptcha returns the Cloudflare Turnstile settings.
 		TurnstileCaptcha(ctx context.Context) *Turnstile
+		// CapCaptcha returns the Cap settings.
+		CapCaptcha(ctx context.Context) *Cap
 		// EmailActivationEnabled returns true if email activation is required.
 		EmailActivationEnabled(ctx context.Context) bool
 		// DefaultGroup returns the default group ID for new users.
@@ -638,6 +640,14 @@ func (s *settingProvider) TurnstileCaptcha(ctx context.Context) *Turnstile {
 	}
 }
 
+func (s *settingProvider) CapCaptcha(ctx context.Context) *Cap {
+	return &Cap{
+		InstanceURL: s.getString(ctx, "captcha_cap_instance_url", ""),
+		KeyID:       s.getString(ctx, "captcha_cap_key_id", ""),
+		KeySecret:   s.getString(ctx, "captcha_cap_key_secret", ""),
+	}
+}
+
 func (s *settingProvider) ReCaptcha(ctx context.Context) *ReCaptcha {
 	return &ReCaptcha{
 		Secret: s.getString(ctx, "captcha_ReCaptchaSecret", ""),

pkg/setting/types.go

@@ -28,6 +28,7 @@ const (
 	CaptchaReCaptcha = CaptchaType("recaptcha")
 	CaptchaTcaptcha  = CaptchaType("tcaptcha")
 	CaptchaTurnstile = CaptchaType("turnstile")
+	CaptchaCap       = CaptchaType("cap")
 )
 
 type ReCaptcha struct {
@@ -47,6 +48,12 @@ type Turnstile struct {
 	Secret string
 }
 
+type Cap struct {
+	InstanceURL string
+	KeyID       string
+	KeySecret   string
+}
+
 type SMTP struct {
 	FromName        string
 	From            string

service/basic/site.go

@@ -28,6 +28,8 @@ type SiteConfig struct {
 	ReCaptchaKey     string              `json:"captcha_ReCaptchaKey,omitempty"`
 	CaptchaType      setting.CaptchaType `json:"captcha_type,omitempty"`
 	TurnstileSiteID  string              `json:"turnstile_site_id,omitempty"`
+	CapInstanceURL   string              `json:"cap_instance_url,omitempty"`
+	CapKeyID         string              `json:"cap_key_id,omitempty"`
 	RegisterEnabled  bool                `json:"register_enabled,omitempty"`
 	TosUrl           string              `json:"tos_url,omitempty"`
 	PrivacyPolicyUrl string              `json:"privacy_policy_url,omitempty"`
@@ -119,6 +121,7 @@ func (s *GetSettingService) GetSiteConfig(c *gin.Context) (*SiteConfig, error) {
 	userRes := user.BuildUser(u, dep.HashIDEncoder())
 	logo := settings.Logo(c)
 	reCaptcha := settings.ReCaptcha(c)
+	capCaptcha := settings.CapCaptcha(c)
 	appSetting := settings.AppSetting(c)
 
 	return &SiteConfig{
@@ -132,6 +135,8 @@ func (s *GetSettingService) GetSiteConfig(c *gin.Context) (*SiteConfig, error) {
 		CaptchaType:     settings.CaptchaType(c),
 		TurnstileSiteID: settings.TurnstileCaptcha(c).Key,
 		ReCaptchaKey:    reCaptcha.Key,
+		CapInstanceURL:  capCaptcha.InstanceURL,
+		CapKeyID:        capCaptcha.KeyID,
 		AppPromotion:    appSetting.Promotion,
 	}, nil
 }