kra-new/internal/server/middleware/cors.go

66 lines
2.1 KiB
Go

package middleware
import (
"net/http"
"strings"
"kra/internal/conf"
"github.com/gin-gonic/gin"
)
const (
defaultCORSHeaders = "Content-Type,AccessToken,X-CSRF-Token, Authorization, Token,X-Token,X-User-Id"
defaultCORSMethods = "POST, GET, OPTIONS,DELETE,PUT"
defaultCORSExpose = "Content-Length, Access-Control-Allow-Origin, Access-Control-Allow-Headers, Content-Type, New-Token, New-Expires-At"
)
// CORS applies the current administration CORS rules on every request so a
// configuration reload takes effect without rebuilding the Gin engine.
func CORS(runtime *conf.Runtime) gin.HandlerFunc {
return func(c *gin.Context) {
config := runtime.Admin()
if config == nil || config.Cors == nil {
c.Next()
return
}
mode := strings.TrimSpace(config.Cors.Mode)
origin := c.GetHeader("Origin")
corsHandled := false
if mode == "allow-all" {
setCORSHeaders(c, origin, defaultCORSHeaders, defaultCORSMethods, defaultCORSExpose, true)
corsHandled = true
} else if rule := matchingCORSRule(config.Cors.Whitelist, origin); rule != nil {
setCORSHeaders(c, rule.AllowOrigin, rule.AllowHeaders, rule.AllowMethods, rule.ExposeHeaders, rule.AllowCredentials)
corsHandled = true
} else if mode == "strict-whitelist" && !(c.Request.Method == http.MethodGet && c.Request.URL.Path == "/health") {
c.AbortWithStatus(http.StatusForbidden)
return
}
if corsHandled && c.Request.Method == http.MethodOptions {
c.AbortWithStatus(http.StatusNoContent)
return
}
c.Next()
}
}
func matchingCORSRule(rules []*conf.AdminBackend_CORSRule, origin string) *conf.AdminBackend_CORSRule {
for _, rule := range rules {
if rule != nil && origin == rule.AllowOrigin {
return rule
}
}
return nil
}
func setCORSHeaders(c *gin.Context, origin, headers, methods, expose string, credentials bool) {
c.Header("Access-Control-Allow-Origin", origin)
c.Header("Access-Control-Allow-Headers", headers)
c.Header("Access-Control-Allow-Methods", methods)
c.Header("Access-Control-Expose-Headers", expose)
if credentials {
c.Header("Access-Control-Allow-Credentials", "true")
}
}