45 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			45 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
package web
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import (
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	"net"
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	"net/http"
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	"github.com/gorilla/handlers"
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	log "github.com/sirupsen/logrus"
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	"goauthentik.io/internal/config"
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)
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// ProxyHeaders Set proxy headers like X-Forwarded-For and such, but only if the direct connection
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// comes from a client that's in a list of trusted CIDRs
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func ProxyHeaders() func(http.Handler) http.Handler {
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	nets := []*net.IPNet{}
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	for _, rn := range config.Get().Listen.TrustedProxyCIDRs {
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		_, cidr, err := net.ParseCIDR(rn)
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		if err != nil {
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			continue
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		}
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		nets = append(nets, cidr)
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	}
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	ph := handlers.ProxyHeaders
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	return func(h http.Handler) http.Handler {
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		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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			host, _, err := net.SplitHostPort(r.RemoteAddr)
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			if err == nil {
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				// remoteAddr will be nil if the IP cannot be parsed
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				remoteAddr := net.ParseIP(host)
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				for _, allowedCidr := range nets {
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					if remoteAddr != nil && allowedCidr.Contains(remoteAddr) {
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						log.WithField("remoteAddr", remoteAddr).WithField("cidr", allowedCidr.String()).Trace("Setting proxy headers")
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						ph(h).ServeHTTP(w, r)
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						return
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					}
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				}
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			}
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			// Request is not directly coming from a CIDR we "trust"
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			// so set XFF to the direct host IP
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			r.Header.Set("X-Forwarded-For", host)
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			h.ServeHTTP(w, r)
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		})
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	}
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}
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