Remove headers set by a trusted proxy from outputs

internal/httputils/http.go

@@ -3,9 +3,11 @@ package httputils
 import (
 	"fmt"
 	"net/http"
+	"net/textproto"
 	"sort"
 	"strings"
 
+	"github.com/dcarrillo/whatismyip/internal/setting"
 	"github.com/gin-gonic/gin"
 )
 
@@ -32,6 +34,17 @@ func HeadersToSortedString(headers http.Header) string {
 	return output
 }
 
+// GetHeadersWithoutTrustedHeaders return a http.Heade object with the original headers except trusted headers
+func GetHeadersWithoutTrustedHeaders(ctx *gin.Context) http.Header {
+	h := ctx.Request.Header
+
+	for _, k := range []string{setting.App.TrustedHeader, setting.App.TrustedPortHeader} {
+		delete(h, textproto.CanonicalMIMEHeaderKey(k))
+	}
+
+	return h
+}
+
 // GetLogFormatter returns our custom log format
 func GetLogFormatter(param gin.LogFormatterParams) string {
 	return fmt.Sprintf("%s - [%s] \"%s %s %s\" %d %d %d %s \"%s\" \"%s\" \"%s\"\n",

internal/setting/app.go

@@ -70,15 +70,17 @@ func Setup(args []string) (output string, err error) {
 	)
 	flags.StringVar(&App.TLSCrtPath, "tls-crt", "", "When using TLS, path to certificate file")
 	flags.StringVar(&App.TLSKeyPath, "tls-key", "", "When using TLS, path to private key file")
-	flags.StringVar(&App.TrustedHeader,
+	flags.StringVar(
+		&App.TrustedHeader,
 		"trusted-header",
 		"",
-		"Trusted request header for remote IP (e.g. X-Real-IP)",
+		"Trusted request header for remote IP (e.g. X-Real-IP). When using this feature if -trusted-port-header is not set the client port is shown as 'unknown'",
 	)
-	flags.StringVar(&App.TrustedPortHeader,
+	flags.StringVar(
+		&App.TrustedPortHeader,
 		"trusted-port-header",
 		"",
-		"Trusted request header for remote client port (e.g. X-Real-Port)",
+		"Trusted request header for remote client port (e.g. X-Real-Port). When this parameter is set -trusted-header becomes mandatory",
 	)
 	flags.BoolVar(&App.version, "version", false, "Output version information and exit")
 	flags.BoolVar(