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(

router/generic.go

@@ -79,8 +79,8 @@ func getAllAsString(ctx *gin.Context) {
 		output += geoASNRecordToString(record) + "\n"
 	}
 
-	h := ctx.Request.Header
+	h := httputils.GetHeadersWithoutTrustedHeaders(ctx)
-	h["Host"] = []string{ctx.Request.Host}
+	h.Set("Host", ctx.Request.Host)
 	output += httputils.HeadersToSortedString(h)
 
 	ctx.String(http.StatusOK, output)
@@ -113,6 +113,6 @@ func jsonOutput(ctx *gin.Context) JSONResponse {
 		ASN:             asnRecord.AutonomousSystemNumber,
 		ASNOrganization: asnRecord.AutonomousSystemOrganization,
 		Host:            ctx.Request.Host,
-		Headers:         ctx.Request.Header,
+		Headers:         httputils.GetHeadersWithoutTrustedHeaders(ctx),
 	}
 }

router/generic_test.go

@@ -102,9 +102,6 @@ func TestClientPort(t *testing.T) {
 		params  []string
 		headers map[string][]string
 	}
-	type expected struct {
-		body string
-	}
 	tests := []struct {
 		name     string
 		args     args
@@ -249,8 +246,6 @@ ASN Organization:
 
 Header1: one
 Host: test
-X-Real-Ip: 81.2.69.192
-X-Real-Port: 1001
 `
 	_, _ = setting.Setup(
 		[]string{

router/headers.go

@@ -10,15 +10,17 @@ import (
 )
 
 func getHeadersAsSortedString(ctx *gin.Context) {
-	h := ctx.Request.Header
+	h := httputils.GetHeadersWithoutTrustedHeaders(ctx)
-	h["Host"] = []string{ctx.Request.Host}
+	h.Set("Host", ctx.Request.Host)
 
 	ctx.String(http.StatusOK, httputils.HeadersToSortedString(h))
 }
 
 func getHeaderAsString(ctx *gin.Context) {
+	headers := httputils.GetHeadersWithoutTrustedHeaders(ctx)
+
 	h := ctx.Params.ByName("header")
-	if v := ctx.GetHeader(h); v != "" {
+	if v := headers.Get(ctx.Params.ByName("header")); v != "" {
 		ctx.String(http.StatusOK, template.HTMLEscapeString(v))
 	} else if strings.ToLower(h) == "host" {
 		ctx.String(http.StatusOK, template.HTMLEscapeString(ctx.Request.Host))

router/headers_test.go

@@ -5,6 +5,7 @@ import (
 	"net/http/httptest"
 	"testing"
 
+	"github.com/dcarrillo/whatismyip/internal/setting"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -26,13 +27,20 @@ Header2: value22
 Header3: value3
 Host: 
 `
-
+	_, _ = setting.Setup([]string{
+		"-geoip2-city", "city",
+		"-geoip2-asn", "asn",
+		"-trusted-header", trustedHeader,
+		"-trusted-port-header", trustedPortHeader,
+	})
 	req, _ := http.NewRequest("GET", "/headers", nil)
 	req.Header = map[string][]string{
 		"Header1": {"value1"},
 		"Header2": {"value21", "value22"},
 		"Header3": {"value3"},
 	}
+	req.Header.Set(trustedHeader, "1.1.1.1")
+	req.Header.Set(trustedPortHeader, "1025")
 
 	w := httptest.NewRecorder()
 	app.ServeHTTP(w, req)

router/setup_test.go

@@ -34,8 +34,8 @@ var (
 		text: "text/plain; charset=utf-8",
 		json: "application/json; charset=utf-8",
 	}
-	jsonIPv4 = `{"client_port":"1001","ip":"81.2.69.192","ip_version":4,"country":"United Kingdom","country_code":"GB","city":"London","latitude":51.5142,"longitude":-0.0931,"postal_code":"","time_zone":"Europe/London","asn":0,"asn_organization":"","host":"test","headers":{"X-Real-Ip":["81.2.69.192"], "X-Real-Port":["1001"]}}`
+	jsonIPv4 = `{"client_port":"1001","ip":"81.2.69.192","ip_version":4,"country":"United Kingdom","country_code":"GB","city":"London","latitude":51.5142,"longitude":-0.0931,"postal_code":"","time_zone":"Europe/London","asn":0,"asn_organization":"","host":"test", "headers": {}}`
-	jsonIPv6 = `{"asn":3352, "asn_organization":"TELEFONICA DE ESPANA", "city":"", "client_port":"1001", "country":"", "country_code":"", "headers":{"X-Real-Ip":["2a02:9000::1"], "X-Real-Port":["1001"]}, "host":"test", "ip":"2a02:9000::1", "ip_version":6, "latitude":0, "longitude":0, "postal_code":"", "time_zone":""}`
+	jsonIPv6 = `{"asn":3352, "asn_organization":"TELEFONICA DE ESPANA", "city":"", "client_port":"1001", "country":"", "country_code":"", "host":"test", "ip":"2a02:9000::1", "ip_version":6, "latitude":0, "longitude":0, "postal_code":"", "time_zone":"", "headers": {}}`
 )
 
 const trustedHeader = "X-Real-IP"