Initial cloud-services repo - gateway service + pkg modules

pkg/utils/certificate_parser.go

@@ -0,0 +1,57 @@
+package utils
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"fiskerinc.com/modules/logger"
+	"fiskerinc.com/modules/validator"
+)
+
+// ParseVINFromRequest retrieves VIN from "Ssl-Client-Subject-Dn"
+//
+//	which is generated by NGINX through a cert on websocket request
+func ParseVINFromRequest(r *http.Request) (vin string, err error) {
+	// Try SDK 1.2 format first: Ssl-Client-Subject-Dn header
+	vin = retrieveCommonNameFromHeaderSSLClientSubject(r)
+
+	if vin == "" {
+		// Try SDK 1.4 format: Ssl header
+		vin = retrieveCommonNameFromHeaderSSL(r)
+	}
+
+	ok := validator.ValidateVINSimple(vin)
+	if ok {
+		return vin, nil
+	}
+	// If neither header format contains a VIN, return error
+	return "", fmt.Errorf("VIN not found in request headers: '%s' bad value", vin)
+}
+
+func retrieveCommonNameFromHeaderSSL(r *http.Request) (vin string) {
+	sslHeader := r.Header.Get("Ssl")
+	logger.Info().Str("SSL Header Value", sslHeader).Msg("CSDK 1.2 VIN Format Failed, trying 1.4")
+	if sslHeader != "" {
+		// Extract VIN from "CN=VIN_HERE" format
+		if strings.HasPrefix(sslHeader, "CN=") {
+			vin = strings.TrimPrefix(sslHeader, "CN=")
+		}
+	}
+	return
+}
+
+func retrieveCommonNameFromHeaderSSLClientSubject(r *http.Request) string {
+	dn := r.Header.Values("Ssl-Client-Subject-Dn")
+
+	for _, d := range dn {
+		fields := strings.Split(d, ",")
+		for _, field := range fields {
+			if len(field) > 3 && field[:3] == "CN=" {
+				return field[3:]
+			}
+		}
+	}
+
+	return ""
+}