Improving security in a C backend while handling JSON from frontend with cJSON library
I'm converting an old project and I'm wondering if anyone has experience with I'm stuck on something that should probably be simple. I'm working on a personal project and Building an application that integrates a frontend framework with a C backend, I need to ensure the data received from the frontend is securely handled... Currently, I'm using the cJSON library to parse JSON objects but realizing I might be exposing myself to buffer overflow vulnerabilities if the JSON structure isn’t strictly controlled. To circumvent this, I’ve implemented basic checks for string lengths and types, but I’m worried about how to handle unexpected or malicious input effectively. Here’s a snippet of what I’m currently working with: ```c #include <stdio.h> #include <stdlib.h> #include <string.h> #include "cJSON.h" void parse_json(const char *json_string) { cJSON *json = cJSON_Parse(json_string); if (!json) { printf("JSON parsing error\n"); return; } cJSON *name = cJSON_GetObjectItem(json, "name"); if (name && cJSON_IsString(name)) { // Secure handling of the name field printf("Name: %s\n", name->valuestring); } cJSON_Delete(json); } ``` While this works in simple cases, I’m not sure if this approach is robust against injections or malformed JSON. I’ve considered extending this by validating input against an expected schema to enhance security further. Has anyone implemented effective strategies for validating JSON input in C? What additional layers of security would you suggest? I’ve also looked into using `snprintf` for safely managing string copies, but I worry about performance impacts. If I want to log detailed error messages without exposing sensitive data, how should I balance performance and security in my logging strategy? Any insights or best practices would be greatly appreciated! Am I missing something obvious? I'm working on a service that needs to handle this. I'd really appreciate any guidance on this. This is for a mobile app running on CentOS. What are your experiences with this? I'd really appreciate any guidance on this.