performing-api-fuzzing-with-restler

# Performing API Fuzzing with RESTler ## When to Use - Performing automated security testing of REST APIs using their OpenAPI/Swagger specifications - Discovering bugs that only manifest through specific sequences of API calls (stateful testing) - Finding 500 Internal Server Error responses that indicate unhandled exceptions or crash conditions - Testing API input validation by fuzzing parameters with malformed, boundary, and injection payloads - Running continuous security regression testing in CI/CD pipelines for API changes **Do not use** against production environments without explicit authorization and monitoring. RESTler creates and deletes resources aggressively during fuzzing. ## Prerequisites - Written authorization specifying the target API and acceptable testing scope - Python 3.12+ and .NET 8.0 runtime installed - RESTler downloaded from https://github.com/microsoft/restler-fuzzer - OpenAPI/Swagger specification (v2 or v3) for the target API - API authentication credentials (tokens, API keys, or OAuth credentials) - Isolated test/staging environment (RESTler can create thousands of resources per hour) ## Workflow ### Step 1: RESTler Installation and Setup ```bash # Clone and build RESTler git clone https://github.com/microsoft/restler-fuzzer.git cd restler-fuzzer # Build RESTler python3 ./build-restler.py --dest_dir /opt/restler # Verify installation /opt/restler/restler/Restler --help # Alternative: Use pre-built release # Download from https://github....