FestIn is a domain-based S3 bucket discovery tool that identifies open Amazon S3 buckets through multiple reconnaissance techniques. The tool performs comprehensive testing and information gathering from various sources including DNS records, web pages through crawling, and S3 bucket configurations such as redirections. FestIn employs multiple discovery methods including web crawling and DNS crawling to locate potentially exposed S3 buckets associated with a target domain. The tool systematically examines DNS infrastructure and web content to identify S3 bucket references and configurations that may indicate security misconfigurations or exposed storage resources.