This project is a Spring MVC-based Java application that implements a security interceptor to validate incoming HTTP requests and prevent common vulnerabilities such as SQL Injection, Cross-Site Scripting (XSS), and malicious file uploads.

• SQL Injection Prevention: Detects and blocks SQL injection patterns in request parameters.
• XSS Protection: Filters out potential cross-site scripting attacks.
• File Upload Validation: Allows only specific file types to be uploaded.
• Input Sanitization: Rejects inputs with dangerous characters, invalid UTF-8 encoding, null bytes, or newline characters.

• Spring Framework: Core framework for building the application and managing interceptors.
• Java: Programming language.
• Regex Patterns: Used for input validation.

This is the main interceptor that performs the following tasks:

• Validates request parameters for SQL Injection, XSS, and other dangerous inputs.
• Checks uploaded files for allowed extensions.
• Rejects invalid or malicious requests.

• preHandle: Validates incoming requests before they reach the controller.
• validateFileInput: Ensures uploaded files have valid extensions.
• containsSQLInjection, containsXSS, etc.: Helper methods to check for specific vulnerabilities.

This is the Spring configuration class that:

• Registers the JavaSecurityInterceptor as a Spring Bean.
• Adds the interceptor to the application's request handling pipeline to validate all incoming requests.

• Java 8 or higher
• Maven 3.6+
• Spring Framework 5+
• An IDE (e.g., IntelliJ IDEA, Eclipse)

1. Clone this repository:

   git clone https://github.com/imdeepakchahar/java-security-interceptor.git
   cd java-security-interceptor

2. Import the project into your IDE.

3. Build the project using Maven:

   mvn clean install

4. Run the Spring Boot application:

   mvn spring-boot:run

1. Interceptor Behavior:

   • The interceptor is applied to all request paths (/**).
   • Malicious requests are blocked with a 400 Bad Request response.

2. File Uploads:

   • Allowed file extensions: jpg, jpeg, png, pdf, docx.

3. Request Validation:

   • SQL keywords, XSS payloads, dangerous characters, invalid UTF-8, and null bytes are blocked.

4. Customization:

   • Modify allowed file extensions in ALLOWED_FILE_EXTENSIONS in JavaSecurityInterceptor.java.
   • Update regex patterns to match your security requirements.

src/main/java/app/
├── config/
│   └── WebConfig.java          # Spring configuration
├── interceptor/
│   └── JavaSecurityInterceptor.java # Security interceptor

Author: Deepak Kumar
Email: imchahardeepak@gmail.com
GitHub: imdeepakchahar

Feel free to raise issues or contribute to this project!

This project is open-source and available under the MIT License.