Secure File Upload System - Technical & Engineering Guide
1. Introduction
1.1 Purpose
This guide outlines the steps for developing a Secure File Upload System, ensuring that uploaded files are scanned, validated, and stored safely.
1.2 Scope
The Secure File Upload System is designed for web applications, enterprise systems, and cloud storage platforms that allow users to upload files. It provides validation, malware scanning, and secure storage to mitigate risks associated with file uploads.
1.3 Definitions & Acronyms
|
Acronym |
Definition |
|
MIME Type |
Multipurpose Internet Mail Extensions Type - indicates the nature and format of a file. |
|
AV Scanner |
Antivirus Scanner - a tool to detect and remove malware. |
|
Sanitization |
Process of cleaning input to remove malicious elements. |
2. System Architecture
The architecture of the Secure File Upload System includes:
- **File Validation Module**: Ensures the file meets predefined requirements.
- **Malware Scanning Module**: Scans files for known threats.
- **Sanitization Module**: Cleans potentially harmful elements from files.
- **Storage Module**: Stores validated files in a secure location.
- **Error Handling & Reporting**: Notifies users of invalid or malicious
files.
3. Key Features
3.1 File Type Validation
Verifies the file type using MIME type and extension checks to ensure only supported file types are accepted.
3.2 Malware Scanning
Utilizes antivirus tools like ClamAV to detect malicious content in uploaded files.
3.3 File Size Restrictions
Limits the size of uploaded files to prevent resource exhaustion attacks.
3.4 Secure Storage
Stores uploaded files in a segregated and protected directory, ensuring access control policies are applied.
4. Implementation Steps
1. **Environment Setup**: Set up a development environment
with Python and necessary libraries.
2. **File Validation**: Implement MIME type and extension checks.
3. **Malware Scanning**: Integrate an antivirus scanner like ClamAV.
4. **Sanitization**: Apply sanitization techniques for specific file types
(e.g., stripping harmful scripts in PDFs).
5. **Secure Storage**: Configure a secure directory with appropriate
permissions.
6. **User Interface**: Develop a user-friendly file upload interface.
7. **Testing**: Test with benign and malicious files.
8. **Deployment**: Deploy on a server with HTTPS enabled.
5. Security Considerations
1. Use HTTPS to secure file uploads.
2. Store files in a non-executable directory.
3. Implement rate limiting to prevent abuse.
4. Regularly update malware scanning tools.
6. Tools and Technologies
- **Programming Language**: Python
- **Libraries**: Flask, ClamAV
- **Storage**: AWS S3, Local storage with access controls
- **User Interface**: HTML/CSS/JavaScript
7. Testing and Validation
1. Test file validation with supported and unsupported file
types.
2. Evaluate malware detection accuracy.
3. Verify secure storage and retrieval processes.
4. Simulate malicious uploads to assess system robustness.