Module entity_classifier 

Entity Classification System for DDEX Builder

This module provides a comprehensive multi-layer classification system to distinguish between legitimate DDEX entities and malicious attempts. It implements defense against XXE attacks, entity expansion attacks, and other XML-based security threats.

Features

• Multi-layer entity classification (SafeBuiltin, SafeDdex, CustomLocal, Suspicious, Malicious)
• Recursive depth tracking and expansion ratio calculation
• DDEX-specific entity whitelist from official schemas
• Pattern matching for known attack vectors
• Metrics collection for security monitoring
• Performance-optimized caching system

Structs

ClassifierConfig

Configuration for entity classification

Entity

Entity definition for analysis

EntityClassifier

DDEX Entity Classifier

EntityMetrics

Security metrics for entity analysis

ValidationResult

Result of entity chain validation

Enums

AttackType

Types of XML entity attacks

EntityClass

Entity classification levels

Functions

create_entity

Helper function to create an Entity from name and value

create_external_entity

Helper function to create an external entity

create_parameter_entity

Helper function to create a parameter entity