Request Interceptor

The Request Interceptor is a critical component of the Policy Enforcement Point (PEP) in security and access control architectures. It operates by intercepting all incoming requests (such as API calls, web requests, or service requests) directed toward protected systems or data. Its primary role is to perform initial inspection, validation, and routing based on predefined security policies, authentication states, and authorization rules before allowing the request to proceed to the Policy Decision Point (PDP) or the target resource.

The Request Interceptor functions by being placed in the request processing pipeline. When a request arrives, it captures the request metadata (headers, parameters, source IP, user identity tokens, etc.). It then applies filtering logic, checks for basic protocol compliance, and may perform initial threat detection. Based on this analysis, it can block malicious requests immediately, log the request for auditing, or forward it along with enriched context to the PDP for a detailed authorization decision. It often works in tandem with other PEP components like response interceptors and session managers.