Security & DLP Guardrails

Flit protects corporate boundaries with real-time data loss prevention (DLP), PII redaction, prompt injection defenses, enterprise SSO, and cryptographic session isolation.

1. In-Flight Data Loss Prevention (Microsoft Presidio)

Flit integrates official Microsoft Presidio Analyzer and Anonymizer (v2.2.362) microservices directly into the gateway pre- and post-call execution pipelines via overlays/docker-compose.presidio.yml:

Guardrail Parameter	Supported Settings	Enforcement Semantics
Directional Scope	`input` OR `output`	Flit enforces strictly independent directional instances; combined `both` instances are rejected to guarantee clean lifecycle removal.
Enforcement Action	`MASK` or `BLOCK`	`MASK` replaces sensitive entities with synthetic anonymized tokens; `BLOCK` aborts the request before any token leaves the enterprise perimeter.
Recognized Entities	Standard PII / Financial / Health	Credit cards, SSN, email addresses, phone numbers, IP addresses, and custom entity recognizers.
Activation Mode	Server-Enforced `default_on`	The gateway adapter strips the `guardrails` field from client payloads, guaranteeing that end-users cannot bypass corporate DLP policies.

2. Enterprise SSO & Identity Architecture

Administrative and browser-based access is protected by enterprise identity standards:

Microsoft Entra ID (Azure AD): Built-in OpenID Connect (OIDC) SSO integration. Configured via MICROSOFT_TENANT_ID, MICROSOFT_CLIENT_ID, and redirect endpoints. Automatically reconciles Entra claims with pre-provisioned Flit accounts.
Local Administrator Security: Local admin accounts are stored in PostgreSQL with brute-force lockout protection (5 failed attempts locks the account for 15 minutes) and mandatory password rotation on first login.
Encrypted Session Cookies: Web application sessions are serialized into HttpOnly, SameSite=Lax cookies encrypted using a 32-byte Fernet key (AES-128 in CBC mode with HMAC SHA-256).
Cryptographic CSRF Protection: All state-mutating requests (such as creating keys, modifying classifier rules, or altering team budgets) require a verified anti-forgery token passed in the X-Aquila-CSRF header.
Comprehensive Audit Logging: Every administrative action is permanently recorded in the admin_audit_log table with actor ID, action verb, target entity, and timestamp.