Section 3 Review
You've finished Auth and Access Control, the third section of API Testing. This page is a dedicated recap — bookmark it as a fast reference, separate from the modules themselves.
Section Summary
✔ API Authentication — proving identity: API keys, bearer tokens, JWTs, OAuth 2.0 concepts, and the full failure-scenario checklist (missing, malformed, expired, tampered, wrong-audience tokens) every protected endpoint should be tested against ✔ Authorization and Access Control — what an authenticated identity can actually do: RBAC, resource ownership, horizontal and vertical privilege escalation, and IDOR ✔ Rate Limiting, Throttling, and Session Management — an API's defenses against abuse and its handling of session lifecycle: 429 responses, burst vs. sustained limits, and server-side token revocation
How they build on each other: Module 7 established who's calling. Module 8 established what that caller can actually do, once identity is known. Module 9 closed the section by covering what happens when a caller — legitimate or not — pushes past reasonable limits, and how a session's lifecycle should genuinely end when it's supposed to. Together, these three modules cover the full gate an API puts between a request and the data or action it's asking for.
Auth Testing Focus Matrix
A quick reference for what each layer is actually checking:
| Layer | Question | Failure Status | Common Missed Defect |
|---|---|---|---|
| Authentication | Who are you? | 401 | Expiration enforced inconsistently across endpoints |
| Authorization (role) | Is this role allowed here at all? | 403 | A role can do something it explicitly shouldn't be able to |
| Authorization (ownership) | Do you own this specific resource? | 403 | IDOR — any ID accepted without an ownership check |
| Rate Limiting | Are you exceeding your allowed usage? | 429 | Limit scoped too narrowly to actually stop the realistic abuse pattern |
| Session Management | Has your session actually ended? | 401 (on reuse) | Client-side logout without server-side token revocation |
Section 3 Knowledge Check
Five realistic scenarios. For each, identify which layer applies and what specifically to test. No answers are provided here. Solutions: Section 3 Solutions.
Scenario 1: AtlasBank's GET /api/v1/accounts/{accountId}/statements correctly rejects an expired token when tested directly against this endpoint — but the tester hasn't yet tested any other endpoint.
Scenario 2: A customer, authenticated and viewing their own AtlasBank account, changes the accountId in the URL of a GET /api/v1/accounts/{accountId}/transactions request to an account number they found in a previous test's data, belonging to a different customer.
Scenario 3: AtlasBank's support-agent role is documented as read-only for customer accounts, but a tester has only confirmed that reading account data works correctly for that role.
Scenario 4: AtlasBank's login endpoint correctly returns 429 after 5 failed attempts against the same username within a minute.
Scenario 5: A customer logs out of AtlasBank's mobile app. The app clears its locally stored token.
Continue to Section 4
Integration and Resilience, starting with Testing Service Integrations — where this section's identity, permission, and abuse-prevention literacy extends into testing how AtlasBank's APIs behave when the systems they depend on are slow, unavailable, or fail mid-request.