42crunch Api Security Testing

42Crunch API Security Skill

Orchestrates two phases: Audit (static OAS analysis and SQG fix loop) and Scan (live conformance + authorization testing). Each phase requires explicit user permission before execution.

Entry Point

1. Pre-flight checks. Read ../../references/pre-flight.md and complete all steps (setup, OAS resolution, tag detection). When prompting for OAS file selection, use the context "pipeline" (e.g. "Which one should I run through the pipeline?"). Do not proceed if any step fails or the user cancels.

2. Ask for Phase 1 permission. Call AskUserQuestion:

   • question: "Ready to run a 42Crunch Audit on <filename>. This will analyse your OAS file and produce a scored report. Shall I proceed?"
   • options: ["Yes, proceed", "No, cancel"]

3. Execute Phase 1 — Audit. Mode is already resolved from pre-flight — do not re-derive it. Read ../../references/audit-workflow.md and apply only the commands for the identified mode throughout. The workflow runs the audit, then presents a developer-readable, risk-classified report (SQG-Blocking / Security / Data Validation tiers) with plain-English titles and risk descriptions — no raw rule IDs. It then pauses and asks the user to consent before applying any fixes. Fixes are only applied after explicit confirmation.

4. Resolve the scan target URL.

   Read servers[0].url from the OAS file.

   • If SCAN42C_HOST environment variable is set → announce silently:

     "Using scan target from SCAN42C_HOST: <url>" Store as SCAN_TARGET_URL and proceed.

   • If not set → call AskUserQuestion:
     • question: "The OAS points to <servers[0].url> as the API target. Is this the right URL to scan against?" — options: ["Yes — use this URL", "No — I'll provide a different URL"]
     • If No → ask the user to provide the URL and store it as SCAN_TARGET_URL.
     • If Yes → store servers[0].url as SCAN_TARGET_URL.

   Reachability check — run immediately after SCAN_TARGET_URL is confirmed. Uses a two-stage probe to distinguish "server is down" from "wrong base URL".

   Stage 1 — probe the base URL:

   bash

   curl -s -o /dev/null -w "%{http_code}" --max-time 5 <SCAN_TARGET_URL>/

   • 2xx, 3xx, 401, 403, or 405 → API is reachable. Proceed silently.
   • Connection refused or timeout → call AskUserQuestion:
     • question: "I couldn't reach <SCAN_TARGET_URL> — the connection timed out or was refused. How would you like to proceed?"
     • options: ["Try a different URL", "Continue anyway — the API may be temporarily down", "Cancel"]
     • If Try a different URL → ask for new URL, store as SCAN_TARGET_URL, re-run from Stage 1.
     • If Continue anyway → proceed with warning noted.
     • If Cancel → stop.
   • 404 → ambiguous (server may be up but nothing is mounted at root). Proceed to Stage 2.

   Stage 2 — probe the first simple OAS path (only reached when Stage 1 returns 404): Find the first GET path in the OAS that has no required path parameters. Strip any {param}-style segments and probe:

   bash

   curl -s -o /dev/null -w "%{http_code}" --max-time 5 <SCAN_TARGET_URL><first_simple_path>

   • Any HTTP response → server is up; root just has no handler. Proceed silently.
   • Connection refused or timeout → same AskUserQuestion as Stage 1.
   • 404 again → call AskUserQuestion:
     • question: "The server responded but both / and <path> returned 404 — the base URL may be incorrect (the API may be mounted at a different prefix). How would you like to proceed?"
     • options: ["Try a different URL", "Continue anyway", "Cancel"]
     • If Try a different URL → ask for new URL, store as SCAN_TARGET_URL, re-run from Stage 1.
     • If Continue anyway → proceed with warning noted.
     • If Cancel → stop.

5. OAS analysis for Phase 2 preview — run silently after Phase 1 completes, before asking for Phase 2 permission.

   Read the OAS file and collect:

   • Total operation count
   • Auth scheme types from securitySchemes (Bearer/JWT, API Key, Basic, OAuth2)
   • BOLA candidate count: operations where the path has {…Id}, {…Key}, {…Ref}, or similar resource-ID placeholders AND the method is GET, PUT, PATCH, or DELETE
   • Whether the OAS contains sample data: any operation with example, examples, or default values on its request body or parameter schemas

6. Ask for Phase 2 permission. Call AskUserQuestion:

   • question: (show the scan preview first, then ask)
     Ready to configure the scan?  Target:   <SCAN_TARGET_URL>  ✓ reachable  /  ⚠ reachability unknown  OAS:      <filename>  (<N> operations)  Auth:     <scheme types>  [+  second user needed — <N> BOLA candidate(s)]  Samples:  OAS has sample data  /  No samples — you'll need to provide test data  Tag:      <category>:<tagname>           ← platform mode only, when a tag is assigned; omit if no tag  Mode:     Platform / Freemium

     "I'm ready to start configuring the scan. I'll ask for credentials, classify your operations, and set up test scenarios — then run a happy path validation before the full scan. Shall I proceed?"
   • options: ["Yes, let's configure", "No, cancel"]

7. Execute Phase 2 — Scan. Mode is already resolved from pre-flight — do not re-derive it. Read ../../references/scan-workflow.md and apply only the commands for the identified mode throughout. The workflow runs the scan, then presents a risk-classified findings report (Authorization failures / SQG-blocking conformance / informational conformance). Fix candidates are determined by SQG-blocking rules and authorization failures — not severity alone. The skill pauses and asks the user to consent before applying any OAS changes.

Mandatory checkpoint: during Phase 2, after any direct edit to CONF_FILE (including environments.default.variables.*, auth wiring, or scenario chains), run scan conf validate and resolve all validation errors before continuing to happy-path or full scan runs.

8. Present the final combined summary (see Output Format below).

9. Recommend next steps based on the outcome:

   If both phases passed and fixes were applied:

   "Both audit and scan are passing. Your OAS is more precise and your security contract is enforced. Consider committing the updated OAS file and rerunning 42crunch-api-security-testing after any significant API change."

   If either phase failed or the user declined fixes:

   "Here's what's still open: [list remaining SQG-failing issues or unfixed scan findings by tier]. When you're ready to address them, run 42crunch-audit or 42crunch-scan individually."

   If no issues were found in either phase:

   "Clean result — your API passed both static analysis and live testing. This is a good baseline to maintain."

Only continue after explicit user confirmation at each permission prompt.

Output Format

After both phases complete, produce a summary in this shape:

Phase 1 — Audit Complete  Score:          <score> / 100  (Security: <sec-score> · Data Validation: <data-score>)  Score change:   <initial-score> → <score>  (<delta>)  |  Data: <initial-data> → <data-score>  (<data-delta>)   ← omit if no fixes applied  Mode:           Platform                          ← or "Freemium"  SQG:            PASSED  (<sqg-name> — your org's security quality gate is met)     ← platform mode, passed  SQG:            FAILED  (<sqg-name> — the quality gate is not met; fixes above are required)    ← platform mode, failed  SQG:            N/A  (Freemium — no automated gate; user-defined thresholds applied this session)    ← freemium mode  Tag:            <category>:<tagname>              ← platform mode only, when a tag is assigned; omit this row if no tag  Issues fixed:   2 SQG-blocking  (0 security · 2 data validation)  OAS updated:    <path/to/openapi.json>
Phase 2 — Scan Complete  Mode:           Platform                          ← or "Freemium"  SQG:            PASSED  (<sqg-name> — your org's security quality gate is met)    ← platform mode, passed  SQG:            FAILED  (<sqg-name> — the quality gate is not met; fixes above are required)    ← platform mode, failed  SQG:            N/A  (Freemium — scan findings are informational; no gate enforced)    ← freemium mode  Authorization:  BOLA confirmed on 1 operation — OAS updated · server-side fix applied  Conformance:    1 SQG-blocking issue fixed (OAS + code) · 3 informational findings surfaced  OAS updated:    <path/to/openapi.json>

Show only the one SQG line per phase that matches the current mode and result.

The Score change: row in Phase 1 is produced from the delta values computed in Step 4 of ../../references/audit-workflow.md. Omit it when no audit fixes were applied (user declined at the consent gate, or there were no SQG-blocking issues).

If a phase was skipped (user declined), note that instead of its results.

Environment Variables

All other variables (API_KEY, PLATFORM_HOST, FREEMIUM_TOKEN) and general constraints are defined in ../../references/pre-flight.md.