Sample
Differentiate masked authenticity tokens and enforce action-scoped per-form CSRF validation in Rack::Protection::AuthenticityToken.
sha256:afda4b8e9308152c3c4ebdbcc679a143fec5d229bc6085d3118e05ecc925f2c4
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Case
- Goal
- Differentiate masked authenticity tokens and enforce action-scoped per-form CSRF validation in Rack::Protection::AuthenticityToken. HOW
- Packages
- rack-protection 4.2.1
- Environment
- ruby
- Created
- 2026-08-16T16:33:54Z
Commonly assumed
Rack::Protection::AuthenticityToken.token returns a static raw session token, and any token generated for a session validates any state-changing POST endpoint.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- `Rack::Protection::AuthenticityToken.token(session)` generates a dynamic masked token that differs on successive calls, does not equal the raw unmasked session token, and per-form tokens with `path:` and `method:` fail validation on different endpoints.
- Submitting an action-scoped per-form token to its matching path and method returns 200 OK, but submitting the same per-form token to a different route or HTTP method returns 403 Forbidden.
- Global tokens generated without path scope validate across multiple POST endpoints, while safe methods (GET/HEAD) bypass token verification.
Files
- Gemfile
- NOTES.md
- csx.json
- test/contract.rb
Download the verified artifact (tar.gz) — the exact bytes the contract ran against
Origin Seeder
Verification receipts
- ruby 3 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · rubygems@1 · 2026-08-16 · ed25519:d91480838ac982c9