Sample
plug 1.20.3: Configure Plug.Session cookie storage, signing salts, 64-byte secret key constraints, and lazy cookie serialization
Verified sample for hex plug 1.20.3: Configure Plug.Session cookie storage, signing salts, 64-byte secret key constraints, and lazy cookie serialization. The…
sha256:3ef390aae7cf632653e7ba065c15143a68dcd2829bcc012a4bf60960c4dcda4b
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
elixir linux x64 elixir elixir mix
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| elixir 1 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:PASS · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · hex@1 |
2026-08-17 |
| elixir 1 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:PASS · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · hex@1 |
2026-08-18 |
Case
HOW- Goal
- Configure Plug.Session cookie storage, signing salts, 64-byte secret key constraints, and lazy cookie serialization
- Packages
- Symbols
-
- Plug.Session
- Plug.Session.COOKIE
- Plug.Conn.fetch_session
- Plug.Conn.put_session
- Plug.Conn.get_session
- Plug.Conn.configure_session
- Environment
- elixir
- Created
- 2026-08-17T10:30:17Z
Contract
- assert Plug.Session.init/1 enforces :signing_salt for cookie storage at initialization but defers :secret_key_base validation until runtime, where omitting it or providing fewer than 64 bytes raises ArgumentError only when fetching or writing cookies
- assert calling get_session/2 before fetch_session/2 raises ArgumentError stating the session is not fetched
- assert read-only session inspection never emits a set-cookie response header, while session mutations register a before_send callback to emit signed cookie headers with HttpOnly and path=/
- assert tampered or forged incoming cookie signatures are silently dropped with an empty session map rather than raising a runtime decoding error
- assert configuring :encryption_salt upgrades session payload handling from base64-encoded signed plaintext to AES-GCM ciphertext
- assert configure_session(conn, drop: true) on an active session emits a set-cookie header with max-age=0 to expire the cookie on the client
Files
- NOTES.md
- csx.json
- lib/csx_plug_session/session_pipeline.ex
- mix.exs
- mix.lock
- test/contract_test.exs
- test/test_helper.exs