# Zastava Evidence Locker (schemas/kit)

Signed 2025-12-02 with Ed25519 key (pub base64url: `mpIEbYRL1q5yhN6wBRvkZ_0xXz3QUJPueJJ8sn__GGc`). Private key stored offline; all signatures use DSSEv1 pre-auth encoding.
Public key copy: `docs/modules/zastava/kit/ed25519.pub`.

## Artefacts
- `schemas/observer_event.schema.json.dsse` (payloadType `application/vnd.stellaops.zastava.schema+json;name=observer_event;version=1`)
- `schemas/webhook_admission.schema.json.dsse` (payloadType `application/vnd.stellaops.zastava.schema+json;name=webhook_admission;version=1`)
- `thresholds.yaml.dsse` (payloadType `application/vnd.stellaops.zastava.thresholds+yaml;version=1`)
- `exports/observer_events.ndjson.dsse` (payloadType `application/vnd.stellaops.zastava.observer-events+ndjson;version=1`)
- `exports/webhook_admissions.ndjson.dsse` (payloadType `application/vnd.stellaops.zastava.webhook-admissions+ndjson;version=1`)
- `kit/zastava-kit.tzst.dsse` (payloadType `application/vnd.stellaops.zastava.kit+tzst;version=1`)

## Evidence Locker targets
- `evidence-locker/zastava/2025-12-02/observer_event.schema.json.dsse`
- `evidence-locker/zastava/2025-12-02/webhook_admission.schema.json.dsse`
- `evidence-locker/zastava/2025-12-02/thresholds.yaml.dsse`
- `evidence-locker/zastava/2025-12-02/observer_events.ndjson.dsse`
- `evidence-locker/zastava/2025-12-02/webhook_admissions.ndjson.dsse`
- `evidence-locker/zastava/2025-12-02/zastava-kit.tzst`
- `evidence-locker/zastava/2025-12-02/zastava-kit.tzst.dsse`
- `evidence-locker/zastava/2025-12-02/SHA256SUMS`

Local staging: all files above are present under `evidence-locker/zastava/2025-12-02/` in the repo root, ready for locker upload/mirroring.

Deterministic tarball (built with `tar --sort=name --mtime='UTC 1970-01-01' --owner=0 --group=0 --numeric-owner` over payloads + DSSE):

```
evidence-locker/zastava/2025-12-02/zastava-evidence.tar  sha256=e1d67424273828c48e9bf5b495a96c2ebcaf1ef2c308f60d8b9c62b8a1b735ae
```

Verification helper (uses the hash above and inner SHA256SUMS):

```
./tools/zastava-verify-evidence-tar.sh [path/to/zastava-evidence.tar]
```

Upload (once locker creds exist):

```bash
export EVIDENCE_LOCKER_URL="<locker-base-url>"
export CI_EVIDENCE_LOCKER_TOKEN="<token>"
./tools/upload-all-evidence.sh   # pushes both Zastava and Signals bundles
```

Helper script for manual push (expects `EVIDENCE_LOCKER_URL` and `CI_EVIDENCE_LOCKER_TOKEN`):
```bash
tools/zastava-upload-evidence.sh
```

Packaging is deterministic (`tar --sort=name --mtime='UTC 1970-01-01' --owner=0 --group=0 --numeric-owner`) and prints the tarball SHA256 before upload. Ensure `kit/verify.sh` passes before pushing.

## CI delivery note
- Locker upload in CI requires a write credential (e.g., `CI_EVIDENCE_LOCKER_TOKEN`) with access to the `evidence-locker/zastava/` namespace.
- If the secret is absent, perform a manual upload from the staged folder and record the locker URI in the sprint log.

## Signing template (Python, ed25519)
```bash
python - <<'PY'
from pathlib import Path
from base64 import urlsafe_b64encode
import json
from cryptography.hazmat.primitives.asymmetric import ed25519
from cryptography.hazmat.primitives import serialization

priv = serialization.load_pem_private_key(Path('/tmp/zastava-ed25519.key').read_bytes(), password=None)
pub = priv.public_key().public_bytes(encoding=serialization.Encoding.Raw, format=serialization.PublicFormat.Raw)
keyid = urlsafe_b64encode(pub).decode().rstrip('=')
pt = '<payload-type>'
payload = Path('<file-to-sign>').read_bytes()
pae = b' '.join([b'DSSEv1', str(len(pt)).encode(), pt.encode(), str(len(payload)).encode(), payload])
sig = priv.sign(pae)
env = {
    'payloadType': pt,
    'payload': urlsafe_b64encode(payload).decode().rstrip('='),
    'signatures': [{'keyid': keyid, 'sig': urlsafe_b64encode(sig).decode().rstrip('=')}],
}
Path('<file-to-sign>.dsse').write_text(json.dumps(env, indent=2, sort_keys=True) + '\n')
print('signed', '<file-to-sign>', 'with keyid', keyid)
PY
```

## Post-sign checklist
1) Run `kit/verify.sh` to validate hashes + DSSE.
2) Upload artefacts + DSSEs + SHA256SUMS to the Evidence Locker paths above.
3) Record URIs in sprint 0144 Decisions & Risks and mark ZASTAVA-SCHEMAS-0001 / ZASTAVA-THRESHOLDS-0001 / ZASTAVA-KIT-0001 as DONE.