feat(tools): add firmware deploy tool (sign + stage for server)

tools/deploy_firmware.py

@@ -0,0 +1,43 @@
+#!/usr/bin/env python3
+"""Sign firmware and stage it for the server OTA endpoint."""
+import argparse, hashlib, json
+from pathlib import Path
+
+from sign_firmware import sign_firmware
+
+
+def deploy(firmware_path: Path, key_path: Path,
+           version: str, output_dir: Path) -> None:
+    output_dir.mkdir(parents=True, exist_ok=True)
+
+    data = firmware_path.read_bytes()
+    sig  = sign_firmware(firmware_path, key_path)
+
+    (output_dir / "current.bin").write_bytes(data)
+    (output_dir / "current.sig").write_bytes(sig)
+    (output_dir / "manifest.json").write_text(json.dumps({
+        "version": version,
+        "size":    len(data),
+        "sha256":  hashlib.sha256(data).hexdigest(),
+    }, indent=2))
+
+    print(f"Deployed {firmware_path.name} v{version} → {output_dir}/")
+
+
+def main() -> None:
+    p = argparse.ArgumentParser(description=__doc__)
+    p.add_argument("firmware",  help="Path to .bin")
+    p.add_argument("version",   help="Version string, e.g. 1.2.3")
+    p.add_argument("--key",     default="secrets/firmware_signing_key.pem")
+    p.add_argument("--out-dir", default="server/firmware")
+    args = p.parse_args()
+    deploy(
+        firmware_path=Path(args.firmware),
+        key_path=Path(args.key),
+        version=args.version,
+        output_dir=Path(args.out_dir),
+    )
+
+
+if __name__ == "__main__":
+    main()

tools/test_deploy_firmware.py

@@ -0,0 +1,63 @@
+import json, hashlib, sys
+from pathlib import Path
+import pytest
+
+REPO_ROOT = Path(__file__).parent.parent
+sys.path.insert(0, str(REPO_ROOT / "tools"))
+
+from cryptography.hazmat.primitives.asymmetric import ec
+from cryptography.hazmat.primitives import serialization
+
+from deploy_firmware import deploy
+
+
+@pytest.fixture()
+def key_pem(tmp_path):
+    key = ec.generate_private_key(ec.SECP256R1())
+    pem_path = tmp_path / "key.pem"
+    pem_path.write_bytes(key.private_bytes(
+        serialization.Encoding.PEM,
+        serialization.PrivateFormat.PKCS8,
+        serialization.NoEncryption(),
+    ))
+    return pem_path
+
+
+def test_deploy_writes_all_artifacts(tmp_path, key_pem):
+    firmware = tmp_path / "firmware.bin"
+    firmware.write_bytes(b"fake firmware" * 200)
+    out_dir = tmp_path / "server_firmware"
+
+    deploy(firmware_path=firmware, key_path=key_pem,
+           version="1.2.3", output_dir=out_dir)
+
+    assert (out_dir / "current.bin").exists()
+    assert (out_dir / "current.sig").exists()
+    assert (out_dir / "manifest.json").exists()
+
+
+def test_manifest_contents(tmp_path, key_pem):
+    data = b"firmware payload"
+    firmware = tmp_path / "fw.bin"
+    firmware.write_bytes(data)
+    out_dir = tmp_path / "out"
+
+    deploy(firmware_path=firmware, key_path=key_pem,
+           version="2.0.1", output_dir=out_dir)
+
+    manifest = json.loads((out_dir / "manifest.json").read_text())
+    assert manifest["version"] == "2.0.1"
+    assert manifest["size"] == len(data)
+    assert manifest["sha256"] == hashlib.sha256(data).hexdigest()
+
+
+def test_signature_is_64_bytes(tmp_path, key_pem):
+    firmware = tmp_path / "fw.bin"
+    firmware.write_bytes(b"fw")
+    out_dir = tmp_path / "out"
+
+    deploy(firmware_path=firmware, key_path=key_pem,
+           version="1.0.0", output_dir=out_dir)
+
+    sig = (out_dir / "current.sig").read_bytes()
+    assert len(sig) == 64