audit-core/tests/test_integrity.py

import json

from audit_core.ingestion import IngestionApplication
from audit_core.integrity import GENESIS, chain_link, load_attestation, write_attestation
from audit_core.interface import AuditEvent
from audit_core.sqlite_backend import SQLiteAuditBackend

from test_ingestion import invoke


def _event(event_id: str, **kw) -> AuditEvent:
    fields = dict(
        event_id=event_id,
        source="user-engine",
        action="membership.added",
        resource="membership-1",
        outcome="recorded",
        tenant="tenant:friendly:binky",
        scope="tenant",
        details={"correlation_id": "corr-1"},
        observed_at="2026-08-09T00:00:00+00:00",
    )
    fields.update(kw)
    return AuditEvent(**fields)


def _digest(event: AuditEvent) -> str:
    import hashlib

    return hashlib.sha256(
        json.dumps(event.as_record(), sort_keys=True).encode()
    ).hexdigest()


def test_first_accept_sets_genesis(tmp_path):
    backend = SQLiteAuditBackend(str(tmp_path / "c.db"))
    event = _event("e1")
    backend.accept(event, _digest(event))
    row = backend.db.execute(
        "SELECT chain_prev, chain_hash FROM events WHERE event_id = 'e1'"
    ).fetchone()
    assert row[0] == GENESIS
    assert row[1] == chain_link(GENESIS, _digest(event), "e1")


def test_second_accept_links(tmp_path):
    backend = SQLiteAuditBackend(str(tmp_path / "c.db"))
    first = _event("e1")
    second = _event("e2")
    backend.accept(first, _digest(first))
    backend.accept(second, _digest(second))
    head = backend.db.execute(
        "SELECT chain_hash FROM events WHERE event_id = 'e1'"
    ).fetchone()[0]
    prev = backend.db.execute(
        "SELECT chain_prev FROM events WHERE event_id = 'e2'"
    ).fetchone()[0]
    assert prev == head


def test_duplicate_does_not_fork(tmp_path):
    backend = SQLiteAuditBackend(str(tmp_path / "c.db"))
    event = _event("e1")
    digest = _digest(event)
    assert backend.accept(event, digest).duplicate is False
    assert backend.accept(event, digest).duplicate is True
    count = backend.db.execute("SELECT count(*) FROM events").fetchone()[0]
    assert count == 1
    assert backend.verify_chain().events == 1


def test_verify_clean_on_fresh_store(tmp_path):
    backend = SQLiteAuditBackend(str(tmp_path / "c.db"))
    empty = backend.verify_chain()
    assert empty.intact is True
    assert empty.events == 0
    assert empty.head == GENESIS
    first = _event("e1")
    second = _event("e2")
    backend.accept(first, _digest(first))
    backend.accept(second, _digest(second))
    report = backend.verify_chain()
    assert report.intact is True
    assert report.events == 2
    assert report.first_break is None


def test_rewritten_payload_fails_verify(tmp_path):
    backend = SQLiteAuditBackend(str(tmp_path / "c.db"))
    first = _event("e1")
    second = _event("e2")
    backend.accept(first, _digest(first))
    backend.accept(second, _digest(second))
    backend.db.execute("UPDATE events SET payload_hash = 'deadbeef' WHERE event_id = 'e2'")
    report = backend.verify_chain()
    assert report.intact is False
    assert report.first_break == "e2"


def test_attestation_mismatch(tmp_path):
    backend = SQLiteAuditBackend(str(tmp_path / "c.db"))
    event = _event("e1")
    backend.accept(event, _digest(event))
    path = tmp_path / "head.json"
    write_attestation(path, backend.verify_chain())
    cited = load_attestation(path)
    assert backend.verify_chain(cited).attestation_match is True
    cited["chain_hash"] = "f" * 64
    broken = backend.verify_chain(cited)
    assert broken.intact is False
    assert broken.first_break == "attestation_mismatch"
    assert broken.attestation_match is False


def test_attestation_still_matches_after_growth(tmp_path):
    backend = SQLiteAuditBackend(str(tmp_path / "c.db"))
    first = _event("e1")
    backend.accept(first, _digest(first))
    cited = backend.attest_chain()
    second = _event("e2")
    backend.accept(second, _digest(second))
    report = backend.verify_chain(cited)
    assert report.intact is True
    assert report.attestation_match is True
    assert report.events == 2


def test_http_integrity_requires_read(tmp_path):
    backend = SQLiteAuditBackend(str(tmp_path / "c.db"))
    app = IngestionApplication(backend, "opaque")
    status, _ = invoke(app, None, path="/v1/integrity", method="GET", body=b"")
    assert status.startswith("200")
    event = _event("e1")
    backend.accept(event, _digest(event))
    status, body = invoke(app, None, path="/v1/integrity", method="GET", body=b"")
    assert status.startswith("200")
    assert body["intact"] is True
    assert body["events"] == 1
    assert "record" not in body