File size: 1,803 Bytes
7cfea77 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 | """Recompute the hash chain from scratch. Run it against a ledger file you
did not produce and it still tells you whether the record is intact."""
from __future__ import annotations
import json
import sys
from dataclasses import dataclass, field
from pathlib import Path
from .chain import GENESIS, _PAYLOAD_KEYS, compute_hash
@dataclass
class VerifyResult:
ok: bool
count: int
problems: list[str] = field(default_factory=list)
def verify(path: str | Path) -> VerifyResult:
path = Path(path)
if not path.exists():
return VerifyResult(False, 0, [f"no such log: {path}"])
problems: list[str] = []
entries = [json.loads(l) for l in path.read_text(encoding="utf-8").splitlines() if l.strip()]
prev = GENESIS
for i, e in enumerate(entries):
if e.get("seq") != i:
problems.append(f"entry {i}: seq is {e.get('seq')}, expected {i}")
if e.get("prev_hash") != prev:
problems.append(f"entry {i}: chain broken")
expected = compute_hash(e.get("prev_hash", ""), {k: e.get(k) for k in _PAYLOAD_KEYS})
if e.get("hash") != expected:
problems.append(f"entry {i}: hash mismatch (altered)")
prev = e.get("hash", "")
return VerifyResult(ok=not problems, count=len(entries), problems=problems)
def main(argv: list[str] | None = None) -> int:
argv = list(sys.argv[1:] if argv is None else argv)
if not argv:
print("usage: python -m sipa_scan_ledger.verify <ledger.jsonl>")
return 2
res = verify(argv[0])
print(f"entries: {res.count}")
if res.ok:
print("OK - chain intact, nothing altered")
return 0
print("FAIL:")
for p in res.problems:
print(f" - {p}")
return 1
if __name__ == "__main__":
raise SystemExit(main())
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