| """Exact TOM canonical seed verification.""" |
| from __future__ import annotations |
|
|
| from dataclasses import dataclass |
| from pathlib import Path |
|
|
| from .canonical import digest_bytes |
|
|
| CANONICAL_SEED_LENGTH = 244 |
| CANONICAL_SEED_SHA256 = "d1417a3136772c0cf3eddcd4962ce07d42cbf87616f7b5bae09fc652d9b807b5" |
| CANONICAL_SEED_TEXT = ( |
| "TOM1[TopologicalOpenModular]|TomKlootwijk|1990-07-10|NL200678942|2026-09-01|" |
| "LUTlogp^{Klein,SDF0@Def}(rho,theta,t->;phi,dt,d2,J,v,a,j1)>P1>L2_BST^b>" |
| "ASweepCone(T,apex)>Pi[pyrSide,circle,sphere]>support>compatibility>guard>event>" |
| "transition>lineage" |
| ) |
|
|
|
|
| @dataclass(frozen=True, slots=True) |
| class SeedIdentity: |
| bytes: int |
| sha256: str |
| text: str |
|
|
| def as_record(self) -> dict[str, object]: |
| return { |
| "bytes": self.bytes, |
| "sha256": self.sha256, |
| "encoding": "ASCII/UTF-8", |
| "terminal_line_feed": False, |
| "grammar": "TOM-SRS-1.0-COMPACT-SEED", |
| } |
|
|
|
|
| def verify_seed_bytes(raw: bytes) -> SeedIdentity: |
| if not isinstance(raw, bytes): |
| raise TypeError("seed must be bytes") |
| if raw.endswith((b"\n", b"\r")): |
| raise ValueError("canonical TOM seed must not have a terminal line ending") |
| try: |
| text = raw.decode("ascii") |
| except UnicodeDecodeError as exc: |
| raise ValueError("canonical TOM seed must contain ASCII characters only") from exc |
| if len(raw) != CANONICAL_SEED_LENGTH: |
| raise ValueError(f"canonical TOM seed length mismatch: {len(raw)}") |
| digest = digest_bytes(raw, prefix=False) |
| if digest != CANONICAL_SEED_SHA256: |
| raise ValueError(f"canonical TOM seed SHA-256 mismatch: {digest}") |
| if text != CANONICAL_SEED_TEXT: |
| raise ValueError("canonical TOM seed literal mismatch") |
| return SeedIdentity(len(raw), digest, text) |
|
|
|
|
| def verify_seed_file(path: str | Path) -> SeedIdentity: |
| return verify_seed_bytes(Path(path).read_bytes()) |
|
|
