The Principia Machina/TPC-PY/tpc digest.py - Revision history

BFP Rauch: 1 revision imported

2026-09-30T13:34:09Z

1 revision imported

← Older revision	Revision as of 13:34, 30 September 2026
(No difference)

BFP Rauch: TPC-PY source tpc_digest.py (0.3.0), SHA-256 7c19ec79236d29ea; conformed TPS 0.5.0; PROPOSED, not declared (TPC-PY 0.3.0)

2026-09-30T13:34:05Z

TPC-PY source tpc_digest.py (0.3.0), SHA-256 7c19ec79236d29ea; conformed TPS 0.5.0; PROPOSED, not declared (TPC-PY 0.3.0)

← Older revision		Revision as of 13:34, 30 September 2026
Line 21:		Line 21:
	the <pre> text of the declared TPS tree's pages. digest_fields,		the <pre> text of the declared TPS tree's pages. digest_fields,
	combine_digests and d_tfk are unchanged.		combine_digests and d_tfk are unchanged.

			0.3.0 (proposed with TPC-PY 0.3.0; D216.1, taken 2026-09-29: the pause
			tpm_post_tpcpy_wave4_pause 0.2.0, D216 Option 1 (c); tps_pages_definition
			0.1.0): tps_pages, the ordered list [title, h] of the kept pages, the very
			list d_tps digests, which TPX publishes beside D(TPS) and D(IS) at each TPS
			declaration and against which PRB names the pages that differ. d_tps is
			built on it (the version checked, then the list digested), so no answer of
			d_tps moves; pre_texts, d_is, digest_fields, combine_digests and d_tfk are
			unchanged.

			tps_pages(pages) -> ["OK", [[title, h], ...]] or ["REFUSED", reason]
			pages as d_tps takes them. The list: the kept pages (the root and the
			section pages with at least one block; the contents page never), in
			d_tps's order, each with h, the SHA-256 of its blocks joined by one
			LF, as UTF-8, in lowercase hex; nothing normalized; [] when no page is
			kept. Reasons: d_tps's less "version", in its order ("pages",
			"title", "root", "pre"), the first that applies whatever the order of
			the pages. d_tps(version, pages) refuses "version" first and otherwise
			exactly when tps_pages(pages) refuses, with the same reason; when it
			answers OK, its digest is digest_fields(["TPC-TPS", "1", version, n,
			title_1, h_1, ..., title_n, h_n]) over this list.

	pre_texts(wikitext) -> ["OK", [block, ...]] or ["REFUSED", "pre"]		pre_texts(wikitext) -> ["OK", [block, ...]] or ["REFUSED", "pre"]
Line 87:		Line 108:
	import re		import re

	TPC_DIGEST_VERSION = "0.2.0"		TPC_DIGEST_VERSION = "0.3.0"
	TPC_DIGEST_STATUS = "RATIFIED (D97.1, 2026-09-22); values VERIFIED; 0.2.0 proposed (~~D203~~.1)"		TPC_DIGEST_STATUS = ("RATIFIED (D97.1, 2026-09-22); values VERIFIED; 0.2.0 declared with TPC-PY 0.2.0 "
			"(D203.1); 0.3.0 proposed (D216.1)")


Line 243:		Line 265:


	def ~~d_tps~~(~~version,~~ pages):		def tps_pages(pages):
	~~if not _version_ok~~(~~version~~):		"""0.3.0 (D216.1): the ordered list [title, h] of the kept pages."""
	~~return _refused(~~"~~version~~")
	if type(pages) is not list or any(		if type(pages) is not list or any(
	type(p) is not list or len(p) != 2 or type(p[0]) is not str or type(p[1]) is not str		type(p) is not list or len(p) != 2 or type(p[0]) is not str or type(p[1]) is not str
Line 271:		Line 292:
	rows.append(((0,) if c[0] == "root" else (1, c[1]), title, h))		rows.append(((0,) if c[0] == "root" else (1, c[1]), title, h))
	rows.sort()		rows.sort()
	fields = [TPS_TAG, TPS_FORM, version, len(~~rows~~)]		return ["OK", [[title, h] for _, title, h in rows]]
	for _, title, h in ~~rows~~:

			def d_tps(version, pages):
			if not _version_ok(version):
			return _refused("version")
			r = tps_pages(pages)
			if r[0] != "OK":
			return r
			fields = [TPS_TAG, TPS_FORM, version, len(r[1])]
			for title, h in r[1]:
	fields += [title, h]		fields += [title, h]
	return ["OK", digest_fields(fields)]		return ["OK", digest_fields(fields)]
Line 296:		Line 326:
	return ["OK", digest_fields(fields)]		return ["OK", digest_fields(fields)]

	# END OF ARTIFACT --- tpc_digest 0.2.0		# END OF ARTIFACT --- tpc_digest 0.3.0
	# If this line is absent, the payload arrived truncated.		# If this line is absent, the payload arrived truncated.

BFP Rauch: 1 revision imported

2026-09-30T02:11:04Z

1 revision imported

← Older revision	Revision as of 02:11, 30 September 2026
(No difference)

BFP Rauch: TPC-PY source tpc_digest.py (0.2.0), SHA-256 5020ae73795f0b93; conformed TPS 0.4.0; PROPOSED, not declared (TPC-PY 0.2.0)

2026-09-30T02:10:58Z

TPC-PY source tpc_digest.py (0.2.0), SHA-256 5020ae73795f0b93; conformed TPS 0.4.0; PROPOSED, not declared (TPC-PY 0.2.0)

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BFP Rauch: 1 revision imported

2026-09-28T04:37:36Z

1 revision imported

← Older revision	Revision as of 04:37, 28 September 2026
(No difference)

BFP Rauch: TPC-PY source tpc_digest.py (0.1.0), SHA-256 43baf0ec8675622b; conformed TPS 0.3.0; PROPOSED, not declared (CO-8)

2026-09-27T15:43:18Z

TPC-PY source tpc_digest.py (0.1.0), SHA-256 43baf0ec8675622b; conformed TPS 0.3.0; PROPOSED, not declared (CO-8)

New page

# -*- coding: utf-8 -*-
"""
TPC-PY --- digest primitive and the D(TFK) combination rule
===========================================================
Discharges the two OWED items in TPS 2.5.3 at the primitive + combination
level (C-02 the convention, C-03 the cross-implementation hash tests):

OWED (C-02): the combination rule for D(TFK) over the three zone digests,
fixed order, fixed algorithm, stated once, so independent
verifiers agree.
OWED (C-03): cross-implementation hash tests, since serialization drift
is the known failure of hash chains.

STATUS: RATIFIED (decision D97.1, 2026-09-22). The convention is fixed and
digest VALUES are VERIFIED. Its text still lands in TPS 2.5 at revision 5
(owed spec edit). Standard-library only; Python 3.7+; Windows/Linux.

WHAT IS FIXED HERE (the proposal)
ALG SHA-256 (agrees with TPS 2.5.4 chain-link hash).
OUTPUT lowercase hex, 64 chars.
ENCODING a drift-proof, self-delimiting netstring of the ordered
fields, so no whitespace, delimiter, or number formatting
can drift between residences:
enc([b1..bn]) = concat_i( decimal(bytelen(bi)) + ":" + bi )
Each field is presented as raw UTF-8 bytes (a string) or as
base-10 ASCII (an integer). SHA-256 is taken over enc(...).
FIELD ORDER fixed per producer (the caller passes fields in TPS order).
D(TFK) combine_digests([D(TPK), D(TrM), D(TMS)]) --- exactly that
order (TPS 2.5.3). D(TrM) itself is header-then-entries in
fixed order (TPS 2.5.9 / 2.3.10); that per-zone field list
is produced by the zone serializer, still owed with the
zone schemas (2.2/2.3/2.4) and NOT fixed in this increment.

WHY NETSTRING. A hash chain fails on serialization drift. A self-delimiting
length-prefixed encoding removes every drift source JSON leaves open
(key order, insignificant whitespace, float/number formatting, escaping):
there is exactly one byte sequence for a given ordered field list, and it
is identical in Python and PHP.
"""

import hashlib

TPC_DIGEST_VERSION = "0.1.0"
TPC_DIGEST_STATUS = "RATIFIED (D97.1, 2026-09-22); values VERIFIED"

def _enc(byte_items):
"""The netstring encoding of an ordered list of byte-strings."""
out = bytearray()
for b in byte_items:
out += str(len(b)).encode("ascii")
out += b":"
out += b
return bytes(out)

def _as_bytes(field):
"""A field's canonical bytes: str -> UTF-8; int (not bool) -> base-10 ASCII."""
if isinstance(field, bool):
raise TypeError("digest field must not be bool; use an explicit token")
if isinstance(field, str):
return field.encode("utf-8")
if isinstance(field, int):
return str(field).encode("ascii")
if isinstance(field, (bytes, bytearray)):
return bytes(field)
raise TypeError("digest field: unsupported type %r" % type(field))

def preimage_fields(fields):
"""The exact bytes hashed by digest_fields --- the auditable artifact.
Returned as bytes; for ASCII content it prints as the netstring."""
return _enc([_as_bytes(f) for f in fields])

def digest_fields(fields):
"""SHA-256 over the netstring of the ordered fields; lowercase hex.
Use for a record's content digest and for each zone once its field
order is fixed (the caller supplies fields in TPS order)."""
return hashlib.sha256(preimage_fields(fields)).hexdigest()

def preimage_digests(hex_digests):
"""The exact bytes hashed by combine_digests (auditable)."""
for h in hex_digests:
if not _is_hex64(h):
raise ValueError("combine: each input must be a 64-char lowercase hex digest")
return _enc([h.encode("ascii") for h in hex_digests])

def combine_digests(hex_digests):
"""SHA-256 over the netstring of an ordered list of hex digests; the
fixed-order, fixed-algorithm combination rule (TPS 2.5.3 C-02)."""
return hashlib.sha256(preimage_digests(hex_digests)).hexdigest()

def d_tfk(d_tpk, d_trm, d_tms):
"""D(TFK) = combine_digests([D(TPK), D(TrM), D(TMS)]) --- TPS 2.5.3.
The container binds to D(TFK)."""
return combine_digests([d_tpk, d_trm, d_tms])

def _is_hex64(s):
if not isinstance(s, str) or len(s) != 64:
return False
return all(c in "0123456789abcdef" for c in s)