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mrwulf
2e48d9c6d0
fips205.slh_verify_128s_accepts_iff (Proofs/ApexSpec.lean): the extracted
top-level SLH-DSA-SHA2-128s verifier returns `ok true` if and only if the
recomputed hypertree root byte-equals the pinned public-key root pk.pk_root.
There is NO acceptance path other than root equality.
slh_verify_128s mprime sig pk
= (do let root ← slhVerifyRoot 63 30 mprime sig pk
ok (decide (root.val = pk.pk_root.val)))
where slhVerifyRoot is byte-for-byte the extracted slh_verify_internal_free
pipeline (H_msg digest -> md/idx_tree/idx_leaf split via to_int + masks ->
fors_pk_from_sig -> hypertree recompute over xmss over wots over chain), with
only the final ht_verify_free comparison factored out.
#print axioms cone = EXACTLY [propext, Classical.choice, Quot.sound,
verify_mono.oracle.{f, h, h_msg, t_l, t_len}] — the three kernel axioms plus
PRECISELY the five SHA-2 hash oracles, and nothing else. No plumbing, no
transpiler artifacts. This is the boundary the whole campaign targeted: the
deployed verify path is machine-checked down to five named hash functions.
Structure:
- arrayEqU8_spec: the library array equality PartialEqArray.eq on two
Array U8 N returns exactly the decidable byte-equality of their lists (a
List.allM induction; the one real lemma). This is what makes "accepts" mean
"root byte-equals pk_root" explicitly, in the spirit of the ed25519
verify_accepts_iff.
- ht_verify_free_split: ht_verify_free = htVerifyRoot >>= (byte-compare to
pk_root), via arrayEqU8_spec on the tail; bind_congr threads the setup.
- slh_verify_internal_accepts_iff (generic, all param sets) + the 128s
corollary: unfold the internal, rewrite the ht tail with the split, flatten
with bind_assoc; both sides become the identical do-block (simp closes
structurally — no whnf of the nested ht_verify_free_loop, the ForsOuter
lesson).
Honest scope: the apex is an ACCEPTANCE characterization — it pins that the
top-level accept is exactly root equality over the extracted recomputation,
whose every loop is individually fidelity-certified by the ten preceding
theorems (chain/wots/xmss/ht/fors/input-prep). It does NOT re-derive the
recomputation as a closed-form mathematical hypertree value; that composition
of all ten fold-fidelity theorems into one expression is a further step, not
claimed here. The security-relevant statement — an accepted signature means
the verifier recomputed a root matching the pinned key, down to five hash
oracles — is exactly what is proven.
check.sh: PROOFS += ApexSpec; CERTS += fips205.slh_verify_128s_accepts_iff;
audit imports it. Green over ALL ELEVEN certificates at default caps.
The verify-path proof pyramid is COMPLETE. What remains before any LTL
attestation is operator-gated and NOT started (the big halt): the pacta
allowed-cone table entry + the append ceremony with the operator signing key.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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|---|---|---|
| .. | ||
| gen/SlhVerify | ||
| Proofs | ||
| check-selftest.sh | ||
| check.sh | ||
| drill.sh | ||
| extract.sh | ||
| lean-guard | ||