Two theorems, split into two files (METHOD-4 discipline — each proof a clean
unit). NB: an early single-file/bare-rfl attempt appeared to "OOM at the clamp",
but that memory pressure was a SYMPTOM of the runaway whnf diagnosed below, not
a real memory need — the fixed proofs compile in seconds at the default caps.
fips205.fors_inner_loop_eq (Proofs/ForsInnerSpec.lean): the extracted inner
Merkle auth-path loop for ONE FORS tree (fors_pk_from_sig_free_loop0_loop0)
equals the explicit auth-path fold — at level j set tree height j+1, test bit j
of THIS tree's leaf index indices[i], hash the current node with auth.tree[j] in
the bit order (even: node||auth[j]; odd: auth[j]||node), halving the tree index.
Structurally the XMSS auth-path loop, but the bit source is indices[i]>>j and the
loop returns the (adrs,node) pair. Cone: kernel-3 + verify_mono.oracle.h.
fips205.fors_outer_loop_eq (Proofs/ForsOuterSpec.lean): the extracted outer
per-tree loop (fors_pk_from_sig_free_loop0) equals the explicit K-tree fold — for
each tree i, compute the leaf with F at tree index (i<<a)+indices[i], run the
inner Merkle loop over the A levels, write the result to root[i]. Consumes the
inner loop as an opaque sub-call. Cone: kernel-3 + verify_mono.oracle.{f,h}
(F per leaf; H transitively through the inner loop).
Fidelity review at authorship (three-way, both loops): extracted bodies (gen
Funs.lean 893-933 inner, 954-985 outer) == Rust verify_mono.rs
fors_pk_from_sig_free (verbatim from upstream fors.rs, hash calls -> oracle) ==
FIPS 205 Algorithm 17, incl. the even/odd sibling order and the (i<<a)+indices[i]
leaf index.
Proof: the branched-Merkle recipe (XMSS) for the inner loop (by_cases on the
index bit, pair-bind matcher made concrete via bind_congr+rintro then full simp);
the HT straight-line recipe for the outer loop, adapted (bind_congr-peeled step
lemma + bind_congr x16 induction, both threading the inner-loop sub-call opaquely). loop_unfold_bind / u32_succ
/ fwd_succ / hnext reused verbatim from ChainSpec.
check.sh: PROOFS += ForsInnerSpec, ForsOuterSpec; CERTS += the two fors certs;
audit imports both; check.sh settings unchanged (400s/4096MB). ForsOuterSpec
compiles in 4.4s / 2.4GB after the fix below. check.sh green over ALL SIX
certificates with the axiom audit. README status -> FIVE certificates.
DIAGNOSIS NOTE (honesty): ForsOuterSpec's fors_outer_step first closed with a
bare `rfl`, which whnf'd the whole 16-bind body INCLUDING the inner-loop `loop`
term and hit a DETERMINISTIC 4M-heartbeat timeout (never actually passed — an
earlier "green" reading was a misread wrapper exit code; the real error was
hidden by check.sh piping per-file output to /dev/null). Fix: peel the 16 binds
with bind_congr so the closing rfl only sees the small loop-tail, and close the
post-pair-rintro tail with a full simp (the pair `let` won't iota via simp only).
This is the HtSpec straight-line recipe adapted for a body that nests a loop.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
fips205.ht_loop_eq (Proofs/HtSpec.lean): the extracted ht_verify_free_loop
equals the explicit d-layer fold — at layer j: idx_leaf = idx_tree masked
to h' bits (mask+cast), idx_tree >>= h', layer address j, tree address to
the shifted index, node recomputed through xmss_pk_from_sig on the j-th
XMSS signature. Pins the hypertree layer schedule; the final node ==
pk_root comparison sits one bind above in ht_verify_free (apex material).
Exact cone: [propext, Classical.choice, Quot.sound, verify_mono.oracle.f,
verify_mono.oracle.h, verify_mono.oracle.t_l] — kernel-3 plus exactly the
three hash primitives the referenced WOTS+/XMSS machinery touches.
THE LAYER'S OBSTRUCTION (one per layer, on pattern) was not the proof but
the CONE: the first extraction of this loop carried Result-conversion
plumbing (try_from/is_err/unwrap; transitively a Take iterator and the
&u32 Sub instance) — all axioms, rightly rejected by the Phase-3 audit.
Fixed at SOURCE level (fips205-source 6f6a9d6, 8 sites, semantics
identical for every FIPS 205 parameter set, differential test re-run
green), then re-extracted: the loop body is now straight-line and the
proof is the plain chain/wots recipe (no branches; base case via
loop.eq_1; step lemma closes by rfl; induction = bind_congr ×12).
Also in this commit:
- gen/ regenerated from the patched snapshot (loop bodies of the three
prior certificates byte-identical modulo source line comments; all
three proofs recompiled unchanged and re-audited green).
- Dead-stub deletion (axiom-shadowing hygiene rule): the five obsoleted
plumbing axioms + vestigial take.default removed from FunsExternal, the
orphaned TryFromIntError type axiom removed from TypesExternal. The
model's external surface is now: 5 SHA-2 oracles (the boundary), the
Take iterator machinery used only by helpers::to_int (apex round's
de-plumbing item), 3 zeroize blanket impls (never on the verify path),
and the discharged-real u32 Step defs.
- check.sh: PROOFS += HtSpec, CERTS += fips205.ht_loop_eq, audit import
(self-test structure anchors untouched). README: four certificates +
the de-plumbing record.
Fidelity review at authorship (three-way): extracted body == Rust
ht_verify_free (verbatim from upstream hypertree.rs, calls -> *_free) ==
FIPS 205 Algorithm 12, incl. mask-then-shift order and layer-then-tree
address order.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
fips205.xmss_loop_eq (Proofs/XmssSpec.lean): the extracted
xmss_pk_from_sig_free_loop equals the explicit Merkle-path fold — at step
k set the tree height to k+1, test bit k of the leaf index; even bit:
tree_index := i/2 and H(node || auth[k]); odd bit: tree_index := (i-1)/2
and H(auth[k] || node). This pins the sibling hash ORDER, the address
schedule, and the auth-path indexing of Merkle verification. Exact cone:
[propext, Classical.choice, Quot.sound, verify_mono.oracle.h] — the first
certificate where H enters; F does not (the loop runs above the WOTS+
computation). check.sh green over all three certificates.
Fidelity review at authorship (three-way): extracted body (gen Funs.lean
761-801) == Rust verify_mono.rs xmss_pk_from_sig_free (verbatim from
upstream xmss.rs, hash calls -> oracle) == FIPS 205 Algorithm 10, incl.
the per-branch operation order (even: node-slice then auth[k]; odd:
auth[k] then node-slice) and the k+1 tree height.
Proof: the chain/wots recipe on a u32 range — u32_succ / fwd_succ / hnext
/ loop_unfold_bind reused VERBATIM from ChainSpec. New layer lesson (the
one novel obstruction, on pattern): the loop body BRANCHES on the index
bit, so the step lemma splits with by_cases + if_pos/if_neg; and the
get_tree_index pair-bind needs its matcher made concrete before the tail
normalizes — bind_congr + rintro to fix the scrutinee, then FULL simp
(only full simp iota-reduces the pair matcher; simp only will not) with
bind_assoc + bind_ok + the loop def closes each branch. The certificate's
own induction threads the IH under the opaque binds of BOTH branches with
bind_congr, per branch, ending exact ih.
check.sh: PROOFS += XmssSpec, CERTS += fips205.xmss_loop_eq, audit
imports XmssSpec (self-test structure anchors untouched). README: status
three certificates, Algorithm numbering per upstream comments (wots=8,
xmss=10).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
fips205.wots_loop1_eq (Proofs/WotsSpec.lean): the extracted WOTS+ chain
loop wots_pk_from_sig_free_loop1 = the explicit fold that, at each index
i in [0, LEN), sets the chain address to i and runs chain_free on sig[i]
starting at digit msg[i] for W-1-msg[i] steps, writing tmp[i]. This is
the layer above chain: it CONSUMES chain_free and machine-checks that the
LEN chains are run with the right start indices, step counts, and output
slots — the WOTS+ verification recomputation.
Cone stays clean: [propext, Classical.choice, Quot.sound,
verify_mono.oracle.f] — the loop uses the REAL Aeneas StepUsize (usize
range, no plumbing axiom) and calls chain_free/index_usize/update, all
real; the try_from / Take-iterator / base_2b input-prep plumbing lives in
the enclosing wots_pk_from_sig_free, NOT in this loop.
Proof mirrors ChainSpec, reusing the generic loop_unfold_bind: usize_succ
+ fwd_succ_usize + hnext_usize (StepUsize iterator step), hbody1 (loop
body as clean do-block), wots_loop1_step (one loop step = one fold step),
wots_loop1_eq (induction, IH under the fatter binds via bind_congr x8).
No sorry; check.sh green over BOTH certificates with the axiom audit.
The chain-proof patterns transferred one-for-one to the next layer.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
verification/check.sh is green (exit 0): 3 phases — model compiles,
proofs compile, axiom audit passes.
fips205.chain_free_loop_eq (Proofs/ChainSpec.lean): the extracted
chain_free loop = the explicit s-fold hash chain, hash address i..i+s-1.
Machine-checked, for the deployed monomorphic SHA2-128s verify path, that
there is no off-by-one loop bound, no wrong address field, no wrong
threading. #print axioms cone = EXACTLY [propext, Classical.choice,
Quot.sound, verify_mono.oracle.f] — kernel three + the one hash oracle,
zero transpiler plumbing (the u32 Step machinery was discharged earlier
with real defs). check.sh Phase 3 enforces cone subset of kernel-3 + the
five SHA-2 oracles, failing the build otherwise.
Proof structure (all lemmas axiom-clean, no sorry): u32_succ + fwd_succ
(the monadic u32 increment, checked against pinned rustc semantics);
loop_unfold_bind (one turn of the Aeneas loop fixpoint, closed by cases
because a hand-written match compiles to a non-defeq matcher);
hnext + hbody (iterator step and loop body as clean equations);
chain_step (one loop step = one fold step); chain_free_loop_eq
(induction, IH threaded under the opaque binds with bind_congr).
Both prior sorries closed. Certificate lives in Proofs/ (not drafts/);
the WIP draft is retired. check.sh committed as -F stdin per the
no-backticks-in-commit-messages rule.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
'What will be claimed' promised cones of exactly the three kernel
axioms — right for ed25519 field/scalar layers, wrong here: the hash
oracles permeate every SLH-DSA layer (chain already calls F). The
honest contract, now stated: each certificate cone = the three kernel
axioms + at most the five named oracles, nothing else; plumbing axioms
must be discharged before any certificate ships, audit-enforced.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The skeleton-era docs said 'six hash oracles' including prf — written
before the cone analysis showed prf/prf_msg are sign-side only. The
extracted model and FunsExternal carry exactly FIVE oracle axioms
(h_msg, f, h, t_l, t_len); the documented boundary now matches the
real one in README, TRUSTED-BASE, and extract.sh. Caught by the
post-flip drill's cross-consistency pass.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The gate-0 fn-pointer blocker is cleared. This commits the phase-1
deliverable:
- verification/extract.sh: re-pointed at the monomorphic root
crate::verify_mono::slh_verify_128s with crate::verify_mono::oracle as
the opaque SHA-2 boundary (against fips205-source @ 2d89ee3).
- verification/gen/SlhVerify: the extracted Lean model — 62 defs, the
full verify cone (chain -> wots -> xmss -> ht -> fors ->
slh_verify_internal) up to the apex verify_mono.slh_verify_128s. No
sorry, no admit.
- verification/gen/SlhVerify/FunsExternal.lean + TypesExternal.lean:
hand-maintained externals with the two-class justification header —
(1) the five SHA-2 hash oracles = the deliberate cryptographic
boundary (the only axioms the apex certificate will carry beyond
Lean's three); (2) transpiler plumbing (try_from, is_err, iterator
Step/Take, zeroize) adopted as axioms for the phase-1 type-check, to
be discharged in the proof phase.
- verification/check.sh: real Phase-1 button — compiles the model under
lean-guard (memory-capped, serialized). GREEN. Still says NOTHING
PROVEN: a well-formed model is not a correct one.
Zero certificates. Proof layers (chain semantics -> ... -> acceptance
equation) are the next task.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Subject pinned: integritychain/fips205 @ 30bac08 via
saymrwulf/fips205-source @ 5dca0db. Parameter set SLH-DSA-SHA2-128s.
Scope: verify path only (slh_verify -> ... -> chain); six SHA-2 hash
oracles opaque per the standing boundary.
Gate-0 record (2026-07-22): charon clean on the full verify cone;
aeneas translates everything except the Hashers fn-pointer struct
(3 unique errors, the sole obstruction) -> phase 1 = named-opaque-
free-function compat patch in the snapshot repo, the established
dalek sha512-shim pattern.
check.sh exits non-green and says NOTHING PROVEN YET (H5, R3).
lean-guard copied; every future compile runs under it (S1, S2).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
