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>
fips205.base2b_outer_loop_eq (Proofs/InputPrepSpec.lean): the extracted
digit-writing outer loop (helpers.base_2b_loop0) equals the explicit fold that,
for each output index, runs the inner `while bits < b` accumulation loop
(base_2b_loop0_loop0, consumed as an OPAQUE sub-call — same treatment as
ht/fors give their sub-loops) then writes baseb[out] = (total >> bits) &
(u32::MAX >> (32-b)). Cone EXACTLY [propext, Classical.choice, Quot.sound] —
kernel-3, no oracle (pure bit/byte digit extraction).
This completes the input-prep layer's named milestone (to_int, to_byte,
base_2b) — all four prep certs kernel-3 clean. base_2b's inner while-loop
VALUE fidelity (a fuel-induction value-level statement) is deliberately NOT
claimed here; the outer loop pins the digit-writing structure with the inner
accumulation threaded opaquely, exactly as every other layer treats its
sub-loops.
Proof: the ForsOuterSpec straight-line-nesting-a-loop recipe. The step lemma
PEELS the inner-loop triple sub-call with `apply bind_congr; rintro
⟨inn1,bits1,total1⟩` then closes the small tail with full simp — a bare rfl
would whnf the nested `loop` term and blow the heartbeat budget (the drill-9
lesson, applied deliberately). Compiled first try.
check.sh: CERTS += fips205.base2b_outer_loop_eq. Green over ALL TEN
certificates at default caps.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Three straight-line range-loop fidelity theorems (Proofs/InputPrepSpec.lean),
each #print axioms = EXACTLY [propext, Classical.choice, Quot.sound] — pure
byte/bit arithmetic, NO hash oracle enters (the cleanest cones in the campaign):
- fips205.to_int_loop_eq (Algorithm 2, toInt): the extracted big-endian
byte->u64 loop = the fold total <- (total<<8) + x[i].
- fips205.to_byte_loop_eq (Algorithm 3, toByte): the extracted u32->byte loop =
the fold writing s[n-1-i] and shifting total right by 8.
- fips205.wots_csum_loop_eq: the WOTS+ checksum loop = the fold
csum <- csum + (W-1-msg[i]).
All three are the straight-line recipe (hbody -> step lemma closed by rfl ->
induction with bind_congr per bind). to_int + checksum use the usize range
helpers (WotsSpec), to_byte the u32 range (ChainSpec); loop_unfold_bind reused.
Also in this commit — DE-PLUMBING ROUND 2 landed (source bea1051, separate
commit in fips205-source): to_int's iter().take() and base_2b's iter_mut()
became index loops, so both extract to real definitions. Consequently:
- gen/ regenerated (to_int_loop / base_2b_loop0 now clean StepUsize range
loops with Slice.index_usize / Slice.update; the six prior certificates
recompiled UNCHANGED and re-audited green against the new gen).
- The core::iter::adapters::take::Take::next AXIOM — the LAST non-oracle,
non-zeroize plumbing axiom on the verify path — is now unreferenced and was
DELETED from FunsExternal (dead-stub hygiene rule). The model's external
surface is now EXACTLY: the 5 SHA-2 oracles + 3 zeroize blanket impls (never
on the verify path) + the discharged-real u32 Step defs. Nothing else.
Fidelity review at authorship (three-way): extracted loop bodies (gen
Funs.lean) == Rust helpers.rs to_int/to_byte + verify_mono checksum (verbatim
FIPS 205 Alg 2/3) == the folds above.
check.sh: PROOFS += InputPrepSpec; CERTS += the 3 certs; audit imports it.
Green over ALL NINE certificates at default caps (400s/4096MB).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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>
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>
