mrwulf 015f467954 phase 2: INPUT-PREP layer — to_int, to_byte, WOTS+ checksum (3 kernel-3 certs) ... 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>		2026-07-24 08:55:34 +02:00
..
SlhVerify	phase 2: INPUT-PREP layer — to_int, to_byte, WOTS+ checksum (3 kernel-3 certs)	2026-07-24 08:55:34 +02:00