dalek-ed25519-verified/verification/extract.sh

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#!/usr/bin/env bash
# Regenerate the Lean model in gen/ from the Rust sources.
#
# SCOPE: field arithmetic + Edwards point arithmetic
# roots: crate::field, crate::backend::serial::u64::field,
# crate::backend::serial::curve_models, crate::edwards
# (same widening the reference solution used for its Tier-1 addition-law
# theorem; scalar-mul backends stay opaque — upstream Aeneas cannot
# translate them; they are modeled/axiomatized in
# gen/CurveField/FunsExternal.lean OUTSIDE every certificate's cone.
# decompress IS extracted since the phase-2 full lift — the source's
# step_2 uses the documented negate-then-conditional-assign rewrite).
#
# Rust --charon--> CurveField.llbc --aeneas--> gen/CurveField/*.lean
#
# The hand-written gen/CurveField/{TypesExternal,FunsExternal}.lean are NOT
# touched by regeneration (Aeneas only rewrites the *_Template variants).
# After regenerating, diff the templates against the hand-written files:
# diff gen/CurveField/FunsExternal_Template.lean gen/CurveField/FunsExternal.lean
#
# Usage: ./extract.sh
set -euo pipefail
source ~/aeneas-toolchain/env.sh
HERE="$(cd "$(dirname "$0")" && pwd)"
CRATE=~/GitClone/FormalVerification/sources/curve25519-dalek-source/curve25519-dalek
echo "[1/4] charon: Rust -> LLBC (field + curve_models + edwards + scalar [MERGED GEN])"
cd "$CRATE"
THE SIGNATURE APEX: the EdDSA verification equation, proven and audited `Proofs/SigApexSpec.lean`: - `verify_loop_full` — the extracted 32-byte comparison loop returns exactly the byte-equality of the two arrays (induction; axiom cone = exactly [propext, Classical.choice, Quot.sound]). - `verify_accepts_iff` — THE APEX: for a signature that parses, the extracted RustCrypto verifier accepts IFF the recomputed compressed point compress( [s]·B − [k]·A ) equals the signature's R byte-for-byte. The recomputation is grounded in the PROVEN curve model (every curve and scalar call is a certified definition); k is whatever scalar the SHA-512 oracle produces — the honest EdDSA acceptance criterion with the hash opaque. Boundary hygiene forced by the audit itself: - The public vartime_double_scalar_mul_basepoint dispatch pulled the AVX2 vector-backend axiom into the apex cone. Fixed at the build level: extract.sh pins RUSTFLAGS --cfg curve25519_dalek_backend="serial", so the SIMD arm compiles out; BackendKind has only Serial and get_selected_backend becomes a real definition (ok Serial). - subtle.Choice.unwrap_u8 upgraded from axiom to the documented model definition (Choice := U8; unwrap_u8 = self.0) — it sits on the verify path via compress → is_negative. - CurveSig modules added to GEN_MODULES (stale-olean incoherence otherwise). check.sh grows Phase 3b: the apex certificate's axiom cone must equal EXACTLY [propext, Classical.choice, Quot.sound, ed25519.Signature, sha2.Sha512, sha512_new, sha512_update, sha512_finalize_bytes, ed25519.Signature.to_bytes, signature.error.Error, Error.new] — the SHA-512 hash oracle plus the opaque wire-format types. NO curve axioms, NO scalar axioms, NO backend axioms, enforced on every button press. Full check.sh green: 16 standard certificates + the apex audit. Phase 2 (the point-level equation [s]B − [k]A = decompress R, needing to_bytes canonicity and decompress) remains deferred and documented. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-04 17:45:55 +00:00
# Force the portable SERIAL backend (the one we verify): the SIMD dispatch
# arm is `#[cfg(curve25519_dalek_backend = "simd")]`, so pinning the cfg to
# "serial" removes it from the extraction — no vector-backend axiom leaks in.
export RUSTFLAGS='--cfg curve25519_dalek_backend="serial"'
charon cargo --preset=aeneas \
--start-from crate::field \
--start-from crate::backend::serial::u64::field \
--start-from crate::backend::serial::curve_models \
--start-from crate::edwards \
Merge scalar into CurveField; integrate the verify glue against the model Gen merge: extract.sh now co-extracts the Scalar52 backend and the public scalar::from_bytes_mod_order[_wide] conversions into the SAME CurveField model, so the whole library — field, curve_models, edwards, scalar — shares one type universe (Scalar is a single structure, not two). The scalar proof chain repoints by one import line (ScalarDenote: CurveScalar.Funs -> CurveField.Funs); check-scalar.sh's gen list follows. Both buttons — the scalar certificates and the field/group/dsm certificates — pass fresh over the merged gen, so the merge is proven-safe, not merely hoped-safe. Verify glue (gen/CurveSig): the extracted ed25519-dalek verify_sha512 path, integrated against the proven model: - TypesExternal.lean imports CurveField.Types, so CompressedEdwardsY / EdwardsPoint / Scalar in the glue ARE the proven model's types. Only the genuinely foreign types stay opaque: sha2.Sha512, ed25519.Signature, signature.error.Error. - FunsExternal.lean imports CurveField.Funs, so every curve/scalar call (compress, vartime_double_scalar_mul_basepoint, as_bytes, neg, from_bytes_mod_order[_wide]) resolves to a proven definition — no axioms. The `?`-operator plumbing (Try::branch, FromResidual::from_residual) and compressed_from_bytes get real definitions. Only the SHA-512 hasher (sha512_new/update/finalize_bytes) and two opaque wire accessors (Signature.to_bytes, Error.new) remain axiomatized — the deliberate, documented hash-oracle boundary. Audited: `verify_sha512`'s entire axiom cone is [propext, Classical.choice, Quot.sound, sha2.Sha512, sha512_new, sha512_update, sha512_finalize_bytes, ed25519.Signature.to_bytes, signature.error.Error.new] — zero curve axioms, zero scalar axioms. The verify path is definitionally grounded in the certified model; the only trust boundary is SHA-512. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-04 16:13:58 +00:00
--start-from 'crate::backend::serial::u64::scalar::_::add' \
--start-from 'crate::backend::serial::u64::scalar::_::sub' \
--start-from 'crate::backend::serial::u64::scalar::_::mul' \
--start-from 'crate::backend::serial::u64::scalar::_::square' \
--start-from 'crate::backend::serial::u64::scalar::_::montgomery_mul' \
--start-from 'crate::backend::serial::u64::scalar::_::montgomery_square' \
--start-from 'crate::backend::serial::u64::scalar::_::montgomery_reduce' \
--start-from 'crate::backend::serial::u64::scalar::_::montgomery_invert' \
--start-from 'crate::backend::serial::u64::scalar::_::as_montgomery' \
--start-from 'crate::backend::serial::u64::scalar::_::from_montgomery' \
--start-from 'crate::backend::serial::u64::scalar::_::from_bytes_wide' \
--start-from 'crate::scalar::_::from_bytes_mod_order' \
--start-from 'crate::scalar::_::from_bytes_mod_order_wide' \
--opaque 'crate::field::_::internal_invert_batch' \
--opaque 'crate::backend::serial::scalar_mul::variable_base' \
--opaque 'crate::backend::serial::scalar_mul::straus' \
--opaque 'crate::backend::serial::scalar_mul::precomputed_straus' \
--opaque 'crate::backend::serial::scalar_mul::pippenger' \
--opaque 'crate::backend::vector' \
--opaque 'crate::backend::get_selected_backend' \
--opaque 'crate::edwards::_::sum' \
--opaque 'crate::edwards::_::from_slice' \
--dest-file "$HERE/CurveField.llbc" \
-- --no-default-features
echo "[2/4] aeneas: LLBC -> Lean (split files, CurveField.* modules)"
cd "$HERE"
aeneas -backend lean -split-files -subdir CurveField -dest gen CurveField.llbc
echo "[3/4] charon: ed25519-dalek verify glue -> LLBC (SHA-512 opaque)"
SIGCRATE="$(dirname "$CRATE")/ed25519-dalek"
cd "$SIGCRATE"
charon cargo --preset=aeneas \
--start-from 'crate::verifying::verify_sha512' \
--start-from 'crate::verifying::recompute_r_sha512' \
--opaque 'crate::verifying::sha512_new' \
--opaque 'crate::verifying::sha512_update' \
--opaque 'crate::verifying::sha512_finalize_bytes' \
--opaque 'crate::signature::compressed_from_bytes' \
--opaque 'curve25519_dalek' \
--opaque 'sha2' --opaque 'digest' --opaque 'ed25519' \
--opaque 'signature' --opaque 'subtle' --opaque 'zeroize' \
--exclude 'hybrid_array' --exclude 'typenum' \
--hide-marker-traits \
--dest-file "$HERE/CurveSig.llbc"
echo "[4/4] aeneas: LLBC -> Lean (CurveSig.* modules; hand-maintained"
echo " TypesExternal.lean / FunsExternal.lean are NOT overwritten)"
cd "$HERE"
aeneas -backend lean -split-files -subdir CurveSig -dest gen CurveSig.llbc
echo "Done. Now run ./check.sh to type-check the regenerated model."