mrwulf
cb628b9119
Third pyramid capped. Identical shape to the risc0 fork (both are sha2-0.10 stacks): the hash oracle is the single monomorphic sha512_hash3(R, A, m) call, extraction runs --no-default-features. - gen/CurveSig: extracted verify glue, definitionally welded to the proven CurveField model (every curve and scalar call resolves to a certified definition; only the hash and wire formats are opaque). - Proofs/SigApexSpec.lean (unchanged from dalek): verify_loop_full with the standard three-axiom cone, and verify_accepts_iff — the verifier accepts IFF compress([s]B - [k]A) = R byte-for-byte. - check.sh Phase 3b enforces the apex cone to be EXACTLY [propext, Classical.choice, Quot.sound, ed25519.Signature, verifying.sha512_hash3, ed25519.Signature.to_bytes, signature.error.Error, signature.error.Error.new]. - extract.sh gains the reproducible CurveSig stanza (same recipe verified byte-exact on the risc0 fork this session). Full check.sh green: all standard certificates + the apex audit. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> |
||
|---|---|---|
| verification | ||
| .gitignore | ||
| README.md | ||
| TRUSTED-BASE.md | ||
betrusted-ed25519-verified
Formal verification of the ed25519 implementation in betrusted-io/curve25519-dalek (Precursor/Xous fork, v4.1.2), built as a coherent proof pyramid in Lean 4 via the Charon/Aeneas transpilation pipeline:
┌──────────────────────────────┐
│ Signature (EdDSA verify) │ accepted ⇒ [8][S]B = [8]R + [8][k]A
├──────────────────────────────┤
│ Scalar arithmetic mod ℓ │ Scalar52 ops correct mod ℓ
├──────────────────────────────┤
│ Group law (twisted Edwards) │ point ops = complete addition law
├──────────────────────────────┤
│ Field 𝔽_p, p = 2²⁵⁵ − 19 │ FieldElement51 ops correct mod p
└──────────────────────────────┘
Every layer states its theorems about the actual Aeneas-transpiled Rust
code (never about a hand-written re-model), and every claim in the status
table below is backed by a compiled proof plus an axiom audit of the named
certificate. Files that do not compile under verification/check.sh are not
in this repository.
Layer status
| Layer | Certificate | Status | Axioms of certificate |
|---|---|---|---|
| Field 𝔽_p | fieldImplementation |
✅ proven | [propext, Classical.choice, Quot.sound] |
| Group law (Edwards) | edwardsImplementation |
✅ proven | [propext, Classical.choice, Quot.sound] |
| Scalar mod ℓ | scalarImplementation (add ✅ sub ✅ mul ✅) |
✅ proven | [propext, Classical.choice, Quot.sound] |
| Signature (EdDSA) | verifyEquation (planned) |
⏳ planned | — |
Status legend: ✅ proven & axiom-audited · ⏳ in progress · ❌ not started.
This table is updated only when verification/check.sh passes for the layer.
Source
- Upstream: betrusted-io/curve25519-dalek, commit
16e087a - Pinned/patched source: saymrwulf/betrusted-curve25519-dalek-source, commit
64ee8f0 - Patches: minimal Aeneas-compatibility only (documented in the source repo)
- Scope caveat: this verifies the fork's pure-Rust
serial/u64path. The Engine25519 hardware-accelerator path on Precursor is different code and is NOT covered by these proofs.
Toolchain (pinned)
| Component | Version |
|---|---|
| Aeneas | bf13c42e |
| Charon | 9dd7f23c |
| Lean | v4.30.0-rc2 |
| OCaml | 5.3.0 |
Reproducing
source ~/aeneas-toolchain/env.sh
cd verification
./extract.sh # Rust → LLBC → Lean (regenerates gen/)
./check.sh # compiles EVERY shipped file + axiom-audits EVERY certificate
The scalar layer has its own pair of buttons:
./extract-scalar.sh # regenerates gen/CurveScalar (Scalar52 limb arithmetic)
./check-scalar.sh # compiles the scalar gen + the proven scalar foundation
Trusted base
See TRUSTED-BASE.md for the complete list of assumptions (Lean kernel, mathlib, Charon/Aeneas semantics, external-function models, and — in the signature layer only — an opaque SHA-512 model).
Provenance
Proof engineering in this repository builds on the verification methodology and proof architecture of PlanetMacro/ed25519-verificationtest (the reference solution). All proofs here are checked against this fork's own extracted code; nothing is claimed that the check script does not compile.