mirror of
https://github.com/saymrwulf/anza-ed25519-verified.git
synced 2026-09-04 20:24:06 +00:00
mrwulf
8440b53bdc
Transpile the Scalar52 limb backend (backend::serial::u64::scalar
add/sub/mul/square/montgomery_*) from Rust to Lean via Charon/Aeneas,
scoped at the function level to the iterator-free arithmetic core.
- verification/extract-scalar.sh: function-level Charon/Aeneas extraction
- verification/gen/CurveScalar/{Types,Funs}.lean: transpiled model (28 defs)
- verification/gen/CurveScalar/{TypesExternal,FunsExternal}.lean: hand-written
external models (subtle.Choice + 2 subtle fns; namespace = curve25519)
- verification/Proofs/ScalarDenote.lean: semantic foundation — Scalar52
denotation into ℤ/ℓℤ, limb-bound invariant, and L_val (the transpiled
constants::L denotes exactly the group order ℓ, kernel-checked)
- verification/check-scalar.sh: guarded compile of the four gen modules
plus the denotation foundation
check-scalar.sh passes: gen compiles; denotation + L = ℓ proven.
add/sub/mul remain in progress.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
36 lines
1.7 KiB
Text
36 lines
1.7 KiB
Text
-- Hand-written external function models for the Scalar52 arithmetic extraction.
|
|
-- The two subtle items reuse the field extraction's proven models verbatim.
|
|
import Aeneas
|
|
import CurveScalar.Types
|
|
open Aeneas Aeneas.Std Result ControlFlow Error
|
|
set_option linter.dupNamespace false
|
|
set_option linter.hashCommand false
|
|
set_option linter.unusedVariables false
|
|
set_option maxHeartbeats 1000000
|
|
set_option maxRecDepth 2048
|
|
open curve25519
|
|
|
|
/-- [subtle::{impl core::convert::From<u8> for subtle::Choice}::from]:
|
|
Source: '/cargo/registry/src/index.crates.io-1949cf8c6b5b557f/subtle-2.6.1/src/lib.rs', lines 238:4-238:32
|
|
Name pattern: [subtle::{core::convert::From<subtle::Choice, u8>}::from]
|
|
|
|
MODEL (faithful): Rust body is `Choice(black_box(input))`; the volatile
|
|
read in `black_box` is semantically the identity. -/
|
|
@[rust_fun "subtle::{core::convert::From<subtle::Choice, u8>}::from"]
|
|
def subtle.Choice.Insts.CoreConvertFromU8.from
|
|
(b : Std.U8) : Result subtle.Choice :=
|
|
ok b
|
|
|
|
/-- [subtle::{impl subtle::ConditionallySelectable for u64}::conditional_select]:
|
|
Source: '/cargo/registry/src/index.crates.io-1949cf8c6b5b557f/subtle-2.6.1/src/lib.rs', lines 513:12-513:77
|
|
Name pattern: [subtle::{subtle::ConditionallySelectable<u64>}::conditional_select]
|
|
|
|
MODEL: `a` if choice = 0, else `b`. The Rust mask trick
|
|
`a ^ (-(choice as i64) as u64 & (a ^ b))` agrees with this on the Choice
|
|
invariant {0,1} (mask = 0 or all-ones). -/
|
|
@[rust_fun
|
|
"subtle::{subtle::ConditionallySelectable<u64>}::conditional_select"]
|
|
def U64.Insts.SubtleConditionallySelectable.conditional_select
|
|
(a b : Std.U64) (choice : subtle.Choice) : Result Std.U64 :=
|
|
ok (if choice.val = 0 then a else b)
|
|
|