subtle 2.6.1: subtle

# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
version = 4

[[package]]
name = "sample-subtle"
version = "1.0.0"
dependencies = [
 "subtle",
]

[[package]]
name = "subtle"
version = "2.6.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"

[package]
name = "sample-subtle"
version = "1.0.0"
edition = "2021"
publish = false

[dependencies]
subtle = "=2.6.1"

[[bin]]
name = "contract"
path = "test/contract.rs"

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify subtle in pkg:cargo/subtle@2.6.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:cargo/subtle@2.6.1
Demonstrate these symbols/APIs:
  - subtle

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:0239341980649346d8667972cc5e29131879a1d4a66157d4445066aaf859124e","contract":["ConstantTimeEq compares scalar integers in constant time returning Choice","ConstantTimeEq compares byte slices of equal length and contents","ConditionallySelectable selects between values based on Choice without branching","ConditionallySelectable conditionally assigns a value in-place based on Choice","CtOption encapsulates an optional value with constant-time is_some check and safe unwrapping","ConstantTimeGreater and ConstantTimeLess compare scalar integers in constant time"],"goal":"verify subtle in pkg:cargo/subtle@2.6.1","kind":"HOW","packages":["pkg:cargo/subtle@2.6.1"],"schemaVersion":1,"symbols":["subtle"]},"contractCommand":["cargo","run","--offline"],"environment":{"arch":"x64","distro":"alpine","ecosystem":"cargo","libc":"musl","os":"linux","packageManager":"cargo","schemaVersion":1},"license":"MIT-0","packages":["pkg:cargo/subtle@2.6.1"],"schemaVersion":1,"subject":"pkg:cargo/subtle@2.6.1","symbols":["subtle"],"verifierAdapter":"cargo@1"}

{
  "schemaVersion": 1,
  "goal": "verify subtle in pkg:cargo/subtle@2.6.1",
  "kind": "HOW",
  "packages": [
    "pkg:cargo/subtle@2.6.1"
  ],
  "symbols": [
    "subtle"
  ]
}

//! Clean-room verification sample for subtle.

pub use subtle::*;

use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, ConstantTimeGreater, ConstantTimeLess, CtOption};

fn main() {
    // 1. ConstantTimeEq compares scalar integers in constant time returning Choice
    let a: u8 = 42;
    let b: u8 = 42;
    let c: u8 = 99;
    assert_eq!(a.ct_eq(&b).unwrap_u8(), 1);
    assert_eq!(bool::from(a.ct_eq(&b)), true);
    assert_eq!(a.ct_eq(&c).unwrap_u8(), 0);
    assert_eq!(bool::from(a.ct_eq(&c)), false);
    assert_eq!(a.ct_ne(&c).unwrap_u8(), 1);

    let x: u64 = 0xdeadbeefcafebabe;
    let y: u64 = 0xdeadbeefcafebabe;
    let z: u64 = 0xdeadbeefcafebaba;
    assert_eq!(x.ct_eq(&y).unwrap_u8(), 1);
    assert_eq!(x.ct_eq(&z).unwrap_u8(), 0);

    // 2. ConstantTimeEq compares byte slices of equal length and contents
    let slice1 = b"cryptographic secret key";
    let slice2 = b"cryptographic secret key";
    let slice3 = b"cryptographic wrong key!";
    assert_eq!(slice1.ct_eq(slice2).unwrap_u8(), 1);
    assert_eq!(slice1.ct_eq(slice3).unwrap_u8(), 0);

    // 3. ConditionallySelectable selects between values based on Choice without branching
    let val_a: u32 = 100;
    let val_b: u32 = 200;
    let sel_0 = u32::conditional_select(&val_a, &val_b, Choice::from(0u8));
    assert_eq!(sel_0, 100);
    let sel_1 = u32::conditional_select(&val_a, &val_b, Choice::from(1u8));
    assert_eq!(sel_1, 200);

    // 4. ConditionallySelectable conditionally assigns a value in-place based on Choice
    let mut target: u64 = 555;
    target.conditional_assign(&999, Choice::from(0u8));
    assert_eq!(target, 555);
    target.conditional_assign(&999, Choice::from(1u8));
    assert_eq!(target, 999);

    // 5. CtOption encapsulates an optional value with constant-time is_some check and safe unwrapping
    let some_opt: CtOption<u32> = CtOption::new(777, Choice::from(1u8));
    assert_eq!(some_opt.is_some().unwrap_u8(), 1);
    assert_eq!(some_opt.is_none().unwrap_u8(), 0);
    assert_eq!(some_opt.unwrap(), 777);
    assert_eq!(Option::<u32>::from(some_opt), Some(777));

    let none_opt: CtOption<u32> = CtOption::new(777, Choice::from(0u8));
    assert_eq!(none_opt.is_some().unwrap_u8(), 0);
    assert_eq!(none_opt.is_none().unwrap_u8(), 1);
    assert_eq!(none_opt.unwrap_or(888), 888);
    assert_eq!(Option::<u32>::from(none_opt), None);

    // 6. ConstantTimeGreater and ConstantTimeLess compare scalar integers in constant time
    let num_10: u32 = 10;
    let num_20: u32 = 20;
    assert_eq!(num_20.ct_gt(&num_10).unwrap_u8(), 1);
    assert_eq!(num_10.ct_gt(&num_20).unwrap_u8(), 0);
    assert_eq!(num_10.ct_lt(&num_20).unwrap_u8(), 1);
    assert_eq!(num_20.ct_lt(&num_10).unwrap_u8(), 0);

    println!("All subtle contract assertions passed successfully.");
}