lys-core 0.2.0

Domain-agnostic cryptographic trust primitives — certificate authority, Merkle transparency log, signed attestations, sealed envelopes, and Ed25519 key management.
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#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]

use super::*;
use crate::checkpoint::verify_checkpoint;
use crate::error::TrustError;
use crate::keys::Ed25519Identity;
use crate::merkle::{AppendOnlyTree, RawLeaf};

const GOLDEN_SEED: &[u8; 32] = b"lys-go-conformance-test-seed-01!";
const GOLDEN_ORIGIN: &str = "example.com/lys/test";

/// The complete golden signed note for the size-3 tree — build output must
/// embed exactly these bytes (deterministic Ed25519).
const GOLDEN_NOTE_SIZE_3: &str = "example.com/lys/test\n3\nz3Y6BByBzu8VeKYIP3XGG+8uABTyo+aDqX/Pylvn8Zo=\n\n\u{2014} example.com/lys/test UlgM2S4MVZwL9PUGADbPhidG6yKCC0hCE+sx7iXFboC6/rex00vtEy4d33ODa1g0afYmx36opQUAXnwdUl9E7eE28QU=\n";

fn golden_identity() -> (tempfile::TempDir, Ed25519Identity) {
    let dir = tempfile::tempdir().unwrap();
    let path = dir.path().join("golden.key");
    std::fs::write(&path, GOLDEN_SEED).unwrap();
    let identity = Ed25519Identity::load(&path).unwrap();
    (dir, identity)
}

fn golden_tree() -> AppendOnlyTree<RawLeaf> {
    AppendOnlyTree::<RawLeaf>::reconstruct_from_raw_leaves([b"leaf-0", b"leaf-1", b"leaf-2"])
}

fn golden_prefix_tree() -> AppendOnlyTree<RawLeaf> {
    AppendOnlyTree::<RawLeaf>::reconstruct_from_raw_leaves([b"leaf-0", b"leaf-1"])
}

fn golden_verifier() -> crate::checkpoint::NoteVerifierKey {
    let (_dir, identity) = golden_identity();
    crate::checkpoint::NoteVerifierKey::new(GOLDEN_ORIGIN, identity.public_key_bytes()).unwrap()
}

#[test]
fn inclusion_artifact_matches_golden_vectors() {
    let (_dir, identity) = golden_identity();
    let tree = golden_tree();
    let artifact = build_inclusion_artifact(&tree, b"leaf-1", GOLDEN_ORIGIN, &identity, 1).unwrap();

    assert_eq!(artifact.format, INCLUSION_PROOF_FORMAT);
    assert_eq!(artifact.tree_size, 3);
    assert_eq!(artifact.leaf_index, 1);
    assert_eq!(
        artifact.hashes,
        vec![
            "MF31n5WQw8msY9KydDw4jjeSRJB4zr9/s9vmRxZDsrc=".to_string(),
            "/KifV8n4yOtAR6f/nTM6z54PM4SyCyVbzqsPIW3Momc=".to_string(),
        ]
    );
    assert_eq!(artifact.checkpoint, GOLDEN_NOTE_SIZE_3);
}

#[test]
fn consistency_artifact_matches_golden_vectors() {
    let (_dir, identity) = golden_identity();
    let artifact = build_consistency_artifact(
        &golden_prefix_tree(),
        &golden_tree(),
        GOLDEN_ORIGIN,
        &identity,
    )
    .unwrap();

    assert_eq!(artifact.format, CONSISTENCY_PROOF_FORMAT);
    assert_eq!(artifact.tree_size_1, 2);
    assert_eq!(artifact.tree_size_2, 3);
    assert_eq!(
        artifact.hashes,
        vec!["/KifV8n4yOtAR6f/nTM6z54PM4SyCyVbzqsPIW3Momc=".to_string()]
    );
    assert_eq!(artifact.checkpoint_2, GOLDEN_NOTE_SIZE_3);

    // checkpoint_1 verifies as the size-2 checkpoint with the golden
    // prefix root.
    let body_1 = verify_checkpoint(artifact.checkpoint_1.as_bytes(), &golden_verifier()).unwrap();
    assert_eq!(body_1.tree_size(), 2);
    assert_eq!(
        crate::hex_lower(&body_1.root_hash()),
        "60a53eed0de87a90c8e59427c59c46253c33a76a09502a51801300927b7e6bdc"
    );
}

#[test]
fn built_artifacts_self_verify_and_verify_externally() {
    let (_dir, identity) = golden_identity();
    let tree = golden_tree();
    let verifier = golden_verifier();

    let inclusion =
        build_inclusion_artifact(&tree, b"leaf-1", GOLDEN_ORIGIN, &identity, 1).unwrap();
    let body = verify_inclusion_artifact(&inclusion, b"leaf-1", &verifier).unwrap();
    assert_eq!(body.tree_size(), 3);

    let consistency =
        build_consistency_artifact(&golden_prefix_tree(), &tree, GOLDEN_ORIGIN, &identity).unwrap();
    let (body_1, body_2) = verify_consistency_artifact(&consistency, &verifier).unwrap();
    assert_eq!(body_1.tree_size(), 2);
    assert_eq!(body_2.tree_size(), 3);
}

#[test]
fn inclusion_build_rejects_out_of_range_index_with_actionable_error() {
    let (_dir, identity) = golden_identity();
    let tree = golden_tree();
    let err = build_inclusion_artifact(&tree, b"leaf-3", GOLDEN_ORIGIN, &identity, 3).unwrap_err();
    assert!(matches!(err, TrustError::MerkleTree { .. }));
}

#[test]
fn inclusion_build_rejects_mismatched_leaf_bytes_via_self_verification() {
    // No silent emission of a broken artifact: leaf bytes that do not
    // match the leaf at the index fail the build-time self-check.
    let (_dir, identity) = golden_identity();
    let tree = golden_tree();
    let err = build_inclusion_artifact(&tree, b"leaf-0", GOLDEN_ORIGIN, &identity, 1).unwrap_err();
    assert!(matches!(err, TrustError::LogArtifactEncoding { .. }));
}

#[test]
fn inclusion_build_rejects_invalid_origin() {
    let (_dir, identity) = golden_identity();
    let tree = golden_tree();
    let err = build_inclusion_artifact(&tree, b"leaf-1", "bad origin", &identity, 1).unwrap_err();
    assert!(matches!(err, TrustError::CheckpointEncoding { .. }));
}

#[test]
fn consistency_build_rejects_size_invariant_violations() {
    let (_dir, identity) = golden_identity();
    let tree = golden_tree();

    // Empty old tree (R8: old >= 1).
    let empty = AppendOnlyTree::<RawLeaf>::new();
    let err = build_consistency_artifact(&empty, &tree, GOLDEN_ORIGIN, &identity).unwrap_err();
    assert!(matches!(err, TrustError::LogArtifactEncoding { .. }));

    // Equal sizes (R8: strict inequality).
    let same = golden_tree();
    let err = build_consistency_artifact(&same, &tree, GOLDEN_ORIGIN, &identity).unwrap_err();
    assert!(matches!(err, TrustError::LogArtifactEncoding { .. }));

    // Old larger than new.
    let err = build_consistency_artifact(&tree, &golden_prefix_tree(), GOLDEN_ORIGIN, &identity)
        .unwrap_err();
    assert!(matches!(err, TrustError::LogArtifactEncoding { .. }));
}

#[test]
fn consistency_build_rejects_non_prefix_old_tree_via_self_verification() {
    // The old tree is a different log entirely: proof recomputation fails
    // in the build-time self-check, never emitting the broken artifact.
    let (_dir, identity) = golden_identity();
    let unrelated =
        AppendOnlyTree::<RawLeaf>::reconstruct_from_raw_leaves([b"other-0", b"other-1"]);
    let err = build_consistency_artifact(&unrelated, &golden_tree(), GOLDEN_ORIGIN, &identity)
        .unwrap_err();
    assert!(matches!(err, TrustError::LogArtifactEncoding { .. }));
}

/// §6.5 emit-side: the 2^53 guard is the first call in both builders.
/// Trees at that scale are unreachable in a test (stated honestly), so the
/// boundary itself is covered on the guard function and the verify side;
/// this test pins that the guard error type surfaces from the build path
/// by proxy of the guard being reachable (empty old tree hits the R8 check
/// AFTER the guard passed for the small tree).
#[test]
fn builders_run_the_json_safety_guard_first() {
    // With a small tree the guard passes and later checks fire — proving
    // the call ordering compiles and the guard does not false-positive.
    let (_dir, identity) = golden_identity();
    let tree = golden_tree();
    build_inclusion_artifact(&tree, b"leaf-0", GOLDEN_ORIGIN, &identity, 0).unwrap();
}