smite: drive commitment tests from JSON vectors

[NishantBansal2003]

The first commit moves all the tests in commitment.rs into a submodule, and the second migrates the commitment signature verification tests to JSON verification.

Pros:

• Removes repetitive code and makes it easier to extend commitment tests with new channel types or HTLC support.
• Makes it easier to generate oracles from LDK/Eclair and print them directly in this schema.

Cons:

• If more than one test vector fails, we only see the first test failure instead of all of them.

[erickcestari]

LGTM!

[erickcestari]

nit: We could collect all the mismatches and log them later.

Suggested change

	/// Runs every commitment vector in a test vector file.
	///
	/// Note: local is the opener.
	pub fn run_commitment_vectors(json: &str) {
	let file: TestVectorFile = serde_json::from_str(json).expect("valid test vector file");
	assert!(
	!file.tests.is_empty(),
	"{}: no test vectors",
	file.description
	);
	let opener_holder = file.build_holder_identity(Side::Opener);
	let acceptor_holder = file.build_holder_identity(Side::Acceptor);
	for vector in &file.tests {
	let context = format!("{}: {}", file.description, vector.name);
	let channel_config = file.build_channel_config(vector);
	let commitment_state = file.build_commitment_state(vector);
	// Opener signs own commitment.
	assert_eq!(
	channel_config.sign_holder_commitment(&commitment_state, &opener_holder),
	vector.local_signature,
	"{context}: local signature mismatch",
	);
	// Acceptor signs opener's commitment.
	assert!(
	channel_config.verify_counterparty_signature(
	&commitment_state,
	&opener_holder,
	&vector.remote_signature,
	),
	"{context}: remote signature does not verify",
	);
	// Opener signs the acceptor's commitment, then the acceptor verifies it.
	let acceptor_commit_sig =
	channel_config.sign_counterparty_commitment(&commitment_state, &opener_holder);
	assert!(
	channel_config.verify_counterparty_signature(
	&commitment_state,
	&acceptor_holder,
	&acceptor_commit_sig,
	),
	"{context}: acceptor commitment signature does not verify",
	);
	}
	}
	/// Runs every commitment vector in a test vector file.
	///
	/// Every vector is checked before failing, so one run reports all mismatches.
	///
	/// Note: local is the opener.
	pub fn run_commitment_vectors(json: &str) {
	let file: TestVectorFile = serde_json::from_str(json).expect("valid test vector file");
	assert!(
	!file.tests.is_empty(),
	"{}: no test vectors",
	file.description
	);
	let failures: Vec<Vec<String>> = file
	.tests
	.iter()
	.map(|vector| file.check_vector(vector))
	.filter(|failures| !failures.is_empty())
	.collect();
	assert!(
	failures.is_empty(),
	"{}: {} of {} vectors failed\n{}",
	file.description,
	failures.len(),
	file.tests.len(),
	failures.concat().join("\n"),
	);
	}
	impl TestVectorFile {
	/// Checks one vector and returns a message per failed assertion.
	fn check_vector(&self, vector: &CommitmentVector) -> Vec<String> {
	let opener_holder = self.build_holder_identity(Side::Opener);
	let acceptor_holder = self.build_holder_identity(Side::Acceptor);
	let channel_config = self.build_channel_config(vector);
	let commitment_state = self.build_commitment_state(vector);
	let mut failures = Vec::new();
	// Opener signs own commitment.
	let local_signature =
	channel_config.sign_holder_commitment(&commitment_state, &opener_holder);
	if local_signature != vector.local_signature {
	failures.push(format!(
	"{}: local signature mismatch\n expected: {}\n actual: {}",
	vector.name, vector.local_signature, local_signature,
	));
	}
	// Acceptor signs opener's commitment.
	if !channel_config.verify_counterparty_signature(
	&commitment_state,
	&opener_holder,
	&vector.remote_signature,
	) {
	failures.push(format!("{}: remote signature does not verify", vector.name));
	}
	// Opener signs the acceptor's commitment, then the acceptor verifies it.
	let acceptor_commit_sig =
	channel_config.sign_counterparty_commitment(&commitment_state, &opener_holder);
	if !channel_config.verify_counterparty_signature(
	&commitment_state,
	&acceptor_holder,
	&acceptor_commit_sig,
	) {
	failures.push(format!(
	"{}: acceptor commitment signature does not verify",
	vector.name
	));
	}
	failures
	}
	}