Add a webpki based test

Fixes #2

Cargo.toml

@@ -25,3 +25,4 @@ chrono = "0.4.6"
 
 [dev-dependencies]
 openssl = { version = "0.10" }
+webpki = "0.18.1"

tests/webpki.rs

@@ -0,0 +1,81 @@
+extern crate webpki;
+extern crate untrusted;
+extern crate rcgen;
+extern crate ring;
+
+use rcgen::{Certificate, CertificateParams,
+	DistinguishedName, DnType,
+	PKCS_WITH_SHA256_WITH_ECDSA_ENCRYPTION,
+	date_time_ymd};
+use untrusted::Input;
+use webpki::{EndEntityCert, TLSServerTrustAnchors};
+use webpki::trust_anchor_util::cert_der_as_trust_anchor;
+use webpki::ECDSA_P256_SHA256;
+use webpki::{Time, DNSNameRef};
+
+use ring::rand::SystemRandom;
+use ring::signature::ECDSAKeyPair;
+use ring::signature::ECDSA_P256_SHA256_ASN1_SIGNING as KALG;
+
+fn sign_msg(cert :&Certificate, msg :&[u8]) -> Vec<u8> {
+	let pk_der = cert.serialize_private_key_der();
+	let key_pair = ECDSAKeyPair::from_pkcs8(&KALG, Input::from(&pk_der)).unwrap();
+	let system_random = SystemRandom::new();
+	let msg_input = Input::from(&msg);
+	let signature = key_pair.sign(msg_input, &system_random).unwrap();
+	signature.as_ref().to_vec()
+}
+
+#[test]
+fn test_webpki() {
+	let not_before = date_time_ymd(1975, 01, 01);
+	let not_after = date_time_ymd(4096, 01, 01);
+	let mut distinguished_name = DistinguishedName::new();
+	distinguished_name.push(DnType::OrganizationName, "Crab widgits SE");
+	distinguished_name.push(DnType::CommonName, "Master CA");
+	let params = CertificateParams {
+		alg : PKCS_WITH_SHA256_WITH_ECDSA_ENCRYPTION,
+		not_before,
+		not_after,
+		serial_number : None,
+		subject_alt_names : vec!["crabs.crabs".to_string(), "localhost".to_string()],
+		distinguished_name,
+	};
+	let cert = Certificate::from_params(params);
+
+	println!("{}", cert.serialize_pem());
+
+	// Now verify the certificate.
+
+	let cert_der = cert.serialize_der();
+	let trust_anchor = cert_der_as_trust_anchor(Input::from(&cert_der)).unwrap();
+	let trust_anchor_list = &[trust_anchor];
+	let trust_anchors = TLSServerTrustAnchors(trust_anchor_list);
+	let end_entity_cert = EndEntityCert::from(Input::from(&cert_der)).unwrap();
+
+	// Set time to Jan 10, 2004
+	let time = Time::from_seconds_since_unix_epoch(0x40_00_00_00);
+
+	// (1/3) Check whether the cert is valid
+	end_entity_cert.verify_is_valid_tls_server_cert(
+		&[&ECDSA_P256_SHA256],
+		&trust_anchors,
+		&[],
+		time,
+	).expect("valid TLS server cert");
+
+	// (2/3) Check that the cert is valid for the given DNS name
+	let dns_name = DNSNameRef::try_from_ascii_str("crabs.crabs").unwrap();
+	end_entity_cert.verify_is_valid_for_dns_name(
+		dns_name,
+	).expect("valid for DNS name");
+
+	// (3/3) Check that a message signed by the cert is valid.
+	let msg = b"Hello, World! This message is signed.";
+	let signature = sign_msg(&cert, msg);
+	end_entity_cert.verify_signature(
+		&ECDSA_P256_SHA256,
+		Input::from(msg),
+		Input::from(&signature),
+	).expect("signature is valid");
+}