[PATCH v2 07/10] tls-suites: Add ECDSA suites from RFC 8422

---
 ell/tls-suites.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 119 insertions(+)

diff --git a/ell/tls-suites.c b/ell/tls-suites.c
index bc6a756422b3..34141ab7fa56 100644
--- a/ell/tls-suites.c
+++ b/ell/tls-suites.c
@@ -262,6 +262,81 @@ static struct tls_signature_algorithm tls_rsa_signature = {
 	.verify = tls_rsa_verify,
 };
 
+static bool tls_ecdsa_validate_cert_key(struct l_cert *cert)
+{
+	return l_cert_get_pubkey_type(cert) == L_CERT_KEY_ECC;
+}
+
+static bool tls_ecdsa_verify(struct l_tls *tls,
+				const uint8_t *in, size_t in_len,
+				tls_get_hash_t get_hash,
+				const uint8_t *data, size_t data_len)
+{
+	/* RFC 8422, Section 5.10: "SHA-1 is used in TLS 1.1 and earlier" */
+	enum handshake_hash_type hash = HANDSHAKE_HASH_SHA1;
+	enum l_checksum_type sign_checksum_type;
+	const uint8_t *opaque;
+	uint16_t opaque_len;
+	uint8_t expected[HANDSHAKE_HASH_MAX_SIZE];
+	size_t expected_len;
+	bool success;
+
+	opaque = validate_digitally_signed(tls, in, in_len,
+				SIGNATURE_ALGORITHM_ECDSA, &opaque_len);
+	if (!opaque)
+		return false;
+
+	if (tls->negotiated_version >= L_TLS_V12) {
+		hash = find_hash_by_id(in[0]);
+		if (hash == __HANDSHAKE_HASH_COUNT) {
+			TLS_DISCONNECT(TLS_ALERT_DECRYPT_ERROR, 0,
+					"Unknown hash type %i", in[0]);
+			return false;
+		}
+
+		/* Hash should match the curve, refer to RFC 5480, Section 4 */
+		switch (tls->peer_pubkey_size) {
+		case 32:
+			if (hash != HANDSHAKE_HASH_SHA256 &&
+					hash != HANDSHAKE_HASH_SHA384)
+				goto bad_hash;
+
+			break;
+		case 48:
+			if (hash != HANDSHAKE_HASH_SHA384)
+				goto bad_hash;
+
+			break;
+		bad_hash:
+		default:
+			TLS_DISCONNECT(TLS_ALERT_DECRYPT_ERROR, 0,
+					"Invalid hash %i",
+					in[0]);
+		}
+	}
+
+	get_hash(tls, hash, data, data_len, expected, &expected_len);
+	sign_checksum_type = tls_handshake_hash_data[hash].l_id;
+
+	success = l_key_verify(tls->peer_pubkey, L_KEY_ECDSA_X962,
+				sign_checksum_type, expected, opaque,
+				expected_len, opaque_len);
+
+	if (!success)
+		TLS_DISCONNECT(TLS_ALERT_DECRYPT_ERROR, 0,
+				"Peer signature verification failed");
+	else
+		TLS_DEBUG("Peer signature verified");
+
+	return success;
+}
+
+static struct tls_signature_algorithm tls_ecdsa_signature = {
+	.id = 3, /* SignatureAlgorithm.ecdsa */
+	.validate_cert_key_type = tls_ecdsa_validate_cert_key,
+	.verify = tls_ecdsa_verify,
+};
+
 static bool tls_send_rsa_client_key_xchg(struct l_tls *tls)
 {
 	uint8_t buf[1024 + 32];
@@ -1350,11 +1425,52 @@ static struct tls_cipher_suite tls_rsa_with_3des_ede_cbc_sha = {
 	.prf_hmac = L_CHECKSUM_SHA384,
 	.signature = &tls_rsa_signature,
 	.key_xchg = &tls_ecdhe,
+}, tls_ecdhe_ecdsa_with_3des_ede_cbc_sha = {
+	.id = { 0xc0, 0x08 },
+	.name = "TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA",
+	.verify_data_length = 12,
+	.encryption = &tls_3des_ede,
+	.mac = &tls_sha,
+	.signature = &tls_ecdsa_signature,
+	.key_xchg = &tls_ecdhe,
+}, tls_ecdhe_ecdsa_with_aes_128_cbc_sha = {
+	.id = { 0xc0, 0x09 },
+	.name = "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
+	.verify_data_length = 12,
+	.encryption = &tls_aes128,
+	.mac = &tls_sha,
+	.signature = &tls_ecdsa_signature,
+	.key_xchg = &tls_ecdhe,
+}, tls_ecdhe_ecdsa_with_aes_256_cbc_sha = {
+	.id = { 0xc0, 0x0a },
+	.name = "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA",
+	.verify_data_length = 12,
+	.encryption = &tls_aes256,
+	.mac = &tls_sha,
+	.signature = &tls_ecdsa_signature,
+	.key_xchg = &tls_ecdhe,
+}, tls_ecdhe_ecdsa_with_aes_128_gcm_sha256 = {
+	.id = { 0xc0, 0x2b },
+	.name = "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
+	.verify_data_length = 12,
+	.encryption = &tls_aes128_gcm,
+	.signature = &tls_ecdsa_signature,
+	.key_xchg = &tls_ecdhe,
+}, tls_ecdhe_ecdsa_with_aes_256_gcm_sha384 = {
+	.id = { 0xc0, 0x2c },
+	.name = "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
+	.verify_data_length = 12,
+	.encryption = &tls_aes256_gcm,
+	.prf_hmac = L_CHECKSUM_SHA384,
+	.signature = &tls_ecdsa_signature,
+	.key_xchg = &tls_ecdhe,
 };
 
 struct tls_cipher_suite *tls_cipher_suite_pref[] = {
 	&tls_ecdhe_rsa_with_aes_256_cbc_sha,
+	&tls_ecdhe_ecdsa_with_aes_256_cbc_sha,
 	&tls_ecdhe_rsa_with_aes_128_cbc_sha,
+	&tls_ecdhe_ecdsa_with_aes_128_cbc_sha,
 	&tls_dhe_rsa_with_aes_256_cbc_sha,
 	&tls_dhe_rsa_with_aes_128_cbc_sha,
 	&tls_rsa_with_aes_256_cbc_sha,
@@ -1367,11 +1483,14 @@ struct tls_cipher_suite *tls_cipher_suite_pref[] = {
 	&tls_rsa_with_aes_128_cbc_sha256,
 	&tls_ecdhe_rsa_with_aes_256_gcm_sha384,
 	&tls_ecdhe_rsa_with_aes_128_gcm_sha256,
+	&tls_ecdhe_ecdsa_with_aes_256_gcm_sha384,
+	&tls_ecdhe_ecdsa_with_aes_128_gcm_sha256,
 	&tls_dhe_rsa_with_aes_256_gcm_sha384,
 	&tls_dhe_rsa_with_aes_128_gcm_sha256,
 	&tls_rsa_with_aes_256_gcm_sha384,
 	&tls_rsa_with_aes_128_gcm_sha256,
 	&tls_ecdhe_rsa_with_3des_ede_cbc_sha,
+	&tls_ecdhe_ecdsa_with_3des_ede_cbc_sha,
 	&tls_dhe_rsa_with_3des_ede_cbc_sha,
 	&tls_rsa_with_3des_ede_cbc_sha,
 	NULL,
-- 
2.35.1