Add domain_match network profile parameter

This is similar with domain_suffix_match, but required a full match of
the domain name rather than allowing suffix match (subdomains) or
wildcard certificates.

Signed-off-by: Jouni Malinen <j@w1.fi>

src/crypto/tls.h

@@ -41,7 +41,8 @@ enum tls_fail_reason {
 	TLS_FAIL_ALTSUBJECT_MISMATCH = 6,
 	TLS_FAIL_BAD_CERTIFICATE = 7,
 	TLS_FAIL_SERVER_CHAIN_PROBE = 8,
-	TLS_FAIL_DOMAIN_SUFFIX_MISMATCH = 9
+	TLS_FAIL_DOMAIN_SUFFIX_MISMATCH = 9,
+	TLS_FAIL_DOMAIN_MISMATCH = 10,
 };
 
 
@@ -107,7 +108,11 @@ struct tls_config {
  * @altsubject_match: String to match in the alternative subject of the peer
  * certificate or %NULL to allow all alternative subjects
  * @suffix_match: String to suffix match in the dNSName or CN of the peer
- * certificate or %NULL to allow all domain names
+ * certificate or %NULL to allow all domain names. This may allow subdomains an
+ * wildcard certificates. Each domain name label must have a full match.
+ * @domain_match: String to match in the dNSName or CN of the peer
+ * certificate or %NULL to allow all domain names. This requires a full,
+ * case-insensitive match.
  * @client_cert: File or reference name for client X.509 certificate in PEM or
  * DER format
  * @client_cert_blob: client_cert as inlined data or %NULL if not used
@@ -151,6 +156,7 @@ struct tls_connection_params {
 	const char *subject_match;
 	const char *altsubject_match;
 	const char *suffix_match;
+	const char *domain_match;
 	const char *client_cert;
 	const u8 *client_cert_blob;
 	size_t client_cert_blob_len;

src/crypto/tls_gnutls.c

@@ -58,6 +58,7 @@ struct tls_connection {
 	gnutls_certificate_credentials_t xcred;
 
 	char *suffix_match;
+	char *domain_match;
 	unsigned int flags;
 };
 
@@ -280,6 +281,7 @@ void tls_connection_deinit(void *ssl_ctx, struct tls_connection *conn)
 	wpabuf_free(conn->push_buf);
 	wpabuf_free(conn->pull_buf);
 	os_free(conn->suffix_match);
+	os_free(conn->domain_match);
 	os_free(conn);
 }
 
@@ -363,6 +365,21 @@ int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
 			return -1;
 	}
 
+#if GNUTLS_VERSION_NUMBER >= 0x030300
+	os_free(conn->domain_match);
+	conn->domain_match = NULL;
+	if (params->domain_match) {
+		conn->domain_match = os_strdup(params->domain_match);
+		if (conn->domain_match == NULL)
+			return -1;
+	}
+#else /* < 3.3.0 */
+	if (params->domain_match) {
+		wpa_printf(MSG_INFO, "GnuTLS: domain_match not supported");
+		return -1;
+	}
+#endif /* >= 3.3.0 */
+
 	conn->flags = params->flags;
 
 	if (params->openssl_ciphers) {
@@ -1111,6 +1128,25 @@ static int tls_connection_verify_peer(gnutls_session_t session)
 				goto out;
 			}
 
+#if GNUTLS_VERSION_NUMBER >= 0x030300
+			if (conn->domain_match &&
+			    !gnutls_x509_crt_check_hostname2(
+				    cert, conn->domain_match,
+				    GNUTLS_VERIFY_DO_NOT_ALLOW_WILDCARDS)) {
+				wpa_printf(MSG_WARNING,
+					   "TLS: Domain match '%s' not found",
+					   conn->domain_match);
+				gnutls_tls_fail_event(
+					conn, &certs[i], i, buf,
+					"Domain mismatch",
+					TLS_FAIL_DOMAIN_MISMATCH);
+				err = GNUTLS_A_BAD_CERTIFICATE;
+				gnutls_x509_crt_deinit(cert);
+				os_free(buf);
+				goto out;
+			}
+#endif /* >= 3.3.0 */
+
 			/* TODO: validate altsubject_match.
 			 * For now, any such configuration is rejected in
 			 * tls_connection_set_params() */

src/crypto/tls_internal.c

@@ -205,6 +205,11 @@ int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
 		return -1;
 	}
 
+	if (params->domain_match) {
+		wpa_printf(MSG_INFO, "TLS: domain_match not supported");
+		return -1;
+	}
+
 	if (params->openssl_ciphers) {
 		wpa_printf(MSG_INFO, "GnuTLS: openssl_ciphers not supported");
 		return -1;

src/crypto/tls_openssl.c

@@ -96,7 +96,7 @@ struct tls_connection {
 	ENGINE *engine;        /* functional reference to the engine */
 	EVP_PKEY *private_key; /* the private key if using engine */
 #endif /* OPENSSL_NO_ENGINE */
-	char *subject_match, *altsubject_match, *suffix_match;
+	char *subject_match, *altsubject_match, *suffix_match, *domain_match;
 	int read_alerts, write_alerts, failed;
 
 	tls_session_ticket_cb session_ticket_cb;
@@ -1098,6 +1098,7 @@ void tls_connection_deinit(void *ssl_ctx, struct tls_connection *conn)
 	os_free(conn->subject_match);
 	os_free(conn->altsubject_match);
 	os_free(conn->suffix_match);
+	os_free(conn->domain_match);
 	os_free(conn->session_ticket);
 	os_free(conn);
 }
@@ -1190,7 +1191,8 @@ static int tls_match_altsubject(X509 *cert, const char *match)
 
 
 #ifndef CONFIG_NATIVE_WINDOWS
-static int domain_suffix_match(const u8 *val, size_t len, const char *match)
+static int domain_suffix_match(const u8 *val, size_t len, const char *match,
+			       int full)
 {
 	size_t i, match_len;
 
@@ -1203,7 +1205,7 @@ static int domain_suffix_match(const u8 *val, size_t len, const char *match)
 	}
 
 	match_len = os_strlen(match);
-	if (match_len > len)
+	if (match_len > len || (full && match_len != len))
 		return 0;
 
 	if (os_strncasecmp((const char *) val + len - match_len, match,
@@ -1222,7 +1224,7 @@ static int domain_suffix_match(const u8 *val, size_t len, const char *match)
 #endif /* CONFIG_NATIVE_WINDOWS */
 
 
-static int tls_match_suffix(X509 *cert, const char *match)
+static int tls_match_suffix(X509 *cert, const char *match, int full)
 {
 #ifdef CONFIG_NATIVE_WINDOWS
 	/* wincrypt.h has conflicting X509_NAME definition */
@@ -1235,7 +1237,8 @@ static int tls_match_suffix(X509 *cert, const char *match)
 	int dns_name = 0;
 	X509_NAME *name;
 
-	wpa_printf(MSG_DEBUG, "TLS: Match domain against suffix %s", match);
+	wpa_printf(MSG_DEBUG, "TLS: Match domain against %s%s",
+		   full ? "": "suffix ", match);
 
 	ext = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL);
 
@@ -1248,8 +1251,10 @@ static int tls_match_suffix(X509 *cert, const char *match)
 				  gen->d.dNSName->data,
 				  gen->d.dNSName->length);
 		if (domain_suffix_match(gen->d.dNSName->data,
-					gen->d.dNSName->length, match) == 1) {
-			wpa_printf(MSG_DEBUG, "TLS: Suffix match in dNSName found");
+					gen->d.dNSName->length, match, full) ==
+		    1) {
+			wpa_printf(MSG_DEBUG, "TLS: %s in dNSName found",
+				   full ? "Match" : "Suffix match");
 			return 1;
 		}
 	}
@@ -1276,13 +1281,16 @@ static int tls_match_suffix(X509 *cert, const char *match)
 			continue;
 		wpa_hexdump_ascii(MSG_DEBUG, "TLS: Certificate commonName",
 				  cn->data, cn->length);
-		if (domain_suffix_match(cn->data, cn->length, match) == 1) {
-			wpa_printf(MSG_DEBUG, "TLS: Suffix match in commonName found");
+		if (domain_suffix_match(cn->data, cn->length, match, full) == 1)
+		{
+			wpa_printf(MSG_DEBUG, "TLS: %s in commonName found",
+				   full ? "Match" : "Suffix match");
 			return 1;
 		}
 	}
 
-	wpa_printf(MSG_DEBUG, "TLS: No CommonName suffix match found");
+	wpa_printf(MSG_DEBUG, "TLS: No CommonName %smatch found",
+		   full ? "": "suffix ");
 	return 0;
 #endif /* CONFIG_NATIVE_WINDOWS */
 }
@@ -1465,7 +1473,7 @@ static int tls_verify_cb(int preverify_ok, X509_STORE_CTX *x509_ctx)
 	SSL *ssl;
 	struct tls_connection *conn;
 	struct tls_context *context;
-	char *match, *altmatch, *suffix_match;
+	char *match, *altmatch, *suffix_match, *domain_match;
 	const char *err_str;
 
 	err_cert = X509_STORE_CTX_get_current_cert(x509_ctx);
@@ -1493,6 +1501,7 @@ static int tls_verify_cb(int preverify_ok, X509_STORE_CTX *x509_ctx)
 	match = conn->subject_match;
 	altmatch = conn->altsubject_match;
 	suffix_match = conn->suffix_match;
+	domain_match = conn->domain_match;
 
 	if (!preverify_ok && !conn->ca_cert_verify)
 		preverify_ok = 1;
@@ -1562,13 +1571,21 @@ static int tls_verify_cb(int preverify_ok, X509_STORE_CTX *x509_ctx)
 				       "AltSubject mismatch",
 				       TLS_FAIL_ALTSUBJECT_MISMATCH);
 	} else if (depth == 0 && suffix_match &&
-		   !tls_match_suffix(err_cert, suffix_match)) {
+		   !tls_match_suffix(err_cert, suffix_match, 0)) {
 		wpa_printf(MSG_WARNING, "TLS: Domain suffix match '%s' not found",
 			   suffix_match);
 		preverify_ok = 0;
 		openssl_tls_fail_event(conn, err_cert, err, depth, buf,
 				       "Domain suffix mismatch",
 				       TLS_FAIL_DOMAIN_SUFFIX_MISMATCH);
+	} else if (depth == 0 && domain_match &&
+		   !tls_match_suffix(err_cert, domain_match, 1)) {
+		wpa_printf(MSG_WARNING, "TLS: Domain match '%s' not found",
+			   domain_match);
+		preverify_ok = 0;
+		openssl_tls_fail_event(conn, err_cert, err, depth, buf,
+				       "Domain mismatch",
+				       TLS_FAIL_DOMAIN_MISMATCH);
 	} else
 		openssl_tls_cert_event(conn, err_cert, depth, buf);
 
@@ -1832,7 +1849,8 @@ int tls_global_set_verify(void *ssl_ctx, int check_crl)
 static int tls_connection_set_subject_match(struct tls_connection *conn,
 					    const char *subject_match,
 					    const char *altsubject_match,
-					    const char *suffix_match)
+					    const char *suffix_match,
+					    const char *domain_match)
 {
 	os_free(conn->subject_match);
 	conn->subject_match = NULL;
@@ -1858,6 +1876,14 @@ static int tls_connection_set_subject_match(struct tls_connection *conn,
 			return -1;
 	}
 
+	os_free(conn->domain_match);
+	conn->domain_match = NULL;
+	if (domain_match) {
+		conn->domain_match = os_strdup(domain_match);
+		if (conn->domain_match == NULL)
+			return -1;
+	}
+
 	return 0;
 }
 
@@ -3322,7 +3348,8 @@ int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
 	if (tls_connection_set_subject_match(conn,
 					     params->subject_match,
 					     params->altsubject_match,
-					     params->suffix_match))
+					     params->suffix_match,
+					     params->domain_match))
 		return -1;
 
 	if (engine_id && ca_cert_id) {

src/crypto/tls_schannel.c

@@ -707,6 +707,11 @@ int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
 		return -1;
 	}
 
+	if (params->domain_match) {
+		wpa_printf(MSG_INFO, "TLS: domain_match not supported");
+		return -1;
+	}
+
 	if (params->openssl_ciphers) {
 		wpa_printf(MSG_INFO, "GnuTLS: openssl_ciphers not supported");
 		return -1;

src/eap_peer/eap_config.h

@@ -229,6 +229,21 @@ struct eap_peer_config {
 	 */
 	char *domain_suffix_match;
 
+	/**
+	 * domain_match - Constraint for server domain name
+	 *
+	 * If set, this FQDN is used as a full match requirement for the
+	 * server certificate in SubjectAltName dNSName element(s). If a
+	 * matching dNSName is found, this constraint is met. If no dNSName
+	 * values are present, this constraint is matched against SubjectName CN
+	 * using same full match comparison. This behavior is similar to
+	 * domain_suffix_match, but has the requirement of a full match, i.e.,
+	 * no subdomains or wildcard matches are allowed. Case-insensitive
+	 * comparison is used, so "Example.com" matches "example.com", but would
+	 * not match "test.Example.com".
+	 */
+	char *domain_match;
+
 	/**
 	 * ca_cert2 - File path to CA certificate file (PEM/DER) (Phase 2)
 	 *
@@ -332,6 +347,14 @@ struct eap_peer_config {
 	 */
 	char *domain_suffix_match2;
 
+	/**
+	 * domain_match2 - Constraint for server domain name
+	 *
+	 * This field is like domain_match, but used for phase 2 (inside
+	 * EAP-TTLS/PEAP/FAST tunnel) authentication.
+	 */
+	char *domain_match2;
+
 	/**
 	 * eap_methods - Allowed EAP methods
 	 *

src/eap_peer/eap_tls_common.c

@@ -91,6 +91,7 @@ static void eap_tls_params_from_conf1(struct tls_connection_params *params,
 	params->subject_match = (char *) config->subject_match;
 	params->altsubject_match = (char *) config->altsubject_match;
 	params->suffix_match = config->domain_suffix_match;
+	params->domain_match = config->domain_match;
 	params->engine = config->engine;
 	params->engine_id = config->engine_id;
 	params->pin = config->pin;
@@ -113,6 +114,7 @@ static void eap_tls_params_from_conf2(struct tls_connection_params *params,
 	params->subject_match = (char *) config->subject_match2;
 	params->altsubject_match = (char *) config->altsubject_match2;
 	params->suffix_match = config->domain_suffix_match2;
+	params->domain_match = config->domain_match2;
 	params->engine = config->engine2;
 	params->engine_id = config->engine2_id;
 	params->pin = config->pin2;

wpa_supplicant/config.c

@@ -1818,6 +1818,7 @@ static const struct parse_data ssid_fields[] = {
 	{ STRe(subject_match) },
 	{ STRe(altsubject_match) },
 	{ STRe(domain_suffix_match) },
+	{ STRe(domain_match) },
 	{ STRe(ca_cert2) },
 	{ STRe(ca_path2) },
 	{ STRe(client_cert2) },
@@ -1827,6 +1828,7 @@ static const struct parse_data ssid_fields[] = {
 	{ STRe(subject_match2) },
 	{ STRe(altsubject_match2) },
 	{ STRe(domain_suffix_match2) },
+	{ STRe(domain_match2) },
 	{ STRe(phase1) },
 	{ STRe(phase2) },
 	{ STRe(pcsc) },
@@ -2052,6 +2054,7 @@ static void eap_peer_config_free(struct eap_peer_config *eap)
 	os_free(eap->subject_match);
 	os_free(eap->altsubject_match);
 	os_free(eap->domain_suffix_match);
+	os_free(eap->domain_match);
 	os_free(eap->ca_cert2);
 	os_free(eap->ca_path2);
 	os_free(eap->client_cert2);
@@ -2061,6 +2064,7 @@ static void eap_peer_config_free(struct eap_peer_config *eap)
 	os_free(eap->subject_match2);
 	os_free(eap->altsubject_match2);
 	os_free(eap->domain_suffix_match2);
+	os_free(eap->domain_match2);
 	os_free(eap->phase1);
 	os_free(eap->phase2);
 	os_free(eap->pcsc);

wpa_supplicant/config_file.c

@@ -691,6 +691,7 @@ static void wpa_config_write_network(FILE *f, struct wpa_ssid *ssid)
 	STR(subject_match);
 	STR(altsubject_match);
 	STR(domain_suffix_match);
+	STR(domain_match);
 	STR(ca_cert2);
 	STR(ca_path2);
 	STR(client_cert2);
@@ -700,6 +701,7 @@ static void wpa_config_write_network(FILE *f, struct wpa_ssid *ssid)
 	STR(subject_match2);
 	STR(altsubject_match2);
 	STR(domain_suffix_match2);
+	STR(domain_match2);
 	STR(phase1);
 	STR(phase2);
 	STR(pcsc);

wpa_supplicant/wpa_supplicant.conf

@@ -873,7 +873,8 @@ fast_reauth=1
 #	/C=US/ST=CA/L=San Francisco/CN=Test AS/emailAddress=as@example.com
 #	Note: Since this is a substring match, this cannot be used securily to
 #	do a suffix match against a possible domain name in the CN entry. For
-#	such a use case, domain_suffix_match should be used instead.
+#	such a use case, domain_suffix_match or domain_match should be used
+#	instead.
 # altsubject_match: Semicolon separated string of entries to be matched against
 #	the alternative subject name of the authentication server certificate.
 #	If this string is set, the server sertificate is only accepted if it
@@ -896,6 +897,16 @@ fast_reauth=1
 #
 #	For example, domain_suffix_match=example.com would match
 #	test.example.com but would not match test-example.com.
+# domain_match: Constraint for server domain name
+#	If set, this FQDN is used as a full match requirement for the
+#	server certificate in SubjectAltName dNSName element(s). If a
+#	matching dNSName is found, this constraint is met. If no dNSName
+#	values are present, this constraint is matched against SubjectName CN
+#	using same full match comparison. This behavior is similar to
+#	domain_suffix_match, but has the requirement of a full match, i.e.,
+#	no subdomains or wildcard matches are allowed. Case-insensitive
+#	comparison is used, so "Example.com" matches "example.com", but would
+#	not match "test.Example.com".
 # phase1: Phase1 (outer authentication, i.e., TLS tunnel) parameters
 #	(string with field-value pairs, e.g., "peapver=0" or
 #	"peapver=1 peaplabel=1")