wpa_supplicant: Allow OpenSSL cipherlist string to be configured

The new openssl_cipher configuration parameter can be used to select
which TLS cipher suites are enabled for TLS-based EAP methods when
OpenSSL is used as the TLS library. This parameter can be used both as a
global parameter to set the default for all network blocks and as a
network block parameter to override the default for each network
profile.

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

src/eap_peer/eap.c

@@ -1418,6 +1418,7 @@ struct eap_sm * eap_peer_sm_init(void *eapol_ctx,
 	tlsconf.opensc_engine_path = conf->opensc_engine_path;
 	tlsconf.pkcs11_engine_path = conf->pkcs11_engine_path;
 	tlsconf.pkcs11_module_path = conf->pkcs11_module_path;
+	tlsconf.openssl_ciphers = conf->openssl_ciphers;
 #ifdef CONFIG_FIPS
 	tlsconf.fips_mode = 1;
 #endif /* CONFIG_FIPS */

src/eap_peer/eap.h

@@ -267,6 +267,14 @@ struct eap_config {
 	 * Usually, path to opensc-pkcs11.so.
 	 */
 	const char *pkcs11_module_path;
+	/**
+	 * openssl_ciphers - OpenSSL cipher string
+	 *
+	 * This is an OpenSSL specific configuration option for configuring the
+	 * default ciphers. If not set, "DEFAULT:!EXP:!LOW" is used as the
+	 * default.
+	 */
+	const char *openssl_ciphers;
 	/**
 	 * wps - WPS context data
 	 *

src/eap_peer/eap_config.h

@@ -686,6 +686,15 @@ struct eap_peer_config {
 	 * has more than one.
 	 */
 	int sim_num;
+
+	/**
+	 * openssl_ciphers - OpenSSL cipher string
+	 *
+	 * This is an OpenSSL specific configuration option for configuring the
+	 * ciphers for this connection. If not set, the default cipher suite
+	 * list is used.
+	 */
+	char *openssl_ciphers;
 };
 
 

src/eap_peer/eap_tls_common.c

@@ -167,6 +167,8 @@ static int eap_tls_params_from_conf(struct eap_sm *sm,
 		return -1;
 	}
 
+	params->openssl_ciphers = config->openssl_ciphers;
+
 	return 0;
 }
 

src/eapol_supp/eapol_supp_sm.c

@@ -2026,6 +2026,7 @@ struct eapol_sm *eapol_sm_init(struct eapol_ctx *ctx)
 	conf.opensc_engine_path = ctx->opensc_engine_path;
 	conf.pkcs11_engine_path = ctx->pkcs11_engine_path;
 	conf.pkcs11_module_path = ctx->pkcs11_module_path;
+	conf.openssl_ciphers = ctx->openssl_ciphers;
 	conf.wps = ctx->wps;
 	conf.cert_in_cb = ctx->cert_in_cb;
 

src/eapol_supp/eapol_supp_sm.h

@@ -209,6 +209,15 @@ struct eapol_ctx {
 	 */
 	const char *pkcs11_module_path;
 
+	/**
+	 * openssl_ciphers - OpenSSL cipher string
+	 *
+	 * This is an OpenSSL specific configuration option for configuring the
+	 * default ciphers. If not set, "DEFAULT:!EXP:!LOW" is used as the
+	 * default.
+	 */
+	const char *openssl_ciphers;
+
 	/**
 	 * wps - WPS context data
 	 *

wpa_supplicant/config.c

@@ -1682,6 +1682,7 @@ static const struct parse_data ssid_fields[] = {
 	{ INTe(engine2) },
 	{ INT(eapol_flags) },
 	{ INTe(sim_num) },
+	{ STRe(openssl_ciphers) },
 #endif /* IEEE8021X_EAPOL */
 	{ FUNC_KEY(wep_key0) },
 	{ FUNC_KEY(wep_key1) },
@@ -1903,6 +1904,7 @@ static void eap_peer_config_free(struct eap_peer_config *eap)
 	os_free(eap->pac_file);
 	bin_clear_free(eap->new_password, eap->new_password_len);
 	str_clear_free(eap->external_sim_resp);
+	os_free(eap->openssl_ciphers);
 }
 #endif /* IEEE8021X_EAPOL */
 
@@ -2023,6 +2025,7 @@ void wpa_config_free(struct wpa_config *config)
 	os_free(config->opensc_engine_path);
 	os_free(config->pkcs11_engine_path);
 	os_free(config->pkcs11_module_path);
+	os_free(config->openssl_ciphers);
 	os_free(config->pcsc_reader);
 	str_clear_free(config->pcsc_pin);
 	os_free(config->driver_param);
@@ -3823,6 +3826,7 @@ static const struct global_parse_data global_fields[] = {
 	{ STR(opensc_engine_path), 0 },
 	{ STR(pkcs11_engine_path), 0 },
 	{ STR(pkcs11_module_path), 0 },
+	{ STR(openssl_ciphers), 0 },
 	{ STR(pcsc_reader), 0 },
 	{ STR(pcsc_pin), 0 },
 	{ INT(external_sim), 0 },

wpa_supplicant/config.h

@@ -516,6 +516,15 @@ struct wpa_config {
 	 */
 	char *pkcs11_module_path;
 
+	/**
+	 * openssl_ciphers - OpenSSL cipher string
+	 *
+	 * This is an OpenSSL specific configuration option for configuring the
+	 * default ciphers. If not set, "DEFAULT:!EXP:!LOW" is used as the
+	 * default.
+	 */
+	char *openssl_ciphers;
+
 	/**
 	 * pcsc_reader - PC/SC reader name prefix
 	 *

wpa_supplicant/config_file.c

@@ -938,6 +938,8 @@ static void wpa_config_write_global(FILE *f, struct wpa_config *config)
 	if (config->pkcs11_module_path)
 		fprintf(f, "pkcs11_module_path=%s\n",
 			config->pkcs11_module_path);
+	if (config->openssl_ciphers)
+		fprintf(f, "openssl_ciphers=%s\n", config->openssl_ciphers);
 	if (config->pcsc_reader)
 		fprintf(f, "pcsc_reader=%s\n", config->pcsc_reader);
 	if (config->pcsc_pin)

wpa_supplicant/eapol_test.c

@@ -568,6 +568,7 @@ static int test_eapol(struct eapol_test_data *e, struct wpa_supplicant *wpa_s,
 	ctx->opensc_engine_path = wpa_s->conf->opensc_engine_path;
 	ctx->pkcs11_engine_path = wpa_s->conf->pkcs11_engine_path;
 	ctx->pkcs11_module_path = wpa_s->conf->pkcs11_module_path;
+	ctx->openssl_ciphers = wpa_s->conf->openssl_ciphers;
 	ctx->eap_param_needed = eapol_test_eap_param_needed;
 	ctx->cert_cb = eapol_test_cert_cb;
 	ctx->cert_in_cb = 1;

wpa_supplicant/wpa_cli.c

@@ -610,7 +610,8 @@ static char ** wpa_cli_complete_set(const char *str, int pos)
 		/* global configuration parameters */
 		"eapol_version", "ap_scan", "disable_scan_offload",
 		"fast_reauth", "opensc_engine_path", "pkcs11_engine_path",
-		"pkcs11_module_path", "pcsc_reader", "pcsc_pin",
+		"pkcs11_module_path", "openssl_ciphers",
+		"pcsc_reader", "pcsc_pin",
 		"driver_param", "dot11RSNAConfigPMKLifetime",
 		"dot11RSNAConfigPMKReauthThreshold",
 		"dot11RSNAConfigSATimeout",

wpa_supplicant/wpa_supplicant.c

@@ -842,7 +842,7 @@ int wpa_supplicant_reload_configuration(struct wpa_supplicant *wpa_s)
 
 	/*
 	 * TODO: should notify EAPOL SM about changes in opensc_engine_path,
-	 * pkcs11_engine_path, pkcs11_module_path.
+	 * pkcs11_engine_path, pkcs11_module_path, openssl_ciphers.
 	 */
 	if (wpa_key_mgmt_wpa_psk(wpa_s->key_mgmt)) {
 		/*

wpa_supplicant/wpa_supplicant.conf

@@ -132,6 +132,16 @@ fast_reauth=1
 # configure the path to the pkcs11 module required by the pkcs11 engine
 #pkcs11_module_path=/usr/lib/pkcs11/opensc-pkcs11.so
 
+# OpenSSL cipher string
+#
+# This is an OpenSSL specific configuration option for configuring the default
+# ciphers. If not set, "DEFAULT:!EXP:!LOW" is used as the default.
+# See https://www.openssl.org/docs/apps/ciphers.html for OpenSSL documentation
+# on cipher suite configuration. This is applicable only if wpa_supplicant is
+# built to use OpenSSL.
+#openssl_ciphers=DEFAULT:!EXP:!LOW
+
+
 # Dynamic EAP methods
 # If EAP methods were built dynamically as shared object files, they need to be
 # loaded here before being used in the network blocks. By default, EAP methods
@@ -932,6 +942,10 @@ fast_reauth=1
 #	1 = try to use OCSP stapling, but not require response
 #	2 = require valid OCSP stapling response
 #
+# openssl_ciphers: OpenSSL specific cipher configuration
+#	This can be used to override the global openssl_ciphers configuration
+#	parameter (see above).
+#
 # EAP-FAST variables:
 # pac_file: File path for the PAC entries. wpa_supplicant will need to be able
 #	to create this file and write updates to it when PAC is being

wpa_supplicant/wpas_glue.c

@@ -881,6 +881,7 @@ int wpa_supplicant_init_eapol(struct wpa_supplicant *wpa_s)
 	ctx->opensc_engine_path = wpa_s->conf->opensc_engine_path;
 	ctx->pkcs11_engine_path = wpa_s->conf->pkcs11_engine_path;
 	ctx->pkcs11_module_path = wpa_s->conf->pkcs11_module_path;
+	ctx->openssl_ciphers = wpa_s->conf->openssl_ciphers;
 	ctx->wps = wpa_s->wps;
 	ctx->eap_param_needed = wpa_supplicant_eap_param_needed;
 	ctx->port_cb = wpa_supplicant_port_cb;