eap-gtc: add EAP-GTC method implementation

Makefile.am

@@ -102,6 +102,7 @@ src_iwd_SOURCES = src/main.c linux/nl80211.h \
 					src/simauth.h src/simauth.c \
 					src/plugin.h src/plugin.c \
 					src/eap-peap.c \
+					src/eap-gtc.c \
 					$(builtin_sources)
 
 src_iwd_LDADD = ell/libell-internal.la -ldl

src/eap-gtc.c

@@ -0,0 +1,116 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2018  Intel Corporation. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <ell/ell.h>
+
+#include "eap.h"
+
+struct eap_gtc_state {
+	char *secret;
+};
+
+static void eap_gtc_free(struct eap_state *eap)
+{
+	struct eap_gtc_state *gtc = eap_get_data(eap);
+
+	eap_set_data(eap, NULL);
+
+	l_free(gtc->secret);
+	l_free(gtc);
+}
+
+static void eap_gtc_handle_request(struct eap_state *eap,
+					const uint8_t *pkt, size_t len)
+{
+	struct eap_gtc_state *gtc = eap_get_data(eap);
+	size_t secret_len = strlen(gtc->secret);
+	uint8_t response[5 + secret_len];
+
+	if (len < 8)
+		goto error;
+
+	if (strncmp((const char *)pkt, "Password", 8))
+		goto error;
+
+	memcpy(response + 5, gtc->secret, secret_len);
+
+	eap_send_response(eap, EAP_TYPE_GTC, response, 5 + secret_len);
+
+	eap_method_success(eap);
+
+	return;
+
+error:
+	l_error("invalid GTC request");
+	eap_method_error(eap);
+}
+
+static bool eap_gtc_load_settings(struct eap_state *eap,
+					struct l_settings *settings,
+					const char *prefix)
+{
+	struct eap_gtc_state *gtc;
+	char setting[64];
+	char *secret;
+
+	snprintf(setting, sizeof(setting), "%sGTC-Secret", prefix);
+	secret = l_strdup(l_settings_get_value(settings, "Security", setting));
+
+	if (!secret) {
+		l_error("EAP-GTC secret is missing");
+		return false;
+	}
+
+	gtc = l_new(struct eap_gtc_state, 1);
+	gtc->secret = secret;
+	eap_set_data(eap, gtc);
+
+	return true;
+}
+
+static struct eap_method eap_gtc = {
+	.request_type = EAP_TYPE_GTC,
+	.exports_msk = false,
+	.name = "GTC",
+	.free = eap_gtc_free,
+	.handle_request = eap_gtc_handle_request,
+	.load_settings = eap_gtc_load_settings,
+};
+
+static int eap_gtc_init(void)
+{
+	l_debug("");
+	return eap_register_method(&eap_gtc);
+}
+
+static void eap_gtc_exit(void)
+{
+	l_debug("");
+	eap_unregister_method(&eap_gtc);
+}
+
+EAP_METHOD_BUILTIN(eap_gtc, eap_gtc_init, eap_gtc_exit)