simauth: new module to handle EAP-SIM/AKA auth

This is the core module that takes care of registering
authentication drivers. EAP-SIM/AKA will be able to acquire
a driver that supports the required algorithms. The driver
implementation (hardcoded/ofono etc.) is isolated into
separate plugin modules.

src/simauth.c

@@ -0,0 +1,185 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2017  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
+ *
+ */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <errno.h>
+#include <ell/ell.h>
+
+#include "watchlist.h"
+#include "simauth.h"
+
+static struct l_queue *auth_providers;
+
+struct iwd_sim_auth {
+	const struct iwd_sim_auth_driver *driver;
+	void *driver_data;
+	bool aka_supported : 1;
+	bool sim_supported : 1;
+	char *nai;
+	int pending;
+	struct watchlist destory_watches;
+};
+
+struct iwd_sim_auth *iwd_sim_auth_create(bool sim_supported, bool aka_supported,
+		char *nai, const struct iwd_sim_auth_driver *driver,
+		void *driver_data)
+{
+	struct iwd_sim_auth *auth = l_new(struct iwd_sim_auth, 1);
+
+	if (!auth)
+		return NULL;
+
+	auth->aka_supported = aka_supported;
+	auth->sim_supported = sim_supported;
+	auth->nai = l_strdup(nai);
+	auth->driver = driver;
+	auth->driver_data = driver_data;
+	watchlist_init(&auth->destory_watches, NULL);
+
+	l_queue_push_head(auth_providers, auth);
+
+	return auth;
+}
+
+void *iwd_sim_auth_get_data(struct iwd_sim_auth *auth)
+{
+	return auth->driver_data;
+}
+
+static void destroy_provider(void *data)
+{
+	struct iwd_sim_auth *auth = data;
+
+	if (auth->driver->cancel_request)
+		auth->driver->cancel_request(auth, auth->pending);
+
+	WATCHLIST_NOTIFY_NO_ARGS(&auth->destory_watches,
+			sim_auth_destroyed_cb_t);
+
+	if (auth->driver->remove)
+		auth->driver->remove(auth);
+
+	l_free(auth->nai);
+	l_free(auth);
+}
+
+int iwd_sim_auth_remove(struct iwd_sim_auth *auth)
+{
+	bool r;
+
+	r = l_queue_remove(auth_providers, auth);
+	if (!r)
+		return -ENOENT;
+
+	destroy_provider(auth);
+
+	return 0;
+}
+
+const char *iwd_sim_auth_get_nai(struct iwd_sim_auth *auth)
+{
+	return auth->nai;
+}
+
+struct iwd_sim_auth *iwd_sim_auth_find(bool sim, bool aka)
+{
+	struct iwd_sim_auth *auth;
+	const struct l_queue_entry *entry;
+
+	for (entry = l_queue_get_entries(auth_providers); entry;
+			entry = entry->next) {
+		auth = entry->data;
+
+		if (sim && !auth->sim_supported)
+			continue;
+
+		if (aka && !auth->aka_supported)
+			continue;
+
+		return auth;
+	}
+
+	return NULL;
+}
+
+unsigned int sim_auth_destroyed_watch_add(struct iwd_sim_auth *auth,
+		sim_auth_destroyed_cb_t cb, void *data)
+{
+	return watchlist_add(&auth->destory_watches, cb, data, NULL);
+}
+
+void sim_auth_destroyed_watch_remove(struct iwd_sim_auth *auth,
+		unsigned int id)
+{
+	watchlist_remove(&auth->destory_watches, id);
+}
+
+bool sim_auth_check_milenage(struct iwd_sim_auth *auth,
+		const uint8_t *rand, const uint8_t *autn,
+		sim_auth_check_milenage_cb_t cb, void *data)
+{
+	if (!auth->aka_supported)
+		return false;
+
+	/* save ID in case simauth is destroyed */
+	auth->pending = auth->driver->check_milenage(auth, rand, autn,
+			cb, data);
+
+	return auth->pending;
+}
+
+bool sim_auth_run_gsm(struct iwd_sim_auth *auth, const uint8_t *rands,
+		int num_rands, sim_auth_run_gsm_cb_t cb, void *data)
+{
+	if (!auth->sim_supported)
+		return false;
+
+	/* save ID in case simauth is destroyed */
+	auth->pending = auth->driver->run_gsm(auth, rands, num_rands, cb, data);
+
+	return auth->pending;
+}
+
+void sim_auth_cancel_request(struct iwd_sim_auth *auth, int id)
+{
+	if (auth->driver->cancel_request)
+		auth->driver->cancel_request(auth, id);
+}
+
+bool sim_auth_init(void)
+{
+	auth_providers = l_queue_new();
+
+	if (!auth_providers)
+		return false;
+
+	return true;
+}
+
+void sim_auth_exit(void)
+{
+	if (l_queue_length(auth_providers) > 0)
+		l_warn("Auth provider queue was not empty on exit!");
+
+	l_queue_destroy(auth_providers, destroy_provider);
+}

src/simauth.h

@@ -0,0 +1,141 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2017  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
+ *
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#define EAP_AKA_KI_LEN		16
+#define EAP_AKA_OPC_LEN		16
+#define EAP_AKA_AMF_LEN		2
+#define EAP_AKA_SQN_LEN		6
+#define EAP_SIM_KC_LEN		8
+#define EAP_SIM_SRES_LEN	4
+
+#define NUM_RANDS_MAX		3
+
+struct iwd_sim_auth;
+
+typedef void (*sim_auth_destroyed_cb_t)(void *data);
+
+/*
+ * Callback containing Milenage keys.
+ *
+ * @param res		RES value
+ * @param ck		CK key
+ * @param ik		IK key
+ * @param auts		AUTS key, if sync failure this will be non NULL. With a
+ *			normal success, this should be NULL.
+ * @param data		User data
+ *
+ * Note: If there was an error (invalid AUTN or some other error), all the keys
+ * (res/ck/ik/auts) will be NULL. A sync error will result in res, ck, and ik
+ * being NULL but auts should point to a valid AUTS key.
+ */
+typedef void (*sim_auth_check_milenage_cb_t)(const uint8_t *res,
+		const uint8_t *ck, const uint8_t *ik, const uint8_t *auts,
+		void *data);
+
+/*
+ * Callback with GSM data
+ *
+ * @param sres		SRES value
+ * @param kc		Kc value
+ * @param user_data	User data
+ *
+ * Note: If GSM authentication was unsuccessful sres and kc will both be NULL
+ */
+typedef void (*sim_auth_run_gsm_cb_t)(const uint8_t *sres,
+		const uint8_t *kc, void *user_data);
+
+struct iwd_sim_auth_driver {
+	const char *name;
+	int (*check_milenage)(struct iwd_sim_auth *auth, const uint8_t *rand,
+			const uint8_t *autn,
+			sim_auth_check_milenage_cb_t cb, void *data);
+	int (*run_gsm)(struct iwd_sim_auth *auth, const uint8_t *rands,
+			int num_rands, sim_auth_run_gsm_cb_t cb,
+			void *data);
+	void (*cancel_request)(struct iwd_sim_auth *auth, int id);
+	void (*remove)(struct iwd_sim_auth *auth);
+};
+
+/*
+ * Create a new authentication provider. This new provider will be added to
+ * the list of available providers. It is expected that the auth provider
+ * should be immediately available for auth requests.
+ */
+struct iwd_sim_auth *iwd_sim_auth_create(bool sim_supported,
+		bool aka_supported, char *nai,
+		const struct iwd_sim_auth_driver *driver, void *driver_data);
+
+void *iwd_sim_auth_get_data(struct iwd_sim_auth *auth);
+
+int iwd_sim_auth_remove(struct iwd_sim_auth *auth);
+
+const char *iwd_sim_auth_get_nai(struct iwd_sim_auth *auth);
+
+unsigned int sim_auth_destroyed_watch_add(struct iwd_sim_auth *auth,
+		sim_auth_destroyed_cb_t cb, void *data);
+
+void sim_auth_destroyed_watch_remove(struct iwd_sim_auth *auth,
+		unsigned int id);
+/*
+ * Find an appropriate driver for running SIM/AKA algorithms
+ *
+ * @param sim		True if the driver should support SIM authentication
+ * @param aka		True if the driver should support AKA authentication
+ *
+ * @returns		Driver handle found, NULL if none available
+ */
+struct iwd_sim_auth *iwd_sim_auth_find(bool sim, bool aka);
+/*
+ * Check that 'rand' and 'autn' are valid from the server.
+ *
+ * @param auth		Auth handle found with iwd_sim_auth_find()
+ * @param rand		List of RAND's from the server
+ * @param autn		AUTN from server
+ * @param cb		Callback with milenage values
+ * @param data		User data
+ *
+ * @param		False if there was an error
+ */
+bool sim_auth_check_milenage(struct iwd_sim_auth *auth,
+		const uint8_t *rand, const uint8_t *autn,
+		sim_auth_check_milenage_cb_t cb, void *data);
+
+/*
+ * Retrieve EAP-SIM Kc and SRES values
+ *
+ * @param Auth		Auth handle found with iwd_sim_auth_find()
+ * @param rands		Buffer containing N 16 byte RANDs (n == 2 || n == 3)
+ * @param num_rands	Number of 16 byte RANDs in 'rand'
+ * @param cb		Callback with GSM key values
+ * @param data		User data
+ *
+ * @return		False if there was an error
+ */
+bool sim_auth_run_gsm(struct iwd_sim_auth *auth, const uint8_t *rands,
+		int num_rands, sim_auth_run_gsm_cb_t cb, void *data);
+
+bool sim_auth_init(void);
+
+void sim_auth_exit(void);