network: Validate 8021x settings and request passwords

Use eap_check_settings directly from network.c before we start the
connection attempt at netdev.c level, to obtain all of the required
passwords/passphrases through the agent.  This is in network.c because
here we can decide the policies for whether to call the agent in
autoconnect or only if we had a request from the user, also whether we
want to save any of that for later re-use (either password data or
kernel-side key serial), etc.

In this patch we save the credentials for the lifetime of the network
object in memory, and we skip the network if it requires any passphrases
we don't have while in autoconnect, same as with PSK networks where the
PSK isn't given in the settings.  Note that NetworkManager does pop up
the password window for PSK or EAP passwords even in autoconnect.

If EAP needs multiple passwords we will call the agent sequentially for
each.

src/network.c

@@ -41,6 +41,7 @@
 #include "src/agent.h"
 #include "src/device.h"
 #include "src/wiphy.h"
+#include "src/eap.h"
 #include "src/network.h"
 
 struct network {
@@ -51,6 +52,7 @@ struct network {
 	unsigned int agent_request;
 	struct l_queue *bss_list;
 	struct l_settings *settings;
+	struct l_queue *secrets;
 	bool update_psk:1;  /* Whether PSK should be written to storage */
 	bool ask_psk:1; /* Whether we should force-ask agent for PSK */
 	int rank;
@@ -333,6 +335,11 @@ const uint8_t *network_get_psk(const struct network *network)
 	return network->psk;
 }
 
+struct l_queue *network_get_secrets(const struct network *network)
+{
+	return network->secrets;
+}
+
 bool network_set_psk(struct network *network, const uint8_t *psk)
 {
 	if (network->info->type != SECURITY_PSK)
@@ -418,10 +425,22 @@ int network_autoconnect(struct network *network, struct scan_bss *bss)
 		break;
 	}
 	case SECURITY_8021X:
+	{
+		struct l_queue *missing_secrets = NULL;
+
 		if (!network_settings_load(network))
 			return -ENOKEY;
 
+		if (!eap_check_settings(network->settings, network->secrets,
+					"EAP-", true, &missing_secrets) ||
+				!l_queue_isempty(missing_secrets)) {
+			l_queue_destroy(missing_secrets, eap_secret_info_free);
+			network_settings_close(network);
+			return -ENOKEY;
+		}
+
 		break;
+	}
 	default:
 		return -ENOTSUP;
 	}
@@ -450,6 +469,9 @@ void network_connect_failed(struct network *network)
 		network->update_psk = false;
 		network->ask_psk = true;
 	}
+
+	l_queue_destroy(network->secrets, eap_secret_info_free);
+	network->secrets = NULL;
 }
 
 bool network_bss_add(struct network *network, struct scan_bss *bss)
@@ -630,6 +652,237 @@ static struct l_dbus_message *network_connect_psk(struct network *network,
 	return NULL;
 }
 
+struct eap_secret_request {
+	struct network *network;
+	struct eap_secret_info *secret;
+	struct l_queue *pending_secrets;
+	void (*callback)(enum agent_result result,
+				struct l_dbus_message *message,
+				struct eap_secret_request *req);
+};
+
+static void eap_secret_request_free(void *data)
+{
+	struct eap_secret_request *req = data;
+
+	eap_secret_info_free(req->secret);
+	l_queue_destroy(req->pending_secrets, eap_secret_info_free);
+	l_free(req);
+}
+
+static bool eap_secret_info_match_local(const void *a, const void *b)
+{
+	const struct eap_secret_info *info = a;
+
+	return info->type == EAP_SECRET_LOCAL_PKEY_PASSPHRASE;
+}
+
+static void eap_password_callback(enum agent_result result, const char *value,
+					struct l_dbus_message *message,
+					void *user_data)
+{
+	struct eap_secret_request *req = user_data;
+
+	req->network->agent_request = 0;
+	req->secret->value = l_strdup(value);
+
+	req->callback(result, message, req);
+}
+
+static void eap_user_password_callback(enum agent_result result,
+					const char *user, const char *passwd,
+					struct l_dbus_message *message,
+					void *user_data)
+{
+	struct eap_secret_request *req = user_data;
+
+	req->network->agent_request = 0;
+
+	if (user && passwd) {
+		size_t len1 = strlen(user) + 1;
+		size_t len2 = strlen(passwd) + 1;
+
+		req->secret->value = l_malloc(len1 + len2);
+		memcpy(req->secret->value, user, len1);
+		memcpy(req->secret->value + len1, passwd, len2);
+	}
+
+	req->callback(result, message, req);
+}
+
+static bool eap_send_agent_req(struct network *network,
+				struct l_queue *pending_secrets,
+				struct l_dbus_message *message,
+				void *callback)
+{
+	struct eap_secret_request *req;
+	struct eap_secret_info *info;
+
+	/*
+	 * Request the locally-verifiable data first, i.e.
+	 * the private key encryption passphrases so that we don't bother
+	 * asking for any other data if these passphrases turn out to
+	 * be wrong.
+	 */
+	info = l_queue_remove_if(pending_secrets, eap_secret_info_match_local,
+					NULL);
+
+	if (!info)
+		info = l_queue_pop_head(pending_secrets);
+
+	req = l_new(struct eap_secret_request, 1);
+	req->network = network;
+	req->secret = info;
+	req->pending_secrets = pending_secrets;
+	req->callback = callback;
+
+	switch (info->type) {
+	case EAP_SECRET_LOCAL_PKEY_PASSPHRASE:
+		network->agent_request = agent_request_pkey_passphrase(
+						network->object_path,
+						eap_password_callback,
+						message, req,
+						eap_secret_request_free);
+		break;
+	case EAP_SECRET_REMOTE_PASSWORD:
+		network->agent_request = agent_request_user_password(
+						network->object_path,
+						info->parameter,
+						eap_password_callback,
+						message, req,
+						eap_secret_request_free);
+		break;
+	case EAP_SECRET_REMOTE_USER_PASSWORD:
+		network->agent_request = agent_request_user_name_password(
+						network->object_path,
+						eap_user_password_callback,
+						message, req,
+						eap_secret_request_free);
+		break;
+	}
+
+	if (network->agent_request)
+		return true;
+
+	eap_secret_request_free(req);
+	return false;
+}
+
+static struct l_dbus_message *network_connect_8021x(struct network *network,
+						struct scan_bss *bss,
+						struct l_dbus_message *message);
+
+static void eap_secret_done(enum agent_result result,
+				struct l_dbus_message *message,
+				struct eap_secret_request *req)
+{
+	struct network *network = req->network;
+	struct eap_secret_info *secret = req->secret;
+	struct l_queue *pending = req->pending_secrets;
+	struct scan_bss *bss;
+
+	l_debug("result %d", result);
+
+	/*
+	 * Agent will release its reference to message after invoking this
+	 * callback.  So if we want this message, we need to take a reference
+	 * to it.
+	 */
+	l_dbus_message_ref(message);
+
+	if (result != AGENT_RESULT_OK) {
+		dbus_pending_reply(&message, dbus_error_aborted(message));
+		goto err;
+	}
+
+	bss = network_bss_select(network);
+
+	/* Did all good BSSes go away while we waited */
+	if (!bss) {
+		dbus_pending_reply(&message, dbus_error_failed(message));
+		goto err;
+	}
+
+	if (!network->secrets)
+		network->secrets = l_queue_new();
+
+	l_queue_push_tail(network->secrets, secret);
+
+	req->secret = NULL;
+
+	/*
+	 * If we have any other missing secrets in the queue, send the
+	 * next request immediately unless we've just received a passphrase
+	 * for a local private key.  In that case we will first call
+	 * network_connect_8021x to have it validate the new passphrase.
+	 */
+	if (secret->type == EAP_SECRET_LOCAL_PKEY_PASSPHRASE ||
+			l_queue_isempty(req->pending_secrets)) {
+		struct l_dbus_message *reply;
+
+		reply = network_connect_8021x(network, bss, message);
+		if (reply)
+			dbus_pending_reply(&message, reply);
+		else
+			l_dbus_message_unref(message);
+
+		return;
+	}
+
+	req->pending_secrets = NULL;
+
+	if (eap_send_agent_req(network, pending, message,
+				eap_secret_done)) {
+		l_dbus_message_unref(message);
+		return;
+	}
+
+	dbus_pending_reply(&message, dbus_error_no_agent(message));
+err:
+	network_settings_close(network);
+}
+
+static struct l_dbus_message *network_connect_8021x(struct network *network,
+						struct scan_bss *bss,
+						struct l_dbus_message *message)
+{
+	bool r;
+	struct l_queue *missing_secrets = NULL;
+
+	l_debug("");
+
+	r = eap_check_settings(network->settings, network->secrets, "EAP-",
+				true, &missing_secrets);
+	if (!r) {
+		l_queue_destroy(missing_secrets, eap_secret_info_free);
+
+		network_settings_close(network);
+
+		l_queue_destroy(network->secrets, eap_secret_info_free);
+		network->secrets = NULL;
+
+		return dbus_error_not_configured(message);
+	}
+
+	l_debug("supplied %u secrets, %u more needed for EAP",
+		l_queue_length(network->secrets),
+		l_queue_length(missing_secrets));
+
+	if (l_queue_isempty(missing_secrets)) {
+		device_connect_network(network->device, network, bss, message);
+
+		return NULL;
+	}
+
+	if (eap_send_agent_req(network, missing_secrets, message,
+				eap_secret_done))
+		return NULL;
+
+	network_settings_close(network);
+
+	return dbus_error_no_agent(message);
+}
+
 static struct l_dbus_message *network_connect(struct l_dbus *dbus,
 						struct l_dbus_message *message,
 						void *user_data)
@@ -664,8 +917,7 @@ static struct l_dbus_message *network_connect(struct l_dbus *dbus,
 		if (!network_settings_load(network))
 			return dbus_error_not_configured(message);
 
-		device_connect_network(device, network, bss, message);
+		return network_connect_8021x(network, bss, message);
-		return NULL;
 	default:
 		return dbus_error_not_supported(message);
 	}
@@ -780,6 +1032,9 @@ void network_remove(struct network *network, int reason)
 	if (network->object_path)
 		network_unregister(network, reason);
 
+	l_queue_destroy(network->secrets, eap_secret_info_free);
+	network->secrets = NULL;
+
 	l_queue_destroy(network->bss_list, NULL);
 	network_info_put(network->info);
 

src/network.h

@@ -40,6 +40,7 @@ struct device *network_get_device(const struct network *network);
 const char *network_get_path(const struct network *network);
 enum security network_get_security(const struct network *network);
 const uint8_t *network_get_psk(const struct network *network);
+struct l_queue *network_get_secrets(const struct network *network);
 int network_get_signal_strength(const struct network *network);
 struct l_settings *network_get_settings(const struct network *network);