/* * * Wireless daemon for Linux * * Copyright (C) 2021 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 #endif #include #include #include "linux/nl80211.h" #include "src/missing.h" #include "src/dbus.h" #include "src/netdev.h" #include "src/module.h" #include "src/dpp-util.h" #include "src/band.h" #include "src/frame-xchg.h" #include "src/offchannel.h" #include "src/wiphy.h" #include "src/ie.h" #include "src/iwd.h" #include "src/util.h" #include "src/crypto.h" #include "src/mpdu.h" #include "ell/useful.h" #include "src/common.h" #include "src/json.h" #include "src/storage.h" #include "src/station.h" #include "src/scan.h" #include "src/network.h" #include "src/handshake.h" #include "src/nl80211util.h" #include "src/knownnetworks.h" #define DPP_FRAME_MAX_RETRIES 5 #define DPP_FRAME_RETRY_TIMEOUT 1 #define DPP_AUTH_PROTO_TIMEOUT 10 #define DPP_PKEX_PROTO_TIMEOUT 120 #define DPP_PKEX_PROTO_PER_FREQ_TIMEOUT 10 static uint32_t netdev_watch; static struct l_genl_family *nl80211; static uint8_t broadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; static struct l_queue *dpp_list; static uint32_t mlme_watch; static uint32_t unicast_watch; static uint8_t dpp_prefix[] = { 0x04, 0x09, 0x50, 0x6f, 0x9a, 0x1a, 0x01 }; enum dpp_state { DPP_STATE_NOTHING, DPP_STATE_PRESENCE, DPP_STATE_PKEX_EXCHANGE, DPP_STATE_PKEX_COMMIT_REVEAL, DPP_STATE_AUTHENTICATING, DPP_STATE_CONFIGURING, }; enum dpp_capability { DPP_CAPABILITY_ENROLLEE = 0x01, DPP_CAPABILITY_CONFIGURATOR = 0x02, }; enum dpp_interface { DPP_INTERFACE_UNBOUND, DPP_INTERFACE_DPP, DPP_INTERFACE_PKEX, }; struct pkex_agent { char *owner; char *path; unsigned int disconnect_watch; uint32_t pending_id; }; struct dpp_sm { struct netdev *netdev; char *uri; uint8_t role; int refcount; uint32_t station_watch; uint32_t known_network_watch; uint64_t wdev_id; uint8_t *own_asn1; size_t own_asn1_len; uint8_t *peer_asn1; size_t peer_asn1_len; uint8_t own_boot_hash[32]; uint8_t peer_boot_hash[32]; const struct l_ecc_curve *curve; size_t key_len; size_t nonce_len; struct l_ecc_scalar *boot_private; struct l_ecc_point *boot_public; struct l_ecc_point *peer_boot_public; enum dpp_state state; enum dpp_interface interface; struct pkex_agent *agent; /* * List of frequencies to jump between. The presence of this list is * also used to signify that a configurator is an initiator vs responder */ uint32_t *freqs; size_t freqs_len; size_t freqs_idx; uint32_t dwell; uint32_t current_freq; uint32_t new_freq; struct scan_freq_set *presence_list; uint32_t max_roc; uint32_t offchannel_id; uint8_t peer_addr[6]; uint8_t r_nonce[32]; uint8_t i_nonce[32]; uint8_t e_nonce[32]; struct l_ecc_scalar *m; uint64_t ke[L_ECC_MAX_DIGITS]; uint64_t k1[L_ECC_MAX_DIGITS]; uint64_t k2[L_ECC_MAX_DIGITS]; uint64_t auth_tag[L_ECC_MAX_DIGITS]; struct l_ecc_scalar *proto_private; struct l_ecc_point *own_proto_public; struct l_ecc_point *peer_proto_public; uint8_t diag_token; /* Timeout of either auth/config protocol */ struct l_timeout *timeout; struct dpp_configuration *config; uint32_t connect_scan_id; uint64_t frame_cookie; uint8_t frame_retry; void *frame_pending; size_t frame_size; struct l_timeout *retry_timeout; struct l_dbus_message *pending; struct l_idle *connect_idle; /* PKEX-specific values */ char *pkex_id; char *pkex_key; uint8_t pkex_version; struct l_ecc_point *peer_encr_key; struct l_ecc_point *pkex_m; /* Ephemeral key Y' or X' for enrollee or configurator */ struct l_ecc_point *y_or_x; /* Ephemeral key pair y/Y or x/X */ struct l_ecc_point *pkex_public; struct l_ecc_scalar *pkex_private; uint8_t z[L_ECC_SCALAR_MAX_BYTES]; size_t z_len; uint8_t u[L_ECC_SCALAR_MAX_BYTES]; size_t u_len; uint32_t pkex_scan_id; bool mcast_support : 1; bool roc_started : 1; bool channel_switch : 1; bool mutual_auth : 1; bool autoconnect : 1; }; static const char *dpp_role_to_string(enum dpp_capability role) { switch (role) { case DPP_CAPABILITY_ENROLLEE: return "enrollee"; case DPP_CAPABILITY_CONFIGURATOR: return "configurator"; default: return NULL; } } static bool dpp_pkex_get_started(struct l_dbus *dbus, struct l_dbus_message *message, struct l_dbus_message_builder *builder, void *user_data) { struct dpp_sm *dpp = user_data; bool started = (dpp->state != DPP_STATE_NOTHING && dpp->interface == DPP_INTERFACE_PKEX); l_dbus_message_builder_append_basic(builder, 'b', &started); return true; } static bool dpp_pkex_get_role(struct l_dbus *dbus, struct l_dbus_message *message, struct l_dbus_message_builder *builder, void *user_data) { struct dpp_sm *dpp = user_data; const char *role; if (dpp->state == DPP_STATE_NOTHING || dpp->interface != DPP_INTERFACE_PKEX) return false; role = dpp_role_to_string(dpp->role); if (L_WARN_ON(!role)) return false; l_dbus_message_builder_append_basic(builder, 's', role); return true; } static bool dpp_get_started(struct l_dbus *dbus, struct l_dbus_message *message, struct l_dbus_message_builder *builder, void *user_data) { struct dpp_sm *dpp = user_data; bool started = (dpp->state != DPP_STATE_NOTHING && dpp->interface == DPP_INTERFACE_DPP); l_dbus_message_builder_append_basic(builder, 'b', &started); return true; } static bool dpp_get_role(struct l_dbus *dbus, struct l_dbus_message *message, struct l_dbus_message_builder *builder, void *user_data) { struct dpp_sm *dpp = user_data; const char *role; if (dpp->state == DPP_STATE_NOTHING || dpp->interface != DPP_INTERFACE_DPP) return false; role = dpp_role_to_string(dpp->role); if (L_WARN_ON(!role)) return false; l_dbus_message_builder_append_basic(builder, 's', role); return true; } static bool dpp_get_uri(struct l_dbus *dbus, struct l_dbus_message *message, struct l_dbus_message_builder *builder, void *user_data) { struct dpp_sm *dpp = user_data; if (dpp->state == DPP_STATE_NOTHING || dpp->interface != DPP_INTERFACE_DPP) return false; l_dbus_message_builder_append_basic(builder, 's', dpp->uri); return true; } static void dpp_property_changed_notify(struct dpp_sm *dpp) { const char *path = netdev_get_path(dpp->netdev); switch (dpp->interface) { case DPP_INTERFACE_DPP: l_dbus_property_changed(dbus_get_bus(), path, IWD_DPP_INTERFACE, "Started"); l_dbus_property_changed(dbus_get_bus(), path, IWD_DPP_INTERFACE, "Role"); l_dbus_property_changed(dbus_get_bus(), path, IWD_DPP_INTERFACE, "URI"); break; case DPP_INTERFACE_PKEX: l_dbus_property_changed(dbus_get_bus(), path, IWD_DPP_PKEX_INTERFACE, "Started"); l_dbus_property_changed(dbus_get_bus(), path, IWD_DPP_PKEX_INTERFACE, "Role"); break; default: break; } } static void *dpp_serialize_iovec(struct iovec *iov, size_t iov_len, size_t *out_len) { unsigned int i; size_t size = 0; uint8_t *ret; for (i = 0; i < iov_len; i++) size += iov[i].iov_len; ret = l_malloc(size); size = 0; for (i = 0; i < iov_len; i++) { memcpy(ret + size, iov[i].iov_base, iov[i].iov_len); size += iov[i].iov_len; } if (out_len) *out_len = size; return ret; } static void dpp_free_pending_pkex_data(struct dpp_sm *dpp) { if (dpp->pkex_id) { l_free(dpp->pkex_id); dpp->pkex_id = NULL; } if (dpp->pkex_key) { l_free(dpp->pkex_key); dpp->pkex_key = NULL; } memset(dpp->peer_addr, 0, sizeof(dpp->peer_addr)); if (dpp->peer_encr_key) { l_ecc_point_free(dpp->peer_encr_key); dpp->peer_encr_key = NULL; } } static void pkex_agent_free(void *data) { struct pkex_agent *agent = data; l_free(agent->owner); l_free(agent->path); l_dbus_remove_watch(dbus_get_bus(), agent->disconnect_watch); l_free(agent); } static void dpp_agent_cancel(struct dpp_sm *dpp) { struct l_dbus_message *msg; const char *reason = "shutdown"; msg = l_dbus_message_new_method_call(dbus_get_bus(), dpp->agent->owner, dpp->agent->path, IWD_SHARED_CODE_AGENT_INTERFACE, "Cancel"); l_dbus_message_set_arguments(msg, "s", reason); l_dbus_message_set_no_reply(msg, true); l_dbus_send(dbus_get_bus(), msg); } static void dpp_agent_release(struct dpp_sm *dpp) { struct l_dbus_message *msg; msg = l_dbus_message_new_method_call(dbus_get_bus(), dpp->agent->owner, dpp->agent->path, IWD_SHARED_CODE_AGENT_INTERFACE, "Release"); l_dbus_message_set_arguments(msg, ""); l_dbus_message_set_no_reply(msg, true); l_dbus_send(dbus_get_bus(), msg); } static void dpp_destroy_agent(struct dpp_sm *dpp) { if (!dpp->agent) return; if (dpp->agent->pending_id) { dpp_agent_cancel(dpp); l_dbus_cancel(dbus_get_bus(), dpp->agent->pending_id); } dpp_agent_release(dpp); l_debug("Released SharedCodeAgent on path %s", dpp->agent->path); pkex_agent_free(dpp->agent); dpp->agent = NULL; } static void dpp_free_auth_data(struct dpp_sm *dpp) { if (dpp->own_proto_public) { l_ecc_point_free(dpp->own_proto_public); dpp->own_proto_public = NULL; } if (dpp->proto_private) { l_ecc_scalar_free(dpp->proto_private); dpp->proto_private = NULL; } if (dpp->peer_proto_public) { l_ecc_point_free(dpp->peer_proto_public); dpp->peer_proto_public = NULL; } if (dpp->peer_boot_public) { l_ecc_point_free(dpp->peer_boot_public); dpp->peer_boot_public = NULL; } if (dpp->m) { l_ecc_scalar_free(dpp->m); dpp->m = NULL; } if (dpp->pkex_m) { l_ecc_point_free(dpp->pkex_m); dpp->pkex_m = NULL; } if (dpp->y_or_x) { l_ecc_point_free(dpp->y_or_x); dpp->y_or_x = NULL; } if (dpp->pkex_public) { l_ecc_point_free(dpp->pkex_public); dpp->pkex_public = NULL; } if (dpp->pkex_private) { l_ecc_scalar_free(dpp->pkex_private); dpp->pkex_private = NULL; } } static void dpp_reset(struct dpp_sm *dpp) { struct station *station = station_find(netdev_get_ifindex(dpp->netdev)); if (dpp->uri) { l_free(dpp->uri); dpp->uri = NULL; } if (dpp->freqs) { l_free(dpp->freqs); dpp->freqs = NULL; } if (dpp->offchannel_id) { offchannel_cancel(dpp->wdev_id, dpp->offchannel_id); dpp->offchannel_id = 0; } if (dpp->timeout) { l_timeout_remove(dpp->timeout); dpp->timeout = NULL; } if (dpp->config) { dpp_configuration_free(dpp->config); dpp->config = NULL; } if (dpp->connect_scan_id) { scan_cancel(dpp->wdev_id, dpp->connect_scan_id); dpp->connect_scan_id = 0; } if (dpp->peer_asn1) { l_free(dpp->peer_asn1); dpp->peer_asn1 = NULL; } if (dpp->frame_pending) { l_free(dpp->frame_pending); dpp->frame_pending = NULL; } if (dpp->retry_timeout) { l_timeout_remove(dpp->retry_timeout); dpp->retry_timeout = NULL; } if (dpp->pkex_scan_id) { scan_cancel(dpp->wdev_id, dpp->pkex_scan_id); dpp->pkex_scan_id = 0; } if (dpp->connect_idle) { l_idle_remove(dpp->connect_idle); dpp->connect_idle = NULL; } dpp->state = DPP_STATE_NOTHING; dpp->new_freq = 0; dpp->frame_retry = 0; dpp->frame_cookie = 0; dpp->pkex_version = 0; explicit_bzero(dpp->r_nonce, dpp->nonce_len); explicit_bzero(dpp->i_nonce, dpp->nonce_len); explicit_bzero(dpp->e_nonce, dpp->nonce_len); explicit_bzero(dpp->ke, dpp->key_len); explicit_bzero(dpp->k1, dpp->key_len); explicit_bzero(dpp->k2, dpp->key_len); explicit_bzero(dpp->auth_tag, dpp->key_len); explicit_bzero(dpp->z, dpp->key_len); explicit_bzero(dpp->u, dpp->u_len); dpp_destroy_agent(dpp); dpp_free_pending_pkex_data(dpp); dpp_free_auth_data(dpp); dpp_property_changed_notify(dpp); dpp->interface = DPP_INTERFACE_UNBOUND; if (station) { if (dpp->station_watch) station_remove_state_watch(station, dpp->station_watch); /* Set the old autoconnect state back to what it was */ if (dpp->role == DPP_CAPABILITY_ENROLLEE) station_set_autoconnect(station, dpp->autoconnect); } } static void dpp_free(struct dpp_sm *dpp) { dpp_reset(dpp); if (dpp->own_asn1) { l_free(dpp->own_asn1); dpp->own_asn1 = NULL; } if (dpp->boot_public) { l_ecc_point_free(dpp->boot_public); dpp->boot_public = NULL; } if (dpp->boot_private) { l_ecc_scalar_free(dpp->boot_private); dpp->boot_private = NULL; } known_networks_watch_remove(dpp->known_network_watch); l_free(dpp); } static void dpp_send_frame_cb(struct l_genl_msg *msg, void *user_data) { struct dpp_sm *dpp = user_data; int err = l_genl_msg_get_error(msg); if (err < 0) { l_error("Error sending frame (%d)", err); return; } if (nl80211_parse_attrs(msg, NL80211_ATTR_COOKIE, &dpp->frame_cookie, NL80211_ATTR_UNSPEC) < 0) l_error("Error parsing frame cookie"); } static void dpp_send_frame(struct dpp_sm *dpp, struct iovec *iov, size_t iov_len, uint32_t freq) { struct l_genl_msg *msg; /* * A received frame could potentially come in after the ROC session has * ended. In this case the frame needs to be stored until ROC is started * and sent at that time. The offchannel_id is also checked since * this is not applicable when DPP is in a responder role waiting * on the currently connected channel i.e. offchannel is never used. */ if (!dpp->roc_started && dpp->offchannel_id) { dpp->frame_pending = dpp_serialize_iovec(iov, iov_len, &dpp->frame_size); return; } msg = l_genl_msg_new_sized(NL80211_CMD_FRAME, 512); l_genl_msg_append_attr(msg, NL80211_ATTR_WDEV, 8, &dpp->wdev_id); l_genl_msg_append_attr(msg, NL80211_ATTR_WIPHY_FREQ, 4, &freq); l_genl_msg_append_attr(msg, NL80211_ATTR_OFFCHANNEL_TX_OK, 0, NULL); l_genl_msg_append_attrv(msg, NL80211_ATTR_FRAME, iov, iov_len); l_debug("Sending frame on frequency %u", freq); if (!l_genl_family_send(nl80211, msg, dpp_send_frame_cb, dpp, NULL)) { l_error("Could not send CMD_FRAME"); l_genl_msg_unref(msg); } } static void dpp_frame_retry(struct dpp_sm *dpp) { struct iovec iov; iov.iov_base = dpp->frame_pending; iov.iov_len = dpp->frame_size; dpp_send_frame(dpp, &iov, 1, dpp->current_freq); l_free(dpp->frame_pending); dpp->frame_pending = NULL; } static size_t dpp_build_header(const uint8_t *src, const uint8_t *dest, enum dpp_frame_type type, uint8_t buf[static 32]) { uint8_t *ptr = buf + 24; memset(buf, 0, 32); l_put_le16(0x00d0, buf); memcpy(buf + 4, dest, 6); memcpy(buf + 10, src, 6); memcpy(buf + 16, broadcast, 6); *ptr++ = 0x04; /* Category: Public */ *ptr++ = 0x09; /* Action: Vendor specific usage */ memcpy(ptr, wifi_alliance_oui, 3); ptr += 3; *ptr++ = 0x1a; /* WiFi Alliance DPP OI type */ *ptr++ = 1; /* Cryptosuite */ *ptr++ = type; return ptr - buf; } static size_t dpp_build_config_header(const uint8_t *src, const uint8_t *dest, uint8_t diag_token, uint8_t buf[static 37]) { uint8_t *ptr = buf + 24; memset(buf, 0, 37); l_put_le16(0x00d0, buf); memcpy(buf + 4, dest, 6); memcpy(buf + 10, src, 6); memcpy(buf + 16, broadcast, 6); *ptr++ = 0x04; /* Public */ *ptr++ = 0x0a; /* Action */ *ptr++ = diag_token; *ptr++ = IE_TYPE_ADVERTISEMENT_PROTOCOL; *ptr++ = 8; /* len */ *ptr++ = 0x00; *ptr++ = IE_TYPE_VENDOR_SPECIFIC; *ptr++ = 5; memcpy(ptr, wifi_alliance_oui, 3); ptr += 3; *ptr++ = 0x1a; *ptr++ = 1; return ptr - buf; } static void dpp_protocol_timeout(struct l_timeout *timeout, void *user_data) { struct dpp_sm *dpp = user_data; l_debug("DPP timed out"); dpp_reset(dpp); } static void dpp_reset_protocol_timer(struct dpp_sm *dpp, uint32_t time) { if (dpp->timeout) l_timeout_modify(dpp->timeout, time); else dpp->timeout = l_timeout_create(time, dpp_protocol_timeout, dpp, NULL); } /* * The configuration protocols use of AD components is somewhat confusing * since the request/response frames are of a different format than the rest. * In addition there are situations where the components length is zero yet it * is still passed as such to AES-SIV. * * For the configuration request/response frames: * * "AAD for use with AES-SIV for protected messages in the DPP Configuration * protocol shall consist of all octets in the Query Request and Query Response * fields up to the first octet of the Wrapped Data attribute, which is the last * attribute in a DPP Configuration frame. When the number of octets of AAD is * zero, the number of components of AAD passed to AES-SIV is zero." * * - For configuration requests the optional query request field is not * included, therefore no AAD data is passed. (dpp_configuration_start) * * - The configuration response does contain a query response field which is * 5 bytes. (dpp_handle_config_response_frame) * * For the configuration result/status, the same rules are used as the * authentication protocol. This is reiterated in section 6.4.1. * * - For the configuration result there is some confusion as to exactly how the * second AAD component should be passed (since the spec specifically * mentions using two components). There are no attributes prior to the * wrapped data component meaning the length would be zero. * Hostapd/wpa_supplicant pass a zero length AAD component to AES-SIV which * does effect the resulting encryption/decryption so this is also what IWD * will do to remain compliant with it. */ static void dpp_configuration_start(struct dpp_sm *dpp, const uint8_t *addr) { const char *json = "{\"name\":\"IWD\",\"wi-fi_tech\":\"infra\"," "\"netRole\":\"sta\"}"; struct iovec iov[3]; uint8_t hdr[37]; uint8_t attrs[512]; size_t json_len = strlen(json); uint8_t *ptr = attrs; l_getrandom(&dpp->diag_token, 1); iov[0].iov_len = dpp_build_config_header( netdev_get_address(dpp->netdev), addr, dpp->diag_token, hdr); iov[0].iov_base = hdr; l_getrandom(dpp->e_nonce, dpp->nonce_len); /* length */ ptr += 2; /* * "AAD for use with AES-SIV for protected messages in the DPP * Configuration protocol shall consist of all octets in the Query * Request and Query Response fields up to the first octet of the * Wrapped Data attribute" * * In this case there is no query request/response fields, nor any * attributes besides wrapped data meaning zero AD components. */ ptr += dpp_append_wrapped_data(NULL, 0, NULL, 0, ptr, sizeof(attrs), dpp->ke, dpp->key_len, 2, DPP_ATTR_ENROLLEE_NONCE, dpp->nonce_len, dpp->e_nonce, DPP_ATTR_CONFIGURATION_REQUEST, json_len, json); l_put_le16(ptr - attrs - 2, attrs); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp->state = DPP_STATE_CONFIGURING; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void send_config_result(struct dpp_sm *dpp, const uint8_t *to) { uint8_t hdr[32]; struct iovec iov[2]; uint8_t attrs[256]; uint8_t *ptr = attrs; uint8_t zero = 0; iov[0].iov_len = dpp_build_header(netdev_get_address(dpp->netdev), to, DPP_FRAME_CONFIGURATION_RESULT, hdr); iov[0].iov_base = hdr; ptr += dpp_append_wrapped_data(hdr + 26, 6, attrs, 0, ptr, sizeof(attrs), dpp->ke, dpp->key_len, 2, DPP_ATTR_STATUS, (size_t) 1, &zero, DPP_ATTR_ENROLLEE_NONCE, dpp->nonce_len, dpp->e_nonce); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void dpp_write_config(struct dpp_configuration *config, struct network *network) { _auto_(l_settings_free) struct l_settings *settings = l_settings_new(); _auto_(l_free) char *path; path = storage_get_network_file_path(SECURITY_PSK, config->ssid); if (l_settings_load_from_file(settings, path)) { /* Remove any existing Security keys */ l_settings_remove_group(settings, "Security"); } if (config->passphrase) l_settings_set_string(settings, "Security", "Passphrase", config->passphrase); else if (config->psk) l_settings_set_string(settings, "Security", "PreSharedKey", config->psk); if (config->send_hostname) l_settings_set_bool(settings, "IPv4", "SendHostname", true); if (config->hidden) l_settings_set_bool(settings, "Settings", "Hidden", true); l_debug("Storing credential for '%s(%s)'", config->ssid, security_to_str(SECURITY_PSK)); storage_network_sync(SECURITY_PSK, config->ssid, settings); } static void dpp_scan_triggered(int err, void *user_data) { /* Not much can be done in this case */ if (err < 0) l_error("Failed to trigger DPP scan"); } static void dpp_start_connect(struct l_idle *idle, void *user_data) { struct dpp_sm *dpp = user_data; struct station *station = station_find(netdev_get_ifindex(dpp->netdev)); struct scan_bss *bss; struct network *network; int ret; network = station_network_find(station, dpp->config->ssid, SECURITY_PSK); dpp_reset(dpp); if (!network) { l_debug("Network was not found!"); return; } l_debug("connecting to %s from DPP", network_get_ssid(network)); bss = network_bss_select(network, true); ret = network_autoconnect(network, bss); if (ret < 0) l_warn("failed to connect after DPP (%d) %s", ret, strerror(-ret)); } static bool dpp_scan_results(int err, struct l_queue *bss_list, const struct scan_freq_set *freqs, void *userdata) { struct dpp_sm *dpp = userdata; struct station *station = station_find(netdev_get_ifindex(dpp->netdev)); if (err < 0) goto reset; if (!bss_list || l_queue_length(bss_list) == 0) goto reset; /* * The station watch _should_ detect this and reset, which cancels the * scan. But just in case... */ if (L_WARN_ON(station_get_connected_network(station))) goto reset; station_set_scan_results(station, bss_list, freqs, false); dpp_start_connect(NULL, dpp); return true; reset: return false; } static void dpp_scan_destroy(void *userdata) { struct dpp_sm *dpp = userdata; dpp->connect_scan_id = 0; dpp_reset(dpp); } static void dpp_known_network_watch(enum known_networks_event event, const struct network_info *info, void *user_data) { struct dpp_sm *dpp = user_data; /* * Check the following * - DPP is enrolling * - DPP finished (dpp->config is set) * - This is for the network DPP just configured * - DPP isn't already trying to connect (e.g. if the profile was * immediately modified after DPP synced it). * - DPP didn't start a scan for the network. */ if (dpp->role != DPP_CAPABILITY_ENROLLEE) return; if (!dpp->config) return; if (strcmp(info->ssid, dpp->config->ssid)) return; if (dpp->connect_idle) return; if (dpp->connect_scan_id) return; switch (event) { case KNOWN_NETWORKS_EVENT_ADDED: case KNOWN_NETWORKS_EVENT_UPDATED: /* * network.c takes care of updating the settings for the * network. This callback just tells us to begin the connection. * We do have use an idle here because there is no strict * guarantee of ordering between known network events, e.g. DPP * could have been called into prior to network and the network * object isn't updated yet. */ dpp->connect_idle = l_idle_create(dpp_start_connect, dpp, NULL); break; case KNOWN_NETWORKS_EVENT_REMOVED: l_warn("profile was removed before DPP could connect"); break; } } static void dpp_handle_config_response_frame(const struct mmpdu_header *frame, const void *body, size_t body_len, int rssi, void *user_data) { struct dpp_sm *dpp = user_data; const uint8_t *ptr = body; uint16_t status; uint16_t fragmented; /* Fragmented/Comeback delay field */ uint8_t adv_protocol_element[] = { 0x6C, 0x08, 0x7F }; uint8_t adv_protocol_id[] = { 0xDD, 0x05, 0x50, 0x6F, 0x9A, 0x1A, 0x01 }; uint16_t query_len; struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; const char *json = NULL; size_t json_len = 0; int dstatus = -1; const uint8_t *wrapped = NULL; const uint8_t *e_nonce = NULL; size_t wrapped_len = 0; _auto_(l_free) uint8_t *unwrapped = NULL; struct dpp_configuration *config; struct station *station = station_find(netdev_get_ifindex(dpp->netdev)); struct network *network = NULL; struct scan_bss *bss = NULL; if (dpp->state != DPP_STATE_CONFIGURING) return; /* * Can a configuration request come from someone other than who you * authenticated to? */ if (memcmp(dpp->peer_addr, frame->address_2, 6)) return; if (body_len < 19) return; ptr += 2; if (*ptr++ != dpp->diag_token) return; status = l_get_le16(ptr); ptr += 2; if (status != 0) { l_debug("Bad configuration status %u", status); return; } fragmented = l_get_le16(ptr); ptr += 2; /* * TODO: handle 0x0001 (fragmented), as well as comeback delay. */ if (fragmented != 0) { l_debug("Fragmented messages not currently supported"); return; } if (memcmp(ptr, adv_protocol_element, sizeof(adv_protocol_element))) { l_debug("Invalid Advertisement protocol element"); return; } ptr += sizeof(adv_protocol_element); if (memcmp(ptr, adv_protocol_id, sizeof(adv_protocol_id))) { l_debug("Invalid Advertisement protocol ID"); return; } ptr += sizeof(adv_protocol_id); query_len = l_get_le16(ptr); ptr += 2; if (query_len > body_len - 19) return; dpp_attr_iter_init(&iter, ptr, query_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_STATUS: dstatus = l_get_u8(data); break; case DPP_ATTR_WRAPPED_DATA: wrapped = data; wrapped_len = len; break; default: /* * TODO: CSR Attribute */ break; } } if (dstatus != DPP_STATUS_OK || !wrapped) { l_debug("Bad status or missing attributes"); return; } unwrapped = dpp_unwrap_attr(ptr, wrapped - ptr - 4, NULL, 0, dpp->ke, dpp->key_len, wrapped, wrapped_len, &wrapped_len); if (!unwrapped) { l_debug("Failed to unwrap"); return; } dpp_attr_iter_init(&iter, unwrapped, wrapped_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_ENROLLEE_NONCE: if (len != dpp->nonce_len) break; if (memcmp(data, dpp->e_nonce, dpp->nonce_len)) break; e_nonce = data; break; case DPP_ATTR_CONFIGURATION_OBJECT: json = (const char *)data; json_len = len; break; default: break; } } if (!json || !e_nonce) { l_debug("No configuration object in response"); return; } config = dpp_parse_configuration_object(json, json_len); if (!config) { l_error("Configuration object did not parse"); return; } /* * We should have a station device, but if not DPP can write the * credentials out and be done */ if (station) { network = station_network_find(station, config->ssid, SECURITY_PSK); if (network) bss = network_bss_select(network, true); } dpp_write_config(config, network); send_config_result(dpp, dpp->peer_addr); offchannel_cancel(dpp->wdev_id, dpp->offchannel_id); if (network && bss) { l_debug("delaying connect until settings are synced"); dpp->config = config; return; } else if (station) { struct scan_parameters params = {0}; params.ssid = (void *) config->ssid; params.ssid_len = config->ssid_len; l_debug("Scanning for %s", config->ssid); dpp->connect_scan_id = scan_active_full(dpp->wdev_id, ¶ms, dpp_scan_triggered, dpp_scan_results, dpp, dpp_scan_destroy); if (dpp->connect_scan_id) { dpp->config = config; return; } } dpp_configuration_free(config); dpp_reset(dpp); } static void dpp_send_config_response(struct dpp_sm *dpp, uint8_t status) { _auto_(l_free) char *json = NULL; struct iovec iov[3]; uint8_t hdr[41]; uint8_t attrs[512]; size_t json_len; uint8_t *ptr = hdr + 24; memset(hdr, 0, sizeof(hdr)); l_put_le16(0x00d0, hdr); memcpy(hdr + 4, dpp->peer_addr, 6); memcpy(hdr + 10, netdev_get_address(dpp->netdev), 6); memcpy(hdr + 16, broadcast, 6); *ptr++ = 0x04; *ptr++ = 0x0b; *ptr++ = dpp->diag_token; l_put_le16(0, ptr); /* status */ ptr += 2; l_put_le16(0, ptr); /* fragmented (no) */ ptr += 2; *ptr++ = IE_TYPE_ADVERTISEMENT_PROTOCOL; *ptr++ = 0x08; *ptr++ = 0x7f; *ptr++ = IE_TYPE_VENDOR_SPECIFIC; *ptr++ = 5; memcpy(ptr, wifi_alliance_oui, sizeof(wifi_alliance_oui)); ptr += sizeof(wifi_alliance_oui); *ptr++ = 0x1a; *ptr++ = 1; iov[0].iov_base = hdr; iov[0].iov_len = ptr - hdr; ptr = attrs; ptr += 2; /* length */ ptr += dpp_append_attr(ptr, DPP_ATTR_STATUS, &status, 1); /* * There are several failure status codes that can be used (defined in * 6.4.3.1), each with their own set of attributes that should be * included. For now IWD's basic DPP implementation will assume * STATUS_CONFIGURE_FAILURE which only includes the E-Nonce. */ if (status == DPP_STATUS_OK) { json = dpp_configuration_to_json(dpp->config); json_len = strlen(json); ptr += dpp_append_wrapped_data(attrs + 2, ptr - attrs - 2, NULL, 0, ptr, sizeof(attrs), dpp->ke, dpp->key_len, 2, DPP_ATTR_ENROLLEE_NONCE, dpp->nonce_len, dpp->e_nonce, DPP_ATTR_CONFIGURATION_OBJECT, json_len, json); } else ptr += dpp_append_wrapped_data(attrs + 2, ptr - attrs - 2, NULL, 0, ptr, sizeof(attrs), dpp->ke, dpp->key_len, 2, DPP_ATTR_ENROLLEE_NONCE, dpp->nonce_len, dpp->e_nonce); l_put_le16(ptr - attrs - 2, attrs); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static bool dpp_check_config_header(const uint8_t *ptr) { /* * Table 58. General Format of DPP Configuration Request frame * * Unfortunately wpa_supplicant hard codes 0x7f as the Query Response * Info so we need to handle both cases. */ return ptr[0] == IE_TYPE_ADVERTISEMENT_PROTOCOL && ptr[1] == 0x08 && (ptr[2] == 0x7f || ptr[2] == 0x00) && ptr[3] == IE_TYPE_VENDOR_SPECIFIC && ptr[4] == 5; } static void dpp_handle_config_request_frame(const struct mmpdu_header *frame, const void *body, size_t body_len, int rssi, void *user_data) { struct dpp_sm *dpp = user_data; const uint8_t *ptr = body; struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; const char *json = NULL; size_t json_len = 0; struct json_contents *c; const uint8_t *wrapped = NULL; const uint8_t *e_nonce = NULL; size_t wrapped_len = 0; _auto_(l_free) uint8_t *unwrapped = NULL; struct json_iter jsiter; _auto_(l_free) char *tech = NULL; _auto_(l_free) char *role = NULL; if (dpp->state != DPP_STATE_AUTHENTICATING) { l_debug("Configuration request in wrong state"); return; } if (dpp->role != DPP_CAPABILITY_CONFIGURATOR) return; if (memcmp(dpp->peer_addr, frame->address_2, 6)) { l_debug("Configuration request not from authenticated peer"); return; } if (body_len < 15) { l_debug("Configuration request data not long enough"); return; } ptr += 2; dpp->diag_token = *ptr++; if (!dpp_check_config_header(ptr)) return; ptr += 5; if (memcmp(ptr, wifi_alliance_oui, sizeof(wifi_alliance_oui))) return; ptr += sizeof(wifi_alliance_oui); if (*ptr != 0x1a && *(ptr + 1) != 1) return; ptr += 2; len = l_get_le16(ptr); ptr += 2; if (len > body_len - 15) return; dpp_attr_iter_init(&iter, ptr, len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_WRAPPED_DATA: wrapped = data; wrapped_len = len; break; default: /* Wrapped data should be only attribute */ return; } } if (!wrapped) { l_debug("Wrapped data missing"); return; } unwrapped = dpp_unwrap_attr(NULL, 0, NULL, 0, dpp->ke, dpp->key_len, wrapped, wrapped_len, &wrapped_len); if (!unwrapped) { l_debug("Failed to unwrap"); return; } dpp_attr_iter_init(&iter, unwrapped, wrapped_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_ENROLLEE_NONCE: if (len != dpp->nonce_len) break; e_nonce = data; break; case DPP_ATTR_CONFIGURATION_REQUEST: json = (const char *)data; json_len = len; break; default: break; } } if (!json || !e_nonce) { l_debug("No configuration object in response"); return; } c = json_contents_new(json, json_len); if (!c) { json_contents_free(c); return; } json_iter_init(&jsiter, c); /* * Check mandatory values (Table 7). There isn't much that can be done * with these, but the spec requires they be included. */ if (!json_iter_parse(&jsiter, JSON_MANDATORY("name", JSON_STRING, NULL), JSON_MANDATORY("wi-fi_tech", JSON_STRING, &tech), JSON_MANDATORY("netRole", JSON_STRING, &role), JSON_UNDEFINED)) goto configure_failure; if (strcmp(tech, "infra")) goto configure_failure; if (strcmp(role, "sta")) goto configure_failure; json_contents_free(c); memcpy(dpp->e_nonce, e_nonce, dpp->nonce_len); dpp->state = DPP_STATE_CONFIGURING; dpp_send_config_response(dpp, DPP_STATUS_OK); return; configure_failure: dpp_send_config_response(dpp, DPP_STATUS_CONFIGURE_FAILURE); /* * The other peer is still authenticated, and can potentially send * additional requests so keep this session alive. */ } static void dpp_handle_config_result_frame(struct dpp_sm *dpp, const uint8_t *from, const void *body, size_t body_len) { struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; int status = -1; const void *e_nonce = NULL; const void *wrapped = NULL; size_t wrapped_len; _auto_(l_free) void *unwrapped = NULL; if (dpp->state != DPP_STATE_CONFIGURING) return; dpp_attr_iter_init(&iter, body + 8, body_len - 8); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_WRAPPED_DATA: wrapped = data; wrapped_len = len; break; default: /* Wrapped data should be only attribute */ return; } } if (!wrapped) return; unwrapped = dpp_unwrap_attr(body + 2, wrapped - body - 6, wrapped, 0, dpp->ke, dpp->key_len, wrapped, wrapped_len, &wrapped_len); if (!unwrapped) { l_debug("Failed to unwrap DPP configuration result"); return; } dpp_attr_iter_init(&iter, unwrapped, wrapped_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_STATUS: status = l_get_u8(data); break; case DPP_ATTR_ENROLLEE_NONCE: e_nonce = data; break; default: break; } } if (status != DPP_STATUS_OK || !e_nonce) l_debug("Enrollee signaled a failed configuration"); else l_debug("Configuration success"); dpp_reset(dpp); } /* * The Authentication protocol has a consistent use of AD components, and this * use is defined in 6.3.1.4: * * "Invocations of AES-SIV in the DPP Authentication protocol that produce * ciphertext that is part of an additional AES-SIV invocation do not use AAD; * in other words, the number of AAD components is set to zero. All other * invocations of AES-SIV in the DPP Authentication protocol shall pass a vector * of AAD having two components of AAD in the following order: (1) the DPP * header, as defined in Table 30, from the OUI field (inclusive) to the DPP * Frame Type field (inclusive); and (2) all octets in a DPP Public Action frame * after the DPP Frame Type field up to and including the last octet of the last * attribute before the Wrapped Data attribute" * * In practice you see this as AD0 being some offset in the frame (offset to the * OUI). For outgoing packets this is 26 bytes offset since the header is built * manually. For incoming packets the offset is 2 bytes. The length is always * 6 bytes for AD0. * * The AD1 data is always the start of the attributes, and length is the number * of bytes from these attributes to wrapped data. e.g. * * ad1 = attrs * ad1_len = ptr - attrs */ static void send_authenticate_response(struct dpp_sm *dpp) { uint8_t hdr[32]; uint8_t attrs[512]; uint8_t *ptr = attrs; uint8_t status = DPP_STATUS_OK; uint64_t r_proto_key[L_ECC_MAX_DIGITS * 2]; uint8_t version = 2; struct iovec iov[3]; uint8_t wrapped2_plaintext[dpp->key_len + 4]; uint8_t wrapped2[dpp->key_len + 16 + 8]; size_t wrapped2_len; l_ecc_point_get_data(dpp->own_proto_public, r_proto_key, sizeof(r_proto_key)); iov[0].iov_len = dpp_build_header(netdev_get_address(dpp->netdev), dpp->peer_addr, DPP_FRAME_AUTHENTICATION_RESPONSE, hdr); iov[0].iov_base = hdr; ptr += dpp_append_attr(ptr, DPP_ATTR_STATUS, &status, 1); ptr += dpp_append_attr(ptr, DPP_ATTR_RESPONDER_BOOT_KEY_HASH, dpp->own_boot_hash, 32); if (dpp->mutual_auth) ptr += dpp_append_attr(ptr, DPP_ATTR_INITIATOR_BOOT_KEY_HASH, dpp->peer_boot_hash, 32); ptr += dpp_append_attr(ptr, DPP_ATTR_RESPONDER_PROTOCOL_KEY, r_proto_key, dpp->key_len * 2); ptr += dpp_append_attr(ptr, DPP_ATTR_PROTOCOL_VERSION, &version, 1); /* Wrap up secondary data (R-Auth) */ wrapped2_len = dpp_append_attr(wrapped2_plaintext, DPP_ATTR_RESPONDER_AUTH_TAG, dpp->auth_tag, dpp->key_len); /* * "Invocations of AES-SIV in the DPP Authentication protocol that * produce ciphertext that is part of an additional AES-SIV invocation * do not use AAD; in other words, the number of AAD components is set * to zero."" */ if (!aes_siv_encrypt(dpp->ke, dpp->key_len, wrapped2_plaintext, dpp->key_len + 4, NULL, 0, wrapped2)) { l_error("Failed to encrypt wrapped data"); return; } wrapped2_len += 16; ptr += dpp_append_wrapped_data(hdr + 26, 6, attrs, ptr - attrs, ptr, sizeof(attrs), dpp->k2, dpp->key_len, 4, DPP_ATTR_RESPONDER_NONCE, dpp->nonce_len, dpp->r_nonce, DPP_ATTR_INITIATOR_NONCE, dpp->nonce_len, dpp->i_nonce, DPP_ATTR_RESPONDER_CAPABILITIES, (size_t) 1, &dpp->role, DPP_ATTR_WRAPPED_DATA, wrapped2_len, wrapped2); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void authenticate_confirm(struct dpp_sm *dpp, const uint8_t *from, const uint8_t *body, size_t body_len) { struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; int status = -1; const uint8_t *r_boot_hash = NULL; const void *wrapped = NULL; const uint8_t *i_auth = NULL; size_t i_auth_len; _auto_(l_free) uint8_t *unwrapped = NULL; size_t wrapped_len = 0; uint64_t i_auth_check[L_ECC_MAX_DIGITS]; const void *unwrap_key; const void *ad0 = body + 2; const void *ad1 = body + 8; struct l_ecc_point *bi = NULL; if (dpp->state != DPP_STATE_AUTHENTICATING) return; if (memcmp(from, dpp->peer_addr, 6)) return; l_debug("authenticate confirm"); dpp_attr_iter_init(&iter, body + 8, body_len - 8); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_STATUS: status = l_get_u8(data); break; case DPP_ATTR_RESPONDER_BOOT_KEY_HASH: r_boot_hash = data; /* * Spec requires this, but does not mention if anything * is to be done with it. */ break; case DPP_ATTR_INITIATOR_BOOT_KEY_HASH: /* No mutual authentication */ break; case DPP_ATTR_WRAPPED_DATA: wrapped = data; wrapped_len = len; break; default: break; } } if (!r_boot_hash || !wrapped) { l_debug("Attributes missing from authenticate confirm"); return; } /* * "The Responder obtains the DPP Authentication Confirm frame and * checks the value of the DPP Status field. If the value of the DPP * Status field is STATUS_NOT_COMPATIBLE or STATUS_AUTH_FAILURE, the * Responder unwraps the wrapped data portion of the frame using k2" */ if (status == DPP_STATUS_OK) unwrap_key = dpp->ke; else if (status == DPP_STATUS_NOT_COMPATIBLE || status == DPP_STATUS_AUTH_FAILURE) unwrap_key = dpp->k2; else goto auth_confirm_failed; unwrapped = dpp_unwrap_attr(ad0, 6, ad1, wrapped - 4 - ad1, unwrap_key, dpp->key_len, wrapped, wrapped_len, &wrapped_len); if (!unwrapped) goto auth_confirm_failed; if (status != DPP_STATUS_OK) { /* * "If unwrapping is successful, the Responder should generate * an alert indicating the reason for the protocol failure." */ l_debug("Authentication failed due to status %s", status == DPP_STATUS_NOT_COMPATIBLE ? "NOT_COMPATIBLE" : "AUTH_FAILURE"); goto auth_confirm_failed; } dpp_attr_iter_init(&iter, unwrapped, wrapped_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_INITIATOR_AUTH_TAG: i_auth = data; i_auth_len = len; break; case DPP_ATTR_RESPONDER_NONCE: /* Only if error */ break; default: break; } } if (!i_auth || i_auth_len != dpp->key_len) { l_debug("I-Auth missing from wrapped data"); goto auth_confirm_failed; } if (dpp->mutual_auth) bi = dpp->peer_boot_public; dpp_derive_i_auth(dpp->r_nonce, dpp->i_nonce, dpp->nonce_len, dpp->own_proto_public, dpp->peer_proto_public, dpp->boot_public, bi, i_auth_check); if (memcmp(i_auth, i_auth_check, i_auth_len)) { l_error("I-Auth did not verify"); goto auth_confirm_failed; } l_debug("Authentication successful"); dpp_reset_protocol_timer(dpp, DPP_AUTH_PROTO_TIMEOUT); if (dpp->role == DPP_CAPABILITY_ENROLLEE) dpp_configuration_start(dpp, from); return; auth_confirm_failed: dpp->state = DPP_STATE_PRESENCE; dpp_free_auth_data(dpp); } static void dpp_auth_request_failed(struct dpp_sm *dpp, enum dpp_status status, void *k1) { uint8_t hdr[32]; uint8_t attrs[128]; uint8_t *ptr = attrs; uint8_t version = 2; uint8_t s = status; struct iovec iov[2]; iov[0].iov_len = dpp_build_header(netdev_get_address(dpp->netdev), dpp->peer_addr, DPP_FRAME_AUTHENTICATION_RESPONSE, hdr); iov[0].iov_base = hdr; ptr += dpp_append_attr(ptr, DPP_ATTR_STATUS, &s, 1); ptr += dpp_append_attr(ptr, DPP_ATTR_RESPONDER_BOOT_KEY_HASH, dpp->own_boot_hash, 32); ptr += dpp_append_attr(ptr, DPP_ATTR_PROTOCOL_VERSION, &version, 1); ptr += dpp_append_wrapped_data(hdr + 26, 6, attrs, ptr - attrs, ptr, sizeof(attrs) - (ptr - attrs), k1, dpp->key_len, 2, DPP_ATTR_INITIATOR_NONCE, dpp->nonce_len, dpp->i_nonce, DPP_ATTR_RESPONDER_CAPABILITIES, (size_t) 1, &dpp->role); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static bool dpp_check_roles(struct dpp_sm *dpp, uint8_t peer_capa) { if (dpp->role == DPP_CAPABILITY_ENROLLEE && !(peer_capa & DPP_CAPABILITY_CONFIGURATOR)) return false; else if (dpp->role == DPP_CAPABILITY_CONFIGURATOR && !(peer_capa & DPP_CAPABILITY_ENROLLEE)) return false; return true; } static void dpp_presence_announce(struct dpp_sm *dpp) { struct netdev *netdev = dpp->netdev; uint8_t hdr[32]; uint8_t attrs[32 + 4]; uint8_t hash[32]; uint8_t *ptr = attrs; const uint8_t *addr = netdev_get_address(netdev); struct iovec iov[2]; iov[0].iov_len = dpp_build_header(addr, broadcast, DPP_FRAME_PRESENCE_ANNOUNCEMENT, hdr); iov[0].iov_base = hdr; dpp_hash(L_CHECKSUM_SHA256, hash, 2, "chirp", strlen("chirp"), dpp->own_asn1, dpp->own_asn1_len); ptr += dpp_append_attr(ptr, DPP_ATTR_RESPONDER_BOOT_KEY_HASH, hash, 32); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; l_debug("Sending presence announcement on frequency %u and waiting %u", dpp->current_freq, dpp->dwell); dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static bool dpp_send_authenticate_request(struct dpp_sm *dpp) { uint8_t hdr[32]; uint8_t attrs[256]; uint8_t *ptr = attrs; uint64_t i_proto_key[L_ECC_MAX_DIGITS * 2]; uint8_t version = 2; struct iovec iov[2]; struct station *station = station_find(netdev_get_ifindex(dpp->netdev)); struct scan_bss *bss = station_get_connected_bss(station); /* Got disconnected by the time the peer was discovered */ if (dpp->role == DPP_CAPABILITY_CONFIGURATOR && !bss) { dpp_reset(dpp); return false; } l_ecc_point_get_data(dpp->own_proto_public, i_proto_key, sizeof(i_proto_key)); iov[0].iov_len = dpp_build_header(netdev_get_address(dpp->netdev), dpp->peer_addr, DPP_FRAME_AUTHENTICATION_REQUEST, hdr); iov[0].iov_base = hdr; ptr += dpp_append_attr(ptr, DPP_ATTR_RESPONDER_BOOT_KEY_HASH, dpp->peer_boot_hash, 32); ptr += dpp_append_attr(ptr, DPP_ATTR_INITIATOR_BOOT_KEY_HASH, dpp->own_boot_hash, 32); ptr += dpp_append_attr(ptr, DPP_ATTR_INITIATOR_PROTOCOL_KEY, i_proto_key, dpp->key_len * 2); ptr += dpp_append_attr(ptr, DPP_ATTR_PROTOCOL_VERSION, &version, 1); if (dpp->role == DPP_CAPABILITY_CONFIGURATOR && dpp->current_freq != bss->frequency) { uint8_t pair[2] = { 81, band_freq_to_channel(bss->frequency, NULL) }; ptr += dpp_append_attr(ptr, DPP_ATTR_CHANNEL, pair, 2); } ptr += dpp_append_wrapped_data(hdr + 26, 6, attrs, ptr - attrs, ptr, sizeof(attrs), dpp->k1, dpp->key_len, 2, DPP_ATTR_INITIATOR_NONCE, dpp->nonce_len, dpp->i_nonce, DPP_ATTR_INITIATOR_CAPABILITIES, (size_t) 1, &dpp->role); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); return true; } static void dpp_send_pkex_exchange_request(struct dpp_sm *dpp) { uint8_t hdr[32]; uint8_t attrs[256]; uint8_t *ptr = attrs; uint64_t m_data[L_ECC_MAX_DIGITS * 2]; uint16_t group; struct iovec iov[2]; const uint8_t *own_mac = netdev_get_address(dpp->netdev); l_put_le16(l_ecc_curve_get_ike_group(dpp->curve), &group); iov[0].iov_len = dpp_build_header(own_mac, broadcast, DPP_FRAME_PKEX_VERSION1_XCHG_REQUEST, hdr); iov[0].iov_base = hdr; ptr += dpp_append_attr(ptr, DPP_ATTR_PROTOCOL_VERSION, &dpp->pkex_version, 1); ptr += dpp_append_attr(ptr, DPP_ATTR_FINITE_CYCLIC_GROUP, &group, 2); if (dpp->pkex_id) ptr += dpp_append_attr(ptr, DPP_ATTR_CODE_IDENTIFIER, dpp->pkex_id, strlen(dpp->pkex_id)); l_ecc_point_get_data(dpp->pkex_m, m_data, sizeof(m_data)); ptr += dpp_append_attr(ptr, DPP_ATTR_ENCRYPTED_KEY, m_data, dpp->key_len * 2); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void dpp_send_commit_reveal_request(struct dpp_sm *dpp) { struct iovec iov[2]; uint8_t hdr[41]; uint8_t attrs[512]; uint8_t *ptr = attrs; uint8_t zero = 0; uint8_t a_pub[L_ECC_POINT_MAX_BYTES]; ssize_t a_len; a_len = l_ecc_point_get_data(dpp->boot_public, a_pub, sizeof(a_pub)); iov[0].iov_len = dpp_build_header(netdev_get_address(dpp->netdev), dpp->peer_addr, DPP_FRAME_PKEX_COMMIT_REVEAL_REQUEST, hdr); iov[0].iov_base = hdr; ptr += dpp_append_wrapped_data(hdr + 26, 6, &zero, 1, ptr, sizeof(attrs), dpp->z, dpp->z_len, 2, DPP_ATTR_BOOTSTRAPPING_KEY, a_len, a_pub, DPP_ATTR_INITIATOR_AUTH_TAG, dpp->u_len, dpp->u); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void dpp_roc_started(void *user_data) { struct dpp_sm *dpp = user_data; /* * - If a configurator, nothing to do but wait for a request * (unless multicast frame registration is unsupported in which case * send an authenticate request now) * - If in the presence state continue sending announcements. * - If authenticating, and this is a result of a channel switch send * the authenticate response now. */ dpp->roc_started = true; /* * The retry timer indicates a frame was not acked in which case we * should not change any state or send any frames until that expires. */ if (dpp->retry_timeout) return; if (dpp->frame_pending) { dpp_frame_retry(dpp); return; } switch (dpp->state) { case DPP_STATE_PRESENCE: if (dpp->role == DPP_CAPABILITY_CONFIGURATOR) return; if (dpp->pending) { struct l_dbus_message *reply = l_dbus_message_new_method_return(dpp->pending); l_dbus_message_set_arguments(reply, "s", dpp->uri); dbus_pending_reply(&dpp->pending, reply); } dpp_presence_announce(dpp); break; case DPP_STATE_AUTHENTICATING: /* * No multicast frame registration support, jump right into * sending auth frames. This diverges from the 2.0 spec, but in * reality the the main path nearly all drivers will hit. */ if (dpp->role == DPP_CAPABILITY_CONFIGURATOR) { if (dpp->mcast_support) return; dpp_send_authenticate_request(dpp); return; } if (dpp->new_freq) { dpp->current_freq = dpp->new_freq; dpp->new_freq = 0; send_authenticate_response(dpp); } break; case DPP_STATE_PKEX_EXCHANGE: if (dpp->role == DPP_CAPABILITY_ENROLLEE) dpp_send_pkex_exchange_request(dpp); break; case DPP_STATE_PKEX_COMMIT_REVEAL: if (dpp->role == DPP_CAPABILITY_ENROLLEE) dpp_send_commit_reveal_request(dpp); break; default: break; } } static void dpp_start_offchannel(struct dpp_sm *dpp, uint32_t freq); static void dpp_offchannel_timeout(int error, void *user_data) { struct dpp_sm *dpp = user_data; dpp->offchannel_id = 0; dpp->roc_started = false; /* * If cancelled this is likely due to netdev going down or from Stop(). * Otherwise there was some other problem which is probably not * recoverable. */ if (error == -ECANCELED) return; else if (error == -EIO) goto next_roc; else if (error < 0) goto protocol_failed; switch (dpp->state) { case DPP_STATE_PKEX_EXCHANGE: if (dpp->role != DPP_CAPABILITY_CONFIGURATOR || !dpp->agent) break; /* * We have a pending agent request but it did not arrive in * time, we cant assume the enrollee will be waiting around * for our response so cancel the request and continue waiting * for another request */ if (dpp->agent->pending_id) { dpp_free_pending_pkex_data(dpp); dpp_agent_cancel(dpp); } /* Fall through */ case DPP_STATE_PRESENCE: break; case DPP_STATE_NOTHING: /* Protocol already terminated */ return; case DPP_STATE_AUTHENTICATING: case DPP_STATE_CONFIGURING: case DPP_STATE_PKEX_COMMIT_REVEAL: goto next_roc; } dpp->freqs_idx++; if (dpp->freqs_idx >= dpp->freqs_len) { l_debug("Max retries offchannel"); dpp->freqs_idx = 0; } dpp->current_freq = dpp->freqs[dpp->freqs_idx]; l_debug("Offchannel timeout, moving to next frequency %u, duration %u", dpp->current_freq, dpp->dwell); next_roc: dpp_start_offchannel(dpp, dpp->current_freq); return; protocol_failed: dpp_reset(dpp); } static void dpp_start_offchannel(struct dpp_sm *dpp, uint32_t freq) { /* * This needs to be handled carefully for a few reasons: * * First, the next offchannel operation needs to be started prior to * canceling an existing one. This is so the offchannel work can * continue uninterrupted without any other work items starting in * between canceling and starting the next (e.g. if a scan request is * sitting in the queue). * * Second, dpp_offchannel_timeout resets dpp->offchannel_id to zero * which is why the new ID is saved and only set to dpp->offchannel_id * once the previous offchannel work is cancelled (i.e. destroy() has * been called). */ uint32_t id = offchannel_start(netdev_get_wdev_id(dpp->netdev), WIPHY_WORK_PRIORITY_OFFCHANNEL, freq, dpp->dwell, dpp_roc_started, dpp, dpp_offchannel_timeout); if (dpp->offchannel_id) offchannel_cancel(dpp->wdev_id, dpp->offchannel_id); dpp->offchannel_id = id; } static void authenticate_request(struct dpp_sm *dpp, const uint8_t *from, const uint8_t *body, size_t body_len) { struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; const uint8_t *r_boot = NULL; const uint8_t *i_boot = NULL; const uint8_t *i_proto = NULL; const void *wrapped = NULL; const uint8_t *i_nonce = NULL; uint8_t i_capa = 0; size_t r_boot_len = 0, i_proto_len = 0, wrapped_len = 0; size_t i_nonce_len = 0; _auto_(l_free) uint8_t *unwrapped = NULL; _auto_(l_ecc_scalar_free) struct l_ecc_scalar *m = NULL; _auto_(l_ecc_scalar_free) struct l_ecc_scalar *n = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *l = NULL; struct l_ecc_point *bi = NULL; uint64_t k1[L_ECC_MAX_DIGITS]; const void *ad0 = body + 2; const void *ad1 = body + 8; uint32_t freq; if (util_is_broadcast_address(from)) return; if (dpp->state != DPP_STATE_PRESENCE && dpp->state != DPP_STATE_AUTHENTICATING) return; l_debug("authenticate request"); dpp_attr_iter_init(&iter, body + 8, body_len - 8); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_INITIATOR_BOOT_KEY_HASH: i_boot = data; /* * This attribute is required by the spec, but only * used for mutual authentication. */ break; case DPP_ATTR_RESPONDER_BOOT_KEY_HASH: r_boot = data; r_boot_len = len; break; case DPP_ATTR_INITIATOR_PROTOCOL_KEY: i_proto = data; i_proto_len = len; break; case DPP_ATTR_WRAPPED_DATA: /* I-Nonce/I-Capabilities part of wrapped data */ wrapped = data; wrapped_len = len; break; /* Optional attributes */ case DPP_ATTR_PROTOCOL_VERSION: if (l_get_u8(data) != 2) { l_debug("Protocol version did not match"); return; } break; case DPP_ATTR_CHANNEL: if (len != 2) return; freq = oci_to_frequency(l_get_u8(data), l_get_u8(data + 1)); if (freq == dpp->current_freq) break; /* * Configurators are already connected to a network, so * to preserve wireless performance the enrollee will * be required to be on this channel, not a channel it * requests. */ if (dpp->role == DPP_CAPABILITY_CONFIGURATOR) return; /* * Otherwise, as an enrollee, we can jump to whatever * channel the configurator requests */ dpp->new_freq = freq; l_debug("Configurator requested a new frequency %u", dpp->new_freq); dpp_start_offchannel(dpp, dpp->new_freq); break; default: break; } } if (!r_boot || !i_boot || !i_proto || !wrapped) goto auth_request_failed; if (r_boot_len != 32 || memcmp(dpp->own_boot_hash, r_boot, r_boot_len)) { l_debug("Responder boot key hash failed to verify"); goto auth_request_failed; } dpp->peer_proto_public = l_ecc_point_from_data(dpp->curve, L_ECC_POINT_TYPE_FULL, i_proto, i_proto_len); if (!dpp->peer_proto_public) { l_debug("Initiators protocol key invalid"); goto auth_request_failed; } m = dpp_derive_k1(dpp->peer_proto_public, dpp->boot_private, k1); if (!m) goto auth_request_failed; unwrapped = dpp_unwrap_attr(ad0, 6, ad1, wrapped - 4 - ad1, k1, dpp->key_len, wrapped, wrapped_len, &wrapped_len); if (!unwrapped) goto auth_request_failed; dpp_attr_iter_init(&iter, unwrapped, wrapped_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_INITIATOR_NONCE: i_nonce = data; i_nonce_len = len; break; case DPP_ATTR_INITIATOR_CAPABILITIES: /* * "If the Responder is not capable of supporting the * role indicated by the Initiator, it shall respond * with a DPP Authentication Response frame indicating * failure by adding the DPP Status field set to * STATUS_NOT_COMPATIBLE" */ i_capa = l_get_u8(data); if (!dpp_check_roles(dpp, i_capa)) { l_debug("Peer does not support required role"); dpp_auth_request_failed(dpp, DPP_STATUS_NOT_COMPATIBLE, k1); goto auth_request_failed; } break; default: break; } } if (i_nonce_len != dpp->nonce_len) { l_debug("I-Nonce has unexpected length %zu", i_nonce_len); goto auth_request_failed; } memcpy(dpp->i_nonce, i_nonce, i_nonce_len); if (dpp->mutual_auth) { l = dpp_derive_lr(dpp->boot_private, dpp->proto_private, dpp->peer_boot_public); bi = dpp->peer_boot_public; } /* Derive keys k2, ke, and R-Auth for authentication response */ n = dpp_derive_k2(dpp->peer_proto_public, dpp->proto_private, dpp->k2); if (!n) goto auth_request_failed; l_getrandom(dpp->r_nonce, dpp->nonce_len); if (!dpp_derive_ke(dpp->i_nonce, dpp->r_nonce, m, n, l, dpp->ke)) goto auth_request_failed; if (!dpp_derive_r_auth(dpp->i_nonce, dpp->r_nonce, dpp->nonce_len, dpp->peer_proto_public, dpp->own_proto_public, bi, dpp->boot_public, dpp->auth_tag)) goto auth_request_failed; memcpy(dpp->peer_addr, from, 6); dpp->state = DPP_STATE_AUTHENTICATING; dpp_reset_protocol_timer(dpp, DPP_AUTH_PROTO_TIMEOUT); /* Don't send if the frequency is changing */ if (!dpp->new_freq) send_authenticate_response(dpp); return; auth_request_failed: dpp->state = DPP_STATE_PRESENCE; dpp_free_auth_data(dpp); } static void dpp_send_authenticate_confirm(struct dpp_sm *dpp) { uint8_t hdr[32]; struct iovec iov[2]; uint8_t attrs[256]; uint8_t *ptr = attrs; uint8_t zero = 0; iov[0].iov_len = dpp_build_header(netdev_get_address(dpp->netdev), dpp->peer_addr, DPP_FRAME_AUTHENTICATION_CONFIRM, hdr); iov[0].iov_base = hdr; ptr += dpp_append_attr(ptr, DPP_ATTR_STATUS, &zero, 1); ptr += dpp_append_attr(ptr, DPP_ATTR_RESPONDER_BOOT_KEY_HASH, dpp->peer_boot_hash, 32); if (dpp->mutual_auth) ptr += dpp_append_attr(ptr, DPP_ATTR_INITIATOR_BOOT_KEY_HASH, dpp->own_boot_hash, 32); ptr += dpp_append_wrapped_data(hdr + 26, 6, attrs, ptr - attrs, ptr, sizeof(attrs), dpp->ke, dpp->key_len, 1, DPP_ATTR_INITIATOR_AUTH_TAG, dpp->key_len, dpp->auth_tag); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void authenticate_response(struct dpp_sm *dpp, const uint8_t *from, const uint8_t *body, size_t body_len) { struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; int status = -1; const void *r_boot_hash = NULL; const void *r_proto = NULL; size_t r_proto_len = 0; const void *wrapped = NULL; size_t wrapped_len; _auto_(l_free) uint8_t *unwrapped1 = NULL; _auto_(l_free) uint8_t *unwrapped2 = NULL; const void *r_nonce = NULL; const void *i_nonce = NULL; const void *r_auth = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *r_proto_key = NULL; _auto_(l_ecc_scalar_free) struct l_ecc_scalar *n = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *l = NULL; struct l_ecc_point *bi = NULL; const void *ad0 = body + 2; const void *ad1 = body + 8; uint64_t r_auth_derived[L_ECC_MAX_DIGITS]; l_debug("Authenticate response"); if (dpp->state != DPP_STATE_AUTHENTICATING) return; if (!dpp->freqs) return; if (memcmp(from, dpp->peer_addr, 6)) return; dpp_attr_iter_init(&iter, body + 8, body_len - 8); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_STATUS: if (len != 1) return; status = l_get_u8(data); break; case DPP_ATTR_RESPONDER_BOOT_KEY_HASH: r_boot_hash = data; break; case DPP_ATTR_RESPONDER_PROTOCOL_KEY: r_proto = data; r_proto_len = len; break; case DPP_ATTR_PROTOCOL_VERSION: if (len != 1 || l_get_u8(data) != 2) return; break; case DPP_ATTR_WRAPPED_DATA: wrapped = data; wrapped_len = len; break; default: break; } } if (status != DPP_STATUS_OK || !r_boot_hash || !r_proto || !wrapped) { l_debug("Auth response bad status or missing attributes"); return; } r_proto_key = l_ecc_point_from_data(dpp->curve, L_ECC_POINT_TYPE_FULL, r_proto, r_proto_len); if (!r_proto_key) { l_debug("Peers protocol key was invalid"); return; } n = dpp_derive_k2(r_proto_key, dpp->proto_private, dpp->k2); unwrapped1 = dpp_unwrap_attr(ad0, 6, ad1, wrapped - 4 - ad1, dpp->k2, dpp->key_len, wrapped, wrapped_len, &wrapped_len); if (!unwrapped1) { l_debug("Failed to unwrap primary data"); return; } wrapped = NULL; dpp_attr_iter_init(&iter, unwrapped1, wrapped_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_RESPONDER_NONCE: if (len != dpp->nonce_len) return; r_nonce = data; break; case DPP_ATTR_INITIATOR_NONCE: if (len != dpp->nonce_len) return; i_nonce = data; break; case DPP_ATTR_RESPONDER_CAPABILITIES: break; case DPP_ATTR_WRAPPED_DATA: wrapped = data; wrapped_len = len; break; default: break; } } if (!r_nonce || !i_nonce || !wrapped) { l_debug("Wrapped data missing attributes"); return; } if (dpp->mutual_auth) { l = dpp_derive_li(dpp->peer_boot_public, r_proto_key, dpp->boot_private); bi = dpp->boot_public; } if (!dpp_derive_ke(i_nonce, r_nonce, dpp->m, n, l, dpp->ke)) { l_debug("Failed to derive ke"); return; } unwrapped2 = dpp_unwrap_attr(NULL, 0, NULL, 0, dpp->ke, dpp->key_len, wrapped, wrapped_len, &wrapped_len); if (!unwrapped2) { l_debug("Failed to unwrap secondary data"); return; } dpp_attr_iter_init(&iter, unwrapped2, wrapped_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_RESPONDER_AUTH_TAG: if (len != dpp->key_len) return; r_auth = data; break; default: break; } } if (!r_auth) { l_debug("R-Auth was not in secondary wrapped data"); return; } if (!dpp_derive_r_auth(i_nonce, r_nonce, dpp->nonce_len, dpp->own_proto_public, r_proto_key, bi, dpp->peer_boot_public, r_auth_derived)) { l_debug("Failed to derive r_auth"); return; } if (memcmp(r_auth, r_auth_derived, dpp->key_len)) { l_debug("R-Auth did not verify"); return; } if (!dpp_derive_i_auth(r_nonce, i_nonce, dpp->nonce_len, r_proto_key, dpp->own_proto_public, dpp->peer_boot_public, bi, dpp->auth_tag)) { l_debug("Could not derive I-Auth"); return; } dpp->channel_switch = false; dpp->current_freq = dpp->new_freq; dpp_send_authenticate_confirm(dpp); if (dpp->role == DPP_CAPABILITY_ENROLLEE) dpp_configuration_start(dpp, from); } static void dpp_handle_presence_announcement(struct dpp_sm *dpp, const uint8_t *from, const uint8_t *body, size_t body_len) { struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; const void *r_boot = NULL; size_t r_boot_len = 0; uint8_t hash[32]; l_debug("Presence announcement "MAC, MAC_STR(from)); /* Must be a configurator, in an initiator role, in PRESENCE state */ if (dpp->state != DPP_STATE_PRESENCE) return; if (dpp->role != DPP_CAPABILITY_CONFIGURATOR) return; if (!dpp->freqs) return; /* * The URI may not have contained a MAC address, if this announcement * verifies set peer_addr then. */ if (!l_memeqzero(dpp->peer_addr, 6) && memcmp(from, dpp->peer_addr, 6)) { l_debug("Unexpected source "MAC" expected "MAC, MAC_STR(from), MAC_STR(dpp->peer_addr)); return; } dpp_attr_iter_init(&iter, body + 8, body_len - 8); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_RESPONDER_BOOT_KEY_HASH: r_boot = data; r_boot_len = len; break; default: break; } } if (!r_boot || r_boot_len != 32) { l_debug("No responder boot hash"); return; } /* Hash what we have for the peer and check its our enrollee */ dpp_hash(L_CHECKSUM_SHA256, hash, 2, "chirp", strlen("chirp"), dpp->peer_asn1, dpp->peer_asn1_len); if (memcmp(hash, r_boot, sizeof(hash))) { l_debug("Peers boot hash did not match"); return; } /* * This is the peer we expected, save away the address and derive the * initial keys. */ memcpy(dpp->peer_addr, from, 6); dpp->state = DPP_STATE_AUTHENTICATING; if (!dpp_send_authenticate_request(dpp)) return; /* * Requested the peer to move to another channel for the remainder of * the protocol. IWD's current logic prohibits a configurator from * running while not connected, so we can assume here that the new * frequency is the same of the connected BSS. Wait until an ACK is * received for the auth request then cancel the offchannel request. */ if (dpp->current_freq != dpp->new_freq) dpp->channel_switch = true; } static void dpp_pkex_bad_group(struct dpp_sm *dpp, uint16_t group) { uint16_t own_group = l_ecc_curve_get_ike_group(dpp->curve); /* * TODO: The spec allows group negotiation, but it is not yet * implemented. */ if (!group) return; /* * Section 5.6.2 * "If the Responder's offered group offers less security * than the Initiator's offered group, then the Initiator should * ignore this message" */ if (group < own_group) { l_debug("Offered group %u is less secure, ignoring", group); return; } /* * Section 5.6.2 * "If the Responder's offered group offers equivalent or better * security than the Initiator's offered group, then the * Initiator may choose to abort its original request and try * another exchange using the group offered by the Responder" */ if (group >= own_group) { l_debug("Offered group %u is the same or more secure, " " but group negotiation is not supported", group); return; } } static void dpp_pkex_bad_code(struct dpp_sm *dpp) { _auto_(l_ecc_point_free) struct l_ecc_point *qr = NULL; qr = dpp_derive_qr(dpp->curve, dpp->pkex_key, dpp->pkex_id, netdev_get_address(dpp->netdev)); if (!qr || l_ecc_point_is_infinity(qr)) { l_debug("Qr computed to zero, new code should be provisioned"); return; } l_debug("Qr computed successfully but responder indicated otherwise"); } static void dpp_handle_pkex_exchange_response(struct dpp_sm *dpp, const uint8_t *from, const uint8_t *body, size_t body_len) { struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; const uint8_t *status = NULL; uint8_t version = 0; const void *identifier = NULL; size_t identifier_len = 0; const void *key = NULL; size_t key_len = 0; uint16_t group = 0; _auto_(l_ecc_point_free) struct l_ecc_point *n = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *j = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *qr = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *k = NULL; const uint8_t *own_addr = netdev_get_address(dpp->netdev); l_debug("PKEX response "MAC, MAC_STR(from)); if (dpp->state != DPP_STATE_PKEX_EXCHANGE) return; if (dpp->role != DPP_CAPABILITY_ENROLLEE) return; memcpy(dpp->peer_addr, from, 6); dpp_attr_iter_init(&iter, body + 8, body_len - 8); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_STATUS: if (len != 1) return; status = data; break; case DPP_ATTR_PROTOCOL_VERSION: if (len != 1) return; version = l_get_u8(data); break; case DPP_ATTR_CODE_IDENTIFIER: identifier = data; identifier_len = len; break; case DPP_ATTR_ENCRYPTED_KEY: if (len != dpp->key_len * 2) return; key = data; key_len = len; break; case DPP_ATTR_FINITE_CYCLIC_GROUP: if (len != 2) return; group = l_get_le16(data); break; default: break; } } if (!status) { l_debug("No status attribute, ignoring"); return; } if (!key) { l_debug("No encrypted key, ignoring"); return; } if (*status != DPP_STATUS_OK) goto handle_status; if (dpp->pkex_id) { if (!identifier || identifier_len != strlen(dpp->pkex_id) || memcmp(dpp->pkex_id, identifier, identifier_len)) { l_debug("mismatch identifier, ignoring"); return; } } if (version && version != dpp->pkex_version) { l_debug("PKEX version does not match, igoring"); return; } n = l_ecc_point_from_data(dpp->curve, L_ECC_POINT_TYPE_FULL, key, key_len); if (!n) { l_debug("failed to parse peers encrypted key"); goto failed; } qr = dpp_derive_qr(dpp->curve, dpp->pkex_key, dpp->pkex_id, dpp->peer_addr); if (!qr) goto failed; dpp->y_or_x = l_ecc_point_new(dpp->curve); /* Y' = N - Qr */ l_ecc_point_inverse(qr); l_ecc_point_add(dpp->y_or_x, n, qr); /* * "The resulting ephemeral key, denoted Y’, is then checked whether it * is the point-at-infinity. If it is not valid, the protocol ends * unsuccessfully" */ if (l_ecc_point_is_infinity(dpp->y_or_x)) { l_debug("Y' computed to infinity, failing"); goto failed; } k = l_ecc_point_new(dpp->curve); /* K = Y' * x */ l_ecc_point_multiply(k, dpp->pkex_private, dpp->y_or_x); dpp_derive_z(own_addr, dpp->peer_addr, n, dpp->pkex_m, k, dpp->pkex_key, dpp->pkex_id, dpp->z, &dpp->z_len); /* J = a * Y' */ j = l_ecc_point_new(dpp->curve); l_ecc_point_multiply(j, dpp->boot_private, dpp->y_or_x); if (!dpp_derive_u(j, own_addr, dpp->boot_public, dpp->y_or_x, dpp->pkex_public, dpp->u, &dpp->u_len)) { l_debug("failed to compute u"); goto failed; } /* * Now that a response was successfully received, start another * offchannel with more time for the remainder of the protocol. After * PKEX, authentication will begin which handles the protocol timeout. * If the remainder of PKEX (commit-reveal exchange) cannot complete in * this time it will fail. */ dpp->dwell = (dpp->max_roc < 2000) ? dpp->max_roc : 2000; dpp->state = DPP_STATE_PKEX_COMMIT_REVEAL; dpp_property_changed_notify(dpp); dpp_start_offchannel(dpp, dpp->current_freq); return; handle_status: switch (*status) { case DPP_STATUS_BAD_GROUP: dpp_pkex_bad_group(dpp, group); break; case DPP_STATUS_BAD_CODE: dpp_pkex_bad_code(dpp); break; default: l_debug("Unhandled status %u", *status); break; } failed: dpp_reset(dpp); } static bool dpp_pkex_start_authentication(struct dpp_sm *dpp) { dpp->uri = dpp_generate_uri(dpp->own_asn1, dpp->own_asn1_len, 2, netdev_get_address(dpp->netdev), &dpp->current_freq, 1, NULL, NULL); l_ecdh_generate_key_pair(dpp->curve, &dpp->proto_private, &dpp->own_proto_public); l_getrandom(dpp->i_nonce, dpp->nonce_len); dpp->peer_asn1 = dpp_point_to_asn1(dpp->peer_boot_public, &dpp->peer_asn1_len); dpp->m = dpp_derive_k1(dpp->peer_boot_public, dpp->proto_private, dpp->k1); dpp_hash(L_CHECKSUM_SHA256, dpp->peer_boot_hash, 1, dpp->peer_asn1, dpp->peer_asn1_len); dpp->state = DPP_STATE_AUTHENTICATING; dpp->mutual_auth = true; dpp_property_changed_notify(dpp); if (dpp->role == DPP_CAPABILITY_ENROLLEE) { dpp->new_freq = dpp->current_freq; return dpp_send_authenticate_request(dpp); } return true; } static void dpp_handle_pkex_commit_reveal_response(struct dpp_sm *dpp, const uint8_t *from, const uint8_t *body, size_t body_len) { struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; const uint8_t *wrapped = NULL; size_t wrapped_len = 0; uint8_t one = 1; _auto_(l_free) uint8_t *unwrapped = NULL; size_t unwrapped_len = 0; const uint8_t *boot_key = NULL; size_t boot_key_len = 0; const uint8_t *r_auth = NULL; uint8_t v[L_ECC_SCALAR_MAX_BYTES]; size_t v_len; _auto_(l_ecc_point_free) struct l_ecc_point *l = NULL; l_debug("PKEX commit reveal "MAC, MAC_STR(from)); if (dpp->state != DPP_STATE_PKEX_COMMIT_REVEAL) return; if (dpp->role != DPP_CAPABILITY_ENROLLEE) return; /* * The URI may not have contained a MAC address, if this announcement * verifies set peer_addr then. */ if (memcmp(from, dpp->peer_addr, 6)) { l_debug("Unexpected source "MAC" expected "MAC, MAC_STR(from), MAC_STR(dpp->peer_addr)); return; } dpp_attr_iter_init(&iter, body + 8, body_len - 8); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_WRAPPED_DATA: wrapped = data; wrapped_len = len; break; default: break; } } if (!wrapped) { l_debug("No wrapped data"); return; } unwrapped = dpp_unwrap_attr(body + 2, 6, &one, 1, dpp->z, dpp->z_len, wrapped, wrapped_len, &unwrapped_len); if (!unwrapped) { l_debug("Failed to unwrap Reveal-Commit message"); return; } dpp_attr_iter_init(&iter, unwrapped, unwrapped_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_BOOTSTRAPPING_KEY: if (len != dpp->key_len * 2) return; boot_key = data; boot_key_len = len; break; case DPP_ATTR_RESPONDER_AUTH_TAG: if (len != 32) return; r_auth = data; break; default: break; } } dpp->peer_boot_public = l_ecc_point_from_data(dpp->curve, L_ECC_POINT_TYPE_FULL, boot_key, boot_key_len); if (!dpp->peer_boot_public) { l_debug("Peer public bootstrapping key was invalid"); goto failed; } /* L = b * X' */ l = l_ecc_point_new(dpp->curve); l_ecc_point_multiply(l, dpp->pkex_private, dpp->peer_boot_public); if (!dpp_derive_v(l, dpp->peer_addr, dpp->peer_boot_public, dpp->pkex_public, dpp->y_or_x, v, &v_len)) { l_debug("Failed to derive v"); goto failed; } if (memcmp(v, r_auth, v_len)) { l_debug("Bootstrapping data did not verify"); goto failed; } if (dpp_pkex_start_authentication(dpp)) return; failed: dpp_reset(dpp); } static void dpp_send_bad_group(struct dpp_sm *dpp, const uint8_t *addr) { uint8_t hdr[32]; uint8_t attrs[256]; uint8_t *ptr = attrs; uint16_t group; uint8_t status = DPP_STATUS_BAD_GROUP; struct iovec iov[2]; const uint8_t *own_mac = netdev_get_address(dpp->netdev); l_put_le16(l_ecc_curve_get_ike_group(dpp->curve), &group); iov[0].iov_len = dpp_build_header(own_mac, addr, DPP_FRAME_PKEX_XCHG_RESPONSE, hdr); iov[0].iov_base = hdr; ptr += dpp_append_attr(ptr, DPP_ATTR_STATUS, &status, 1); ptr += dpp_append_attr(ptr, DPP_ATTR_PROTOCOL_VERSION, &dpp->pkex_version, 1); ptr += dpp_append_attr(ptr, DPP_ATTR_FINITE_CYCLIC_GROUP, &group, 2); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void dpp_send_bad_code(struct dpp_sm *dpp, const uint8_t *addr) { uint8_t hdr[32]; uint8_t attrs[256]; uint8_t *ptr = attrs; uint8_t status = DPP_STATUS_BAD_CODE; struct iovec iov[2]; const uint8_t *own_mac = netdev_get_address(dpp->netdev); iov[0].iov_len = dpp_build_header(own_mac, addr, DPP_FRAME_PKEX_XCHG_RESPONSE, hdr); iov[0].iov_base = hdr; ptr += dpp_append_attr(ptr, DPP_ATTR_STATUS, &status, 1); ptr += dpp_append_attr(ptr, DPP_ATTR_PROTOCOL_VERSION, &dpp->pkex_version, 1); if (dpp->pkex_id) ptr += dpp_append_attr(ptr, DPP_ATTR_CODE_IDENTIFIER, dpp->pkex_id, strlen(dpp->pkex_id)); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void dpp_send_pkex_exchange_response(struct dpp_sm *dpp, struct l_ecc_point *n) { uint8_t hdr[32]; uint8_t attrs[256]; uint8_t *ptr = attrs; uint64_t n_data[L_ECC_MAX_DIGITS * 2]; uint16_t group; uint8_t status = DPP_STATUS_OK; struct iovec iov[2]; const uint8_t *own_mac = netdev_get_address(dpp->netdev); l_put_le16(l_ecc_curve_get_ike_group(dpp->curve), &group); iov[0].iov_len = dpp_build_header(own_mac, dpp->peer_addr, DPP_FRAME_PKEX_XCHG_RESPONSE, hdr); iov[0].iov_base = hdr; ptr += dpp_append_attr(ptr, DPP_ATTR_STATUS, &status, 1); if (dpp->pkex_id) ptr += dpp_append_attr(ptr, DPP_ATTR_CODE_IDENTIFIER, dpp->pkex_id, strlen(dpp->pkex_id)); l_ecc_point_get_data(n, n_data, sizeof(n_data)); ptr += dpp_append_attr(ptr, DPP_ATTR_ENCRYPTED_KEY, n_data, dpp->key_len * 2); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp->state = DPP_STATE_PKEX_COMMIT_REVEAL; dpp_property_changed_notify(dpp); dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void dpp_process_pkex_exchange_request(struct dpp_sm *dpp, struct l_ecc_point *m) { _auto_(l_ecc_point_free) struct l_ecc_point *n = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *qr = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *qi = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *k = NULL; const uint8_t *own_addr = netdev_get_address(dpp->netdev); /* Qi = H(MAC-Initiator | [identifier | ] code) * Pi */ qi = dpp_derive_qi(dpp->curve, dpp->pkex_key, dpp->pkex_id, dpp->peer_addr); if (!qi) { l_debug("could not derive Qi"); return; } /* X' = M - Qi */ dpp->y_or_x = l_ecc_point_new(dpp->curve); l_ecc_point_inverse(qi); l_ecc_point_add(dpp->y_or_x, m, qi); /* * "The resulting ephemeral key, denoted X’, is checked whether it is * the point-at-infinity. If it is not valid, the protocol silently * fails" */ if (l_ecc_point_is_infinity(dpp->y_or_x)) { l_debug("X' is at infinity, ignore message"); dpp_reset(dpp); return; } qr = dpp_derive_qr(dpp->curve, dpp->pkex_key, dpp->pkex_id, own_addr); if (!qr || l_ecc_point_is_infinity(qr)) { l_debug("Qr did not derive"); l_ecc_point_free(dpp->y_or_x); dpp->y_or_x = NULL; goto bad_code; } /* * "The Responder then generates a random ephemeral keypair, y/Y, * encrypts Y with Qr to obtain the result, denoted N." */ l_ecdh_generate_key_pair(dpp->curve, &dpp->pkex_private, &dpp->pkex_public); /* N = Y + Qr */ n = l_ecc_point_new(dpp->curve); l_ecc_point_add(n, dpp->pkex_public, qr); /* K = y * X' */ k = l_ecc_point_new(dpp->curve); l_ecc_point_multiply(k, dpp->pkex_private, dpp->y_or_x); /* z = HKDF(<>, info | M.x | N.x | code, K.x) */ dpp_derive_z(dpp->peer_addr, own_addr, n, m, k, dpp->pkex_key, dpp->pkex_id, dpp->z, &dpp->z_len); dpp_send_pkex_exchange_response(dpp, n); return; bad_code: dpp_send_bad_code(dpp, dpp->peer_addr); return; } static void dpp_pkex_agent_reply(struct l_dbus_message *message, void *user_data) { struct dpp_sm *dpp = user_data; const char *error, *text; const char *code; dpp->agent->pending_id = 0; l_debug("SharedCodeAgent %s path %s replied", dpp->agent->owner, dpp->agent->path); if (l_dbus_message_get_error(message, &error, &text)) { l_error("RequestSharedCode(%s) returned %s(\"%s\")", dpp->pkex_id, error, text); goto reset; } if (!l_dbus_message_get_arguments(message, "s", &code)) { l_debug("Invalid arguments, check SharedCodeAgent!"); goto reset; } dpp->pkex_key = l_strdup(code); dpp_process_pkex_exchange_request(dpp, dpp->peer_encr_key); return; reset: dpp_free_pending_pkex_data(dpp); } static bool dpp_pkex_agent_request(struct dpp_sm *dpp) { struct l_dbus_message *msg; if (!dpp->agent) return false; if (L_WARN_ON(dpp->agent->pending_id)) return false; msg = l_dbus_message_new_method_call(dbus_get_bus(), dpp->agent->owner, dpp->agent->path, IWD_SHARED_CODE_AGENT_INTERFACE, "RequestSharedCode"); l_dbus_message_set_arguments(msg, "s", dpp->pkex_id); dpp->agent->pending_id = l_dbus_send_with_reply(dbus_get_bus(), msg, dpp_pkex_agent_reply, dpp, NULL); return dpp->agent->pending_id != 0; } static void dpp_handle_pkex_exchange_request(struct dpp_sm *dpp, const uint8_t *from, const uint8_t *body, size_t body_len) { struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; uint8_t version = 0; uint16_t group = 0; const void *id = NULL; size_t id_len = 0; const void *key = NULL; size_t key_len = 0; _auto_(l_ecc_point_free) struct l_ecc_point *m = NULL; l_debug("PKEX exchange request "MAC, MAC_STR(from)); if (dpp->state != DPP_STATE_PKEX_EXCHANGE) return; if (dpp->role != DPP_CAPABILITY_CONFIGURATOR) return; if (!l_memeqzero(dpp->peer_addr, 6)) { l_debug("Already configuring enrollee, ignoring"); return; } dpp_attr_iter_init(&iter, body + 8, body_len - 8); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_PROTOCOL_VERSION: if (len != 1) return; version = l_get_u8(data); break; case DPP_ATTR_FINITE_CYCLIC_GROUP: if (len != 2) return; group = l_get_le16(data); break; case DPP_ATTR_CODE_IDENTIFIER: id = data; id_len = len; break; case DPP_ATTR_ENCRYPTED_KEY: key = data; key_len = len; break; default: break; } } if (!key || !group) { l_debug("initiator did not provide group or key, ignoring"); return; } if (group != l_ecc_curve_get_ike_group(dpp->curve)) { l_debug("initiator is not using the same group"); goto bad_group; } /* * If the group isn't the same the key length won't match, so check * this here after we've determined the groups are equal */ if (key_len != dpp->key_len * 2) { l_debug("Unexpected encrypted key length"); return; } if (version && version != dpp->pkex_version) { l_debug("initiator is not using the same version, ignoring"); return; } if (dpp->pkex_id) { if (!id || id_len != strlen(dpp->pkex_id) || memcmp(dpp->pkex_id, id, id_len)) { l_debug("mismatch identifier, ignoring"); return; } } m = l_ecc_point_from_data(dpp->curve, L_ECC_POINT_TYPE_FULL, key, key_len); if (!m) { l_debug("could not parse key from initiator, ignoring"); return; } memcpy(dpp->peer_addr, from, 6); if (!dpp->pkex_key) { /* * "If an optional code identifier is used, it shall be a UTF-8 * string not greater than eighty (80) octets" */ if (!id || id_len > 80 || !l_utf8_validate(id, id_len, NULL)) { l_debug("Configurator started with agent but enrollee " "sent invalid or no identifier, ignoring"); return; } dpp->pkex_id = l_strndup(id, id_len); /* Need to obtain code from agent */ if (!dpp_pkex_agent_request(dpp)) { l_debug("Failed to request code from agent!"); dpp_free_pending_pkex_data(dpp); return; } /* Save the encrypted key/identifier for the agent callback */ dpp->peer_encr_key = l_steal_ptr(m); return; } dpp_process_pkex_exchange_request(dpp, m); return; bad_group: dpp_send_bad_group(dpp, from); } static void dpp_send_commit_reveal_response(struct dpp_sm *dpp, const uint8_t *v, size_t v_len) { uint8_t hdr[32]; uint8_t attrs[256]; uint8_t *ptr = attrs; uint8_t one = 1; struct iovec iov[2]; const uint8_t *own_mac = netdev_get_address(dpp->netdev); uint8_t b_pub[L_ECC_POINT_MAX_BYTES]; size_t b_len; b_len = l_ecc_point_get_data(dpp->boot_public, b_pub, sizeof(b_pub)); iov[0].iov_len = dpp_build_header(own_mac, dpp->peer_addr, DPP_FRAME_PKEX_COMMIT_REVEAL_RESPONSE, hdr); iov[0].iov_base = hdr; ptr += dpp_append_wrapped_data(hdr + 26, 6, &one, 1, ptr, sizeof(attrs), dpp->z, dpp->z_len, 2, DPP_ATTR_BOOTSTRAPPING_KEY, b_len, b_pub, DPP_ATTR_RESPONDER_AUTH_TAG, v_len, v); iov[1].iov_base = attrs; iov[1].iov_len = ptr - attrs; dpp_send_frame(dpp, iov, 2, dpp->current_freq); } static void dpp_handle_pkex_commit_reveal_request(struct dpp_sm *dpp, const uint8_t *from, const uint8_t *body, size_t body_len) { struct dpp_attr_iter iter; enum dpp_attribute_type type; size_t len; const uint8_t *data; const void *wrapped = NULL; size_t wrapped_len = 0; _auto_(l_free) uint8_t *unwrapped = NULL; size_t unwrapped_len; uint8_t zero = 0; const void *key = 0; size_t key_len = 0; const void *i_auth = NULL; size_t i_auth_len = 0; _auto_(l_ecc_point_free) struct l_ecc_point *j = NULL; _auto_(l_ecc_point_free) struct l_ecc_point *l = NULL; uint8_t u[L_ECC_SCALAR_MAX_BYTES]; size_t u_len = 0; uint8_t v[L_ECC_SCALAR_MAX_BYTES]; size_t v_len = 0; const uint8_t *own_addr = netdev_get_address(dpp->netdev); l_debug("PKEX commit-reveal request "MAC, MAC_STR(from)); if (dpp->state != DPP_STATE_PKEX_COMMIT_REVEAL) return; if (dpp->role != DPP_CAPABILITY_CONFIGURATOR) return; dpp_attr_iter_init(&iter, body + 8, body_len - 8); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_WRAPPED_DATA: wrapped = data; wrapped_len = len; break; default: break; } } if (!wrapped) { l_debug("No wrapped data"); return; } unwrapped = dpp_unwrap_attr(body + 2, 6, &zero, 1, dpp->z, dpp->z_len, wrapped, wrapped_len, &unwrapped_len); if (!unwrapped) { l_debug("Failed to unwrap attributes"); return; } dpp_attr_iter_init(&iter, unwrapped, unwrapped_len); while (dpp_attr_iter_next(&iter, &type, &len, &data)) { switch (type) { case DPP_ATTR_BOOTSTRAPPING_KEY: if (len != dpp->key_len * 2) return; key = data; key_len = len; break; case DPP_ATTR_INITIATOR_AUTH_TAG: if (len != 32) return; i_auth = data; i_auth_len = len; break; default: break; } } if (!key || !i_auth) { l_debug("missing attributes"); return; } dpp->peer_boot_public = l_ecc_point_from_data(dpp->curve, L_ECC_POINT_TYPE_FULL, key, key_len); if (!dpp->peer_boot_public) { l_debug("peers boostrapping key did not validate"); goto failed; } /* J' = y * A' */ j = l_ecc_point_new(dpp->curve); l_ecc_point_multiply(j, dpp->pkex_private, dpp->peer_boot_public); dpp_derive_u(j, dpp->peer_addr, dpp->peer_boot_public, dpp->pkex_public, dpp->y_or_x, u, &u_len); if (memcmp(u, i_auth, i_auth_len)) { l_debug("Initiator auth tag did not verify"); goto failed; } /* L' = x * B' */ l = l_ecc_point_new(dpp->curve); l_ecc_point_multiply(l, dpp->boot_private, dpp->y_or_x); if (!dpp_derive_v(l, own_addr, dpp->boot_public, dpp->y_or_x, dpp->pkex_public, v, &v_len)) { l_debug("Failed to derive v"); goto failed; } dpp_send_commit_reveal_response(dpp, v, v_len); dpp_pkex_start_authentication(dpp); return; failed: dpp_reset(dpp); } static void dpp_handle_frame(struct dpp_sm *dpp, const struct mmpdu_header *frame, const void *body, size_t body_len) { const uint8_t *ptr; /* * Both handlers offset by 8 bytes to reach the beginning of the DPP * attributes. Easier checking this in one place, which also covers the * frame type byte. */ if (body_len < 8) return; ptr = body + 7; switch (*ptr) { case DPP_FRAME_AUTHENTICATION_REQUEST: authenticate_request(dpp, frame->address_2, body, body_len); break; case DPP_FRAME_AUTHENTICATION_RESPONSE: authenticate_response(dpp, frame->address_2, body, body_len); break; case DPP_FRAME_AUTHENTICATION_CONFIRM: authenticate_confirm(dpp, frame->address_2, body, body_len); break; case DPP_FRAME_CONFIGURATION_RESULT: dpp_handle_config_result_frame(dpp, frame->address_2, body, body_len); break; case DPP_FRAME_PRESENCE_ANNOUNCEMENT: dpp_handle_presence_announcement(dpp, frame->address_2, body, body_len); break; case DPP_FRAME_PKEX_XCHG_RESPONSE: dpp_handle_pkex_exchange_response(dpp, frame->address_2, body, body_len); break; case DPP_FRAME_PKEX_COMMIT_REVEAL_RESPONSE: dpp_handle_pkex_commit_reveal_response(dpp, frame->address_2, body, body_len); break; case DPP_FRAME_PKEX_VERSION1_XCHG_REQUEST: dpp_handle_pkex_exchange_request(dpp, frame->address_2, body, body_len); break; case DPP_FRAME_PKEX_COMMIT_REVEAL_REQUEST: dpp_handle_pkex_commit_reveal_request(dpp, frame->address_2, body, body_len); break; default: l_debug("Unhandled DPP frame %u", *ptr); break; } } static bool match_wdev(const void *a, const void *b) { const struct dpp_sm *dpp = a; const uint64_t *wdev_id = b; return *wdev_id == dpp->wdev_id; } static void dpp_frame_timeout(struct l_timeout *timeout, void *user_data) { struct dpp_sm *dpp = user_data; l_timeout_remove(timeout); dpp->retry_timeout = NULL; /* * ROC has not yet started (in between an ROC timeout and starting a * new session), this will most likely result in the frame failing to * send. Just bail out now and the roc_started callback will take care * of sending this out. */ if (dpp->offchannel_id && !dpp->roc_started) return; dpp_frame_retry(dpp); } static void dpp_mlme_notify(struct l_genl_msg *msg, void *user_data) { struct dpp_sm *dpp; uint64_t wdev_id = 0; uint64_t cookie = 0; bool ack = false; struct iovec iov; uint8_t cmd = l_genl_msg_get_command(msg); if (cmd != NL80211_CMD_FRAME_TX_STATUS) return; if (nl80211_parse_attrs(msg, NL80211_ATTR_WDEV, &wdev_id, NL80211_ATTR_COOKIE, &cookie, NL80211_ATTR_ACK, &ack, NL80211_ATTR_FRAME, &iov, NL80211_ATTR_UNSPEC) < 0) return; dpp = l_queue_find(dpp_list, match_wdev, &wdev_id); if (!dpp) return; /* * Don't retransmit for presence or PKEX exchange if an enrollee, both * are broadcast frames which don't expect an ack. */ if (dpp->state == DPP_STATE_NOTHING || dpp->state == DPP_STATE_PRESENCE || (dpp->state == DPP_STATE_PKEX_EXCHANGE && dpp->role == DPP_CAPABILITY_ENROLLEE)) return; if (dpp->frame_cookie != cookie) return; /* * Only want to handle the no-ACK case. Re-transmitting an ACKed * frame likely wont do any good, at least in the case of DPP. */ if (!ack) goto retransmit; /* * Special handling for a channel transition when acting as a * configurator. The auth request was sent offchannel so we need to * wait for the ACK before going back to the connected channel. */ if (dpp->channel_switch) { if (dpp->offchannel_id) { offchannel_cancel(dpp->wdev_id, dpp->offchannel_id); dpp->offchannel_id = 0; } dpp->channel_switch = false; } return; retransmit: if (dpp->frame_retry > DPP_FRAME_MAX_RETRIES) { dpp_reset(dpp); return; } /* This should never happen */ if (L_WARN_ON(dpp->frame_pending)) return; l_debug("No ACK from peer, re-transmitting in %us", DPP_FRAME_RETRY_TIMEOUT); dpp->frame_retry++; dpp->frame_pending = l_memdup(iov.iov_base, iov.iov_len); dpp->frame_size = iov.iov_len; dpp->retry_timeout = l_timeout_create(DPP_FRAME_RETRY_TIMEOUT, dpp_frame_timeout, dpp, NULL); } static void dpp_unicast_notify(struct l_genl_msg *msg, void *user_data) { struct dpp_sm *dpp; const uint64_t *wdev_id = NULL; struct l_genl_attr attr; uint16_t type, len, frame_len; const void *data; const struct mmpdu_header *mpdu = NULL; const uint8_t *body; size_t body_len; if (l_genl_msg_get_command(msg) != NL80211_CMD_FRAME) return; if (!l_genl_attr_init(&attr, msg)) return; while (l_genl_attr_next(&attr, &type, &len, &data)) { switch (type) { case NL80211_ATTR_WDEV: if (len != 8) break; wdev_id = data; break; case NL80211_ATTR_FRAME: mpdu = mpdu_validate(data, len); if (!mpdu) { l_warn("Frame didn't validate as MMPDU"); return; } frame_len = len; break; } } if (!wdev_id) { l_warn("Bad wdev attribute"); return; } dpp = l_queue_find(dpp_list, match_wdev, wdev_id); if (!dpp) return; if (!mpdu) { l_warn("Missing frame data"); return; } body = mmpdu_body(mpdu); body_len = (const uint8_t *) mpdu + frame_len - body; if (body_len < sizeof(dpp_prefix) || memcmp(body, dpp_prefix, sizeof(dpp_prefix)) != 0) return; dpp_handle_frame(dpp, mpdu, body, body_len); } static void dpp_frame_watch_cb(struct l_genl_msg *msg, void *user_data) { if (l_genl_msg_get_error(msg) < 0) l_error("Could not register frame watch type %04x: %i", L_PTR_TO_UINT(user_data), l_genl_msg_get_error(msg)); } /* * Special case the frame watch which includes the presence frames since they * require multicast support. This is only supported by ath9k, so adding * general support to frame-xchg isn't desireable. */ static void dpp_frame_watch(struct dpp_sm *dpp, uint16_t frame_type, const uint8_t *prefix, size_t prefix_len) { struct l_genl_msg *msg; msg = l_genl_msg_new_sized(NL80211_CMD_REGISTER_FRAME, 32 + prefix_len); l_genl_msg_append_attr(msg, NL80211_ATTR_WDEV, 8, &dpp->wdev_id); l_genl_msg_append_attr(msg, NL80211_ATTR_FRAME_TYPE, 2, &frame_type); l_genl_msg_append_attr(msg, NL80211_ATTR_FRAME_MATCH, prefix_len, prefix); if (dpp->mcast_support) l_genl_msg_append_attr(msg, NL80211_ATTR_RECEIVE_MULTICAST, 0, NULL); l_genl_family_send(nl80211, msg, dpp_frame_watch_cb, L_UINT_TO_PTR(frame_type), NULL); } static void dpp_start_enrollee(struct dpp_sm *dpp); static bool dpp_start_pkex_enrollee(struct dpp_sm *dpp); /* * Station is unaware of DPP's state so we need to handle a few cases here so * weird stuff doesn't happen: * * - While configuring we should stay connected, a disconnection/roam should * stop DPP since it would fail regardless due to the hardware going idle * or changing channels since configurators assume all comms will be * on-channel. * - While enrolling we should stay disconnected. If station connects during * enrolling it would cause 2x calls to __station_connect_network after * DPP finishes. * * Other conditions shouldn't ever happen i.e. configuring and going into a * connecting state or enrolling and going to a roaming state. */ static void dpp_station_state_watch(enum station_state state, void *user_data) { struct dpp_sm *dpp = user_data; if (dpp->state == DPP_STATE_NOTHING || dpp->interface == DPP_INTERFACE_UNBOUND) return; switch (state) { case STATION_STATE_DISCONNECTED: /* DPP-initiated disconnect, the enrollee can now start */ if (dpp->role == DPP_CAPABILITY_ENROLLEE) { l_debug("Starting enrollee after disconnect"); if (dpp->interface == DPP_INTERFACE_DPP) dpp_start_enrollee(dpp); else dpp_start_pkex_enrollee(dpp); return; } break; case STATION_STATE_DISCONNECTING: /* Normal part of disconnecting prior to enrolling */ if (dpp->role == DPP_CAPABILITY_ENROLLEE) return; /* fall through */ case STATION_STATE_ROAMING: case STATION_STATE_FT_ROAMING: case STATION_STATE_FW_ROAMING: /* * An enrollee will always be disconnected prior to starting * so a roaming condition should never happen. */ if (L_WARN_ON(dpp->role == DPP_CAPABILITY_ENROLLEE)) goto reset; if (dpp->role == DPP_CAPABILITY_CONFIGURATOR) { l_debug("Disconnected while configuring, stopping DPP"); goto reset; } break; case STATION_STATE_CONNECTING: case STATION_STATE_CONNECTED: case STATION_STATE_CONNECTING_AUTO: case STATION_STATE_NETCONFIG: case STATION_STATE_AUTOCONNECT_FULL: case STATION_STATE_AUTOCONNECT_QUICK: /* * The user could have issued a connection request during * enrolling, in which case DPP should be canceled. We should * never hit this case as a configurator as a disconnect would * need to come prior. */ L_WARN_ON(dpp->role == DPP_CAPABILITY_CONFIGURATOR); goto reset; } reset: l_debug("Resetting DPP after station state change (state=%u)", state); dpp_reset(dpp); } static void dpp_create(struct netdev *netdev) { struct l_dbus *dbus = dbus_get_bus(); struct dpp_sm *dpp = l_new(struct dpp_sm, 1); uint8_t dpp_conf_response_prefix[] = { 0x04, 0x0b }; uint8_t dpp_conf_request_prefix[] = { 0x04, 0x0a }; uint64_t wdev_id = netdev_get_wdev_id(netdev); dpp->netdev = netdev; dpp->state = DPP_STATE_NOTHING; dpp->interface = DPP_INTERFACE_UNBOUND; dpp->wdev_id = wdev_id; dpp->curve = l_ecc_curve_from_ike_group(19); dpp->key_len = l_ecc_curve_get_scalar_bytes(dpp->curve); dpp->nonce_len = dpp_nonce_len_from_key_len(dpp->key_len); dpp->max_roc = wiphy_get_max_roc_duration(wiphy_find_by_wdev(wdev_id)); dpp->mcast_support = wiphy_has_ext_feature( wiphy_find_by_wdev(dpp->wdev_id), NL80211_EXT_FEATURE_MULTICAST_REGISTRATIONS); l_ecdh_generate_key_pair(dpp->curve, &dpp->boot_private, &dpp->boot_public); dpp->own_asn1 = dpp_point_to_asn1(dpp->boot_public, &dpp->own_asn1_len); dpp_hash(L_CHECKSUM_SHA256, dpp->own_boot_hash, 1, dpp->own_asn1, dpp->own_asn1_len); l_dbus_object_add_interface(dbus, netdev_get_path(netdev), IWD_DPP_INTERFACE, dpp); l_dbus_object_add_interface(dbus, netdev_get_path(netdev), IWD_DPP_PKEX_INTERFACE, dpp); /* * Since both interfaces share the dpp_sm set this to 2. Currently both * interfaces are added/removed in unison so we _could_ simply omit the * destroy callback on one of them. But for consistency and future * proofing use a reference count and the final interface being removed * will destroy the dpp_sm. */ dpp->refcount = 2; dpp_frame_watch(dpp, 0x00d0, dpp_prefix, sizeof(dpp_prefix)); frame_watch_add(netdev_get_wdev_id(netdev), 0, 0x00d0, dpp_conf_response_prefix, sizeof(dpp_conf_response_prefix), dpp_handle_config_response_frame, dpp, NULL); frame_watch_add(netdev_get_wdev_id(netdev), 0, 0x00d0, dpp_conf_request_prefix, sizeof(dpp_conf_request_prefix), dpp_handle_config_request_frame, dpp, NULL); dpp->known_network_watch = known_networks_watch_add( dpp_known_network_watch, dpp, NULL); l_queue_push_tail(dpp_list, dpp); } static void dpp_netdev_watch(struct netdev *netdev, enum netdev_watch_event event, void *userdata) { switch (event) { case NETDEV_WATCH_EVENT_NEW: case NETDEV_WATCH_EVENT_UP: if (netdev_get_iftype(netdev) == NETDEV_IFTYPE_STATION && netdev_get_is_up(netdev)) dpp_create(netdev); break; case NETDEV_WATCH_EVENT_DEL: case NETDEV_WATCH_EVENT_DOWN: l_dbus_object_remove_interface(dbus_get_bus(), netdev_get_path(netdev), IWD_DPP_INTERFACE); l_dbus_object_remove_interface(dbus_get_bus(), netdev_get_path(netdev), IWD_DPP_PKEX_INTERFACE); break; default: break; } } /* * EasyConnect 2.0 - 6.2.2 */ static uint32_t *dpp_add_default_channels(struct dpp_sm *dpp, size_t *len_out) { struct wiphy *wiphy = wiphy_find_by_wdev( netdev_get_wdev_id(dpp->netdev)); const struct scan_freq_set *list = wiphy_get_supported_freqs(wiphy); uint32_t freq; if (!dpp->presence_list) dpp->presence_list = scan_freq_set_new(); scan_freq_set_add(dpp->presence_list, band_channel_to_freq(6, BAND_FREQ_2_4_GHZ)); /* * "5 GHz: Channel 44 (5.220 GHz) if local regulations permit operation * only in the 5.150 - 5.250 GHz band and Channel 149 (5.745 GHz) * otherwise" */ freq = band_channel_to_freq(149, BAND_FREQ_5_GHZ); if (scan_freq_set_contains(list, freq)) scan_freq_set_add(dpp->presence_list, freq); else scan_freq_set_add(dpp->presence_list, band_channel_to_freq(44, BAND_FREQ_5_GHZ)); /* TODO: 60GHz: Channel 2 */ return scan_freq_set_to_fixed_array(dpp->presence_list, len_out); } /* * TODO: There is an entire procedure defined in the spec where you increase * the ROC timeout with each unsuccessful iteration of channels, wait on channel * for long periods of time etc. Due to offchannel issues in the kernel this * procedure is not being fully implemented. In reality doing this would result * in quite terrible DPP performance anyways. */ static void dpp_start_presence(struct dpp_sm *dpp, uint32_t *limit_freqs, size_t limit_len) { if (limit_freqs) { dpp->freqs = l_memdup(limit_freqs, sizeof(uint32_t) * limit_len); dpp->freqs_len = limit_len; } else dpp->freqs = dpp_add_default_channels(dpp, &dpp->freqs_len); dpp->dwell = (dpp->max_roc < 2000) ? dpp->max_roc : 2000; dpp->freqs_idx = 0; dpp->current_freq = dpp->freqs[0]; dpp_start_offchannel(dpp, dpp->current_freq); } static int dpp_try_disconnect_station(struct dpp_sm *dpp, bool *out_disconnect_started) { struct station *station = station_find(netdev_get_ifindex(dpp->netdev)); int ret; bool started = false; /* Unusual case, but an enrollee could still be started */ if (!station) goto done; dpp->autoconnect = station_get_autoconnect(station); station_set_autoconnect(station, false); switch (station_get_state(station)) { case STATION_STATE_AUTOCONNECT_QUICK: case STATION_STATE_AUTOCONNECT_FULL: /* Should never happen since we just set autoconnect false */ l_warn("Still in autoconnect state after setting false!"); /* fall through */ case STATION_STATE_DISCONNECTED: break; case STATION_STATE_ROAMING: case STATION_STATE_FT_ROAMING: case STATION_STATE_FW_ROAMING: case STATION_STATE_CONNECTING: case STATION_STATE_CONNECTING_AUTO: case STATION_STATE_CONNECTED: case STATION_STATE_NETCONFIG: /* * For any connected or connection in progress state, start a * disconnect */ ret = station_disconnect(station); if (ret < 0) { l_warn("failed to start disconnecting (%d)", ret); station_set_autoconnect(station, dpp->autoconnect); return ret; } /* fall through */ case STATION_STATE_DISCONNECTING: l_debug("Delaying DPP start until after disconnect"); started = true; break; } dpp->station_watch = station_add_state_watch(station, dpp_station_state_watch, dpp, NULL); done: *out_disconnect_started = started; return 0; } static void dpp_start_enrollee(struct dpp_sm *dpp) { uint32_t freq = band_channel_to_freq(6, BAND_FREQ_2_4_GHZ); dpp->uri = dpp_generate_uri(dpp->own_asn1, dpp->own_asn1_len, 2, netdev_get_address(dpp->netdev), &freq, 1, NULL, NULL); l_ecdh_generate_key_pair(dpp->curve, &dpp->proto_private, &dpp->own_proto_public); l_debug("DPP Start Enrollee: %s", dpp->uri); /* * Going off spec here. Select a single channel to send presence * announcements on. This will be advertised in the URI. The full * presence procedure can be implemented if it is ever needed. */ dpp_start_presence(dpp, &freq, 1); dpp_property_changed_notify(dpp); } static struct l_dbus_message *dpp_dbus_start_enrollee(struct l_dbus *dbus, struct l_dbus_message *message, void *user_data) { struct dpp_sm *dpp = user_data; bool wait_for_disconnect; int ret; if (dpp->state != DPP_STATE_NOTHING || dpp->interface != DPP_INTERFACE_UNBOUND) return dbus_error_busy(message); dpp->state = DPP_STATE_PRESENCE; dpp->role = DPP_CAPABILITY_ENROLLEE; dpp->interface = DPP_INTERFACE_DPP; ret = dpp_try_disconnect_station(dpp, &wait_for_disconnect); if (ret < 0) { dpp_reset(dpp); return dbus_error_from_errno(ret, message); } if (!wait_for_disconnect) dpp_start_enrollee(dpp); /* * If a disconnect was started/in progress the enrollee will start once * that has finished */ dpp->pending = l_dbus_message_ref(message); return NULL; } /* * Set up the configurator for an initiator role. The configurator * will go offchannel to frequencies advertised by the enrollees URI or, * if no channels are provided, use a default channel list. */ static bool dpp_configurator_start_presence(struct dpp_sm *dpp, const char *uri) { _auto_(l_free) uint32_t *freqs = NULL; size_t freqs_len = 0; struct dpp_uri_info *info; info = dpp_parse_uri(uri); if (!info) return false; /* * Very few drivers actually support registration of multicast frames. * This renders the presence procedure impossible on most drivers. * But not all is lost. If the URI contains the MAC and channel * info we an start going through channels sending auth requests which * is basically DPP 1.0. Otherwise DPP cannot start. */ if (!dpp->mcast_support && (l_memeqzero(info->mac, 6) || !info->freqs)) { l_error("No multicast registration support, URI must contain " "MAC and channel information"); dpp_free_uri_info(info); return false; } if (!l_memeqzero(info->mac, 6)) memcpy(dpp->peer_addr, info->mac, 6); if (info->freqs) freqs = scan_freq_set_to_fixed_array(info->freqs, &freqs_len); dpp->peer_boot_public = l_ecc_point_clone(info->boot_public); dpp->peer_asn1 = dpp_point_to_asn1(info->boot_public, &dpp->peer_asn1_len); dpp_free_uri_info(info); if (!dpp->peer_asn1) { l_debug("Peer boot key did not convert to asn1"); return false; } dpp_hash(L_CHECKSUM_SHA256, dpp->peer_boot_hash, 1, dpp->peer_asn1, dpp->peer_asn1_len); dpp_start_presence(dpp, freqs, freqs_len); return true; } static struct l_dbus_message *dpp_start_configurator_common( struct l_dbus *dbus, struct l_dbus_message *message, void *user_data, bool responder) { struct dpp_sm *dpp = user_data; struct l_dbus_message *reply; struct station *station = station_find(netdev_get_ifindex(dpp->netdev)); struct scan_bss *bss; struct network *network; struct l_settings *settings; struct handshake_state *hs = netdev_get_handshake(dpp->netdev); const char *uri; /* * For now limit the configurator to only configuring enrollees to the * currently connected network. */ if (!station) return dbus_error_not_available(message); bss = station_get_connected_bss(station); network = station_get_connected_network(station); if (!bss || !network) return dbus_error_not_connected(message); settings = network_get_settings(network); if (!settings) return dbus_error_not_configured(message); if (network_get_security(network) != SECURITY_PSK) return dbus_error_not_supported(message); if (dpp->state != DPP_STATE_NOTHING || dpp->interface != DPP_INTERFACE_UNBOUND) return dbus_error_busy(message); l_ecdh_generate_key_pair(dpp->curve, &dpp->proto_private, &dpp->own_proto_public); dpp->state = DPP_STATE_PRESENCE; if (!responder) { if (!l_dbus_message_get_arguments(message, "s", &uri)) return dbus_error_invalid_args(message); if (!dpp_configurator_start_presence(dpp, uri)) return dbus_error_invalid_args(message); /* Since we have the peer's URI generate the keys now */ l_getrandom(dpp->i_nonce, dpp->nonce_len); dpp->m = dpp_derive_k1(dpp->peer_boot_public, dpp->proto_private, dpp->k1); if (!dpp->mcast_support) dpp->state = DPP_STATE_AUTHENTICATING; dpp->new_freq = bss->frequency; } else dpp->current_freq = bss->frequency; dpp->uri = dpp_generate_uri(dpp->own_asn1, dpp->own_asn1_len, 2, netdev_get_address(dpp->netdev), &bss->frequency, 1, NULL, NULL); dpp->role = DPP_CAPABILITY_CONFIGURATOR; dpp->interface = DPP_INTERFACE_DPP; dpp->config = dpp_configuration_new(settings, network_get_ssid(network), hs->akm_suite); dpp_property_changed_notify(dpp); dpp->station_watch = station_add_state_watch(station, dpp_station_state_watch, dpp, NULL); l_debug("DPP Start Configurator: %s", dpp->uri); reply = l_dbus_message_new_method_return(message); l_dbus_message_set_arguments(reply, "s", dpp->uri); return reply; } static struct l_dbus_message *dpp_dbus_start_configurator(struct l_dbus *dbus, struct l_dbus_message *message, void *user_data) { return dpp_start_configurator_common(dbus, message, user_data, true); } static struct l_dbus_message *dpp_dbus_configure_enrollee(struct l_dbus *dbus, struct l_dbus_message *message, void *user_data) { return dpp_start_configurator_common(dbus, message, user_data, false); } static struct l_dbus_message *dpp_dbus_stop(struct l_dbus *dbus, struct l_dbus_message *message, void *user_data) { struct dpp_sm *dpp = user_data; l_debug(""); if (dpp->interface != DPP_INTERFACE_DPP) return dbus_error_not_found(message); dpp_reset(dpp); return l_dbus_message_new_method_return(message); } static void dpp_pkex_scan_trigger(int err, void *user_data) { struct dpp_sm *dpp = user_data; if (err < 0) dpp_reset(dpp); } /* * Section 5.6.1 * In lieu of specific channel information obtained in a manner outside * the scope of this specification, PKEX responders shall select one of * the following channels: * - 2.4 GHz: Channel 6 (2.437 GHz) * - 5 GHz: Channel 44 (5.220 GHz) if local regulations permit * operation only in the 5.150 - 5.250 GHz band and Channel * 149 (5.745 GHz) otherwise */ static uint32_t *dpp_default_freqs(struct dpp_sm *dpp, size_t *out_len) { struct wiphy *wiphy = wiphy_find_by_wdev(dpp->wdev_id); uint32_t default_channels[3] = { 2437, 5220, 5745 }; uint32_t *freqs_out; size_t len = 0; if ((wiphy_get_supported_bands(wiphy) & BAND_FREQ_2_4_GHZ) && scan_get_band_rank_modifier(BAND_FREQ_2_4_GHZ) != 0) default_channels[len++] = 2437; if ((wiphy_get_supported_bands(wiphy) & BAND_FREQ_5_GHZ) && scan_get_band_rank_modifier(BAND_FREQ_5_GHZ) != 0) { default_channels[len++] = 5220; default_channels[len++] = 5745; } if (!len) { l_warn("No bands are allowed, check BandModifier* settings!"); return NULL; } freqs_out = l_memdup(default_channels, sizeof(uint32_t) * len); *out_len = len; return freqs_out; } static void __dpp_pkex_start_enrollee(struct dpp_sm *dpp) { dpp->current_freq = dpp->freqs[0]; dpp_reset_protocol_timer(dpp, dpp->freqs_len * DPP_PKEX_PROTO_PER_FREQ_TIMEOUT); l_debug("PKEX start enrollee (id=%s)", dpp->pkex_id ?: "unset"); dpp_start_offchannel(dpp, dpp->current_freq); } static bool dpp_pkex_scan_notify(int err, struct l_queue *bss_list, const struct scan_freq_set *freqs, void *user_data) { struct dpp_sm *dpp = user_data; const struct l_queue_entry *e; _auto_(scan_freq_set_free) struct scan_freq_set *freq_set = NULL; if (err < 0) goto failed; freq_set = scan_freq_set_new(); if (!bss_list || l_queue_isempty(bss_list)) { dpp->freqs = dpp_default_freqs(dpp, &dpp->freqs_len); if (!dpp->freqs) goto failed; l_debug("No BSS's seen, using default frequency list"); goto start; } for (e = l_queue_get_entries(bss_list); e; e = e->next) { const struct scan_bss *bss = e->data; scan_freq_set_add(freq_set, bss->frequency); } l_debug("Found %u frequencies to search for configurator", l_queue_length(bss_list)); dpp->freqs = scan_freq_set_to_fixed_array(freq_set, &dpp->freqs_len); start: __dpp_pkex_start_enrollee(dpp); return false; failed: dpp_reset(dpp); return false; } static void dpp_pkex_scan_destroy(void *user_data) { struct dpp_sm *dpp = user_data; dpp->pkex_scan_id = 0; } static bool dpp_start_pkex_enrollee(struct dpp_sm *dpp) { dpp_property_changed_notify(dpp); /* Already have a set (or single) frequency */ if (dpp->freqs) { __dpp_pkex_start_enrollee(dpp); return true; } /* * The 'dpp_default_freqs' function returns the default frequencies * outlined in section 5.6.1. For 2.4/5GHz this is only 3 frequencies * which is unlikely to result in discovery of a configurator. The spec * does allow frequencies to be "obtained in a manner outside the scope * of this specification" which is what is being done here. * * This is mainly geared towards IWD-based configurators; banking on the * fact that they are currently connected to nearby APs. Scanning lets * us see nearby BSS's which should be the same frequencies as our * target configurator. */ l_debug("Performing scan for frequencies to start PKEX"); dpp->pkex_scan_id = scan_active(dpp->wdev_id, NULL, 0, dpp_pkex_scan_trigger, dpp_pkex_scan_notify, dpp, dpp_pkex_scan_destroy); if (!dpp->pkex_scan_id) goto failed; return true; failed: dpp_reset(dpp); return false; } static bool dpp_parse_pkex_args(struct l_dbus_message *message, const char **key_out, const char **id_out, const char **mac_out, uint32_t *freq_out) { struct l_dbus_message_iter iter; struct l_dbus_message_iter variant; const char *dict_key; const char *key = NULL; const char *id = NULL; const char *mac = NULL; uint32_t freq = 0; if (!l_dbus_message_get_arguments(message, "a{sv}", &iter)) return false; while (l_dbus_message_iter_next_entry(&iter, &dict_key, &variant)) { if (!strcmp(dict_key, "Code")) { if (!l_dbus_message_iter_get_variant(&variant, "s", &key)) return false; } else if (!strcmp(dict_key, "Identifier")) { if (!l_dbus_message_iter_get_variant(&variant, "s", &id)) return false; } else if (!strcmp(dict_key, "Address")) { if (!l_dbus_message_iter_get_variant(&variant, "s", &mac)) return false; } else if (!strcmp(dict_key, "Frequency")) { if (!l_dbus_message_iter_get_variant(&variant, "u", &freq)) return false; } } if (!key) return false; if (id && strlen(id) > 80) return false; *key_out = key; *id_out = id; if (mac_out) *mac_out = mac; if (freq_out) *freq_out = freq; return true; } static bool dpp_pkex_derive_keys(struct dpp_sm *dpp) { _auto_(l_ecc_point_free) struct l_ecc_point *qi = NULL; /* * In theory a driver could support a lesser duration than 200ms. This * complicates things since we would need to tack on additional * offchannel requests to meet the 200ms requirement. This could be done * but for now use max_roc or 200ms, whichever is less. */ dpp->dwell = (dpp->max_roc < 200) ? dpp->max_roc : 200; /* "DPP R2 devices are expected to use PKEXv1 by default" */ dpp->pkex_version = 1; if (!l_ecdh_generate_key_pair(dpp->curve, &dpp->pkex_private, &dpp->pkex_public)) return false; /* * "If Qi is the point-at-infinity, the code shall be deleted and the * user should be notified to provision a new code" */ qi = dpp_derive_qi(dpp->curve, dpp->pkex_key, dpp->pkex_id, netdev_get_address(dpp->netdev)); if (!qi || l_ecc_point_is_infinity(qi)) { l_debug("Cannot derive Qi, provision a new code"); return false; } dpp->pkex_m = l_ecc_point_new(dpp->curve); return l_ecc_point_add(dpp->pkex_m, dpp->pkex_public, qi); } static struct l_dbus_message *dpp_dbus_pkex_start_enrollee(struct l_dbus *dbus, struct l_dbus_message *message, void *user_data) { struct dpp_sm *dpp = user_data; const char *key; const char *id; const char *mac_str; uint32_t freq; bool wait_for_disconnect; int ret; l_debug(""); if (dpp->state != DPP_STATE_NOTHING || dpp->interface != DPP_INTERFACE_UNBOUND) return dbus_error_busy(message); if (!dpp_parse_pkex_args(message, &key, &id, &mac_str, &freq)) goto invalid_args; if (mac_str && !util_string_to_address(mac_str, dpp->peer_addr)) goto invalid_args; else if (!mac_str) memcpy(dpp->peer_addr, broadcast, 6); if (freq) { dpp->freqs = l_new(uint32_t, 1); dpp->freqs[0] = freq; dpp->freqs_len = 1; } dpp->pkex_key = l_strdup(key); if (id) dpp->pkex_id = l_strdup(id); dpp->role = DPP_CAPABILITY_ENROLLEE; dpp->state = DPP_STATE_PKEX_EXCHANGE; dpp->interface = DPP_INTERFACE_PKEX; ret = dpp_try_disconnect_station(dpp, &wait_for_disconnect); if (ret < 0) { dpp_reset(dpp); return dbus_error_from_errno(ret, message); } if (!dpp_pkex_derive_keys(dpp)) { dpp_reset(dpp); return dbus_error_failed(message); } if (!wait_for_disconnect && !dpp_start_pkex_enrollee(dpp)) goto invalid_args; /* * If a disconnect was started/in progress the PKEX enrollee will start * once that has finished */ return l_dbus_message_new_method_return(message); invalid_args: return dbus_error_invalid_args(message); } static void pkex_agent_disconnect(struct l_dbus *dbus, void *user_data) { struct dpp_sm *dpp = user_data; l_debug("SharedCodeAgent %s disconnected", dpp->agent->path); dpp_reset(dpp); } static void dpp_create_agent(struct dpp_sm *dpp, const char *path, struct l_dbus_message *message) { const char *sender = l_dbus_message_get_sender(message); dpp->agent = l_new(struct pkex_agent, 1); dpp->agent->owner = l_strdup(sender); dpp->agent->path = l_strdup(path); dpp->agent->disconnect_watch = l_dbus_add_disconnect_watch( dbus_get_bus(), sender, pkex_agent_disconnect, dpp, NULL); l_debug("Registered a SharedCodeAgent on path %s", path); } static struct l_dbus_message *dpp_start_pkex_configurator(struct dpp_sm *dpp, const char *key, const char *identifier, const char *agent_path, struct l_dbus_message *message) { struct handshake_state *hs = netdev_get_handshake(dpp->netdev); struct station *station = station_find(netdev_get_ifindex(dpp->netdev)); struct network *network = station_get_connected_network(station); struct scan_bss *bss = station_get_connected_bss(station); const struct l_settings *settings; if (dpp->state != DPP_STATE_NOTHING || dpp->interface != DPP_INTERFACE_UNBOUND) return dbus_error_busy(message); if (!dpp->mcast_support) l_debug("Multicast frame registration not supported, only " "enrollees sending uncast will be supported"); if (!network || !bss) return dbus_error_not_connected(message); settings = network_get_settings(network); if (!settings) { l_debug("No settings for network, is this a known network?"); return dbus_error_not_configured(message); } if (identifier) dpp->pkex_id = l_strdup(identifier); if (key) dpp->pkex_key = l_strdup(key); if (agent_path) dpp_create_agent(dpp, agent_path, message); dpp->role = DPP_CAPABILITY_CONFIGURATOR; dpp->state = DPP_STATE_PKEX_EXCHANGE; dpp->interface = DPP_INTERFACE_PKEX; dpp->current_freq = bss->frequency; dpp->pkex_version = 1; dpp->config = dpp_configuration_new(network_get_settings(network), network_get_ssid(network), hs->akm_suite); dpp_reset_protocol_timer(dpp, DPP_PKEX_PROTO_TIMEOUT); dpp_property_changed_notify(dpp); dpp->station_watch = station_add_state_watch(station, dpp_station_state_watch, dpp, NULL); if (dpp->pkex_key) l_debug("Starting PKEX configurator for single enrollee"); else l_debug("Starting PKEX configurator with agent"); return l_dbus_message_new_method_return(message); } static struct l_dbus_message *dpp_dbus_pkex_configure_enrollee( struct l_dbus *dbus, struct l_dbus_message *message, void *user_data) { struct dpp_sm *dpp = user_data; const char *key; const char *id; l_debug(""); if (!dpp_parse_pkex_args(message, &key, &id, NULL, NULL)) return dbus_error_invalid_args(message); return dpp_start_pkex_configurator(dpp, key, id, NULL, message); } static struct l_dbus_message *dpp_dbus_pkex_start_configurator( struct l_dbus *dbus, struct l_dbus_message *message, void *user_data) { struct dpp_sm *dpp = user_data; const char *path; if (!l_dbus_message_get_arguments(message, "o", &path)) return dbus_error_invalid_args(message); return dpp_start_pkex_configurator(dpp, NULL, NULL, path, message); } static void dpp_setup_interface(struct l_dbus_interface *interface) { l_dbus_interface_method(interface, "StartEnrollee", 0, dpp_dbus_start_enrollee, "s", "", "uri"); l_dbus_interface_method(interface, "StartConfigurator", 0, dpp_dbus_start_configurator, "s", "", "uri"); l_dbus_interface_method(interface, "ConfigureEnrollee", 0, dpp_dbus_configure_enrollee, "", "s", "uri"); l_dbus_interface_method(interface, "Stop", 0, dpp_dbus_stop, "", ""); l_dbus_interface_property(interface, "Started", 0, "b", dpp_get_started, NULL); l_dbus_interface_property(interface, "Role", 0, "s", dpp_get_role, NULL); l_dbus_interface_property(interface, "URI", 0, "s", dpp_get_uri, NULL); } static struct l_dbus_message *dpp_dbus_pkex_stop(struct l_dbus *dbus, struct l_dbus_message *message, void *user_data) { struct dpp_sm *dpp = user_data; l_debug(""); if (dpp->interface != DPP_INTERFACE_PKEX) return dbus_error_not_found(message); dpp_reset(dpp); return l_dbus_message_new_method_return(message); } static void dpp_setup_pkex_interface(struct l_dbus_interface *interface) { l_dbus_interface_method(interface, "StartEnrollee", 0, dpp_dbus_pkex_start_enrollee, "", "a{sv}", "args"); l_dbus_interface_method(interface, "Stop", 0, dpp_dbus_pkex_stop, "", ""); l_dbus_interface_method(interface, "ConfigureEnrollee", 0, dpp_dbus_pkex_configure_enrollee, "", "a{sv}", "args"); l_dbus_interface_method(interface, "StartConfigurator", 0, dpp_dbus_pkex_start_configurator, "", "o", "path"); l_dbus_interface_property(interface, "Started", 0, "b", dpp_pkex_get_started, NULL); l_dbus_interface_property(interface, "Role", 0, "s", dpp_pkex_get_role, NULL); } static void dpp_destroy_interface(void *user_data) { struct dpp_sm *dpp = user_data; if (--dpp->refcount) return; l_queue_remove(dpp_list, dpp); dpp_free(dpp); } static int dpp_init(void) { nl80211 = l_genl_family_new(iwd_get_genl(), NL80211_GENL_NAME); if (!nl80211) { l_error("Failed to obtain nl80211"); return -EIO; } netdev_watch = netdev_watch_add(dpp_netdev_watch, NULL, NULL); l_dbus_register_interface(dbus_get_bus(), IWD_DPP_INTERFACE, dpp_setup_interface, dpp_destroy_interface, false); l_dbus_register_interface(dbus_get_bus(), IWD_DPP_PKEX_INTERFACE, dpp_setup_pkex_interface, dpp_destroy_interface, false); mlme_watch = l_genl_family_register(nl80211, "mlme", dpp_mlme_notify, NULL, NULL); unicast_watch = l_genl_add_unicast_watch(iwd_get_genl(), NL80211_GENL_NAME, dpp_unicast_notify, NULL, NULL); dpp_list = l_queue_new(); return 0; } static void dpp_exit(void) { l_debug(""); l_dbus_unregister_interface(dbus_get_bus(), IWD_DPP_INTERFACE); l_dbus_unregister_interface(dbus_get_bus(), IWD_DPP_PKEX_INTERFACE); netdev_watch_remove(netdev_watch); l_genl_remove_unicast_watch(iwd_get_genl(), unicast_watch); l_genl_family_unregister(nl80211, mlme_watch); mlme_watch = 0; l_genl_family_free(nl80211); nl80211 = NULL; l_queue_destroy(dpp_list, (l_queue_destroy_func_t) dpp_free); } IWD_MODULE(dpp, dpp_init, dpp_exit); IWD_MODULE_DEPENDS(dpp, netdev);