/* * DPP PKEX functionality * Copyright (c) 2017, Qualcomm Atheros, Inc. * Copyright (c) 2018-2020, The Linux Foundation * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include "utils/includes.h" #include "utils/common.h" #include "common/wpa_ctrl.h" #include "crypto/aes.h" #include "crypto/aes_siv.h" #include "crypto/crypto.h" #include "dpp.h" #include "dpp_i.h" #ifdef CONFIG_TESTING_OPTIONS u8 dpp_pkex_own_mac_override[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 }; u8 dpp_pkex_peer_mac_override[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 }; u8 dpp_pkex_ephemeral_key_override[600]; size_t dpp_pkex_ephemeral_key_override_len = 0; #endif /* CONFIG_TESTING_OPTIONS */ static struct wpabuf * dpp_pkex_build_exchange_req(struct dpp_pkex *pkex, bool v2) { struct crypto_ec *ec = NULL; const struct crypto_ec_point *X; struct crypto_ec_point *Qi = NULL, *M = NULL; u8 *Mx, *My; struct wpabuf *msg = NULL; size_t attr_len; const struct dpp_curve_params *curve = pkex->own_bi->curve; wpa_printf(MSG_DEBUG, "DPP: Build PKEX %sExchange Request", v2 ? "" : "Version 1 "); /* Qi = H([MAC-Initiator |] [identifier |] code) * Pi */ Qi = dpp_pkex_derive_Qi(curve, v2 ? NULL : pkex->own_mac, pkex->code, pkex->identifier, &ec); if (!Qi) goto fail; /* Generate a random ephemeral keypair x/X */ #ifdef CONFIG_TESTING_OPTIONS if (dpp_pkex_ephemeral_key_override_len) { const struct dpp_curve_params *tmp_curve; wpa_printf(MSG_INFO, "DPP: TESTING - override ephemeral key x/X"); pkex->x = dpp_set_keypair(&tmp_curve, dpp_pkex_ephemeral_key_override, dpp_pkex_ephemeral_key_override_len); } else { pkex->x = dpp_gen_keypair(curve); } #else /* CONFIG_TESTING_OPTIONS */ pkex->x = dpp_gen_keypair(curve); #endif /* CONFIG_TESTING_OPTIONS */ if (!pkex->x) goto fail; /* M = X + Qi */ X = crypto_ec_key_get_public_key(pkex->x); M = crypto_ec_point_init(ec); if (!X || !M) goto fail; crypto_ec_point_debug_print(ec, X, "DPP: X"); if (crypto_ec_point_add(ec, X, Qi, M)) goto fail; crypto_ec_point_debug_print(ec, M, "DPP: M"); /* Initiator -> Responder: group, [identifier,] M */ attr_len = 4 + 2; #ifdef CONFIG_DPP2 if (v2) attr_len += 4 + 1; #endif /* CONFIG_DPP2 */ if (pkex->identifier) attr_len += 4 + os_strlen(pkex->identifier); attr_len += 4 + 2 * curve->prime_len; msg = dpp_alloc_msg(v2 ? DPP_PA_PKEX_EXCHANGE_REQ : DPP_PA_PKEX_V1_EXCHANGE_REQ, attr_len); if (!msg) goto fail; #ifdef CONFIG_DPP2 if (v2) { /* Protocol Version */ wpabuf_put_le16(msg, DPP_ATTR_PROTOCOL_VERSION); wpabuf_put_le16(msg, 1); wpabuf_put_u8(msg, DPP_VERSION); } #endif /* CONFIG_DPP2 */ #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_NO_FINITE_CYCLIC_GROUP_PKEX_EXCHANGE_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - no Finite Cyclic Group"); goto skip_finite_cyclic_group; } #endif /* CONFIG_TESTING_OPTIONS */ /* Finite Cyclic Group attribute */ wpabuf_put_le16(msg, DPP_ATTR_FINITE_CYCLIC_GROUP); wpabuf_put_le16(msg, 2); wpabuf_put_le16(msg, curve->ike_group); #ifdef CONFIG_TESTING_OPTIONS skip_finite_cyclic_group: #endif /* CONFIG_TESTING_OPTIONS */ /* Code Identifier attribute */ if (pkex->identifier) { wpabuf_put_le16(msg, DPP_ATTR_CODE_IDENTIFIER); wpabuf_put_le16(msg, os_strlen(pkex->identifier)); wpabuf_put_str(msg, pkex->identifier); } #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_NO_ENCRYPTED_KEY_PKEX_EXCHANGE_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - no Encrypted Key"); goto out; } #endif /* CONFIG_TESTING_OPTIONS */ /* M in Encrypted Key attribute */ wpabuf_put_le16(msg, DPP_ATTR_ENCRYPTED_KEY); wpabuf_put_le16(msg, 2 * curve->prime_len); #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_INVALID_ENCRYPTED_KEY_PKEX_EXCHANGE_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - invalid Encrypted Key"); if (dpp_test_gen_invalid_key(msg, curve) < 0) goto fail; goto out; } #endif /* CONFIG_TESTING_OPTIONS */ Mx = wpabuf_put(msg, curve->prime_len); My = wpabuf_put(msg, curve->prime_len); if (crypto_ec_point_to_bin(ec, M, Mx, My)) goto fail; os_memcpy(pkex->Mx, Mx, curve->prime_len); out: crypto_ec_point_deinit(M, 1); crypto_ec_point_deinit(Qi, 1); crypto_ec_deinit(ec); return msg; fail: wpa_printf(MSG_INFO, "DPP: Failed to build PKEX Exchange Request"); wpabuf_free(msg); msg = NULL; goto out; } static void dpp_pkex_fail(struct dpp_pkex *pkex, const char *txt) { wpa_msg(pkex->msg_ctx, MSG_INFO, DPP_EVENT_FAIL "%s", txt); } struct dpp_pkex * dpp_pkex_init(void *msg_ctx, struct dpp_bootstrap_info *bi, const u8 *own_mac, const char *identifier, const char *code, bool v2) { struct dpp_pkex *pkex; #ifdef CONFIG_TESTING_OPTIONS if (!is_zero_ether_addr(dpp_pkex_own_mac_override)) { wpa_printf(MSG_INFO, "DPP: TESTING - own_mac override " MACSTR, MAC2STR(dpp_pkex_own_mac_override)); own_mac = dpp_pkex_own_mac_override; } #endif /* CONFIG_TESTING_OPTIONS */ pkex = os_zalloc(sizeof(*pkex)); if (!pkex) return NULL; pkex->msg_ctx = msg_ctx; pkex->initiator = 1; pkex->v2 = v2; pkex->own_bi = bi; os_memcpy(pkex->own_mac, own_mac, ETH_ALEN); if (identifier) { pkex->identifier = os_strdup(identifier); if (!pkex->identifier) goto fail; } pkex->code = os_strdup(code); if (!pkex->code) goto fail; pkex->exchange_req = dpp_pkex_build_exchange_req(pkex, v2); if (!pkex->exchange_req) goto fail; return pkex; fail: dpp_pkex_free(pkex); return NULL; } static struct wpabuf * dpp_pkex_build_exchange_resp(struct dpp_pkex *pkex, enum dpp_status_error status, const u8 *Nx, const u8 *Ny) { struct wpabuf *msg = NULL; size_t attr_len; const struct dpp_curve_params *curve = pkex->own_bi->curve; /* Initiator -> Responder: DPP Status, [Protocol Version,] [identifier,] * N */ attr_len = 4 + 1; #ifdef CONFIG_DPP2 if (pkex->v2) attr_len += 4 + 1; #endif /* CONFIG_DPP2 */ if (pkex->identifier) attr_len += 4 + os_strlen(pkex->identifier); attr_len += 4 + 2 * curve->prime_len; msg = dpp_alloc_msg(DPP_PA_PKEX_EXCHANGE_RESP, attr_len); if (!msg) goto fail; #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_NO_STATUS_PKEX_EXCHANGE_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - no Status"); goto skip_status; } if (dpp_test == DPP_TEST_INVALID_STATUS_PKEX_EXCHANGE_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - invalid Status"); status = 255; } #endif /* CONFIG_TESTING_OPTIONS */ /* DPP Status */ dpp_build_attr_status(msg, status); #ifdef CONFIG_TESTING_OPTIONS skip_status: #endif /* CONFIG_TESTING_OPTIONS */ #ifdef CONFIG_DPP2 if (pkex->v2) { /* Protocol Version */ wpabuf_put_le16(msg, DPP_ATTR_PROTOCOL_VERSION); wpabuf_put_le16(msg, 1); wpabuf_put_u8(msg, DPP_VERSION); } #endif /* CONFIG_DPP2 */ /* Code Identifier attribute */ if (pkex->identifier) { wpabuf_put_le16(msg, DPP_ATTR_CODE_IDENTIFIER); wpabuf_put_le16(msg, os_strlen(pkex->identifier)); wpabuf_put_str(msg, pkex->identifier); } if (status != DPP_STATUS_OK) goto skip_encrypted_key; #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_NO_ENCRYPTED_KEY_PKEX_EXCHANGE_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - no Encrypted Key"); goto skip_encrypted_key; } #endif /* CONFIG_TESTING_OPTIONS */ /* N in Encrypted Key attribute */ wpabuf_put_le16(msg, DPP_ATTR_ENCRYPTED_KEY); wpabuf_put_le16(msg, 2 * curve->prime_len); #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_INVALID_ENCRYPTED_KEY_PKEX_EXCHANGE_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - invalid Encrypted Key"); if (dpp_test_gen_invalid_key(msg, curve) < 0) goto fail; goto skip_encrypted_key; } #endif /* CONFIG_TESTING_OPTIONS */ wpabuf_put_data(msg, Nx, curve->prime_len); wpabuf_put_data(msg, Ny, curve->prime_len); os_memcpy(pkex->Nx, Nx, curve->prime_len); skip_encrypted_key: if (status == DPP_STATUS_BAD_GROUP) { /* Finite Cyclic Group attribute */ wpabuf_put_le16(msg, DPP_ATTR_FINITE_CYCLIC_GROUP); wpabuf_put_le16(msg, 2); wpabuf_put_le16(msg, curve->ike_group); } return msg; fail: wpabuf_free(msg); return NULL; } static int dpp_pkex_identifier_match(const u8 *attr_id, u16 attr_id_len, const char *identifier) { if (!attr_id && identifier) { wpa_printf(MSG_DEBUG, "DPP: No PKEX code identifier received, but expected one"); return 0; } if (attr_id && !identifier) { wpa_printf(MSG_DEBUG, "DPP: PKEX code identifier received, but not expecting one"); return 0; } if (attr_id && identifier && (os_strlen(identifier) != attr_id_len || os_memcmp(identifier, attr_id, attr_id_len) != 0)) { wpa_printf(MSG_DEBUG, "DPP: PKEX code identifier mismatch"); return 0; } return 1; } struct dpp_pkex * dpp_pkex_rx_exchange_req(void *msg_ctx, struct dpp_bootstrap_info *bi, const u8 *own_mac, const u8 *peer_mac, const char *identifier, const char *code, const u8 *buf, size_t len, bool v2) { const u8 *attr_group, *attr_id, *attr_key; u16 attr_group_len, attr_id_len, attr_key_len; const struct dpp_curve_params *curve = bi->curve; u16 ike_group; struct dpp_pkex *pkex = NULL; struct crypto_ec_point *Qi = NULL, *Qr = NULL, *M = NULL, *X = NULL, *N = NULL; struct crypto_ec *ec = NULL; const struct crypto_ec_point *Y; u8 *x_coord = NULL, *y_coord = NULL; u8 Kx[DPP_MAX_SHARED_SECRET_LEN]; size_t Kx_len; int res; u8 peer_version = 0; if (bi->pkex_t >= PKEX_COUNTER_T_LIMIT) { wpa_msg(msg_ctx, MSG_INFO, DPP_EVENT_FAIL "PKEX counter t limit reached - ignore message"); return NULL; } #ifdef CONFIG_DPP2 if (v2) { const u8 *version; u16 version_len; version = dpp_get_attr(buf, len, DPP_ATTR_PROTOCOL_VERSION, &version_len); if (!version || version_len < 1 || version[0] == 0) { wpa_msg(msg_ctx, MSG_INFO, "Missing or invalid Protocol Version attribute"); return NULL; } peer_version = version[0]; wpa_printf(MSG_DEBUG, "DPP: Peer protocol version %u", peer_version); } #endif /* CONFIG_DPP2 */ #ifdef CONFIG_TESTING_OPTIONS if (!is_zero_ether_addr(dpp_pkex_peer_mac_override)) { wpa_printf(MSG_INFO, "DPP: TESTING - peer_mac override " MACSTR, MAC2STR(dpp_pkex_peer_mac_override)); peer_mac = dpp_pkex_peer_mac_override; } if (!is_zero_ether_addr(dpp_pkex_own_mac_override)) { wpa_printf(MSG_INFO, "DPP: TESTING - own_mac override " MACSTR, MAC2STR(dpp_pkex_own_mac_override)); own_mac = dpp_pkex_own_mac_override; } #endif /* CONFIG_TESTING_OPTIONS */ attr_id_len = 0; attr_id = dpp_get_attr(buf, len, DPP_ATTR_CODE_IDENTIFIER, &attr_id_len); if (!dpp_pkex_identifier_match(attr_id, attr_id_len, identifier)) return NULL; attr_group = dpp_get_attr(buf, len, DPP_ATTR_FINITE_CYCLIC_GROUP, &attr_group_len); if (!attr_group || attr_group_len != 2) { wpa_msg(msg_ctx, MSG_INFO, DPP_EVENT_FAIL "Missing or invalid Finite Cyclic Group attribute"); return NULL; } ike_group = WPA_GET_LE16(attr_group); if (ike_group != curve->ike_group) { wpa_msg(msg_ctx, MSG_INFO, DPP_EVENT_FAIL "Mismatching PKEX curve: peer=%u own=%u", ike_group, curve->ike_group); pkex = os_zalloc(sizeof(*pkex)); if (!pkex) goto fail; pkex->v2 = v2; pkex->peer_version = peer_version; pkex->own_bi = bi; pkex->failed = 1; pkex->exchange_resp = dpp_pkex_build_exchange_resp( pkex, DPP_STATUS_BAD_GROUP, NULL, NULL); if (!pkex->exchange_resp) goto fail; return pkex; } /* M in Encrypted Key attribute */ attr_key = dpp_get_attr(buf, len, DPP_ATTR_ENCRYPTED_KEY, &attr_key_len); if (!attr_key || attr_key_len & 0x01 || attr_key_len < 2 || attr_key_len / 2 > DPP_MAX_SHARED_SECRET_LEN) { wpa_msg(msg_ctx, MSG_INFO, DPP_EVENT_FAIL "Missing Encrypted Key attribute"); return NULL; } /* Qi = H([MAC-Initiator |] [identifier |] code) * Pi */ Qi = dpp_pkex_derive_Qi(curve, v2 ? NULL : peer_mac, code, identifier, &ec); if (!Qi) goto fail; /* X' = M - Qi */ X = crypto_ec_point_init(ec); M = crypto_ec_point_from_bin(ec, attr_key); if (!X || !M || crypto_ec_point_is_at_infinity(ec, M) || !crypto_ec_point_is_on_curve(ec, M) || crypto_ec_point_invert(ec, Qi) || crypto_ec_point_add(ec, M, Qi, X) || crypto_ec_point_is_at_infinity(ec, X) || !crypto_ec_point_is_on_curve(ec, X)) { wpa_msg(msg_ctx, MSG_INFO, DPP_EVENT_FAIL "Invalid Encrypted Key value"); bi->pkex_t++; goto fail; } crypto_ec_point_debug_print(ec, M, "DPP: M"); crypto_ec_point_debug_print(ec, X, "DPP: X'"); pkex = os_zalloc(sizeof(*pkex)); if (!pkex) goto fail; pkex->v2 = v2; pkex->peer_version = peer_version; pkex->t = bi->pkex_t; pkex->msg_ctx = msg_ctx; pkex->own_bi = bi; os_memcpy(pkex->own_mac, own_mac, ETH_ALEN); os_memcpy(pkex->peer_mac, peer_mac, ETH_ALEN); if (identifier) { pkex->identifier = os_strdup(identifier); if (!pkex->identifier) goto fail; } pkex->code = os_strdup(code); if (!pkex->code) goto fail; os_memcpy(pkex->Mx, attr_key, attr_key_len / 2); x_coord = os_malloc(curve->prime_len); y_coord = os_malloc(curve->prime_len); if (!x_coord || !y_coord || crypto_ec_point_to_bin(ec, X, x_coord, y_coord)) goto fail; pkex->x = crypto_ec_key_set_pub(curve->ike_group, x_coord, y_coord, crypto_ec_prime_len(ec)); if (!pkex->x) goto fail; /* Qr = H([MAC-Responder |] [identifier |] code) * Pr */ Qr = dpp_pkex_derive_Qr(curve, v2 ? NULL : own_mac, code, identifier, NULL); if (!Qr) goto fail; /* Generate a random ephemeral keypair y/Y */ #ifdef CONFIG_TESTING_OPTIONS if (dpp_pkex_ephemeral_key_override_len) { const struct dpp_curve_params *tmp_curve; wpa_printf(MSG_INFO, "DPP: TESTING - override ephemeral key y/Y"); pkex->y = dpp_set_keypair(&tmp_curve, dpp_pkex_ephemeral_key_override, dpp_pkex_ephemeral_key_override_len); } else { pkex->y = dpp_gen_keypair(curve); } #else /* CONFIG_TESTING_OPTIONS */ pkex->y = dpp_gen_keypair(curve); #endif /* CONFIG_TESTING_OPTIONS */ if (!pkex->y) goto fail; /* N = Y + Qr */ Y = crypto_ec_key_get_public_key(pkex->y); if (!Y) goto fail; crypto_ec_point_debug_print(ec, Y, "DPP: Y"); N = crypto_ec_point_init(ec); if (!N || crypto_ec_point_add(ec, Y, Qr, N) || crypto_ec_point_to_bin(ec, N, x_coord, y_coord)) goto fail; crypto_ec_point_debug_print(ec, N, "DPP: N"); pkex->exchange_resp = dpp_pkex_build_exchange_resp(pkex, DPP_STATUS_OK, x_coord, y_coord); if (!pkex->exchange_resp) goto fail; /* K = y * X' */ if (dpp_ecdh(pkex->y, pkex->x, Kx, &Kx_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (K.x)", Kx, Kx_len); /* z = HKDF(<>, info | M.x | N.x | code, K.x) */ res = dpp_pkex_derive_z(pkex->v2 ? NULL : pkex->peer_mac, pkex->v2 ? NULL : pkex->own_mac, pkex->peer_version, DPP_VERSION, pkex->Mx, curve->prime_len, pkex->Nx, curve->prime_len, pkex->code, Kx, Kx_len, pkex->z, curve->hash_len); os_memset(Kx, 0, Kx_len); if (res < 0) goto fail; pkex->exchange_done = 1; out: os_free(x_coord); os_free(y_coord); crypto_ec_point_deinit(Qi, 1); crypto_ec_point_deinit(Qr, 1); crypto_ec_point_deinit(M, 1); crypto_ec_point_deinit(N, 1); crypto_ec_point_deinit(X, 1); crypto_ec_deinit(ec); return pkex; fail: wpa_printf(MSG_DEBUG, "DPP: PKEX Exchange Request processing failed"); dpp_pkex_free(pkex); pkex = NULL; goto out; } static struct wpabuf * dpp_pkex_build_commit_reveal_req(struct dpp_pkex *pkex, const struct wpabuf *A_pub, const u8 *u) { const struct dpp_curve_params *curve = pkex->own_bi->curve; struct wpabuf *msg = NULL; size_t clear_len, attr_len; struct wpabuf *clear = NULL; u8 *wrapped; u8 octet; const u8 *addr[2]; size_t len[2]; /* {A, u, [bootstrapping info]}z */ clear_len = 4 + 2 * curve->prime_len + 4 + curve->hash_len; clear = wpabuf_alloc(clear_len); attr_len = 4 + clear_len + AES_BLOCK_SIZE; #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_AFTER_WRAPPED_DATA_PKEX_CR_REQ) attr_len += 5; #endif /* CONFIG_TESTING_OPTIONS */ msg = dpp_alloc_msg(DPP_PA_PKEX_COMMIT_REVEAL_REQ, attr_len); if (!clear || !msg) goto fail; #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_NO_BOOTSTRAP_KEY_PKEX_CR_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - no Bootstrap Key"); goto skip_bootstrap_key; } if (dpp_test == DPP_TEST_INVALID_BOOTSTRAP_KEY_PKEX_CR_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - invalid Bootstrap Key"); wpabuf_put_le16(clear, DPP_ATTR_BOOTSTRAP_KEY); wpabuf_put_le16(clear, 2 * curve->prime_len); if (dpp_test_gen_invalid_key(clear, curve) < 0) goto fail; goto skip_bootstrap_key; } #endif /* CONFIG_TESTING_OPTIONS */ /* A in Bootstrap Key attribute */ wpabuf_put_le16(clear, DPP_ATTR_BOOTSTRAP_KEY); wpabuf_put_le16(clear, wpabuf_len(A_pub)); wpabuf_put_buf(clear, A_pub); #ifdef CONFIG_TESTING_OPTIONS skip_bootstrap_key: if (dpp_test == DPP_TEST_NO_I_AUTH_TAG_PKEX_CR_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - no I-Auth tag"); goto skip_i_auth_tag; } if (dpp_test == DPP_TEST_I_AUTH_TAG_MISMATCH_PKEX_CR_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - I-Auth tag mismatch"); wpabuf_put_le16(clear, DPP_ATTR_I_AUTH_TAG); wpabuf_put_le16(clear, curve->hash_len); wpabuf_put_data(clear, u, curve->hash_len - 1); wpabuf_put_u8(clear, u[curve->hash_len - 1] ^ 0x01); goto skip_i_auth_tag; } #endif /* CONFIG_TESTING_OPTIONS */ /* u in I-Auth tag attribute */ wpabuf_put_le16(clear, DPP_ATTR_I_AUTH_TAG); wpabuf_put_le16(clear, curve->hash_len); wpabuf_put_data(clear, u, curve->hash_len); #ifdef CONFIG_TESTING_OPTIONS skip_i_auth_tag: if (dpp_test == DPP_TEST_NO_WRAPPED_DATA_PKEX_CR_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - no Wrapped Data"); goto skip_wrapped_data; } #endif /* CONFIG_TESTING_OPTIONS */ addr[0] = wpabuf_head_u8(msg) + 2; len[0] = DPP_HDR_LEN; octet = 0; addr[1] = &octet; len[1] = sizeof(octet); wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]); wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]); wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA); wpabuf_put_le16(msg, wpabuf_len(clear) + AES_BLOCK_SIZE); wrapped = wpabuf_put(msg, wpabuf_len(clear) + AES_BLOCK_SIZE); wpa_hexdump_buf(MSG_DEBUG, "DPP: AES-SIV cleartext", clear); if (aes_siv_encrypt(pkex->z, curve->hash_len, wpabuf_head(clear), wpabuf_len(clear), 2, addr, len, wrapped) < 0) goto fail; wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext", wrapped, wpabuf_len(clear) + AES_BLOCK_SIZE); #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_AFTER_WRAPPED_DATA_PKEX_CR_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - attr after Wrapped Data"); dpp_build_attr_status(msg, DPP_STATUS_OK); } skip_wrapped_data: #endif /* CONFIG_TESTING_OPTIONS */ out: wpabuf_free(clear); return msg; fail: wpabuf_free(msg); msg = NULL; goto out; } struct wpabuf * dpp_pkex_rx_exchange_resp(struct dpp_pkex *pkex, const u8 *peer_mac, const u8 *buf, size_t buflen) { const u8 *attr_status, *attr_id, *attr_key, *attr_group; u16 attr_status_len, attr_id_len, attr_key_len, attr_group_len; struct crypto_ec *ec = NULL; struct wpabuf *msg = NULL, *A_pub = NULL, *X_pub = NULL, *Y_pub = NULL; const struct dpp_curve_params *curve = pkex->own_bi->curve; struct crypto_ec_point *Qr = NULL, *Y = NULL, *N = NULL; u8 *x_coord = NULL, *y_coord = NULL; size_t Jx_len, Kx_len; u8 Jx[DPP_MAX_SHARED_SECRET_LEN], Kx[DPP_MAX_SHARED_SECRET_LEN]; const u8 *addr[4]; size_t len[4]; size_t num_elem; u8 u[DPP_MAX_HASH_LEN]; int res; if (pkex->failed || pkex->t >= PKEX_COUNTER_T_LIMIT || !pkex->initiator) return NULL; #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_STOP_AT_PKEX_EXCHANGE_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - stop at PKEX Exchange Response"); pkex->failed = 1; return NULL; } if (!is_zero_ether_addr(dpp_pkex_peer_mac_override)) { wpa_printf(MSG_INFO, "DPP: TESTING - peer_mac override " MACSTR, MAC2STR(dpp_pkex_peer_mac_override)); peer_mac = dpp_pkex_peer_mac_override; } #endif /* CONFIG_TESTING_OPTIONS */ #ifdef CONFIG_DPP2 if (pkex->v2) { const u8 *version; u16 version_len; version = dpp_get_attr(buf, buflen, DPP_ATTR_PROTOCOL_VERSION, &version_len); if (!version || version_len < 1 || version[0] == 0) { dpp_pkex_fail(pkex, "Missing or invalid Protocol Version attribute"); return NULL; } pkex->peer_version = version[0]; wpa_printf(MSG_DEBUG, "DPP: Peer protocol version %u", pkex->peer_version); } #endif /* CONFIG_DPP2 */ os_memcpy(pkex->peer_mac, peer_mac, ETH_ALEN); attr_status = dpp_get_attr(buf, buflen, DPP_ATTR_STATUS, &attr_status_len); if (!attr_status || attr_status_len != 1) { dpp_pkex_fail(pkex, "No DPP Status attribute"); return NULL; } wpa_printf(MSG_DEBUG, "DPP: Status %u", attr_status[0]); if (attr_status[0] == DPP_STATUS_BAD_GROUP) { attr_group = dpp_get_attr(buf, buflen, DPP_ATTR_FINITE_CYCLIC_GROUP, &attr_group_len); if (attr_group && attr_group_len == 2) { wpa_msg(pkex->msg_ctx, MSG_INFO, DPP_EVENT_FAIL "Peer indicated mismatching PKEX group - proposed %u", WPA_GET_LE16(attr_group)); return NULL; } } if (attr_status[0] != DPP_STATUS_OK) { dpp_pkex_fail(pkex, "PKEX failed (peer indicated failure)"); return NULL; } attr_id_len = 0; attr_id = dpp_get_attr(buf, buflen, DPP_ATTR_CODE_IDENTIFIER, &attr_id_len); if (!dpp_pkex_identifier_match(attr_id, attr_id_len, pkex->identifier)) { dpp_pkex_fail(pkex, "PKEX code identifier mismatch"); return NULL; } /* N in Encrypted Key attribute */ attr_key = dpp_get_attr(buf, buflen, DPP_ATTR_ENCRYPTED_KEY, &attr_key_len); if (!attr_key || attr_key_len & 0x01 || attr_key_len < 2) { dpp_pkex_fail(pkex, "Missing Encrypted Key attribute"); return NULL; } /* Qr = H([MAC-Responder |] [identifier |] code) * Pr */ Qr = dpp_pkex_derive_Qr(curve, pkex->v2 ? NULL : pkex->peer_mac, pkex->code, pkex->identifier, &ec); if (!Qr) goto fail; /* Y' = N - Qr */ Y = crypto_ec_point_init(ec); N = crypto_ec_point_from_bin(ec, attr_key); if (!Y || !N || crypto_ec_point_is_at_infinity(ec, N) || !crypto_ec_point_is_on_curve(ec, N) || crypto_ec_point_invert(ec, Qr) || crypto_ec_point_add(ec, N, Qr, Y) || crypto_ec_point_is_at_infinity(ec, Y) || !crypto_ec_point_is_on_curve(ec, Y)) { dpp_pkex_fail(pkex, "Invalid Encrypted Key value"); pkex->t++; goto fail; } crypto_ec_point_debug_print(ec, N, "DPP: N"); crypto_ec_point_debug_print(ec, Y, "DPP: Y'"); pkex->exchange_done = 1; /* ECDH: J = a * Y' */ x_coord = os_malloc(curve->prime_len); y_coord = os_malloc(curve->prime_len); if (!x_coord || !y_coord || crypto_ec_point_to_bin(ec, Y, x_coord, y_coord)) goto fail; pkex->y = crypto_ec_key_set_pub(curve->ike_group, x_coord, y_coord, curve->prime_len); if (!pkex->y) goto fail; if (dpp_ecdh(pkex->own_bi->pubkey, pkex->y, Jx, &Jx_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (J.x)", Jx, Jx_len); /* u = HMAC(J.x, [MAC-Initiator |] A.x | Y'.x | X.x) */ A_pub = crypto_ec_key_get_pubkey_point(pkex->own_bi->pubkey, 0); Y_pub = crypto_ec_key_get_pubkey_point(pkex->y, 0); X_pub = crypto_ec_key_get_pubkey_point(pkex->x, 0); if (!A_pub || !Y_pub || !X_pub) goto fail; num_elem = 0; if (!pkex->v2) { addr[num_elem] = pkex->own_mac; len[num_elem] = ETH_ALEN; num_elem++; } addr[num_elem] = wpabuf_head(A_pub); len[num_elem] = wpabuf_len(A_pub) / 2; num_elem++; addr[num_elem] = wpabuf_head(Y_pub); len[num_elem] = wpabuf_len(Y_pub) / 2; num_elem++; addr[num_elem] = wpabuf_head(X_pub); len[num_elem] = wpabuf_len(X_pub) / 2; num_elem++; if (dpp_hmac_vector(curve->hash_len, Jx, Jx_len, num_elem, addr, len, u) < 0) goto fail; wpa_hexdump(MSG_DEBUG, "DPP: u", u, curve->hash_len); /* K = x * Y' */ if (dpp_ecdh(pkex->x, pkex->y, Kx, &Kx_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (K.x)", Kx, Kx_len); /* z = HKDF(<>, info | M.x | N.x | code, K.x) */ res = dpp_pkex_derive_z(pkex->v2 ? NULL : pkex->own_mac, pkex->v2 ? NULL : pkex->peer_mac, DPP_VERSION, pkex->peer_version, pkex->Mx, curve->prime_len, attr_key /* N.x */, attr_key_len / 2, pkex->code, Kx, Kx_len, pkex->z, curve->hash_len); os_memset(Kx, 0, Kx_len); if (res < 0) goto fail; msg = dpp_pkex_build_commit_reveal_req(pkex, A_pub, u); if (!msg) goto fail; out: wpabuf_free(A_pub); wpabuf_free(X_pub); wpabuf_free(Y_pub); os_free(x_coord); os_free(y_coord); crypto_ec_point_deinit(Qr, 1); crypto_ec_point_deinit(Y, 1); crypto_ec_point_deinit(N, 1); crypto_ec_deinit(ec); return msg; fail: wpa_printf(MSG_DEBUG, "DPP: PKEX Exchange Response processing failed"); goto out; } static struct wpabuf * dpp_pkex_build_commit_reveal_resp(struct dpp_pkex *pkex, const struct wpabuf *B_pub, const u8 *v) { const struct dpp_curve_params *curve = pkex->own_bi->curve; struct wpabuf *msg = NULL; const u8 *addr[2]; size_t len[2]; u8 octet; u8 *wrapped; struct wpabuf *clear = NULL; size_t clear_len, attr_len; /* {B, v [bootstrapping info]}z */ clear_len = 4 + 2 * curve->prime_len + 4 + curve->hash_len; clear = wpabuf_alloc(clear_len); attr_len = 4 + clear_len + AES_BLOCK_SIZE; #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_AFTER_WRAPPED_DATA_PKEX_CR_RESP) attr_len += 5; #endif /* CONFIG_TESTING_OPTIONS */ msg = dpp_alloc_msg(DPP_PA_PKEX_COMMIT_REVEAL_RESP, attr_len); if (!clear || !msg) goto fail; #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_NO_BOOTSTRAP_KEY_PKEX_CR_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - no Bootstrap Key"); goto skip_bootstrap_key; } if (dpp_test == DPP_TEST_INVALID_BOOTSTRAP_KEY_PKEX_CR_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - invalid Bootstrap Key"); wpabuf_put_le16(clear, DPP_ATTR_BOOTSTRAP_KEY); wpabuf_put_le16(clear, 2 * curve->prime_len); if (dpp_test_gen_invalid_key(clear, curve) < 0) goto fail; goto skip_bootstrap_key; } #endif /* CONFIG_TESTING_OPTIONS */ /* B in Bootstrap Key attribute */ wpabuf_put_le16(clear, DPP_ATTR_BOOTSTRAP_KEY); wpabuf_put_le16(clear, wpabuf_len(B_pub)); wpabuf_put_buf(clear, B_pub); #ifdef CONFIG_TESTING_OPTIONS skip_bootstrap_key: if (dpp_test == DPP_TEST_NO_R_AUTH_TAG_PKEX_CR_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - no R-Auth tag"); goto skip_r_auth_tag; } if (dpp_test == DPP_TEST_R_AUTH_TAG_MISMATCH_PKEX_CR_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - R-Auth tag mismatch"); wpabuf_put_le16(clear, DPP_ATTR_R_AUTH_TAG); wpabuf_put_le16(clear, curve->hash_len); wpabuf_put_data(clear, v, curve->hash_len - 1); wpabuf_put_u8(clear, v[curve->hash_len - 1] ^ 0x01); goto skip_r_auth_tag; } #endif /* CONFIG_TESTING_OPTIONS */ /* v in R-Auth tag attribute */ wpabuf_put_le16(clear, DPP_ATTR_R_AUTH_TAG); wpabuf_put_le16(clear, curve->hash_len); wpabuf_put_data(clear, v, curve->hash_len); #ifdef CONFIG_TESTING_OPTIONS skip_r_auth_tag: if (dpp_test == DPP_TEST_NO_WRAPPED_DATA_PKEX_CR_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - no Wrapped Data"); goto skip_wrapped_data; } #endif /* CONFIG_TESTING_OPTIONS */ addr[0] = wpabuf_head_u8(msg) + 2; len[0] = DPP_HDR_LEN; octet = 1; addr[1] = &octet; len[1] = sizeof(octet); wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]); wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]); wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA); wpabuf_put_le16(msg, wpabuf_len(clear) + AES_BLOCK_SIZE); wrapped = wpabuf_put(msg, wpabuf_len(clear) + AES_BLOCK_SIZE); wpa_hexdump_buf(MSG_DEBUG, "DPP: AES-SIV cleartext", clear); if (aes_siv_encrypt(pkex->z, curve->hash_len, wpabuf_head(clear), wpabuf_len(clear), 2, addr, len, wrapped) < 0) goto fail; wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext", wrapped, wpabuf_len(clear) + AES_BLOCK_SIZE); #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_AFTER_WRAPPED_DATA_PKEX_CR_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - attr after Wrapped Data"); dpp_build_attr_status(msg, DPP_STATUS_OK); } skip_wrapped_data: #endif /* CONFIG_TESTING_OPTIONS */ out: wpabuf_free(clear); return msg; fail: wpabuf_free(msg); msg = NULL; goto out; } struct wpabuf * dpp_pkex_rx_commit_reveal_req(struct dpp_pkex *pkex, const u8 *hdr, const u8 *buf, size_t buflen) { const struct dpp_curve_params *curve = pkex->own_bi->curve; size_t Jx_len, Lx_len; u8 Jx[DPP_MAX_SHARED_SECRET_LEN]; u8 Lx[DPP_MAX_SHARED_SECRET_LEN]; const u8 *wrapped_data, *b_key, *peer_u; u16 wrapped_data_len, b_key_len, peer_u_len = 0; const u8 *addr[4]; size_t len[4]; size_t num_elem; u8 octet; u8 *unwrapped = NULL; size_t unwrapped_len = 0; struct wpabuf *msg = NULL, *A_pub = NULL, *X_pub = NULL, *Y_pub = NULL; struct wpabuf *B_pub = NULL; u8 u[DPP_MAX_HASH_LEN], v[DPP_MAX_HASH_LEN]; #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_STOP_AT_PKEX_CR_REQ) { wpa_printf(MSG_INFO, "DPP: TESTING - stop at PKEX CR Request"); pkex->failed = 1; return NULL; } #endif /* CONFIG_TESTING_OPTIONS */ if (!pkex->exchange_done || pkex->failed || pkex->t >= PKEX_COUNTER_T_LIMIT || pkex->initiator) goto fail; wrapped_data = dpp_get_attr(buf, buflen, DPP_ATTR_WRAPPED_DATA, &wrapped_data_len); if (!wrapped_data || wrapped_data_len < AES_BLOCK_SIZE) { dpp_pkex_fail(pkex, "Missing or invalid required Wrapped Data attribute"); goto fail; } wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext", wrapped_data, wrapped_data_len); unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE; unwrapped = os_malloc(unwrapped_len); if (!unwrapped) goto fail; addr[0] = hdr; len[0] = DPP_HDR_LEN; octet = 0; addr[1] = &octet; len[1] = sizeof(octet); wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]); wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]); if (aes_siv_decrypt(pkex->z, curve->hash_len, wrapped_data, wrapped_data_len, 2, addr, len, unwrapped) < 0) { dpp_pkex_fail(pkex, "AES-SIV decryption failed - possible PKEX code mismatch"); pkex->failed = 1; pkex->t++; goto fail; } wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext", unwrapped, unwrapped_len); if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) { dpp_pkex_fail(pkex, "Invalid attribute in unwrapped data"); goto fail; } b_key = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_BOOTSTRAP_KEY, &b_key_len); if (!b_key || b_key_len != 2 * curve->prime_len) { dpp_pkex_fail(pkex, "No valid peer bootstrapping key found"); goto fail; } pkex->peer_bootstrap_key = dpp_set_pubkey_point(pkex->x, b_key, b_key_len); if (!pkex->peer_bootstrap_key) { dpp_pkex_fail(pkex, "Peer bootstrapping key is invalid"); goto fail; } dpp_debug_print_key("DPP: Peer bootstrap public key", pkex->peer_bootstrap_key); /* ECDH: J' = y * A' */ if (dpp_ecdh(pkex->y, pkex->peer_bootstrap_key, Jx, &Jx_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (J.x)", Jx, Jx_len); /* u' = HMAC(J'.x, [MAC-Initiator |] A'.x | Y.x | X'.x) */ A_pub = crypto_ec_key_get_pubkey_point(pkex->peer_bootstrap_key, 0); Y_pub = crypto_ec_key_get_pubkey_point(pkex->y, 0); X_pub = crypto_ec_key_get_pubkey_point(pkex->x, 0); if (!A_pub || !Y_pub || !X_pub) goto fail; num_elem = 0; if (!pkex->v2) { addr[num_elem] = pkex->peer_mac; len[num_elem] = ETH_ALEN; num_elem++; } addr[num_elem] = wpabuf_head(A_pub); len[num_elem] = wpabuf_len(A_pub) / 2; num_elem++; addr[num_elem] = wpabuf_head(Y_pub); len[num_elem] = wpabuf_len(Y_pub) / 2; num_elem++; addr[num_elem] = wpabuf_head(X_pub); len[num_elem] = wpabuf_len(X_pub) / 2; num_elem++; if (dpp_hmac_vector(curve->hash_len, Jx, Jx_len, num_elem, addr, len, u) < 0) goto fail; peer_u = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_I_AUTH_TAG, &peer_u_len); if (!peer_u || peer_u_len != curve->hash_len || os_memcmp(peer_u, u, curve->hash_len) != 0) { dpp_pkex_fail(pkex, "No valid u (I-Auth tag) found"); wpa_hexdump(MSG_DEBUG, "DPP: Calculated u'", u, curve->hash_len); wpa_hexdump(MSG_DEBUG, "DPP: Received u", peer_u, peer_u_len); pkex->t++; goto fail; } wpa_printf(MSG_DEBUG, "DPP: Valid u (I-Auth tag) received"); /* ECDH: L = b * X' */ if (dpp_ecdh(pkex->own_bi->pubkey, pkex->x, Lx, &Lx_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (L.x)", Lx, Lx_len); /* v = HMAC(L.x, [MAC-Responder |] B.x | X'.x | Y.x) */ B_pub = crypto_ec_key_get_pubkey_point(pkex->own_bi->pubkey, 0); if (!B_pub) goto fail; num_elem = 0; if (!pkex->v2) { addr[num_elem] = pkex->own_mac; len[num_elem] = ETH_ALEN; num_elem++; } addr[num_elem] = wpabuf_head(B_pub); len[num_elem] = wpabuf_len(B_pub) / 2; num_elem++; addr[num_elem] = wpabuf_head(X_pub); len[num_elem] = wpabuf_len(X_pub) / 2; num_elem++; addr[num_elem] = wpabuf_head(Y_pub); len[num_elem] = wpabuf_len(Y_pub) / 2; num_elem++; if (dpp_hmac_vector(curve->hash_len, Lx, Lx_len, num_elem, addr, len, v) < 0) goto fail; wpa_hexdump(MSG_DEBUG, "DPP: v", v, curve->hash_len); msg = dpp_pkex_build_commit_reveal_resp(pkex, B_pub, v); if (!msg) goto fail; out: os_free(unwrapped); wpabuf_free(A_pub); wpabuf_free(B_pub); wpabuf_free(X_pub); wpabuf_free(Y_pub); return msg; fail: wpa_printf(MSG_DEBUG, "DPP: PKEX Commit-Reveal Request processing failed"); goto out; } int dpp_pkex_rx_commit_reveal_resp(struct dpp_pkex *pkex, const u8 *hdr, const u8 *buf, size_t buflen) { const struct dpp_curve_params *curve = pkex->own_bi->curve; const u8 *wrapped_data, *b_key, *peer_v; u16 wrapped_data_len, b_key_len, peer_v_len = 0; const u8 *addr[4]; size_t len[4]; size_t num_elem; u8 octet; u8 *unwrapped = NULL; size_t unwrapped_len = 0; int ret = -1; u8 v[DPP_MAX_HASH_LEN]; size_t Lx_len; u8 Lx[DPP_MAX_SHARED_SECRET_LEN]; struct wpabuf *B_pub = NULL, *X_pub = NULL, *Y_pub = NULL; #ifdef CONFIG_TESTING_OPTIONS if (dpp_test == DPP_TEST_STOP_AT_PKEX_CR_RESP) { wpa_printf(MSG_INFO, "DPP: TESTING - stop at PKEX CR Response"); pkex->failed = 1; goto fail; } #endif /* CONFIG_TESTING_OPTIONS */ if (!pkex->exchange_done || pkex->failed || pkex->t >= PKEX_COUNTER_T_LIMIT || !pkex->initiator) goto fail; wrapped_data = dpp_get_attr(buf, buflen, DPP_ATTR_WRAPPED_DATA, &wrapped_data_len); if (!wrapped_data || wrapped_data_len < AES_BLOCK_SIZE) { dpp_pkex_fail(pkex, "Missing or invalid required Wrapped Data attribute"); goto fail; } wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext", wrapped_data, wrapped_data_len); unwrapped_len = wrapped_data_len - AES_BLOCK_SIZE; unwrapped = os_malloc(unwrapped_len); if (!unwrapped) goto fail; addr[0] = hdr; len[0] = DPP_HDR_LEN; octet = 1; addr[1] = &octet; len[1] = sizeof(octet); wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]); wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]); if (aes_siv_decrypt(pkex->z, curve->hash_len, wrapped_data, wrapped_data_len, 2, addr, len, unwrapped) < 0) { dpp_pkex_fail(pkex, "AES-SIV decryption failed - possible PKEX code mismatch"); pkex->t++; goto fail; } wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV cleartext", unwrapped, unwrapped_len); if (dpp_check_attrs(unwrapped, unwrapped_len) < 0) { dpp_pkex_fail(pkex, "Invalid attribute in unwrapped data"); goto fail; } b_key = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_BOOTSTRAP_KEY, &b_key_len); if (!b_key || b_key_len != 2 * curve->prime_len) { dpp_pkex_fail(pkex, "No valid peer bootstrapping key found"); goto fail; } pkex->peer_bootstrap_key = dpp_set_pubkey_point(pkex->x, b_key, b_key_len); if (!pkex->peer_bootstrap_key) { dpp_pkex_fail(pkex, "Peer bootstrapping key is invalid"); goto fail; } dpp_debug_print_key("DPP: Peer bootstrap public key", pkex->peer_bootstrap_key); /* ECDH: L' = x * B' */ if (dpp_ecdh(pkex->x, pkex->peer_bootstrap_key, Lx, &Lx_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: ECDH shared secret (L.x)", Lx, Lx_len); /* v' = HMAC(L.x, [MAC-Responder |] B'.x | X.x | Y'.x) */ B_pub = crypto_ec_key_get_pubkey_point(pkex->peer_bootstrap_key, 0); X_pub = crypto_ec_key_get_pubkey_point(pkex->x, 0); Y_pub = crypto_ec_key_get_pubkey_point(pkex->y, 0); if (!B_pub || !X_pub || !Y_pub) goto fail; num_elem = 0; if (!pkex->v2) { addr[num_elem] = pkex->peer_mac; len[num_elem] = ETH_ALEN; num_elem++; } addr[num_elem] = wpabuf_head(B_pub); len[num_elem] = wpabuf_len(B_pub) / 2; num_elem++; addr[num_elem] = wpabuf_head(X_pub); len[num_elem] = wpabuf_len(X_pub) / 2; num_elem++; addr[num_elem] = wpabuf_head(Y_pub); len[num_elem] = wpabuf_len(Y_pub) / 2; num_elem++; if (dpp_hmac_vector(curve->hash_len, Lx, Lx_len, num_elem, addr, len, v) < 0) goto fail; peer_v = dpp_get_attr(unwrapped, unwrapped_len, DPP_ATTR_R_AUTH_TAG, &peer_v_len); if (!peer_v || peer_v_len != curve->hash_len || os_memcmp(peer_v, v, curve->hash_len) != 0) { dpp_pkex_fail(pkex, "No valid v (R-Auth tag) found"); wpa_hexdump(MSG_DEBUG, "DPP: Calculated v'", v, curve->hash_len); wpa_hexdump(MSG_DEBUG, "DPP: Received v", peer_v, peer_v_len); pkex->t++; goto fail; } wpa_printf(MSG_DEBUG, "DPP: Valid v (R-Auth tag) received"); ret = 0; out: wpabuf_free(B_pub); wpabuf_free(X_pub); wpabuf_free(Y_pub); os_free(unwrapped); return ret; fail: goto out; } struct dpp_bootstrap_info * dpp_pkex_finish(struct dpp_global *dpp, struct dpp_pkex *pkex, const u8 *peer, unsigned int freq) { struct dpp_bootstrap_info *bi; bi = os_zalloc(sizeof(*bi)); if (!bi) return NULL; bi->id = dpp_next_id(dpp); bi->type = DPP_BOOTSTRAP_PKEX; os_memcpy(bi->mac_addr, peer, ETH_ALEN); bi->num_freq = 1; bi->freq[0] = freq; bi->curve = pkex->own_bi->curve; bi->pubkey = pkex->peer_bootstrap_key; pkex->peer_bootstrap_key = NULL; if (dpp_bootstrap_key_hash(bi) < 0) { dpp_bootstrap_info_free(bi); return NULL; } dpp_pkex_free(pkex); dl_list_add(&dpp->bootstrap, &bi->list); return bi; } void dpp_pkex_free(struct dpp_pkex *pkex) { if (!pkex) return; os_free(pkex->identifier); os_free(pkex->code); crypto_ec_key_deinit(pkex->x); crypto_ec_key_deinit(pkex->y); crypto_ec_key_deinit(pkex->peer_bootstrap_key); wpabuf_free(pkex->exchange_req); wpabuf_free(pkex->exchange_resp); os_free(pkex); }