/* * * Wireless daemon for Linux * * Copyright (C) 2017-2019 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 "src/ie.h" #include "src/handshake.h" #include "src/crypto.h" #include "src/ft.h" #include "src/mpdu.h" #include "src/auth-proto.h" #include "src/band.h" struct ft_sm { struct auth_proto ap; struct handshake_state *hs; ft_tx_authenticate_func_t tx_auth; ft_tx_associate_func_t tx_assoc; void *user_data; }; /* * Calculate the MIC field of the FTE and write it directly to that FTE, * assuming it was all zeros before. See 12.8.4 and 12.8.5. */ static bool ft_calculate_fte_mic(struct handshake_state *hs, uint8_t seq_num, const uint8_t *rsne, const uint8_t *fte, const uint8_t *ric, uint8_t *out_mic) { struct iovec iov[10]; int iov_elems = 0; struct l_checksum *checksum; const uint8_t *kck = handshake_state_get_kck(hs); size_t kck_len = handshake_state_get_kck_len(hs); uint8_t zero_mic[24] = {}; iov[iov_elems].iov_base = hs->spa; iov[iov_elems++].iov_len = 6; iov[iov_elems].iov_base = hs->aa; iov[iov_elems++].iov_len = 6; iov[iov_elems].iov_base = &seq_num; iov[iov_elems++].iov_len = 1; if (rsne) { iov[iov_elems].iov_base = (void *) rsne; iov[iov_elems++].iov_len = rsne[1] + 2; } iov[iov_elems].iov_base = hs->mde; iov[iov_elems++].iov_len = hs->mde[1] + 2; if (fte) { iov[iov_elems].iov_base = (void *) fte; iov[iov_elems++].iov_len = 4; iov[iov_elems].iov_base = zero_mic; iov[iov_elems++].iov_len = kck_len; iov[iov_elems].iov_base = (void *) (fte + 4 + kck_len); iov[iov_elems++].iov_len = fte[1] + 2 - 4 - kck_len; } if (ric) { iov[iov_elems].iov_base = (void *) ric; iov[iov_elems++].iov_len = ric[1] + 2; } if (kck_len == 16) checksum = l_checksum_new_cmac_aes(kck, kck_len); else checksum = l_checksum_new_hmac(L_CHECKSUM_SHA384, kck, kck_len); if (!checksum) return false; l_checksum_updatev(checksum, iov, iov_elems); l_checksum_get_digest(checksum, out_mic, kck_len); l_checksum_free(checksum); return true; } /* * Validate the FC, the addresses, Auth Type and authentication sequence * number of an FT Authentication Response frame, return status code, and * the start of the IE array (RSN, MD, FT, TI and RIC). * See 8.3.3.1 for the header and 8.3.3.11 for the body format. */ static bool ft_parse_authentication_resp_frame(const uint8_t *data, size_t len, const uint8_t *addr1, const uint8_t *addr2, const uint8_t *addr3, uint16_t auth_seq, uint16_t *out_status, const uint8_t **out_ies, size_t *out_ies_len) { const uint16_t frame_type = 0x00b0; uint16_t status = 0; if (len < 30) return false; /* Check FC == Management Frame -> Authentication */ if (l_get_le16(data + 0) != frame_type) return false; if (memcmp(data + 4, addr1, 6)) return false; if (memcmp(data + 10, addr2, 6)) return false; if (memcmp(data + 16, addr3, 6)) return false; /* Check Authentication algorithm number is FT (2) */ if (l_get_le16(data + 24) != 2) return false; if (l_get_le16(data + 26) != auth_seq) return false; if (auth_seq == 2 || auth_seq == 4) status = l_get_le16(data + 28); if (out_status) *out_status = status; if (status == 0 && out_ies) { *out_ies = data + 28; *out_ies_len = len - 28; } return true; } static bool ft_parse_associate_resp_frame(const uint8_t *frame, size_t frame_len, uint16_t *out_status, const uint8_t **rsne, const uint8_t **mde, const uint8_t **fte) { const struct mmpdu_header *mpdu; const struct mmpdu_association_response *body; struct ie_tlv_iter iter; mpdu = mpdu_validate(frame, frame_len); if (!mpdu) return false; body = mmpdu_body(mpdu); ie_tlv_iter_init(&iter, body->ies, (const uint8_t *) mpdu + frame_len - body->ies); while (ie_tlv_iter_next(&iter)) { switch (ie_tlv_iter_get_tag(&iter)) { case IE_TYPE_RSN: if (*rsne) return false; *rsne = ie_tlv_iter_get_data(&iter) - 2; break; case IE_TYPE_MOBILITY_DOMAIN: if (*mde) return false; *mde = ie_tlv_iter_get_data(&iter) - 2; break; case IE_TYPE_FAST_BSS_TRANSITION: if (*fte) return false; *fte = ie_tlv_iter_get_data(&iter) - 2; break; } } *out_status = L_LE16_TO_CPU(body->status_code); return true; } static int ft_tx_reassociate(struct ft_sm *ft) { struct iovec iov[3]; int iov_elems = 0; struct handshake_state *hs = ft->hs; uint32_t kck_len = handshake_state_get_kck_len(hs); bool is_rsn = hs->supplicant_ie != NULL; uint8_t *rsne = NULL; if (is_rsn) { struct ie_rsn_info rsn_info; /* * Rebuild the RSNE to include the PMKR1Name and append * MDE + FTE. * * 12.8.4: "If present, the RSNE shall be set as follows: * - Version field shall be set to 1. * - PMKID Count field shall be set to 1. * - PMKID field shall contain the PMKR1Name. * - All other fields shall be as specified in 8.4.2.27 * and 11.5.3." */ if (ie_parse_rsne_from_data(hs->supplicant_ie, hs->supplicant_ie[1] + 2, &rsn_info) < 0) goto error; rsn_info.num_pmkids = 1; rsn_info.pmkids = hs->pmk_r1_name; rsne = alloca(256); ie_build_rsne(&rsn_info, rsne); iov[iov_elems].iov_base = rsne; iov[iov_elems].iov_len = rsne[1] + 2; iov_elems += 1; } /* The MDE advertised by the BSS must be passed verbatim */ iov[iov_elems].iov_base = (void *) hs->mde; iov[iov_elems].iov_len = hs->mde[1] + 2; iov_elems += 1; if (is_rsn) { struct ie_ft_info ft_info; uint8_t *fte; /* * 12.8.4: "If present, the FTE shall be set as follows: * - ANonce, SNonce, R0KH-ID, and R1KH-ID shall be set to * the values contained in the second message of this * sequence. * - The Element Count field of the MIC Control field shall * be set to the number of elements protected in this * frame (variable). * [...] * - All other fields shall be set to 0." */ memset(&ft_info, 0, sizeof(ft_info)); ft_info.mic_element_count = 3; memcpy(ft_info.r0khid, hs->r0khid, hs->r0khid_len); ft_info.r0khid_len = hs->r0khid_len; memcpy(ft_info.r1khid, hs->r1khid, 6); ft_info.r1khid_present = true; memcpy(ft_info.anonce, hs->anonce, 32); memcpy(ft_info.snonce, hs->snonce, 32); /* * IEEE 802.11-2020 Section 13.7.1 FT reassociation in an RSN * * "If dot11RSNAOperatingChannelValidationActivated is true and * the FTO indicates OCVC capability, the target AP shall * ensure that OCI subelement of the FTE matches by ensuring * that all of the following are true: * - OCI subelement is present * - Channel information in the OCI matches current * operating channel parameters (see 12.2.9)" */ if (hs->supplicant_ocvc && hs->chandef) { oci_from_chandef(hs->chandef, ft_info.oci); ft_info.oci_present = true; } fte = alloca(256); ie_build_fast_bss_transition(&ft_info, kck_len, fte); if (!ft_calculate_fte_mic(hs, 5, rsne, fte, NULL, ft_info.mic)) goto error; /* Rebuild the FT IE now with the MIC included */ ie_build_fast_bss_transition(&ft_info, kck_len, fte); iov[iov_elems].iov_base = fte; iov[iov_elems].iov_len = fte[1] + 2; iov_elems += 1; } return ft->tx_assoc(iov, iov_elems, ft->user_data); error: return -EINVAL; } static bool ft_verify_rsne(const uint8_t *rsne, const uint8_t *pmk_r0_name, const uint8_t *authenticator_ie) { /* * In an RSN, check for an RSNE containing the PMK-R0-Name and * the remaining fields same as in the advertised RSNE. * * 12.8.3: "The RSNE shall be present only if dot11RSNAActivated * is true. If present, the RSNE shall be set as follows: * - Version field shall be set to 1. * - PMKID Count field shall be set to 1. * - PMKID List field shall be set to the value contained in the * first message of this sequence. * - All other fields shall be identical to the contents of the * RSNE advertised by the AP in Beacon and Probe Response frames." */ struct ie_rsn_info msg2_rsne; if (!rsne) return false; if (ie_parse_rsne_from_data(rsne, rsne[1] + 2, &msg2_rsne) < 0) return false; if (msg2_rsne.num_pmkids != 1 || memcmp(msg2_rsne.pmkids, pmk_r0_name, 16)) return false; if (!handshake_util_ap_ie_matches(&msg2_rsne, authenticator_ie, false)) return false; return true; } static int ft_parse_ies(struct handshake_state *hs, const uint8_t *ies, size_t ies_len, const uint8_t **mde_out, const uint8_t **fte_out) { struct ie_tlv_iter iter; const uint8_t *rsne = NULL; const uint8_t *mde = NULL; const uint8_t *fte = NULL; bool is_rsn; ie_tlv_iter_init(&iter, ies, ies_len); while (ie_tlv_iter_next(&iter)) { switch (ie_tlv_iter_get_tag(&iter)) { case IE_TYPE_RSN: if (rsne) goto ft_error; rsne = ie_tlv_iter_get_data(&iter) - 2; break; case IE_TYPE_MOBILITY_DOMAIN: if (mde) goto ft_error; mde = ie_tlv_iter_get_data(&iter) - 2; break; case IE_TYPE_FAST_BSS_TRANSITION: if (fte) goto ft_error; fte = ie_tlv_iter_get_data(&iter) - 2; break; } } is_rsn = hs->supplicant_ie != NULL; if (is_rsn) { if (!ft_verify_rsne(rsne, hs->pmk_r0_name, hs->authenticator_ie)) goto ft_error; } else if (rsne) goto ft_error; if (mde_out) *mde_out = mde; if (fte_out) *fte_out = fte; return 0; ft_error: return -EINVAL; } static bool ft_parse_fte(struct handshake_state *hs, const uint8_t *snonce, const uint8_t *fte, struct ie_ft_info *ft_info) { /* * In an RSN, check for an FT IE with the same R0KH-ID and the same * SNonce that we sent, and check that the R1KH-ID and the ANonce * are present. Use them to generate new PMK-R1, PMK-R1-Name and PTK * in handshake.c. * * 12.8.3: "The FTE shall be present only if dot11RSNAActivated is * true. If present, the FTE shall be set as follows: * - R0KH-ID shall be identical to the R0KH-ID provided by the FTO * in the first message. * - R1KH-ID shall be set to the R1KH-ID of the target AP, from * dot11FTR1KeyHolderID. * - ANonce shall be set to a value chosen randomly by the target AP, * following the recommendations of 11.6.5. * - SNonce shall be set to the value contained in the first message * of this sequence. * - All other fields shall be set to 0." */ uint8_t zeros[24] = {}; uint32_t kck_len = handshake_state_get_kck_len(hs); if (!fte) return false; if (ie_parse_fast_bss_transition_from_data(fte, fte[1] + 2, kck_len, ft_info) < 0) return false; if (ft_info->mic_element_count != 0 || memcmp(ft_info->mic, zeros, kck_len)) return false; if (hs->r0khid_len != ft_info->r0khid_len || memcmp(hs->r0khid, ft_info->r0khid, hs->r0khid_len) || !ft_info->r1khid_present) return false; if (memcmp(ft_info->snonce, snonce, 32)) return false; return true; } static bool mde_equal(const uint8_t *mde1, const uint8_t *mde2) { if (!mde1 || !mde2) return false; /* * Check for an MD IE identical to the one we sent in message 1 * * 12.8.3: "The MDE shall contain the MDID and FT Capability and * Policy fields. This element shall be the same as the MDE * advertised by the target AP in Beacon and Probe Response frames." */ return memcmp(mde1, mde1, mde1[1] + 2) == 0; } bool ft_over_ds_parse_action_ies(struct ft_ds_info *info, struct handshake_state *hs, const uint8_t *ies, size_t ies_len) { const uint8_t *mde = NULL; const uint8_t *fte = NULL; bool is_rsn = hs->supplicant_ie != NULL; if (ft_parse_ies(hs, ies, ies_len, &mde, &fte) < 0) return false; if (!mde_equal(info->mde, mde)) goto ft_error; if (is_rsn) { if (!ft_parse_fte(hs, info->snonce, fte, &info->ft_info)) goto ft_error; info->fte = l_memdup(fte, fte[1] + 2); } else if (fte) goto ft_error; return true; ft_error: return false; } static int ft_process_ies(struct handshake_state *hs, const uint8_t *ies, size_t ies_len) { const uint8_t *mde = NULL; const uint8_t *fte = NULL; bool is_rsn = hs->supplicant_ie != NULL; /* Check 802.11r IEs */ if (!ies) goto ft_error; if (ft_parse_ies(hs, ies, ies_len, &mde, &fte) < 0) goto ft_error; if (!mde_equal(hs->mde, mde)) goto ft_error; if (is_rsn) { struct ie_ft_info ft_info; if (!ft_parse_fte(hs, hs->snonce, fte, &ft_info)) goto ft_error; handshake_state_set_fte(hs, fte); handshake_state_set_anonce(hs, ft_info.anonce); handshake_state_set_kh_ids(hs, ft_info.r0khid, ft_info.r0khid_len, ft_info.r1khid); handshake_state_derive_ptk(hs); } else if (fte) goto ft_error; return 0; ft_error: return -EBADMSG; } int ft_over_ds_parse_action_response(const uint8_t *frame, size_t frame_len, const uint8_t **spa_out, const uint8_t **aa_out, const uint8_t **ies_out, size_t *ies_len) { uint16_t status; const uint8_t *aa; const uint8_t *spa; if (frame_len < 16) return -EINVAL; /* Category FT */ if (frame[0] != 6) return -EINVAL; /* FT Action */ if (frame[1] != 2) return -EINVAL; spa = frame + 2; aa = frame + 8; status = l_get_le16(frame + 14); if (status != 0) return (int)status; if (spa_out) *spa_out = spa; if (aa_out) *aa_out = aa; if (ies_out && ies_len) { *ies_out = frame + 16; *ies_len = frame_len - 16; } return 0; } bool ft_over_ds_prepare_handshake(struct ft_ds_info *info, struct handshake_state *hs) { if (!hs->supplicant_ie) return true; memcpy(hs->snonce, info->snonce, sizeof(hs->snonce)); handshake_state_set_fte(hs, info->fte); handshake_state_set_anonce(hs, info->ft_info.anonce); handshake_state_set_kh_ids(hs, info->ft_info.r0khid, info->ft_info.r0khid_len, info->ft_info.r1khid); handshake_state_derive_ptk(hs); return true; } void ft_ds_info_free(struct ft_ds_info *info) { __typeof__(info->free) destroy = info->free; if (info->fte) l_free(info->fte); if (destroy) destroy(info); } static int ft_rx_authenticate(struct auth_proto *ap, const uint8_t *frame, size_t frame_len) { struct ft_sm *ft = l_container_of(ap, struct ft_sm, ap); uint16_t status_code = MMPDU_STATUS_CODE_UNSPECIFIED; const uint8_t *ies = NULL; size_t ies_len; int ret; /* * Parse the Authentication Response and validate the contents * according to 12.5.2 / 12.5.4: RSN or non-RSN Over-the-air * FT Protocol. */ if (!ft_parse_authentication_resp_frame(frame, frame_len, ft->hs->spa, ft->hs->aa, ft->hs->aa, 2, &status_code, &ies, &ies_len)) goto auth_error; /* AP Rejected the authenticate / associate */ if (status_code != 0) goto auth_error; ret = ft_process_ies(ft->hs, ies, ies_len); if (ret < 0) goto auth_error; return ft_tx_reassociate(ft); auth_error: return (int)status_code; } static int ft_rx_associate(struct auth_proto *ap, const uint8_t *frame, size_t frame_len) { struct ft_sm *ft = l_container_of(ap, struct ft_sm, ap); struct handshake_state *hs = ft->hs; uint32_t kck_len = handshake_state_get_kck_len(hs); const uint8_t *rsne = NULL; const uint8_t *mde = NULL; const uint8_t *fte = NULL; const uint8_t *sent_mde = hs->mde; bool is_rsn = hs->supplicant_ie != NULL; uint16_t out_status; if (!ft_parse_associate_resp_frame(frame, frame_len, &out_status, &rsne, &mde, &fte)) return -EBADMSG; /* * During a transition in an RSN, check for an RSNE containing the * PMK-R1-Name and the remaining fields same as in the advertised * RSNE. * * 12.8.5: "The RSNE shall be present only if dot11RSNAActivated is * true. If present, the RSNE shall be set as follows: * - Version field shall be set to 1. * - PMKID Count field shall be set to 1. * - PMKID field shall contain the PMKR1Name * - All other fields shall be identical to the contents of the RSNE * advertised by the target AP in Beacon and Probe Response frames." */ if (is_rsn) { struct ie_rsn_info msg4_rsne; if (!rsne) return -EBADMSG; if (ie_parse_rsne_from_data(rsne, rsne[1] + 2, &msg4_rsne) < 0) return -EBADMSG; if (msg4_rsne.num_pmkids != 1 || memcmp(msg4_rsne.pmkids, hs->pmk_r1_name, 16)) return -EBADMSG; if (!handshake_util_ap_ie_matches(&msg4_rsne, hs->authenticator_ie, false)) return -EBADMSG; } else { if (rsne) return -EBADMSG; } /* An MD IE identical to the one we sent must be present */ if (sent_mde && (!mde || memcmp(sent_mde, mde, sent_mde[1] + 2))) return -EBADMSG; /* * An FT IE is required in an initial mobility domain * association and re-associations in an RSN but not present * in a non-RSN (12.4.2 vs. 12.4.3). */ if (sent_mde && is_rsn && !fte) return -EBADMSG; if (!(sent_mde && is_rsn) && fte) return -EBADMSG; if (fte) { struct ie_ft_info ft_info; uint8_t mic[24]; if (ie_parse_fast_bss_transition_from_data(fte, fte[1] + 2, kck_len, &ft_info) < 0) return -EBADMSG; /* * In an RSN, check for an FT IE with the same * R0KH-ID, R1KH-ID, ANonce and SNonce that we * received in message 2, MIC Element Count * of 6 and the correct MIC. */ if (!ft_calculate_fte_mic(hs, 6, rsne, fte, NULL, mic)) return -EBADMSG; if (ft_info.mic_element_count != 3 || memcmp(ft_info.mic, mic, kck_len)) return -EBADMSG; if (hs->r0khid_len != ft_info.r0khid_len || memcmp(hs->r0khid, ft_info.r0khid, hs->r0khid_len) || !ft_info.r1khid_present || memcmp(hs->r1khid, ft_info.r1khid, 6)) return -EBADMSG; if (memcmp(ft_info.anonce, hs->anonce, 32)) return -EBADMSG; if (memcmp(ft_info.snonce, hs->snonce, 32)) return -EBADMSG; if (ft_info.gtk_len) { uint8_t gtk[32]; if (!handshake_decode_fte_key(hs, ft_info.gtk, ft_info.gtk_len, gtk)) return -EBADMSG; if (ft_info.gtk_rsc[6] != 0x00 || ft_info.gtk_rsc[7] != 0x00) return -EBADMSG; handshake_state_install_gtk(hs, ft_info.gtk_key_id, gtk, ft_info.gtk_len, ft_info.gtk_rsc, 6); } if (ft_info.igtk_len) { uint8_t igtk[16]; if (!handshake_decode_fte_key(hs, ft_info.igtk, ft_info.igtk_len, igtk)) return -EBADMSG; handshake_state_install_igtk(hs, ft_info.igtk_key_id, igtk, ft_info.igtk_len, ft_info.igtk_ipn); } handshake_state_install_ptk(ft->hs); } return 0; } static void ft_sm_free(struct auth_proto *ap) { struct ft_sm *ft = l_container_of(ap, struct ft_sm, ap); l_free(ft); } static bool ft_over_ds_start(struct auth_proto *ap) { struct ft_sm *ft = l_container_of(ap, struct ft_sm, ap); return ft_tx_reassociate(ft) == 0; } bool ft_build_authenticate_ies(struct handshake_state *hs, const uint8_t *new_snonce, uint8_t *buf, size_t *len) { uint32_t kck_len = handshake_state_get_kck_len(hs); bool is_rsn = hs->supplicant_ie != NULL; uint8_t *ptr = buf; if (is_rsn) { struct ie_rsn_info rsn_info; /* * Rebuild the RSNE to include the PMKR0Name and append * MDE + FTE. * * 12.8.2: "If present, the RSNE shall be set as follows: * - Version field shall be set to 1. * - PMKID Count field shall be set to 1. * - PMKID List field shall contain the PMKR0Name. * - All other fields shall be as specified in 8.4.2.27 * and 11.5.3." */ if (ie_parse_rsne_from_data(hs->supplicant_ie, hs->supplicant_ie[1] + 2, &rsn_info) < 0) return false; rsn_info.num_pmkids = 1; rsn_info.pmkids = hs->pmk_r0_name; ie_build_rsne(&rsn_info, ptr); ptr += ptr[1] + 2; } /* The MDE advertised by the BSS must be passed verbatim */ ptr[0] = IE_TYPE_MOBILITY_DOMAIN; ptr[1] = 3; memcpy(ptr + 2, hs->mde + 2, 3); ptr += 5; if (is_rsn) { struct ie_ft_info ft_info; /* * 12.8.2: "If present, the FTE shall be set as follows: * - R0KH-ID shall be the value of R0KH-ID obtained by the * FTO during its FT initial mobility domain association * exchange. * - SNonce shall be set to a value chosen randomly by the * FTO, following the recommendations of 11.6.5. * - All other fields shall be set to 0." */ memset(&ft_info, 0, sizeof(ft_info)); memcpy(ft_info.r0khid, hs->r0khid, hs->r0khid_len); ft_info.r0khid_len = hs->r0khid_len; memcpy(ft_info.snonce, new_snonce, 32); ie_build_fast_bss_transition(&ft_info, kck_len, ptr); ptr += ptr[1] + 2; } if (len) *len = ptr - buf; return true; } static bool ft_start(struct auth_proto *ap) { struct ft_sm *ft = l_container_of(ap, struct ft_sm, ap); struct handshake_state *hs = ft->hs; struct iovec iov; uint8_t buf[512]; size_t len; if (!ft_build_authenticate_ies(hs, hs->snonce, buf, &len)) return false; iov.iov_base = buf; iov.iov_len = len; ft->tx_auth(&iov, 1, ft->user_data); return true; } struct auth_proto *ft_over_air_sm_new(struct handshake_state *hs, ft_tx_authenticate_func_t tx_auth, ft_tx_associate_func_t tx_assoc, void *user_data) { struct ft_sm *ft = l_new(struct ft_sm, 1); ft->tx_auth = tx_auth; ft->tx_assoc = tx_assoc; ft->hs = hs; ft->user_data = user_data; ft->ap.rx_authenticate = ft_rx_authenticate; ft->ap.rx_associate = ft_rx_associate; ft->ap.start = ft_start; ft->ap.free = ft_sm_free; return &ft->ap; } struct auth_proto *ft_over_ds_sm_new(struct handshake_state *hs, ft_tx_associate_func_t tx_assoc, void *user_data) { struct ft_sm *ft = l_new(struct ft_sm, 1); ft->tx_assoc = tx_assoc; ft->hs = hs; ft->user_data = user_data; ft->ap.rx_associate = ft_rx_associate; ft->ap.start = ft_over_ds_start; ft->ap.free = ft_sm_free; return &ft->ap; }