From cf137f4199272451e520f39a843e7e3006243e54 Mon Sep 17 00:00:00 2001 From: James Prestwood Date: Wed, 6 Dec 2023 12:17:57 -0800 Subject: [PATCH] ft: add FTE/RSNE building to ft_prepare_handshake In preparation to remove ft_associate build the FTE/RSNE in ft_prepare_handshake and set into the handshake object directly. --- src/ft.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 82 insertions(+), 2 deletions(-) diff --git a/src/ft.c b/src/ft.c index 43399828..d3b9234a 100644 --- a/src/ft.c +++ b/src/ft.c @@ -904,9 +904,15 @@ static void ft_info_destroy(void *data) l_free(info); } -static void ft_prepare_handshake(struct ft_info *info, +static bool ft_prepare_handshake(struct ft_info *info, struct handshake_state *hs) { + uint32_t kck_len = handshake_state_get_kck_len(hs); + struct ie_rsn_info rsn_info; + struct ie_ft_info ft_info; + uint8_t *fte; + uint8_t *rsne; + handshake_state_set_authenticator_address(hs, info->aa); memcpy(hs->mde + 2, info->mde, 3); @@ -914,7 +920,7 @@ static void ft_prepare_handshake(struct ft_info *info, handshake_state_set_chandef(hs, NULL); if (!hs->supplicant_ie) - return; + return true; if (info->authenticator_ie) handshake_state_set_authenticator_ie(hs, @@ -931,6 +937,80 @@ static void ft_prepare_handshake(struct ft_info *info, info->ft_info.r1khid); handshake_state_derive_ptk(hs); + + /* + * 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) + return false; + + rsn_info.num_pmkids = 1; + rsn_info.pmkids = hs->pmk_r1_name; + /* Always set OCVC false for FT for now */ + rsn_info.ocvc = false; + rsne = alloca(256); + + ie_build_rsne(&rsn_info, rsne); + handshake_state_set_supplicant_ie(hs, rsne); + + /* + * 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)) + return false; + + /* Rebuild the FT IE now with the MIC included */ + ie_build_fast_bss_transition(&ft_info, kck_len, fte); + + handshake_state_set_supplicant_fte(hs, fte); + + return true; } static bool ft_send_action(struct wiphy_radio_work_item *work)