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netdev: Handle the FT Authentication Response message

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Parse the second message of the FT transition, validate and build the
third message, the Reassociation Request.
This commit is contained in:
Andrew Zaborowski 2017-01-12 03:36:01 -05:00 committed by Denis Kenzior
parent d52683a2cb
commit 0854b90687
4 changed files with 598 additions and 26 deletions
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1
Makefile.am
View File

@ -82,6 +82,7 @@ src_iwd_SOURCES = src/main.c linux/nl80211.h \
src/knownnetworks.c \
src/rfkill.h src/rfkill.c \
src/watchlist.h src/watchlist.c \
src/ftutil.h src/ftutil.c \
src/iwd.h
src_iwd_LDADD = ell/libell-internal.la -ldl

142
src/ftutil.c Normal file
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@ -0,0 +1,142 @@
/*
*
* Wireless daemon for Linux
*
* Copyright (C) 2017 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 <config.h>
#endif
#include "linux/nl80211.h"
#include <ell/ell.h>
#include "src/ie.h"
#include "src/handshake.h"
#include "src/crypto.h"
#include "src/ftutil.h"
/*
* 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.
*/
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 struct crypto_ptk *ptk = handshake_state_get_ptk(hs);
uint8_t zero_mic[16] = {};
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 = 16;
iov[iov_elems].iov_base = (void *) (fte + 20);
iov[iov_elems++].iov_len = fte[1] + 2 - 20;
}
if (ric) {
iov[iov_elems].iov_base = (void *) ric;
iov[iov_elems++].iov_len = ric[1] + 2;
}
checksum = l_checksum_new_cmac_aes(ptk->kck, 16);
if (!checksum)
return false;
l_checksum_updatev(checksum, iov, iov_elems);
l_checksum_get_digest(checksum, out_mic, 16);
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.
*/
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 */
if (l_get_le16(data + 24) != NL80211_AUTHTYPE_FT)
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;
}

35
src/ftutil.h Normal file
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@ -0,0 +1,35 @@
/*
*
* Wireless daemon for Linux
*
* Copyright (C) 2017 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
*
*/
#include <stdbool.h>
struct handshake_state;
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);
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);

446
src/netdev.c
View File

@ -49,6 +49,7 @@
#include "src/scan.h"
#include "src/netdev.h"
#include "src/wscutil.h"
#include "src/ftutil.h"
struct netdev {
uint32_t index;
@ -1243,10 +1244,403 @@ error:
netdev_connect_failed(NULL, netdev);
}
/*
* Build an FT Reassociation Request frame according to 12.5.2 / 12.5.4:
* RSN or non-RSN Over-the-air FT Protocol, and with the IE contents
* according to 12.8.4: FT authentication sequence: contents of third message.
*/
static struct l_genl_msg *netdev_build_cmd_ft_reassociate(struct netdev *netdev,
uint32_t frequency,
const uint8_t *prev_bssid)
{
struct l_genl_msg *msg;
struct iovec iov[3];
int iov_elems = 0;
struct handshake_state *hs = netdev_get_handshake(netdev);
bool is_rsn = hs->own_ie != NULL;
uint8_t *rsne = NULL;
msg = l_genl_msg_new_sized(NL80211_CMD_ASSOCIATE, 600);
l_genl_msg_append_attr(msg, NL80211_ATTR_IFINDEX, 4, &netdev->index);
l_genl_msg_append_attr(msg, NL80211_ATTR_WIPHY_FREQ, 4, &frequency);
l_genl_msg_append_attr(msg, NL80211_ATTR_MAC, ETH_ALEN, hs->aa);
l_genl_msg_append_attr(msg, NL80211_ATTR_PREV_BSSID, ETH_ALEN,
prev_bssid);
l_genl_msg_append_attr(msg, NL80211_ATTR_SSID, hs->ssid_len, hs->ssid);
if (is_rsn) {
uint32_t nl_cipher;
uint32_t nl_akm;
uint32_t wpa_version;
struct ie_rsn_info rsn_info;
if (hs->pairwise_cipher == IE_RSN_CIPHER_SUITE_CCMP)
nl_cipher = CRYPTO_CIPHER_CCMP;
else
nl_cipher = CRYPTO_CIPHER_TKIP;
l_genl_msg_append_attr(msg, NL80211_ATTR_CIPHER_SUITES_PAIRWISE,
4, &nl_cipher);
if (hs->group_cipher == IE_RSN_CIPHER_SUITE_CCMP)
nl_cipher = CRYPTO_CIPHER_CCMP;
else
nl_cipher = CRYPTO_CIPHER_TKIP;
l_genl_msg_append_attr(msg, NL80211_ATTR_CIPHER_SUITE_GROUP,
4, &nl_cipher);
if (hs->mfp) {
uint32_t use_mfp = NL80211_MFP_REQUIRED;
l_genl_msg_append_attr(msg, NL80211_ATTR_USE_MFP,
4, &use_mfp);
}
if (hs->akm_suite == IE_RSN_AKM_SUITE_FT_OVER_8021X)
nl_akm = CRYPTO_AKM_FT_OVER_8021X;
else
nl_akm = CRYPTO_AKM_FT_USING_PSK;
l_genl_msg_append_attr(msg, NL80211_ATTR_AKM_SUITES,
4, &nl_akm);
wpa_version = NL80211_WPA_VERSION_2;
l_genl_msg_append_attr(msg, NL80211_ATTR_WPA_VERSIONS,
4, &wpa_version);
l_genl_msg_append_attr(msg, NL80211_ATTR_CONTROL_PORT, 0, NULL);
/*
* 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->own_ie, hs->own_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);
fte = alloca(256);
ie_build_fast_bss_transition(&ft_info, 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, fte);
iov[iov_elems].iov_base = fte;
iov[iov_elems].iov_len = fte[1] + 2;
iov_elems += 1;
}
l_genl_msg_append_attrv(msg, NL80211_ATTR_IE, iov, iov_elems);
return msg;
error:
l_genl_msg_unref(msg);
return NULL;
}
static void netdev_cmd_ft_reassociate_cb(struct l_genl_msg *msg,
void *user_data)
{
struct netdev *netdev = user_data;
netdev->connect_cmd_id = 0;
if (l_genl_msg_get_error(msg) < 0) {
struct l_genl_msg *cmd_deauth;
netdev->result = NETDEV_RESULT_ASSOCIATION_FAILED;
cmd_deauth = netdev_build_cmd_deauthenticate(netdev,
MPDU_REASON_CODE_UNSPECIFIED);
netdev->disconnect_cmd_id = l_genl_family_send(nl80211,
cmd_deauth,
netdev_connect_failed,
netdev, NULL);
}
}
static void netdev_authenticate_event(struct l_genl_msg *msg,
struct netdev *netdev)
{
struct l_genl_msg *cmd_associate, *cmd_deauth;
struct l_genl_attr attr;
uint16_t type, len;
const void *data;
uint16_t status_code;
const uint8_t *ies = NULL;
size_t ies_len;
const uint8_t *frame = NULL;
size_t frame_len = 0;
struct ie_tlv_iter iter;
const uint8_t *rsne = NULL;
const uint8_t *mde = NULL;
const uint8_t *fte = NULL;
struct handshake_state *hs = netdev->handshake;
bool is_rsn = hs->own_ie != NULL;
l_debug("");
/*
* During Fast Transition we use the authenticate event to start the
* reassociation step because the FTE necessary before we can build
* the FT Associate command is included in the attached frame and is
* not available in the Authenticate command callback.
*/
if (!netdev->in_ft)
return;
if (!l_genl_attr_init(&attr, msg)) {
l_debug("attr init failed");
goto auth_error;
}
while (l_genl_attr_next(&attr, &type, &len, &data)) {
switch (type) {
case NL80211_ATTR_TIMED_OUT:
l_warn("authentication timed out");
goto auth_error;
case NL80211_ATTR_FRAME:
if (frame)
goto auth_error;
frame = data;
frame_len = len;
break;
}
}
if (!frame)
goto auth_error;
/*
* 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,
netdev->addr, hs->aa, hs->aa, 2,
&status_code, &ies, &ies_len))
goto auth_error;
/* AP Rejected the authenticate / associate */
if (status_code != 0)
goto auth_error;
/* Check 802.11r IEs */
if (!ies)
goto ft_error;
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;
}
}
/*
* 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."
*/
if (is_rsn) {
struct ie_rsn_info msg2_rsne;
if (!rsne)
goto ft_error;
if (ie_parse_rsne_from_data(rsne, rsne[1] + 2,
&msg2_rsne) < 0)
goto ft_error;
if (msg2_rsne.num_pmkids != 1 ||
memcmp(msg2_rsne.pmkids, hs->pmk_r0_name, 16))
goto ft_error;
if (!handshake_util_ap_ie_matches(rsne, hs->ap_ie, false))
goto ft_error;
} else if (rsne)
goto ft_error;
/*
* 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."
*/
if (!mde || memcmp(hs->mde, mde, hs->mde[1] + 2))
goto ft_error;
/*
* 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."
*/
if (is_rsn) {
struct ie_ft_info ft_info;
uint8_t zeros[16] = {};
if (!fte)
goto ft_error;
if (ie_parse_fast_bss_transition_from_data(fte, fte[1] + 2,
&ft_info) < 0)
goto ft_error;
if (ft_info.mic_element_count != 0 ||
memcmp(ft_info.mic, zeros, 16))
goto ft_error;
if (hs->r0khid_len != ft_info.r0khid_len ||
memcmp(hs->r0khid, ft_info.r0khid,
hs->r0khid_len) ||
!ft_info.r1khid_present)
goto ft_error;
if (memcmp(ft_info.snonce, hs->snonce, 32))
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;
cmd_associate = netdev_build_cmd_ft_reassociate(netdev,
netdev->frequency,
netdev->prev_bssid);
if (!cmd_associate)
goto ft_error;
netdev->connect_cmd_id = l_genl_family_send(nl80211,
cmd_associate,
netdev_cmd_ft_reassociate_cb,
netdev, NULL);
if (!netdev->connect_cmd_id) {
l_genl_msg_unref(cmd_associate);
goto ft_error;
}
if (netdev->sm)
eapol_register(netdev->sm); /* See netdev_cmd_connect_cb */
return;
auth_error:
netdev->result = NETDEV_RESULT_AUTHENTICATION_FAILED;
netdev_connect_failed(NULL, netdev);
return;
ft_error:
netdev->result = NETDEV_RESULT_AUTHENTICATION_FAILED;
cmd_deauth = netdev_build_cmd_deauthenticate(netdev,
MPDU_REASON_CODE_UNSPECIFIED);
netdev->disconnect_cmd_id = l_genl_family_send(nl80211, cmd_deauth,
netdev_connect_failed,
netdev, NULL);
}
static void netdev_associate_event(struct l_genl_msg *msg,
@ -1255,6 +1649,32 @@ static void netdev_associate_event(struct l_genl_msg *msg,
l_debug("");
}
static unsigned int ie_rsn_akm_suite_to_nl80211(enum ie_rsn_akm_suite akm)
{
switch (akm) {
case IE_RSN_AKM_SUITE_8021X:
return CRYPTO_AKM_8021X;
case IE_RSN_AKM_SUITE_PSK:
return CRYPTO_AKM_PSK;
case IE_RSN_AKM_SUITE_FT_OVER_8021X:
return CRYPTO_AKM_FT_OVER_8021X;
case IE_RSN_AKM_SUITE_FT_USING_PSK:
return CRYPTO_AKM_FT_USING_PSK;
case IE_RSN_AKM_SUITE_8021X_SHA256:
return CRYPTO_AKM_8021X_SHA256;
case IE_RSN_AKM_SUITE_PSK_SHA256:
return CRYPTO_AKM_PSK_SHA256;
case IE_RSN_AKM_SUITE_TDLS:
return CRYPTO_AKM_TDLS;
case IE_RSN_AKM_SUITE_SAE_SHA256:
return CRYPTO_AKM_SAE_SHA256;
case IE_RSN_AKM_SUITE_FT_OVER_SAE_SHA256:
return CRYPTO_AKM_FT_OVER_SAE_SHA256;
}
return 0;
}
static void netdev_cmd_connect_cb(struct l_genl_msg *msg, void *user_data)
{
struct netdev *netdev = user_data;
@ -1285,32 +1705,6 @@ static void netdev_cmd_connect_cb(struct l_genl_msg *msg, void *user_data)
netdev_connect_failed(NULL, netdev);
}
static unsigned int ie_rsn_akm_suite_to_nl80211(enum ie_rsn_akm_suite akm)
{
switch (akm) {
case IE_RSN_AKM_SUITE_8021X:
return CRYPTO_AKM_8021X;
case IE_RSN_AKM_SUITE_PSK:
return CRYPTO_AKM_PSK;
case IE_RSN_AKM_SUITE_FT_OVER_8021X:
return CRYPTO_AKM_FT_OVER_8021X;
case IE_RSN_AKM_SUITE_FT_USING_PSK:
return CRYPTO_AKM_FT_USING_PSK;
case IE_RSN_AKM_SUITE_8021X_SHA256:
return CRYPTO_AKM_8021X_SHA256;
case IE_RSN_AKM_SUITE_PSK_SHA256:
return CRYPTO_AKM_PSK_SHA256;
case IE_RSN_AKM_SUITE_TDLS:
return CRYPTO_AKM_TDLS;
case IE_RSN_AKM_SUITE_SAE_SHA256:
return CRYPTO_AKM_SAE_SHA256;
case IE_RSN_AKM_SUITE_FT_OVER_SAE_SHA256:
return CRYPTO_AKM_FT_OVER_SAE_SHA256;
}
return 0;
}
static struct l_genl_msg *netdev_build_cmd_connect(struct netdev *netdev,
struct scan_bss *bss,
struct handshake_state *hs)