Remark: Most of the text here and the other commends are taken 1:1 from the v3 of the series. There are some tweaks but besides providing new test tgz for this version of the patch all important bits are in the change log for the patch below. Extended Key ID for Individually Addressed Frames has been added to the IEEE 802.11 - 2012 standard to allow STAs to rekey the pairwise key without interruption for ongoing data traffic. A good and easy to follow introduction to Extended Key ID can be found here: https://mentor.ieee.org/802.11/dcn/10/11-10-0313-01-000m-rekeying-protocol-fix.ppt In a nutshell Extended Key ID is just allowing to also use keyid 1 for pairwise keys: We can now have two pairwise keys in parallel, allowing to switch between them comparable how it's already done for GTK and IGTK keys. All implementations of IEEE 802.11 without Extended Key ID only use the keyid 0 for unicast MPDUs. Since each STA can only have a single unicast key installed at any time there is no time window able to handle the old and the new key at the same time. When rekeying the unicast key under load MPDU losses are unavoidable: Each STA will get MPDUs encrypted with a key which is either no longer installed or has not yet been installed. In both cases the remote STA will be unable to decrypt the MPDUs and drop them. (Since only the decryption fails and the frames are still acknowledged these are truly lost. It's up to e.g. tcp to retransmit them.) Especially on high speed connections this can easily affect a few dozen MPDUs, drastically throttle the speed for tcp due to high frame losses or causing dropouts in voice or video transmissions. (Most implementations are not able to rekeys correctly, making matters worse. But that's not really relevant for this patch series.) This patch series implements Extended Key ID for both hostapd and wpa_supplicant to allow unicast key rekeys without MPDU loss and/or impact to the performance. While there are still ways to extend or improve this patch set it's already quite complex and I believe this to be good enough to be merged in the current state. Or in other words: It's high time to get some feedback on this surprisingly big patchset instead of adding more to it. Since Extended Key ID breaks the long-standing agreement of only one pairwise key (keyid 0) and also has to postpone the Tx usage of a newly installed key this can only work with drivers actively supporting Extended Key ID. So far Extended Key ID is only supported for linux kernels >=5.2 and cards only providing SW crypto. This patch series has been developed using hwsim (works out of the box with a kernel >= 5.2.0) and - not yet official supported - iwlwifi cards (supporting HW crypto). (All iwlwifi cards prior to the current 22000 series are working and probably will officially start to support Extended Key ID with the 5.4 kernel.) Some early versions of this series also have been tested with ath9, but that required special mac80211 workarounds which have not been merged upstream and abandoned for the time being. The patch series consist of basically five parts: 01-nl80211: Migrate to current netlink key message format 02-Driver: Introduce key_types and Extended Key ID driver flag 03-Add new argument key_type to all set_key() functions 04-hostapd: Set the correct key_type for key installs 05-wpa_supplicant: Set the correct key_type for key installs 06-drivers: Migrate drivers from set_tx to key_type API 07-nl80211: Switch to the new key_type API & cleanup 08-nl80211,wpa_supplicant: Drop outdated tdls hack 1) The first 8 patches are addressing issues not directly tied to the Extended Key ID support. More details are directly in the individual patch descriptions, but they are primarily related to deprecating the set_tx "boolean" used in various set_key() functions and replace it with something more flexible which also can handle Extended Key ID key installs. 09-hostapd: Add support for Extended Key ID 10-wpa_supplicant: AP Extended Key ID support 11-tests: Extended Key ID tests 2) The patches 9-11 are handling the Extended Key ID support for hostapd/wpa_supplicant and modify/amend to the existing tests to be able to work correctly with and without Extended Key ID support. 12-hostapd: FILS Extended Key ID support 13-wpa_supplicant: FILS Extended Key ID support 3) Patches 12 and 13 are trying to close a gap not covered in the official standard. I'm far from sure that this is the correct way and hope we can have a discussion here how to best handle FILS and probably also FT. (The standard does not have any guidance for that, too.) 14-nl80211: Extended Key ID support 4) The patch 14 is adding Extended Key ID support to nl80211, basically activating all the previous Extended Key ID patches when you are using linux 5.2 or greater with a compatible card. As of now all cards using mac80211 and NOT providing the "set_key()" callback are compatible. There is also a patch allowing to use it with most iwlwifi cards: https://patchwork.kernel.org/patch/11101659/ There is currently an API bug in all released linux kernels supporting Extended Key ID, preventing unicast keys using keyid 1 to be installed for FILS and FT handshakes. The fix should get merged in 5.3 and 5.2.10. Till that is done you'll either have to apply the patch https://patchwork.kernel.org/patch/11077311/ manually or use the workaround patch provided in V2 of this series when you want to test FILS or FT. (The comment in the workaround patch is wrong.) You find the workaround patch here: https://patchwork.ozlabs.org/patch/1148791/) 15-Drop set_tx from all set_key() functions 16-hostapd: Extended Key ID stress test 5) The last two patches, (15+16) are kind of optional. Patch 15 is finishing the work the first 8 patches started. Since redesigning the set_tx API is the most invasive part of the patch series it is sometimes interesting to see how the old set_tx key calls would have performed. Patch 16 is so far just a proof that everything still works when we use keyid 1 at the initial connect instead of the more traditional keyid 0. I have some ideas to extend that, allowing hostapd to detect broken STAs claiming to be compatible with Extended Key ID - due to broken capability announcement - and still work with APs supporting it. (At least the Samsung Galaxy Tab S3 is setting the RSN capabilities wrong and chances are there are more broken devices...) Besides using the hostapd tests I've also verified the function with a real AP using a patched iwlwifi driver with HW crypto offload. The integration of Extended Key ID support in hostapd/wpa_supplicant tries to maintain full backward compatibility with kernels not supporting Extended Key ID. While this is foreseen in the standard for normal operation it was more challenging for the built-in test cases. Instead of basically doubling all test cases and execute them with and without Extended Key ID support I've just modified all test cases to be able to run with and without Extended Key ID support. All tests will per default use Extended Key ID when supported or silently fall back to the "classical" way to do things. The downside here is, that the same tests executed on a system supporting Extended Key ID will test something slightly different than a system not supporting it... There are just two "gate-keeper" tests which are together making sure that rekeying also works without Extended Key ID when it's supported: ap_wpa2_ptk_rekey and ap_wpa2_ptk_extended_key_id_rekey To make it a bit simpler to see what the patches are changing I've uploaded you some files containing multiple full test runs: 1) head-2019-08-17.tgz Tests run with a unpatched hostapd (542913943) 2) patched-2019-08-23.tgz Test run with hwsim supporting Extended Key ID and all patches of the v4 (current) of this series applied. 3) patched-2019-08-17.tgz Test run with hwsim supporting Extended Key ID and all patches of the v3 (outdated!) of this series applied. 4) patched-legacy-2019-08-23.tgz All patches of v4 of this series applied, but Extended Key ID detection sabotaged, to force classical unicast rekeys. 5) patched-legacy-2019-08-17.tgz All patches of v3 (outdated!) of this series applied, but Extended Key ID detection sabotaged, to force classical unicast rekeys. Each file is roughly 185MB big and can be downloaded here: https://www.awhome.eu/index.php/s/jDQfpZmDGwsLPXA To allow direct comparison of the test results all tests were done with the git version 542913943 of hostapd. All tests were executed running wt-2019-08-06 from wireless-testing. (The kernel has three additional patched on top of the official version to use Extended Key ID with iwlwifi, my proposed patch to fix the Extended Key ID install checks in cfg80211 and a debug patch with printk's informing me when installing or activating any PTK. Most of the failed tests are related to a wrong Python call to AES encrypt data, missing one argument. (I'm using Python 3.6.9) All failing tests seem to be unrelated to the changes here and can be reproduced without the patches. I've added two extra files in each test directory: - failed.log All tests failed in this run. With a comment when it worked when trying the test a second time. (But without adding the output from the rerun.) - script.log The output of the actual test run. Version history: Patch version 1: Initial release Patch version 2: - typo fix in commit message Patch version 3: - use key_type (enum) instead of key_flag (bit array) - migrate set_tx to the new key_type API and clean up related workarounds and bugs. - also support Extended Key ID for OSEN, FT and FILS - wpa_supplicant is now checking RSN capabilities instead of the presence of the KeyID KDE to enable Extended Key ID support to follow the wording of the standard - detect and prevent dropping or adding Extended Key ID support on rekey. (Initial connection decides if we can use it.) - Don't use Extended Key ID for TKIP. (Not allowed in the standard.) - also flip KeyIDs for WPA_REAUTH and WPA_REAUTH_EAPOL - fixed many "test-only" bugs (both tests and test only code) - split fixes and extensions in different patches - dropped "GET drv_flags" and handle it differently - better description of the patches Patch version 4: - Fixed sequence number key queries (undo invalid switch to new API names.) - get rid of some forgotten "int key_flag" references and switched them over to the correct "enum key_flag key_flag" - Dropped the workaround patch enabling FILS and FT key installs with current released kernels (API is being updated upstream) - removed some stray newlines - reworded Extended Key ID description in wpa_supplicant.conf - minor updates to commit messages - Overhauled and updated commit remarks (nothing critical) Alexander Wetzel (16): nl80211: Migrate to current netlink key message format Driver: Introduce key_types and Extended Key ID driver flag Add new argument key_type to all set_key() functions hostapd: Set the correct key_type for key installs wpa_supplicant: Set the correct key_type for key installs drivers: Migrate drivers from set_tx to key_type API nl80211: Switch to the new key_type API & cleanup nl80211,wpa_supplicant: Drop outdated tdls hack hostapd: Add support for Extended Key ID wpa_supplicant: AP Extended Key ID support tests: Extended Key ID tests hostapd: FILS Extended Key ID support wpa_supplicant: FILS Extended Key ID support nl80211: Extended Key ID support Drop set_tx from all set_key() functions hostapd: Extended Key ID stress test hostapd/config_file.c | 2 + hostapd/ctrl_iface.c | 68 ++++---- hostapd/hostapd.conf | 10 ++ src/ap/ap_config.c | 1 + src/ap/ap_config.h | 1 + src/ap/ap_drv_ops.c | 9 +- src/ap/ap_drv_ops.h | 5 +- src/ap/hostapd.c | 17 +- src/ap/hs20.c | 2 + src/ap/ieee802_11.c | 6 +- src/ap/ieee802_1x.c | 14 +- src/ap/wpa_auth.c | 98 +++++++++-- src/ap/wpa_auth.h | 4 +- src/ap/wpa_auth_ft.c | 13 +- src/ap/wpa_auth_glue.c | 38 +++- src/ap/wpa_auth_i.h | 3 + src/ap/wpa_auth_ie.c | 43 ++++- src/common/wpa_common.c | 1 + src/common/wpa_common.h | 9 + src/crypto/crypto_libtomcrypt.c | 2 +- src/drivers/driver.h | 35 +++- src/drivers/driver_atheros.c | 10 +- src/drivers/driver_bsd.c | 12 +- src/drivers/driver_hostap.c | 9 +- src/drivers/driver_ndis.c | 25 +-- src/drivers/driver_nl80211.c | 164 ++++++++++-------- src/drivers/driver_nl80211_capa.c | 4 + src/drivers/driver_openbsd.c | 4 +- src/drivers/driver_privsep.c | 12 +- src/drivers/driver_wext.c | 27 +-- src/drivers/driver_wext.h | 4 +- src/rsn_supp/tdls.c | 9 +- src/rsn_supp/wpa.c | 155 ++++++++++++++--- src/rsn_supp/wpa.h | 11 +- src/rsn_supp/wpa_ft.c | 17 +- src/rsn_supp/wpa_i.h | 15 +- src/rsn_supp/wpa_ie.c | 11 ++ src/rsn_supp/wpa_ie.h | 1 + tests/fuzzing/eapol-key-supp/eapol-key-supp.c | 2 +- tests/hwsim/hostapd.py | 19 +- tests/hwsim/test_ap_ciphers.py | 2 +- tests/hwsim/test_ap_eap.py | 20 ++- tests/hwsim/test_ap_psk.py | 76 +++++++- tests/hwsim/test_ocv.py | 13 +- tests/hwsim/test_rrm.py | 7 +- tests/hwsim/wpasupplicant.py | 7 +- tests/test-eapol.c | 2 +- wlantest/bss.c | 4 +- wlantest/rx_eapol.c | 4 + wpa_supplicant/config.c | 2 + wpa_supplicant/config_file.c | 1 + wpa_supplicant/config_ssid.h | 10 ++ wpa_supplicant/ctrl_iface.c | 34 ++-- wpa_supplicant/driver_i.h | 25 ++- wpa_supplicant/ibss_rsn.c | 21 +-- wpa_supplicant/mesh_mpm.c | 12 +- wpa_supplicant/mesh_rsn.c | 14 +- wpa_supplicant/preauth_test.c | 4 +- wpa_supplicant/wpa_cli.c | 3 +- wpa_supplicant/wpa_supplicant.c | 40 ++++- wpa_supplicant/wpa_supplicant.conf | 5 + wpa_supplicant/wpas_glue.c | 26 +-- 62 files changed, 892 insertions(+), 332 deletions(-) -- 2.23.0 _______________________________________________ Hostap mailing list Hostap@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/hostap
