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Collaboration document for PSK Identity 02

interfect edited this page Mar 6, 2023 · 272 revisions

Here we will share and organize our findings and data from #483

Please help edit this document!

Much of this was bulk copy-pasted and needs to be transformed into a useful form

Does output in your smarthack-psk.log look like this?:

new client on port 443 from
ID: 0242416f68626d6436614739314946523126e9b5b5bdabbb170482e008c373d879b5d1540ec094d09bb7d53fa3fc9645df
PSK: 2a9cf84b7a1b6bf1ede712edb7ee53c04b065f673e600f43627a67fea9a9d05d
could not establish sslpsk socket: [SSL: DECRYPTION_FAILED_OR_BAD_RECORD_MAC] decryption failed or bad record mac (_ssl.c:1056)

If so, you are in the right place. This is where we aim to fix the issue with ID: 02 and we need your help!

The Goal

  • Derive the PSK from the PSK identity or other known information, if that is even possible with the information we can obtain before a TLS connection is established.

How can you help?

  1. Grab a pcap (see below)
  2. Compare to other pcap signatures in this wiki
  3. Flag if different

Why this is hard?

The challenge of this issue is mapping known information (ie gwId) to the PSK (pskKey), which as mentioned before is indeed unique to every device. This is not possible to extract from the firmware, because to obtain the firmware would require we already know the PSK (or open the device at which point OTA becomes moot).

The previous implementation leaked information through the PSK ID (the MD5 of the auzKey), but this latest implementation uses already public information (the SHA256 of the gwId) as the PSK ID.

It may be that the pskKey is totally random and only stored on Tuya servers and the smart device. If this turns out to be the case, there is no solution to our challenge and this strategy of flashing firmware OTA is no longer viable. §

The prod_idx is used to compute the PSK identity. This is handed to the server by the client during the handshake, so it is not secret information.

prod_idx is not secret information, it is the first part of the gwId. The gwId is what is being hashed here, which is prod_idx + mac.

The point is that the previous implementation did leak secret information through the PSK identity, which we could use to compute the PSK. Now that it does not, our job is harder.

Open questions

  • How is pskKey used to decrypt identity 02 TLS sessions
  • Where does pskKey get stored on devices that have been updated from pre-pskKey versions?
  • What is with pskKey being 37 characters long? And why does it consist of a-zA-Z0-9 (like base64 but without '+' and '/')
    • If it's base62, then this would be a (16+12) 28-byte value, which are 224 bits. Maybe it's a SHA-224 hash?
  • How can we encourage people to check back in this section for things to help with?
    • I would 1) suggest creating a discussion thread than is pinned, much like #483 was and posting any useful information that comes out of it here. 2) rather than pin issue #483, it would be better to pin a link directly to this wiki. Maybe create a new issue that is closed/locked that only contains a link to this wiki if pinning the wiki itself isn't possible.

Findings (and comments that need to be edited into findings)

  • firmware ESP8266 RTOS SDK version did not change, but the hash and build time did
    • versions before PSK change are:
      • OS SDK ver: 2.0.0(898b733) compiled @ May 27 2019 18:49:04
      • OS SDK ver: 2.0.0(e8c5810) compiled @ Jan 25 2019 14:26:04
    • versions after PSK change are:
      • OS SDK ver: 2.0.0(29f7e05) compiled @ Sep 30 2019 11:19:12
        • interesting that this build date corresponds with the release of tuya-convert 2.0, coincidence?
      • OS SDK ver: 2.1.1(317e50f) compiled @ Dec 10 2019 11:05:04
      • OS SDK ver: 2.1.1(8d30f72) compiled @ Jul 28 2020 12:33:05
  • Tuya version also is changed.
    • versions before PSK change are:
    • versions after PSK change are:
      • tuya sdk compiled at Jan 4 2020 18:50:11 (oem_esp_plug)
      • tuya sdk compiled at Mar 6 2020 20:27:48
      • tuya sdk compiled at Apr 8 2020 11:36:25 (oem_esp_switch)
      • tuya sdk compiled at Apr 9 2020 02:33:43 (oem_esp_light_tuya)
      • tuya sdk compiled at Apr 9 2020 04:37:24 (oem_esp_light)
      • tuya sdk compiled at Apr 10 2020 14:44:10 (oem_esp_dltj)
      • tuya sdk compiled at Apr 12 2020 09:45:06 (oem_esp_plug)
      • tuya sdk compiled at Apr 13 2020 20:17:41 (oem_esp_light1_pwm_e2l_jbt_onoff)
      • tuya sdk compiled at Mar 19 2020 17:08:43 (smart_lamp_test2)
  • PSK ID begins with:
    • 01 tuya-convert handles these nicely
    • 02 This is the problem at hand
      • derivation:
        • '\x02' + 'BAohbmd6aG91IFR1' + sha256(gwId)
          • where gwId = prod_idx + mac_addr
            • where prod_idx is an 8 digit ASCII numeric identifier for that device model
            • where mac_addr is the lowercase hex representation of the device MAC address
        • Example: 0242416f68626d6436614739314946523126e9b5b5bdabbb170482e008c373d879b5d1540ec094d09bb7d53fa3fc9645df
          • '\x02' + 'BAohbmd6aG91IFR1' is hex 0242416f68626d64366147393149465231
            • many smarthack-psk.log files have repeating f3 in this section; firmware bug?
          • sha256('81550705c82b9615a3f2') is hex 26e9b5b5bdabbb170482e008c373d879b5d1540ec094d09bb7d53fa3fc9645df
            • prod_idx = '81550705'
            • mac_addr = 'c82b9615a3f2'
    • 03 On OHLUX bulbs
      • is this device using certificate pinning?
  • disabled most of the serial debugging output
    • unfortunate as this was a useful reverse engineering resource
    • system_uart_swap() is called, switching uart over to GPIO2 (at least for LSC devices). There, the debug output is still shown.
  • did not respond to our smartconfig procedure
    • it may use a new mechanism or additional restrictions have been imposed
  • MAC address in flash appears to be compared with actual device MAC
    • likely to foil reverse engineering attempts by running firmware on a dev board
    • this means that a given firmware backup will only run on the original device
    • MAC address is stored at several places in flash:
      • shuffled at 0x79060: the MAC address 11:22:33:44:55:66 is seen here as 55 44 00 B2 33 22 11 66
      • 0xFB000 in the json string
      • 0xFE484, this is a part of the boot- and network settings (0xFE000)
      • 0xFD484,which contains a copy of the boot- and network settings
        • the sector at 0xFE000 is identical to 0xFD000, except when settings are changed during the last session
  • new factory written key found in flash, "pskKey"
    • the app never has access to the PSK, it is only used between the IoT device and the cloud
    • once written to flash it is never transmitted, period.
    • stored in JSON blob at 0xFB000
      • from factory only; updated devices do not have pskKey at 0xFB000
        • so where is pskKey stored on field updated devices?
    • this is indeed the PSK key, unencrypted
      • this means if you have a firmware backup you can use this to decrypt captures from the same device
      • since obtaining the firmware requires a working hack or physically opening the device, this doesn't help us for OTA purposes
    • the PSK key does not change with each new session
      • previously the PSK key changed each session, computed using the PSK ID (fixed) and PSK hint from the server (variable)
      • the previous implementation leaked information via the PSK ID while 02 does not
    • this may mean the encryption key will no longer be derived deterministically, big bummer
    • only found in @rsbob's backup, looks like @Farfar's was updated to this firmware and thus lacks this factory written key
      • this may mean there is still hope for devices that came with a lower firmware, since updating to this firmware would require fetching the key
      • this is a very interesting new endpoint: tuya.device.uuid.pskkey.get
        • if we can figure out the format of this call, we could try faking it and seeing what it returns after multiple calls
        • to do this, we'll need to capture network traffic from a device upgrading to this firmware from an older one without PSK 02
  • The device can request the server downgrade to the old authentication, but the server cannot ask the device to downgrade
    • Since we emulate the server, the downgrade path doesn't help us.
  • outside of updating a vulnerable device to the new firmware, the PSK never leaves Tuya's servers
    • Since this communication is encrypted by the highest version of the encryption scheme that the device supports, this isn't too helpful. Currently we can only decrypt that communication if the device is on the old firmware or we have a firmware dumps from that particular device.
  • the PSK is unique to each device, not shared among an entire model
  • there is currently unused code for what I think is certificate pinning in the Tuya SDK (the one on the device)
    • why do they use PSK, why not do the certificate pinning to the cloud?
      • likely answer is that the public key cryptography necessary to validate a certificate or chain is too slow on the ESP8266
  • the server cannot tell Tuya devices to turn off encryption
    • The devices will reject any connection not secured with the TLS_PSK_WITH_AES_128_CBC_SHA256 cipher suite.
  • The alphabet for both auz_key and pskKey seem to be (a-z, A-Z, 0-9)
    • We know that is it likely not base64, as we have plenty of samples and no instances of the +/ characters
    • It is possible that it is base62, but it seems more likely that this is a random string generated at the factory and stored only on the device and the cloud.
      • That would lead me to the guess, that they are not the result of any computation (like hashing the mac_addr or the like), because converting the binary result of such a computation into the above format is not straight forward.
      • If it's base62, then this would be a (2*8) 24-byte value, which are 192 bits. Maybe it's an AES key?
    • Does anybody have an idea, why the length of the pskKey is 37? That sounds rather random.


Decrypting network captures with known PSK

tshark -o "ssl.psk:3ce2b65bc30c7d91bf2e50884a49f6ddc77a8c44b991a1120b298ab846e97704" -z follow,ssl,ascii,9 -r gosund-upgrade.pcap -Y null

This assumes you:

  • want to look at stream number 9
  • are reading gosund-upgrade.pcap, found below as #34
  • will replace 3ce2b65bc30c7d91bf2e50884a49f6ddc77a8c44b991a1120b298ab846e97704 with the actual psk if you want to look at a different pcap or stream using a different hint
    • see for how to calculate psk when looking at streams using identity 01

Creating network captures and firmware backups

  1. Install create_ap
git clone
cd create_ap
sudo make install
cd ..
  1. Setup a pass-through AP (assuming your interface is wlan0)
sudo create_ap wlan0 wlan0 MyAccessPoint MyPassPhrase
  1. Start recording
tcpdump -i wlan0 -w capture.pcap
  1. Connect your phone to MyAccessPoint (or whatever you decide to call it)
  2. Use the app (SmartLife or vendor branded app) to pair the device
  3. Wait for registration to complete
  4. Disconnect the device
  5. Go back to tcpdump and press Ctrl + C
  6. Disassemble the device and connect to the serial port of the ESP
  7. Download the firmware using esptool read_flash 0 0x100000 firmware.bin
  1. Upload both capture.pcap and firmware.bin


The question here is how are devices with old firmware being integrated into Tuya's newer security scheme, which can help us understand how these new PSKs are created.

  • It may be when a device is first updated through the app, that the new randomly generated PSK is linked to the device MAC (or other device identifier), and that same PSK is issued again after downgrading and updating
    • we could potentially obtain the PSK by faking the API call to the cloud, however this strategy would likely be patched against quickly
  • Or a random PSK is generated each time
    • this would be bad
  • Tuya device with
    • old firmware that works with TuyaConvert, or
    • a converted device with the original backup for that device (MAC address must match)
  • firmware upgrade available for that device model in the Tuya app
    • Confirmed that it is possible to get the new PSK firmware through the app, but not guaranteed to be there for all devices
    • Teckin SB50 firmware was upgraded through Tuya app to new PSK firmware
    • Powertech SL225X sold with new PSK firmware, but no firmware update available in Tuya app for SL225x devices with old firmware
  • ability to open the device and serial flash it
  1. take a device with pre-patched Tuya firmware and back it up
  2. step up network capture via WireShark or tcpdump
  3. register the device to the app and get the updated patched firmware
  4. backup the new firmware to determine the new PSK
  5. flash the device back to the pre-patched firmware
  6. register the device again to the Tuya app to get the patched firmware
  7. backup the new firmware, extract the PSK and determine if it matches the PSK from step 3)
  8. share your findings here!

Several attempts have been made to follow the steps above (see files 10 and 34 in the Firmware table above). It seems that devices which ship with PSK ID 01 firmware and then are updated to firmware which uses PSK ID 02, do not store the pskKey at 0xfb000 as expected. So this experiment is stalled until we can find where pskKey is being stored on these devices, if at all. It is not found in the same 37 character base64-ish format.


Known Affected Devices

  • AIMASON BSD34 Smart WLAN Plug (4 Pack, Amazon - March 2021)
  • AISIRER WiFi Smart Bulb 10W RGBCW (4 pack, Amazon - December 2020)
  • Aoycocr U2S (4 pack, Amazon - December 03, 2020)
  • Aoycocr U3S (4 pack, Amazon - October 13, 2020)
  • Aoycocr X5P Ordered from (4 pack Amazon US November 23, 2020, FCC ID 2AKBP-X5)
  • Aoycocr X10S Ordered from Amazon April 21, 2020 (FCC ID 2AKBP-X10S)
  • Amzdest C168 Outdoor Plug (Amazon 1 OCT 2020)
  • AL Above Lights 810lm
  • Anko HEGSM40 Fan (Kmart December 2020)
  • AOFO Smart Power Strip (ZLD-44EU-W)
  • Arlec GLD060HA lamp
  • Arlec GLD064HA E14 Bulb (November 2020)
  • Arlec GLD120HA (Bunnings September 2020)
  • Arlec GLD112HA (Bunnings May 2021)
  • Arlec GLD081HA (Bunnings October 2020)
  • Arlec PC190HA
  • Arlec PC389HA
  • Arlec PC399HA
  • AHRise AHR-083 Power Strip
  • AHRise AHR-085 Power Strip (Amazon, Oct 24 2020)
  • Aubees smart plug 10-240V european plug. wireless version 2.4 GHz
  • Avatar Mini Smart Socket AWP14H (4 pack, Amazon - October 16, 2020) - note: board is marked HYS-U1S-SOCKET-V1.3 2018-09-21.
  • AWOW EU3S smart socket
  • Avatto NAS-WR01W 10 Amps / 2300 Watt smart socket
  • Avatto NAS-WR01W 16 Amps / 3680 Watt smart socket
  • Bearware WDP 303899 / 20200422WZ001 (/20190809WZ001 is working!) (Amazon, Nov. 17 2020)
  • BAC-002ALW (unbranded) fan coil thermostat (H33711B-2) (Aliexpress, Oct 06 2020)
  • Bakibo TB95
  • Bakibo TP22Y
  • BENEXMART Wifi Tuya WiFi Roller Shade Driver
  • BHT-002-GALW (Decdeal, Moes, MoesGo, etc.) room thermostat (ordered Oct 15, 2020 over Amazon - Moes Go)
  • BHT-002GBLW room thermostat (ordered Sept 16, 2020)
  • BHT-3000GBLW room thermostat (ordered Sept 28, 2020)
  • Blitzwolf BW-LT11
  • Blitzwolf BW-LT20
  • Blitzwolf BW-LT29
  • Blitzwolf BW-SHP8
  • Blitzwolf BW-SHP11 (ordered via banggood 5th nov, 2020)
  • BNETA IoT Smart WiFi LED Bulb+ (IO-WIFI60-E27P)
  • BNETA IoT Smart WiFi Plug WITH POWER METER IO-WiFi-PlugSA (ordered via Takealot oct, 2022)
  • BN-Link BNC-60 (ordered Amazon Sept 6, 2020)
  • BN-Link Smart Wall Socket KS-604S (w/ USB, Amazon purchase April 2021)
  • Brennenstuhl Ecolor 3AC (ordered at Amazon NL on Nov 21, 2022)
  • BSD33 smart socket (ordered at Aliexpress on Dec 21, 2020)
  • BSD34 smart socket
  • Calex Multi Color Floor Lamp
  • Calex Smart RGB Reflector
  • Connect SmartHome CCT Downlight
  • Deltaco SH-LE27W (Post-ESP8266: ESP8285 TYWE2L)
  • Deltaco SH-LE27RGB (More recent units (at least since 2020 summer?) have new PSK. ESP8285 on Tuya TYWE2L)
  • Deltaco SH-LFE27G125 G125 golden globe with CCT
  • Deltaco SH-OP01
  • Deltaco SH-P01
  • Deltaco SH-P01E
  • Deltaco SH-LGU10W
  • DENVER SHP-100 Smart home power plug
  • DENVER PLO-109 Smart home power plug
  • DETA Quad Smart Switch (6904HA)
  • DETA Smart Downlight (DET902HA)
  • DETA Triple Smart Switch
  • Dogain E12 (packaging says GDT-smart bulb Q5-4) (Amazon Nov 20, 2020)
  • Eachen WiFi-IR Universal Remote (SANT-IR-01)
  • eLinkSmart BSD29 (packaging says Smart Plug eLinkSmart 16A - Amazon Nov 20, 2020)
  • EKAZA EKNX-T005 (same product as NX-SM400) (Mercado Livre / Nova Digital - Jan 2021 2 pack)
  • Etersky WF-CS01 Curtain Switch
  • Etersky Wifi Smart Bulb (LDS-WF-A60-9W-E27-RGB) (Amazon Dec 2020, 2 pack)
  • Esicoo Wifi Smart Plug (US package listes device model is 'YX-WS01', Amazon US May 2021, 4 pack) Suspect RelTek IC Not ESP8266 IC based
  • FCMILA Smart Bulb RGBW
  • Feit Smart Wifi Bulb
  • Feit OM100/RGBW/CA/AG (fccid: SYW-A21RGBWAGT2R - non R versions seem to be unaffected)
  • Feit OM100/RGBW/CA/AG(C) (Amazon purchase in Oct 2021, TYWE3L module, OS SDK: 2.1.1(317e50f), Tuya SDK: Apr 13 2020 10:28:31, firmware info name: oem_esp_light_v1_tuya version:1.1.1, FCC ID SYW-A12RGBWAGT2R)
  • Feit Smart Dimmer
  • Feit Smart Plug (SYW-PLUGWIFIG2)
  • Fitop Smart Bulb E27
  • Freecube Smart Bulb E14 5W ( Dec 2020)
  • GD.Home LED Floor Lamp (Anten, Amazon Jan 2021)
  • Geeni Prisma 10W 1050lm RGBCCT Bulb
    • 17 Dec 20 - Latest firmware for GN-BW94-999 is 1.0.3. Unable to use latest Tuya-Convert from development branch - #54277bcf. Bulb connects to vtrust AP but that's it. Nothing in the logs of any use).
  • Girier 16A Power Monitoring Plug (JR-PM01)
  • Globe Smart Ambient Light (Amazon May 2022)
  • Globe Smart Bulb [3.0] (A19, E26 Medium Base, RGB, 2000k - 5000k, 60W, 800 lumens. From Costco Canada)
  • GoKlug WIFI Light Switch (Amazon, Jan 2021, GoKlug logo on front), but can be opened & flashed directly
  • Gosund 800l bulb
  • Gosund EP2 (2500W, sucessor of SP111 Plug - now glued and soldered, ESP8285. Amazon, Oct 2020)
  • Gosund SP 1 (new PSK: Amazon, Nov. 2020, 4 Pack)
  • Gosund SP 112
  • Gosund SW 1 (1-way switch; new PSK: Amazon, Dec. 2020, 4 pack)
  • Gosund SW2 1-way Dimmer Smart Switch
  • Gosund SW6 3-way Smart Switch (ESP8285-based as of Amazon Dec 2020 purchase)
  • Gosund WB4 bulb
  • Gosund WB5 bulb
  • Gosund WP2 socket (new PSK: Amazon 2021-06-10 (2-pack, ASIN B07F58N32V); ESP8266EX; mfg. date on device: 02/2021; prod_idx 34751287)
  • Gosund WP3 socket (old PSK: Amazon 2020-08-26; new PSK: Amazon 2020-10-20)
  • Gosund WP5 socket (Amazon, October 8, 2020)
  • Gosund WP6 socket (Amazon, December 31, 2020)
  • Halonix Prime Prizm 12W RGB Bulb(, October 28, 2020)
  • Hama 10W 1050lm RGBW E27 Bulb (Amazon, October 2020)
  • Hama Outdoor WiFi socket 176570
  • HBN Outdoor Smart WiFi Plug U151T (Amazon, December 2020)
  • Hiking DDS238-2 Wifi - Smart Meter with relay
  • Hombli Smart Socket power plug - HBPP-0204
  • iiglo Wi-Fi Smart Power Strip – IISMART0003 (Komplett, November 2020, SKU:1174244) (Shows up with ESP_xxxxxx in the DHCP lease, returns PSK 02)
  • Jasco Enbrighten Smart Plug, model WFD4105E
  • Jinvoo SM-AW713 Valve
  • Jinvoo SM-PW713
  • KHSUIN A19 E26 RGBCW 7w 800lm bulb (Amazon, June 2020)
  • Klas Remo SWA11
  • Kogan KASMCDSKTLA 1.7L Smart Kettle
  • Kogan SmarterHome Smart Plug with Energy Meter [KASPEMHA, KASPEMHUSBA] (Kogan, June 2020, but by Oct 2021, KASPEMHA now WB2S, incompatible with tasmota)
  • Kogan KAB22RGBC1A Smart Bulb (B22) 10W 806LM
  • LangPlus+ 40W 3500LM Smart Outdoor Floodlight (Amazon, 16 APR 2021)
  • Legelight Smart Light Bulb (2pack - 7W 650LM - E26)
  • Lenovo SE-241EB Smart Bulb (Mfg Date: 20/9/9)
  • LOHAS E14 bulb
  • LOHAS Candelabra LED Bulb E12 Base
  • Lonsonho X801A-L Light Switch (No neutral)
  • Loratap sc500w curtain switch
  • Loratap SC511WSC Curtain switch module with remote
  • LSC Filament E27 Dimmable Bulb
  • LSC Filament C35/E14 Dimmable Bulb
  • LSC Garden Spots
  • Lumary Downlights 18W (Amazon ES, 15 Apr 2022) comes with WB2S, incompatible with tasmota)
  • Luminea NX-4491-675 (from Pearl)
  • Luminea ZX-2820-675 Smartmeter Plug (from Pearl)
  • LUMIMAN ‎LM530-4P-US
  • ‎LUMIMAN LM650-2P-CA
  • LVWIT A70-3 WIFI DIM+CCT+RGB 12W E27 X-Y X0014O0801 LED Bulb 4pack (Amazon, December 2020)
  • Maxcio YX-L01C-E14
  • Maxcio YX-L01C-E27
  • Merkury MI-BW320-999W Light bulb
  • Merkury MI-BW944-999W 11W 1050LM Light Bulb
  • Merkury MI-EW003-999W LED Light strip
  • Merkury MI-OW101 (DR-1703) Outdoor smart plug
  • Minoston MP22W Outdoor Plug
  • Milfra Smart Module TB41
  • Mirabella Genio 5W 450lm Candle RGBCCT Bulb (E14) (Kmart, May 2021)
  • Mirabella Genio 9W 800lm RGBW Bulb (B22) - (I002608, Coles 10 Dec 2020; Note: "Sale" (AU) units bought from Coles 20 Sep 2020 and KMart approx Oct 2020 both PSK 01)
  • Mirabella Genio 9W LED Wi-Fi Dimmable Downlight - I002741
  • Mirabella Genio Christmas Wi-Fi 200 LED Colour Wheel Icicle Lights (Big W, 14 Nov 2020)
  • Mirabella Genio 5W LED Wi-Fi Dimmable Downlight - I002943
  • Mirabella Genio Smart IR Controller (Kmart, 18 Dec 2020)
  • MoesHouse Smart Downlight
  • Moes WS-US1-W 1 Gang
  • Moes Wi-Fi Smart Wall Socket KS-604S (w/ USB, Amazon purchase April 2021)
  • NEO Coolcam NAS-WR01W
  • Nedis Wi-Fi Smart Plug WIFIP110FWT
  • Nedis Wi-Fi Smart Plug WIFIP130FWT
  • Nedis Wi-Fi Smart Outdoor Plug WIFIPO120FWT (November 25 2020)
  • Nedis Wi-Fi Smart Bulb WIFILT10GDA60 (December 2020)
  • Nedis Wi-Fi Smart Bulb WIFILW13WT (May 2021)
  • Nedis Wi-Fi Smart Extension Socket WIFIP311FWT (Dec 2021)
  • Nedis Wi-Fi Smoke Detector WIFIDS10WT (Dec 2021)
  • NOUS Smart WIFI Socket A1 "NOUS A1" (4 pack,, Feb 2022)
  • Novostella 20w Smart LED Floodlight
  • Novostella 13W Smart LED Light Bulbs RGBCW (Model: UT55509, Amazon purchase in Oct 2021, TYWE3L module, OS SDK: 2.1.1(317e50f), Tuya SDK: Apr 9 2020 04:37:24, firmware info name: oem_esp_light version:1.6.1)
  • NX-SM112
  • NX-SM400
  • OHLUX Smart WiFi LED (ASIN B08CL2CKW3, OS SDK ver: 2.0.0(29f7e05) compiled @ Sep 30 2019 11:19:12)
  • OHLUX 40W 4000LM Smart Outdoor Flood Lights (ASIN B083TZFB29)
  • Olafus 10W WiFi LED (2 pack,, Mar 2022, Model: E10WIFI, SKU LA-E10-78FDRGBW-EU02)
  • Polux WI-FI SMART LED, 400lm, 5,5W, GU10 (GU10SMDWWCW+RBG) (Model: MK-010011001067, Series: SE2006MK-1)
  • Polux WI-FI SMART LED, 400lm, 5,5W, E12 (E12SMDWWCW+RBG) (Model: MK-010052019005, Series: SE2004MK-1)
  • Polux WI-FI SMART LED, 1055lm, 13W, E27 (E27SMDWWCW+RBG) (Model: MK-010112048001, Series: SE2006MK-1)
  • Polux Wi-Fi SMART LED Strip RGB+NW 4000K 2m, 540lm, 6,5W, (Model: CL-5050RGB2835WWaaaHYbb-Wcc-WiFi, Series: SE20006CL-1)
  • Powertech SL225X (firmware V3.3.16 TC compatible, V3.3.30 new PSK)
  • Prime WiFi SmartOutlet Outdoor (Date Code: 08/20, from
  • QS-WIFI-S03 Module Switch
  • SANA SW02-02 Smart Switch
  • SHENZHEN LONG SI PU TECHNOLOGY LIMITED FCCID: 2AV9Z-LSPA6, tuya product: jorlvalcdf5lz6qa, FCCID
  • Sinotimer TM608 Smart Timer & Meter (from 09-2021)
  • SmartPoint Smart WIFI Universal Remote Control SPCNTRL-WM (Walmart)
  • SMRTLite (Costco) LED Panel Light DS18901
  • Spectrum SMART GLS LED lamp, 5W COG E-27 Wi-Fi CCT DIMM Milky
  • Spectrum SMART 2 LED lamp, 5W E-14 Wi-Fi CCT DIMM (WOJ14414, 1322050)
  • Stirling Black Premium Fan Tower with Wi-Fi (TF4601TR-S) (Aldi)
  • Stitch Wireless Smart Power Strip (, Oct 26 2020, P/N 34082)
  • Sunco G25 RGBW Smart Bulb
  • Sunco PAR38 WIFI LED SMART (PAR38_S-13W-27K_5K-2PK)
  • SRL Glass Wallplate Touch Switches (all gang combos)
  • Swisstone SH 320 (ordered from
  • TCP Smart 13A Plug (WISSINWUK)
  • Teckin SB50 (firmware V1.61 new PSK, was previously TC compatible until firmware update through Tuya app).
  • Teckin SB53 (some of them, even BNIB never updated)
  • Teckin SS31 Outdoor smart outlet
  • Teckin SS42 Outdoor smart outlet
  • Teckin SR40 Wi-Fi Smart Wall Socket (Amazon Jan 2021)
  • Tellur TLL331031 (, Jan 2021)
  • TopGreener TGWF15RM smart outlet with Energy Monitor (4 pack, purchased Amazon Nov 2020)
  • Treatlife A19 8W 650lm RGBCCT Bulb
  • Treatlife Ceiling Fan & Light Dimmer Switch DS03
  • TreatLife Smart Dimmer Switch DS01C
  • Treatlife Smart Dimmer Switch DS02S
  • TreatLife Smart Plug-in Dimmer DP10
  • TreatLife SS01S (4 pack, purchased on Amazon Nov 2020)
  • Treatlife SS01 3-Way Switch
  • Treatlife SS02S Single Pole Switch
  • UCOMEN Outdoor Sockets PA-GEBA-01SWP2
  • UFO-R1 / SRW-001 Smart Wifi Infrared Controller (tested version is labeled by MOES)
  • Ultra Link UL-P01W (Takealot, 26 November 2020)
  • Veargree Smart Timer ATMS1601
  • WiFi Smart Power Strip 4 AC - SA-P402A (Zeoota)
  • Wipro Garnet 9W RGBCCT Bulb
  • Wipro Smart Extension DSE2150
  • Wipro Smart Plug 16A
  • Wofea Smart Garage Controller WG-088
  • Woox r5024 (pack of 4 bought on ibood in june 2020)
  • Zebronics ZEB-SP116
  • Zemismart 4 inch 10W Wifi RGBW
  • Zemismart 6 inch 14W WiFi RGBCW
  • Zemismart Curtain Motor ZM79E-DT WiFi here
  • Zemismart WiFi Roller Shutter YH002
  • Zeoota ZLD-44EU-W - WiFi Smart Power Strip


🔢 pcap SDK_ver_A SDK_ver_B mac mac_addr prod_idx auz_key pskKey
1 🔴29f7e05 c44f33bc1794 65046664 tKzPU69mMe3ns8PmA5M2cAuUUDOtrTeA yhULg57DUA3Uo1xTP5xhoI0C1kRpWQOwqjMO8
2 🟢e8c5810 🟡29f7e05 5e1 84067851 iyTIVyDnqiMiMfzWf5KZZsZIcn7gfvMI
3 🔴29f7e05 98f4abc96ac3 06402221 Yw0VAIvFe3aWlvdKEZfmBPg8xfQ3Jg4Q kPJ6yZaAbTUqlk5fHrCN6DyWY2Flz9LLI49un
4 🔴29f7e05 d8f15bd5c898 83203175 JQ1YB6PV5AHHLttPZwkKDs9plRFSWpoY x8rMeGHKE4KVEQiNyUUSyvWxc561vIIN82PMt
5 🔴29f7e05 2462ab3989fe 08488420 diI5mLzLQx5GBNCQQZsZ8J0dQLYMaAeT Z9ir6z2hsTlRVJKwEZyqpfyIzfLyzkMBkwyGd
6b 🔴29f7e05 98f4abc96ab3 06402221 L14IZWNkHhToWQR60Q8cC2BOMSEQ42DF ynYDVOPHIhOH7oBHvcbAIbTrlvAar8slGyNBv
6a 🔴29f7e05 98f4abc96ab3 06402221 L14IZWNkHhToWQR60Q8cC2BOMSEQ42DF ynYDVOPHIhOH7oBHvcbAIbTrlvAar8slGyNBv
7b2 🔴29f7e05 98f4abc96ac8 06402221 dhDirFfJylXSWmkpdXUhcVlY5XK97YtW sLPbe7MDpYMdaQzEYID8gX3flbuUuUHxmQ3Mz
7a2 🔴29f7e05 98f4abc96ac8 06402221 dhDirFfJylXSWmkpdXUhcVlY5XK97YtW sLPbe7MDpYMdaQzEYID8gX3flbuUuUHxmQ3Mz
7b3 🔴29f7e05 98f4abc96bde 06402221 lpb6dZ9qFwE4beS6SYepUQtPAUOdBmlI f0xlg6wbkihLXju2ZVaXmbwJlf2qzsGvxBlqX
7a3 🔴29f7e05 98f4abc96bde 06402221 lpb6dZ9qFwE4beS6SYepUQtPAUOdBmlI f0xlg6wbkihLXju2ZVaXmbwJlf2qzsGvxBlqX
7b4 🔴29f7e05 98f4abc96ab3 06402221 L14IZWNkHhToWQR60Q8cC2BOMSEQ42DF ynYDVOPHIhOH7oBHvcbAIbTrlvAar8slGyNBv
7a4 🔴29f7e05 98f4abc96ab3 06402221 L14IZWNkHhToWQR60Q8cC2BOMSEQ42DF ynYDVOPHIhOH7oBHvcbAIbTrlvAar8slGyNBv
8 🔴29f7e05 600194facb50 02063503 oDg2MkXuvbyxqNEp1Uz1myBAyQarmnUf 6CJRAyEyBuUzueuVBCItKRnQMfOJhdBWm4BvO
9 🔴29f7e05 500291e8f141 26636676 wg7xdxUcsi7W0EmnPUlEtuwoyZwcF2W2 GUKgTWzsxGCn8UR5tIFFluuKD2qA8FYmaZwY2
10b 🟢e8c5810 🟡29f7e05 b60 10801581 qxm7SD7sgStYPZUBfIjlUgtDVAN6AoGP
10a 🟢e8c5810 🟡29f7e05 b60 10801581 qxm7SD7sgStYPZUBfIjlUgtDVAN6AoGP
11 🟡29f7e05 c44f33b5ed3e 22885450 fMFu4XqaRa8f1HLzI9QDm7DJXSdGqJzf
12b 🔴29f7e05 c82b9615a3f2 81550705 DWH2FCFhYROGKFyFrflC3hNAUc0HlPdX rgHG2E1ToDyRq1d4rB1fsSaZJQn3fArLFmTGE
12a 🔴29f7e05 c82b9615a3f2 81550705 DWH2FCFhYROGKFyFrflC3hNAUc0HlPdX rgHG2E1ToDyRq1d4rB1fsSaZJQn3fArLFmTGE
13 🟢23fbe10 2c3ae838e6e4 01200101 opTcwaOCLL2nhutEvmdqJMgspspjiAA7
14 🔴29f7e05 c82b96580af8 54354408 AA8tiO3d0Mm8L1tXxVrvjxUrC4ecwjg4 2ncs17NzxeXXlu0rdSVuWBy1PH9CQvvhtFWPK
15 🔴? a4cf12e5b2ec 62531570 DAuwPH9PaBKgFzBg7Zq4CpUhYDzG4rDQ y5Vsp5b5OTWUqLjp6kOLYxu0Z0PBByRTYuYym
16d1 🔴29f7e05 c82b964e3b29 64785071 eDOnWtAUy5gJOiKtcXkNplBMqOMjJmM3 ggD99i71cC7R7MTVnHadCtjaK28H2f6fOJLrG
16d2 🔴29f7e05 c82b964e3b22 64785071 in18hm8DJch2NzlkjkSVHVuFJ3kpUo6k hcXNpRfvnob0zqZWQ4zL4oxa0BHHRzC6jns3X
17 🔴317e50f f4cfa209f296 02017786 XAQxizdPqgrnvQbOIghkjPVfKfucx57H jJ0OviSFn83XvHf8mkcqxtDPupbv9ahGcMMOk
18 🟢e8c5810 0cc 66058212 lUYMJPQn6rXCboADiborfnCqTUreKyAT
19b1 🔴317e50f 600194fa3ee6 62520020 ra6mACgWjH95YpxmYKGOY8lBJrBOApq0 2addWd7o1Qv9duggcFeklHqI3A3oSaKMJMrYx
19b2 🔴317e50f d8f15bb9ce4d 62520020 54SbITkxFzL2bUPjFqijQJH3AxRdaT6e 92JWevlzWoAHtlYEOHkX4LsCsQPGyqIWW3bEm
20 🔴29f7e05 🔴317e50f 2462ab3d3499 80340470 yXbeuWdxJyD8IVYCvukoSvKrApH4fOaf Tln7d8Uou2pp8TtJbe5JTfdw3b7SYj2YOkmfY
21 🟢898b733 b4e 27080852 mJOBHtZuvzvAK0g8JiRaqyYHn2FOS5Cb
22 🔴29f7e05 50029178b020 54436323 AG1rTspXIeEv0VIciXnD8kAcGu8QUR4c bPzGF9hhpAOCzTZ1bnyEPcLtFXnQlMJSxF1A0
23 🟢898b733 133 06847238 iL4ePi4zaV1V7TjAgOWKcyzBkdI34e2r
24 🟢e8c5810 6ac 03733058 rlPU5cNvqskvc5TpT6tA2AfupOyLrlYl
25 🔴317e50f fcf5c4800682 40426764 UOLjYJbk07gHZO0VBHaZshkxW65HsW0d WgWAqXlPnX8qAdaD8GU2Ljoa8TYaTcD65r6Ur
26 🔴317e50f c82b96ccd0e2 68116280 3KEWyyZHNAOzqyZ8gHpu1IqLasrMlOJZ pfQ9jVNRUArItWV4qaSUuP3ojC5vsXY0L6SIB
27 🔴29f7e05 d8f15bdf7e98 20432477 5RpboSdogNamQInfsrpMeVbr01fvAd9V eH3eYWXmNxaAxTJXPLhJSCucK0N8VkPwCxp24
28 🔴317e50f fcf5c4800682 40426764 UOLjYJbk07gHZO0VBHaZshkxW65HsW0d WgWAqXlPnX8qAdaD8GU2Ljoa8TYaTcD65r6Ur
29 🔴317e50f 50029117b5d0 07045557 CTuF4WV3hKInKYPt6QrJPgX9LaK9M4Bk gibTC21CwXiuH4S3Wjg2wOOqj0Tx1PTtnCknc
30 🟢e8c5810 2d8 56435352 ZJO0QadxOoDTlPFbwW8Larh2r7L8AOBW
31 🟢898b733 6fb 04453323 yzCEW1vz7Y1ZvoCEeEynhxO36JVdZcKA
32 🟢898b733 8f4 78677700 HkXr1p695mO3YpjniaFqhR7PFd3XDHpB
33 🟢898b733 09d 78677700 DAY0eL57GnmVALIvgqDm7YUVkzsWuAEh
34b 🟢e8c5810 610 50135502 0Pefl6UBLqtAvamfrPBimHvM7Oy2AOek
34a1 🟢e8c5810 🟡8d30f72 610 50135502 0Pefl6UBLqtAvamfrPBimHvM7Oy2AOek
34a2 🟢e8c5810 🟡8d30f72 610 50135502 0Pefl6UBLqtAvamfrPBimHvM7Oy2AOek
34a3 🟢e8c5810 🟡8d30f72 610 50135502 0Pefl6UBLqtAvamfrPBimHvM7Oy2AOek
35 🔴317e50f 8caab5e5a280 87860851 fCAAa6f5iNYRj7NzCZGPWpnzMq4cOizF WSWCRf3nG93ttY4j90V3HGXjB1sDeCXYBoVVa
36 🔴317e50f c82b966b3de4 05653062 IG95zG4NOs4hKNtLHxAGz1Mu9h9UiEj1 PeB57pbhtNUVANIstnaGUFBGWyWjwLqWf1uBk
37 🔴317e50f 70039f8968a6 22057624 x9cW1Vg3FEr6s7RKoys8FmTj5SgGHGqO k8WTEIHdy0VBeqovXFdSo2WxwuvlwTLbMZJt1
38 🔴317e50f 24a16016e177 00080070 whhqiFzXBinHg33dheVvwyWhRJBBcFV4 gIjRhFwGBgSibk8czel34IsYoWmImUi2lnjwQ
39 [] 🔴29f7e05 e09806009aed 35558538 CRiNIby4WavZFUX7enncDcFK0M43WQRM fJNQuzsUEBT8TIY88fpATIdaSka3dfZ0hp1Bu
40 [] 🔴29f7e05 d8f15bad691d 40014435 KLeaREf1DijkQ5uFmPidcE0gv0A4VfQG YR0fEdw2QVwyhCCqwJDBd4WiU1G8BhQPzd9bC
  • There can be two firmware builds in a single 1MB image if the device has been updated; listed as SDK_ver_A and SDK_ver_B
  • 🟢 build doesn't know about pskKey (Tuya-Convert probably works)
  • 🟡 build knows about pskKey but doesn't appear to have one set
  • 🔴 build knows about pskKey and has one set in 0xfb000 JSON blob
  • 11 is interesting because it is not upgraded and a build known to use pskKey elsewhere, but doesn't include the string literal pskKey
  • 13 is an older SDK ver (1.4.2 compiled @ Sep 22 2016 13:09:03) and has full MAC address as mac rather than mac_addr
  • 15 is missing the "OS SDK ver:" string
  • 34 are the following firmwares: Original + 3 different upgrades (from the same device) via reflashing original and then upgrading. Hope this helps. I'm available on digiBlur's discord channel @jschwalbe#6176 - hit me up if any questions or something you need that I missed.
  • The pcap from 34a1 shows a spurious retransmit of a "change cipher spec" which prevents wireshark/tshark from decoding the response to the tuya.device.uuid.pskkey.get call. Ignoring that packet allows it to be decoded, yielding the following JSON: {"result":"EqY/PCRBZBAhkpujEEx/X9NrCDCOWuqpmCBIXztwprnMeDhTV4cd9flrbszbTDFlmQ99FJWjDwwrsjr9uDBjKGJ76hlBrDLSxPXMJvFfyMrM6sQezfgCpkIpys5lOBK7","sign":"5dd1747ae9294467","t":1599425271}
  • 35 are images of 2 identical devices, one booted original firmware and tryed wifi flashing, other never booted original fw.
  • None of the images captured so far of a Tuya-Convert compatible build that are updated to an incompatible pskKey build include the pskKey in the JSON blob at 0xfb000

Additional Network Captures


OS SDK ver: 2.0.0(29f7e05) compiled @ Sep 30 2019 11:19:12
[N]%s:%d metedata is without encryption, cover this partition with encrypted data
[N]%s:%d var block [%d] last version is without encryption,now need to encrypt data and cover this partition
[ERR]%s:%d flash_aes128_ecb_encrypt err
[ERR]%s:%d !!!!!!CHIP_MAC:%s FLASH_MAC:%s!!!!!!

Novostella RBGWC 13W E27 {"mac_addr":"e098060153ad","prod_idx":"80157022","auz_key":"ksJHynYgCMs7caHDzXtvb8EwtCtFsLxC","pskKey":"eZklnPtc0xuRVn8mf6bj1Hzarr7p7uTBfgKt3","prod_test":false} ``

Useful Info/Links

More Investigations in Tuya IoT Platform:

Reverse Engineering Tools

maybe this helps someone:

Using mitmproxy with a rooted Android device and TCP Smart

  • It is possible to use mitmproxy to inspect the TLS traffic when pairing one of these devices using the Android TCP Smart application
  • The application will note that it is being run on a rooted device, but will permit you to continue
  • The mitmproxy certificate must be installed as a system certificate, as pretty much everything on Android will not trust a user certificate and will ignore the cert
  • Note that the the smart device will need access to a DHCP server, so this may influence your proxy setup
  • The pairing won't complete if the smart device is proxied, as the device won't trust the mitmproxy certificate
  • Unless there are alternative methods for configuring pinning, network_security_config.xml suggests that the Android app is not using certificate pinning
  • Proxying just the Android device (and not the smart device) allows the pairing process to complete
  • When decrypted, the TLS communication between the app and the servers is json encoded and appears to be encrypted and signed (I can understand the latter as an additional authentication step, but not the former)
  • Next steps:
    • Find out how the communication between the app and the servers is further encrypted
    • Attempt to build firmware for the smart device that has the mitmproxy embedded?