
KeepKey
Our wallet review process
We examine wallets starting at the code level and continue all the way up to the finished app that lives on your device. Provided below is an outline of each of these steps along with security tips for you and general test results.
Released
1st August 2014
Custody
Private keys generated and held by user
As part of our Methodology, we ask: Is the provider ignorant of the keys?
The answer is "yes". Private keys are generated by the user on the wallet.
Read more
Application build
See the last Issue we created.
If you have a binary for a version that doesn't appear on the list, you can drop the file here to register it so somebody can verify its reproducibility:
Passed all 12 tests
We answered the following questions in this order:
The answer is "yes".
If the answer was "no", we would mark it as "Fake" and the following would apply:
The answer is "no". We marked it as "Fake".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Fake" and the following would apply:
The bigger wallets often get imitated by scammers that abuse the reputation of the product by imitating its name, logo or both.
Imitating a competitor is a huge red flag and we urge you to not put any money into this product!
The answer is "yes".
If the answer was "no", we would mark it as "Announced but never delivered" and the following would apply:
The answer is "no". We marked it as "Announced but never delivered".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Announced but never delivered" and the following would apply:
Some products are promoted with great fund raising, marketing and ICOs, to disappear from one day to the other a week later or they are one-man side projects that get refined for months or even years to still never materialize in an actual product. Regardless, those are projects we consider “vaporware”.
The answer is "yes".
If the answer was "no", we would mark it as "Un-Released" and the following would apply:
The answer is "no". We marked it as "Un-Released".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Un-Released" and the following would apply:
We focus on products that have the biggest impact if things go wrong and while pre-sales sometimes reach many thousands to buy into promises that never materialize, the damage is limited and there would be little definite to be said about an unreleased product anyway.
If you find a product in this category that was released meanwhile, please contact us to do a proper review!
The answer is "yes".
If the answer was "no", we would mark it as "Not a wallet" and the following would apply:
The answer is "no". We marked it as "Not a wallet".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Not a wallet" and the following would apply:
If it’s called “wallet” but is actually only a portfolio tracker, we don’t look any deeper, assuming it is not meant to control funds. What has no funds, can’t lose your coins. It might still leak your financial history!
If you can buy Bitcoins with this app but only into another wallet, it’s not a wallet itself.
The answer is "yes".
If the answer was "no", we would mark it as "A wallet but not for Bitcoin" and the following would apply:
The answer is "no". We marked it as "A wallet but not for Bitcoin".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "A wallet but not for Bitcoin" and the following would apply:
At this point we only look into wallets that at least also support BTC.
The answer is "yes".
If the answer was "no", we would mark it as "Provided private keys" and the following would apply:
The answer is "no". We marked it as "Provided private keys".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Provided private keys" and the following would apply:
The best hardware wallet cannot guarantee that the provider deleted the keys if the private keys were put onto the device by them in the first place.
There is no way of knowing if the provider took a copy in the process. If they did, all funds controlled by those devices are potentially also under the control of the provider and could be moved out of the client’s control at any time at the provider’s discretion.
The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.The answer is "yes".
If the answer was "no", we would mark it as "Leaks Keys" and the following would apply:
The answer is "no". We marked it as "Leaks Keys".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Leaks Keys" and the following would apply:
Some people claim their paper wallet is a hardware wallet. Others use RFID chips with the private keys on them. A very crucial drawback of those systems is that in order to send a transaction, the private key has to be brought onto a different system that doesn’t necessarily share all the desired aspects of a hardware wallet.
Paper wallets need to be printed, exposing the keys to the PC and the printer even before sending funds to it.
Simple RFID based devices can’t sign transactions - they share the keys with whoever asked to use them for whatever they please.
There are even products that are perfectly capable of working in an air-gapped fashion but they still expose the keys to connected devices.
This verdict is reserved for key leakage under normal operation and does not apply to devices where a hack is known to be possible with special hardware.
The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.The answer is "yes".
If the answer was "no", we would mark it as "Bad Interface" and the following would apply:
The answer is "no". We marked it as "Bad Interface".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Bad Interface" and the following would apply:
These are devices that might generate secure private key material, outside the reach of the provider but that do not have the means to let the user verify transactions on the device itself. This verdict includes screen-less smart cards or USB-dongles.
The wallet lacks either a screen or buttons or both. In consequence, crucial elements of approving transactions is being delegated to other hardware such as a general purpose PC or phone which defeats the purpose of a hardware wallet. For big exit scams, a companion app could always request two signatures - one for the coffee you are paying and a second to empty your wallet completely. The former could be broadcast while the latter only gets collected for later use.
Another consquence of a missing screen is that the user is faced with the dilemma of either not making a backup or having to pass the backup through an insecure device for display or storage.
The software of the device might be perfect but this device cannot be recommended due to this fundamental flaw.
The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.The answer is "yes".
If the answer was "no", we would mark it as "No source for current release found" and the following would apply:
The answer is "no". We marked it as "No source for current release found".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "No source for current release found" and the following would apply:
A wallet that claims to not give the provider the means to steal the users’ funds might actually be lying. In the spirit of “Don’t trust - verify!” you don’t want to take the provider at his word, but trust that people hunting for fame and bug bounties could actually find flaws and back-doors in the wallet so the provider doesn’t dare to put these in.
Back-doors and flaws are frequently found in closed source products but some remain hidden for years. And even in open source security software there might be catastrophic flaws undiscovered for years.
An evil wallet provider would certainly prefer not to publish the code, as hiding it makes audits orders of magnitude harder.
For your security, you thus want the code to be available for review.
If the wallet provider doesn’t share up to date code, our analysis stops there as the wallet could steal your funds at any time, and there is no protection except the provider’s word.
“Up to date” strictly means that any instance of the product being updated without the source code being updated counts as closed source. This puts the burden on the provider to always first release the source code before releasing the product’s update. This paragraph is a clarification to our rules following a little poll.
We are not concerned about the license as long as it allows us to perform our analysis. For a security audit, it is not necessary that the provider allows others to use their code for a competing wallet. You should still prefer actual open source licenses as a competing wallet won’t use the code without giving it careful scrutiny.
The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.The answer is "yes".
If the answer was "no", we would mark it as "Failed to build from source provided!" and the following would apply:
The answer is "no". We marked it as "Failed to build from source provided!".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Failed to build from source provided!" and the following would apply:
Published code doesn’t help much if the app fails to compile.
We try to compile the published source code using the published build instructions into a binary. If that fails, we might try to work around issues but if we consistently fail to build the app, we give it this verdict and open an issue in the issue tracker of the provider to hopefully verify their app later.
The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.The answer is "yes".
If the answer was "no", we would mark it as "Not reproducible from source provided" and the following would apply:
The answer is "no". We marked it as "Not reproducible from source provided".
We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Not reproducible from source provided" and the following would apply:
Published code doesn’t help much if it is not what the published binary was built from. That is why we try to reproduce the binary. We
- obtain the binary from the provider
- compile the published source code using the published build instructions into a binary
- compare the two binaries
- we might spend some time working around issues that are easy to work around
If this fails, we might search if other revisions match or if we can deduct the source of the mismatch but generally consider it on the provider to provide the correct source code and build instructions to reproduce the build, so we usually open a ticket in their code repository.
In any case, the result is a discrepancy between the binary we can create and the binary we can find for download and any discrepancy might leak your backup to the server on purpose or by accident.
As we cannot verify that the source provided is the source the binary was compiled from, this category is only slightly better than closed source but for now we have hope projects come around and fix verifiability issues.
The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.Application build test result
Updated Review 2025-02-28 for version 7.10.0
Running our script on the latest version we get these results:
$ scripts/test/hardware/keepKey.sh 7.10.0
...
518ad41643ee8a0aa6a6422f8534ac94f56cd65bc637aea4db7f3fdbb53255c3 firmware.keepkey.bin
958764cf3baa53eec0002eab9c54e02ce6f5fdab71e7efbbe723f958e26ff419 -
958764cf3baa53eec0002eab9c54e02ce6f5fdab71e7efbbe723f958e26ff419 -
In the order shown:
The first line is the signed binary (firmware.keepkey.bin). The second line is that same signed binary with its signature overwritten. The third line is our recompiled binary with its signature overwritten.
Since the latter two lines match, it indicates that version 7.10.0 is reproducible.
Original Analysis with all our considerations
Update 2021-07-31: Reid Rankin, a contributor to the project replied to our questions about reproducibility and provided instructions on how to reproduce the firmware after all. Find it at the end of the Analysis.
KeepKey is a clone of the
Trezor One
and as such we will hopefully come to the same conclusions.
Stress-Free Security
Generate and manage your private keys offline in cold storage, guarded from computer vulnerabilities and viruses, while utilizing wallet software for safe transactions.
Sleek and Simple Display
The large display gives clarity to every digital asset sent and received on your device. Each transaction must be manually approved using the confirmation button, giving you control and visibility over your transactions.
That sounds like it’s a hardware wallet by our standards.
On their help page they also clarify:
Is KeepKey Open Source?
KeepKey’s firmware is 100% open source.
Take a look at our source code on GitHub page!
So, let’s see how that goes:
$ docker pull kktech/firmware:v5-beta
$ git clone git@github.com:keepkey/keepkey-firmware.git
… this command requires a configured github account. This should not be
necessary and work using git clone https://github.com/keepkey/keepkey-firmware.git
instead.
$ git submodule update --init --recursive
fatal: not a git repository (or any of the parent directories): .git
… of course this command works only in the newly created folder:
$ cd keepkey-firmware/
$ git submodule update --init --recursive
Submodule 'code-signing-keys' (https://github.com/keepkey/code-signing-keys.git) registered for path 'code-signing-keys'
Submodule 'deps/trezor-firmware' (https://github.com/keepkey/trezor-firmware.git) registered for path 'deps/crypto/trezor-firmware'
Submodule 'deps/device-protocol' (https://github.com/keepkey/device-protocol.git) registered for path 'deps/device-protocol'
Submodule 'googletest' (https://github.com/google/googletest.git) registered for path 'deps/googletest'
Submodule 'deps/python-keepkey' (https://github.com/keepkey/python-keepkey.git) registered for path 'deps/python-keepkey'
Submodule 'deps/qrenc/QR-Code-generator' (https://github.com/keepkey/QR-Code-generator.git) registered for path 'deps/qrenc/QR-Code-generator'
Submodule 'deps/sca-hardening/SecAESSTM32' (https://github.com/keepkey/SecAESSTM32.git) registered for path 'deps/sca-hardening/SecAESSTM32'
Cloning into 'code-signing-keys'...
Cloning into 'deps/crypto/trezor-firmware'...
Cloning into 'deps/device-protocol'...
Cloning into 'deps/googletest'...
Cloning into 'deps/python-keepkey'...
Cloning into 'deps/qrenc/QR-Code-generator'...
Cloning into 'deps/sca-hardening/SecAESSTM32'...
Submodule path 'code-signing-keys': checked out 'a6470bd8598e5e9a7bfc38bf139a5e5a616f05ec'
Submodule path 'deps/crypto/trezor-firmware': checked out '10a177abe2bebec6864ecba21e7cd9e66f6a43a0'
Submodule 'common/defs/ethereum/chains' (https://github.com/ethereum-lists/chains) registered for path 'deps/crypto/trezor-firmware/common/defs/ethereum/chains'
Submodule 'common/defs/ethereum/tokens' (https://github.com/ethereum-lists/tokens.git) registered for path 'deps/crypto/trezor-firmware/common/defs/ethereum/tokens'
Submodule 'crypto/tests/wycheproof' (https://github.com/google/wycheproof) registered for path 'deps/crypto/trezor-firmware/crypto/tests/wycheproof'
Submodule 'vendor/QR-Code-generator' (https://github.com/nayuki/QR-Code-generator.git) registered for path 'deps/crypto/trezor-firmware/vendor/QR-Code-generator'
Submodule 'vendor/fido2-tests' (https://github.com/trezor/fido2-tests.git) registered for path 'deps/crypto/trezor-firmware/vendor/fido2-tests'
Submodule 'legacy/libopencm3' (https://github.com/libopencm3/libopencm3.git) registered for path 'deps/crypto/trezor-firmware/vendor/libopencm3'
Submodule 'vendor/micropython' (https://github.com/trezor/micropython.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython'
Submodule 'legacy/vendor/nanopb' (https://github.com/nanopb/nanopb.git) registered for path 'deps/crypto/trezor-firmware/vendor/nanopb'
Submodule 'vendor/secp256k1-zkp' (https://github.com/ElementsProject/secp256k1-zkp.git) registered for path 'deps/crypto/trezor-firmware/vendor/secp256k1-zkp'
Cloning into 'deps/crypto/trezor-firmware/common/defs/ethereum/chains'...
Cloning into 'deps/crypto/trezor-firmware/common/defs/ethereum/tokens'...
Cloning into 'deps/crypto/trezor-firmware/crypto/tests/wycheproof'...
Cloning into 'deps/crypto/trezor-firmware/vendor/QR-Code-generator'...
Cloning into 'deps/crypto/trezor-firmware/vendor/fido2-tests'...
Cloning into 'deps/crypto/trezor-firmware/vendor/libopencm3'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython'...
Cloning into 'deps/crypto/trezor-firmware/vendor/nanopb'...
Cloning into 'deps/crypto/trezor-firmware/vendor/secp256k1-zkp'...
Submodule path 'deps/crypto/trezor-firmware/common/defs/ethereum/chains': checked out '143a38eee7f5d7072969d25e7cf37760a2503b41'
Submodule path 'deps/crypto/trezor-firmware/common/defs/ethereum/tokens': checked out 'c0fd515d273adf532e9751ca7310e1e1b74975ad'
Submodule path 'deps/crypto/trezor-firmware/crypto/tests/wycheproof': checked out '2904be69e9d666bf3064fdc15093747e695cfae6'
Submodule path 'deps/crypto/trezor-firmware/vendor/QR-Code-generator': checked out '40d24f38aa0a8180b271b6c88be8633f842ed9d4'
Submodule path 'deps/crypto/trezor-firmware/vendor/fido2-tests': checked out '6dcf78409ac439da55a99290eaa6ad268ad6039e'
Submodule path 'deps/crypto/trezor-firmware/vendor/libopencm3': checked out '5617ed466444790b787b6df8d7f21d1611905fd1'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython': checked out 'f7e780ae16bc62519e6b78672e43ecae9138ed0a'
Submodule 'lib/asf4' (https://github.com/adafruit/asf4) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/asf4'
Submodule 'lib/axtls' (https://github.com/pfalcon/axtls) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/axtls'
Submodule 'lib/berkeley-db-1.xx' (https://github.com/pfalcon/berkeley-db-1.xx) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/berkeley-db-1.xx'
Submodule 'lib/btstack' (https://github.com/bluekitchen/btstack.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/btstack'
Submodule 'lib/libffi' (https://github.com/atgreen/libffi) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/libffi'
Submodule 'lib/lwip' (https://git.savannah.gnu.org/r/lwip.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/lwip'
Submodule 'lib/mbedtls' (https://github.com/ARMmbed/mbedtls.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/mbedtls'
Submodule 'lib/mynewt-nimble' (https://github.com/apache/mynewt-nimble.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/mynewt-nimble'
Submodule 'lib/nrfx' (https://github.com/NordicSemiconductor/nrfx.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/nrfx'
Submodule 'lib/nxp_driver' (https://github.com/hathach/nxp_driver.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/nxp_driver'
Submodule 'lib/stm32lib' (https://github.com/micropython/stm32lib) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/stm32lib'
Submodule 'lib/tinyusb' (https://github.com/hathach/tinyusb) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb'
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/asf4'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/axtls'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/berkeley-db-1.xx'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/btstack'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/libffi'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/lwip'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/mbedtls'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/mynewt-nimble'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/nrfx'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/nxp_driver'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/stm32lib'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb'...
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/asf4': checked out 'd270f79aa16dd8fd4ae3b6c14544283dcb992e9c'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/axtls': checked out '43a6e6bd3bbc03dc501e16b89fba0ef042ed3ea0'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/berkeley-db-1.xx': checked out '35aaec4418ad78628a3b935885dd189d41ce779b'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/btstack': checked out 'c8b9823f68c6af0fa52e2c4e009aba4dbf257232'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/libffi': checked out 'e9de7e35f2339598b16cbb375f9992643ed81209'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/lwip': checked out '159e31b689577dbf69cf0683bbaffbd71fa5ee10'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/mbedtls': checked out '3f8d78411a26e833db18d9fbde0e2f0baeda87f0'
Submodule 'crypto' (https://github.com/ARMmbed/mbed-crypto) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/mbedtls/crypto'
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/mbedtls/crypto'...
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/mbedtls/crypto': checked out 'a78c958b17d75ddf63d8dd17255b6379dcbf259f'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/mynewt-nimble': checked out '97ce3eacaaa79e8ed6cf71717149ced4f5328ee7'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/nrfx': checked out '7a4c9d946cf1801771fc180acdbf7b878f270093'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/nxp_driver': checked out 'b618cb1d521cc9e133bdcd0fca154dee2d925dfe'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/stm32lib': checked out '58fee7c92bd576814d3f2afd92fbc62990270ecc'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb': checked out 'a6b916ba85bef6aad50f1652532b02984dfe2484'
Submodule 'hw/mcu/microchip' (https://github.com/hathach/microchip_driver.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/microchip'
Submodule 'hw/mcu/nordic/nrfx' (https://github.com/NordicSemiconductor/nrfx.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/nordic/nrfx'
Submodule 'hw/mcu/nuvoton' (https://github.com/majbthrd/nuc_driver.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/nuvoton'
Submodule 'hw/mcu/nxp' (https://github.com/hathach/nxp_driver.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/nxp'
Submodule 'hw/mcu/sony/cxd56/spresense-exported-sdk' (https://github.com/sonydevworld/spresense-exported-sdk.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/sony/cxd56/spresense-exported-sdk'
Submodule 'hw/mcu/st/st_driver' (https://github.com/hathach/st_driver.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/st/st_driver'
Submodule 'hw/mcu/ti' (https://github.com/hathach/ti_driver.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/ti'
Submodule 'tools/uf2' (https://github.com/microsoft/uf2.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/tools/uf2'
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/microchip'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/nordic/nrfx'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/nuvoton'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/nxp'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/sony/cxd56/spresense-exported-sdk'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/st/st_driver'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/ti'...
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/tools/uf2'...
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/microchip': checked out '66b5a11995025426224e0ba6f377322e6e8893b6'
Submodule 'samd/asf4' (https://github.com/adafruit/asf4.git) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/microchip/samd/asf4'
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/microchip/samd/asf4'...
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/microchip/samd/asf4': checked out '039b5f3bbc3f4ba4421e581db290560d59fef625'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/nordic/nrfx': checked out '7a4c9d946cf1801771fc180acdbf7b878f270093'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/nuvoton': checked out 'dc96fff794d14818c93ea1d4d760d51a014d70c5'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/nxp': checked out 'b618cb1d521cc9e133bdcd0fca154dee2d925dfe'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/sony/cxd56/spresense-exported-sdk': checked out 'b473b28a14a03f3d416b6e2c071bcfd4fb92cb63'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/st/st_driver': checked out '3fc2e0f3db155b33177bb0705e0dd65cadb58412'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/hw/mcu/ti': checked out 'ed52d354c99e25a5e9db2376eb5e7058c81c3ebd'
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/tools/uf2': checked out '19615407727073e36d81bf239c52108ba92e7660'
Submodule 'hidapi' (https://github.com/signal11/hidapi) registered for path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/tools/uf2/hidapi'
Cloning into 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/tools/uf2/hidapi'...
Submodule path 'deps/crypto/trezor-firmware/vendor/micropython/lib/tinyusb/tools/uf2/hidapi': checked out 'a6a622ffb680c55da0de787ff93b80280498330f'
Submodule path 'deps/crypto/trezor-firmware/vendor/nanopb': checked out '2b48a361786dfb1f63d229840217a93aae064667'
Submodule path 'deps/crypto/trezor-firmware/vendor/secp256k1-zkp': checked out 'fac477f822a9d493b0d23cc604d741b24a0c9719'
Submodule path 'deps/device-protocol': checked out '59c86a41a06f1a6c9242be222cc6ce2273f4ff43'
Submodule path 'deps/googletest': checked out '7888184f28509dba839e3683409443e0b5bb8948'
Submodule path 'deps/python-keepkey': checked out 'ea281adc0ed27d0b366efd159016c5c1869825f0'
Submodule 'device-protocol' (https://github.com/keepkey/device-protocol.git) registered for path 'deps/python-keepkey/device-protocol'
Submodule 'keepkeylib/eth/ethereum-lists' (https://github.com/keepkey/ethereum-lists.git) registered for path 'deps/python-keepkey/keepkeylib/eth/ethereum-lists'
Cloning into 'deps/python-keepkey/device-protocol'...
Cloning into 'deps/python-keepkey/keepkeylib/eth/ethereum-lists'...
Submodule path 'deps/python-keepkey/device-protocol': checked out '59c86a41a06f1a6c9242be222cc6ce2273f4ff43'
Submodule path 'deps/python-keepkey/keepkeylib/eth/ethereum-lists': checked out 'e216e92d3f28821b2baea2ff9596e9a6b698f39f'
Submodule path 'deps/qrenc/QR-Code-generator': checked out '6dfbfdad5d9303ed190d1c3cb7bec34b565b6ce8'
Submodule path 'deps/sca-hardening/SecAESSTM32': checked out '71d356a1141624994cf613bd2d2583892e8e6d5a'
… that is a truly impressive amount of submodules, many of which are required due to alt-coins. The bigger the code base, the bigger the attack surface.
The latest binary available on GitHub is 7.1.7
:
$ git checkout v7.1.7
$ git submodule update --init --recursive
$ scripts/build/docker/device/release.sh
$ wget https://github.com/keepkey/keepkey-firmware/releases/download/v7.1.7/firmware.keepkey.bin
$ sha256sum firmware.keepkey.bin ; tail -c +257 firmware.keepkey.bin | sha256sum ; tail -c +257 ./bin/firmware.keepkey.bin | sha256sum
2b7edd319536076e0a00058d0cfd1b1863c8d616ba5851668796d04966df8594 firmware.keepkey.bin
5528034fec8334a7ee494c2ec50d5f0368e2e5fe403f4bc29a54c70fa026e2c0 -
14b831edbe0555dd1f1c11f98cf1a42338b4058274496b7f45f0f66d9523ff94 -
That’s not a match.
A closer look, comparing the two files after the first 256 bytes that are all
0
in our build and signatures (?) in the signed download:
9 11 15
13 235 241
21 235 241
25 235 241
49 237 243
57 237 243
61 237 243
65 235 241
69 235 241
73 235 241
77 235 241
81 235 241
85 235 241
89 235 241
93 235 241
97 235 241
101 235 241
105 235 241
109 235 241
113 235 241
117 235 241
121 235 241
125 235 241
129 235 241
133 235 241
137 235 241
141 235 241
145 235 241
149 235 241
153 235 241
161 235 241
165 235 241
169 235 241
173 235 241
177 235 241
181 235 241
189 235 241
193 235 241
197 235 241
201 235 241
205 235 241
209 235 241
213 235 241
217 235 241
221 235 241
225 235 241
229 235 241
233 235 241
237 235 241
241 235 241
245 235 241
249 235 241
253 235 241
257 235 241
261 235 241
265 235 241
269 235 241
273 235 241
277 235 241
281 235 241
285 235 241
289 235 241
293 235 241
297 235 241
301 235 241
305 235 241
309 235 241
313 235 241
317 235 241
321 235 241
325 235 241
329 235 241
333 235 241
337 235 241
341 235 241
345 235 241
349 235 241
353 235 241
357 235 241
361 235 241
365 235 241
369 235 241
373 235 241
377 235 241
381 235 241
385 235 241
403 150 152
405 30 31
407 376 0
408 377 370
425 37 41
435 164 166
467 6 10
475 334 336
495 374 376
513 217 221
543 266 270
549 374 4
550 2 3
553 11 21
589 127 131
601 217 221
605 153 155
615 226 230
633 215 217
643 376 0
644 373 374
653 337 341
657 61 63
661 121 123
669 25 27
673 111 113
687 276 300
693 311 313
705 377 1
706 375 376
719 274 276
725 143 145
735 264 266
743 152 154
763 234 236
791 336 340
811 246 250
825 365 371
837 175 201
841 375 1
842 236 237
857 21 31
861 174 204
865 264 274
869 323 333
877 217 227
881 347 357
885 377 7
886 3 4
945 15 17
...
$ cmp --ignore-initial=256:256 --verbose firmware.keepkey.bin ./bin/firmware.keepkey.bin | wc -l
cmp: EOF on firmware.keepkey.bin after byte 526748
360449
… that’s the next 1000 bytes and while some bytes match, 136 bytes don’t match and over the whole file, most bytes don’t match. That is not reproducible and thus not verifiable.
But … as mentione above, a developer provided us with more instructions on how to reproduce it after all. Let’s see …
We have to start from zero, picking what works from above …
$ git clone https://github.com/keepkey/keepkey-firmware
$ cd keepkey-firmware
$ git checkout v7.1.7
$ git submodule update --init --recursive
$ rm deps/python-keepkey/keepkeylib/eth/ethereum-lists/src/tokens/eth/0x45804880de22913dafe09f4980848ece6ecbaf78.json
$ ./scripts/build/docker/device/release.sh
$ wget https://github.com/keepkey/keepkey-firmware/releases/download/v7.1.7/firmware.keepkey.bin
$ sha256sum firmware.keepkey.bin ; tail -c +257 firmware.keepkey.bin | sha256sum ; tail -c +257 ./bin/firmware.keepkey.bin | sha256sum
2b7edd319536076e0a00058d0cfd1b1863c8d616ba5851668796d04966df8594 firmware.keepkey.bin
5528034fec8334a7ee494c2ec50d5f0368e2e5fe403f4bc29a54c70fa026e2c0 -
5528034fec8334a7ee494c2ec50d5f0368e2e5fe403f4bc29a54c70fa026e2c0 -
So that looks better. The firmware we downloaded is the same as in the last round and the chopped part matches. As all we did was delete a part of the provided source code, all promises we provide hold true: If you reviewed the code and it’s all good, the firmware binary is also good. This product is reproducible.
Tests performed by Leo Wandersleb, Mohammad, Daniel Andrei R. Garcia
Disclaimer
Our Analysis is not a full code review! We plan to make code reviews available in the future but even then it will never be a stamp of approval but rather a list of incidents and questionable coding practice. Nasa sends probes to space that crash due to software bugs despite a huge budget and stringent scrutiny.
Do your own research
In addition to reading our analysis, it is important to do your own checks. Before transferring any bitcoin to your wallet, look up reviews for the wallet you want to use. They should be easy to find. If they aren't, that itself is a reason to be extra careful.