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KeepKey

Latest Release: 7.8.0 15th April 2023

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.

Developer

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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

Source code

Public on github

Released

1st August 2014

Application build

We could not verify that the provided code matches the binary!
See the last Issue we created.

See test result
Tested 25th May 2023

Platform notes

There is no globally accepted definition of a hardware wallet. Some consider a paper with 12 words a hardware wallet - after all paper is a sort of hardware or at least not software and the 12 words are arguably a wallet(‘s backup). For the purpose of this project we adhere to higher standards in the hardware wallet section. We only consider a hardware wallet if dedicated hardware protects the private keys in a way that leaves the user in full and exclusive control of what transactions he signs or not. That means:

  • The device allows to create private keys offline

  • The device never shares private key material apart from an offline backup mechanism

  • The device displays receive addresses for confirmation
  • The device shares signed transactions after informed approval on the device without reliance on insecure external hardware

Passed 11 of 12 tests

We answered the following questions in this order:
We stopped asking questions after we encountered a failed answer.

Is this product the original?

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 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.
Can we expect the product to ever be released?

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”.

Is this product available yet?

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!

Is it a wallet?

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.

Is it for bitcoins?

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.

Is the provider ignorant of the keys?

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.
Does the device hide your keys from other devices?

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.
Can the user verify and approve transactions on the device?

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.
Is the source code publicly available?

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.
Is the decompiled binary legible?

The answer is "yes".
If the answer was "no", we would mark it as "Obfuscated" and the following would apply:

The answer is "no". We marked it as "Obfuscated".

We did not ask this question because we failed at a previous question.
If the answer was "no", we would mark it as "Obfuscated" and the following would apply:

When compiling source code to binary, usually a lot of meta information is retained. A variable storing a masterseed would usually still be called masterseed, so an auditor could inspect what happens to the masterseed. Does it get sent to some server? But obfuscation would rename it for example to _t12, making it harder to find what the product is doing with the masterseed.

In benign cases, code symbols are replaced by short strings to make the binary smaller but for the sake of transparency this should not be done for non-reproducible Bitcoin wallets. (Reproducible wallets could obfuscate the binary for size improvements as the reproducibility would assure the link between code and binary.)

Especially in the public source cases, obfuscation is a red flag. If the code is public, why obfuscate it?

As obfuscation is such a red flag when looking for transparency, we do also sometimes inspect the binaries of closed source apps.

As looking for code obfuscation is a more involved task, we do not inspect many apps but if we see other red flags, we might test this to then put the product into this red-flag category.

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.
Can the product be built from the source provided?

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.
Does the published binary match the published source code?

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

  1. obtain the binary from the provider
  2. compile the published source code using the published build instructions into a binary
  3. compare the two binaries
  4. 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

Update 2023-05-25 Running our script on v7.8.0 we get these results:

$ scripts/test/hardware/keepKey.sh 7.8.0
...
31c1cdd945a7331e01b3cced866cb28add5b49eef87c2bbc08370e5aa7daf9bf  firmware.keepkey.bin
b0fc047c7789bee9fba72e5720fb5c8129c9a32f94f7fe9dca4f4675c8d3ddc2  -
aa5d303ae15d2b5dd3ace06ad4d8665c644efbfba1946c25aa5e25d6d17ed917  -

The diff of the binaries after removing the signature is as follows:

18563,18566c18563,18566
< 00048820: 3a00 556e 6b6e 6f77 6e00 3036 3834 3465  :.Unknown.06844e
< 00048830: 6239 3761 3765 3563 3430 6366 6161 3835  b97a7e5c40cfaa85
< 00048840: 3232 3935 3437 6163 3534 6235 3734 6536  229547ac54b574e6
< 00048850: 3339 004e 6f74 2069 6e20 626f 6f74 6c6f  39.Not in bootlo
---
> 00048820: 3a00 556e 6b6e 6f77 6e00 3737 3933 6539  :.Unknown.7793e9
> 00048830: 3236 3938 3863 3063 3364 6164 3664 3062  26988c0c3dad6d0b
> 00048840: 3762 6639 3937 3235 3734 6139 3232 3864  7bf9972574a9228d
> 00048850: 6131 004e 6f74 2069 6e20 626f 6f74 6c6f  a1.Not in bootlo

So we marked this firmware version as not verifiable as far as this issue gets resolved by the team.

Review of version 7.2.1 Running our script on the latest version we get these results:

$ scripts/test/hardware/keepKey.sh 7.2.1
...
c6cf79e7c2cc1b9cf7eca57aacaab5310b4dd0eff1559cda307295d753251eff  firmware.keepkey.bin
dfa772aac4d9ae7d7afa4d1074bc43af1d943c19119a299f6682214490ef109e  -
dfa772aac4d9ae7d7afa4d1074bc43af1d943c19119a299f6682214490ef109e  -

which is in this order the hash of the

  • signed binary
  • signed binary with signature overwritten with zeroes
  • our compiled binary with signature overwritten with zeroes

The latter two matching means the firmware 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

Previous application build tests

7th August 2022 7.2.1  
31st July 2021 7.1.7  

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.