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BRD Bitcoin Wallet. Bitcoin Cash BCH, Bitcoin BTC

latest release: 4.13.0 ( 27th September 2021 ) last analysed  29th June 2021 Not reproducible from source provided 
4.2 ★★★★★
33151 ratings
5 million
21st July 2016

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Do your own research!

Try out searching for "lost bitcoins", "stole my money" or "scammers" together with the wallet's name, even if you think the wallet is generally trustworthy. For all the bigger wallets you will find accusations. Make sure you understand why they were made and if you are comfortable with the provider's reaction.

If you find something we should include, you can create an issue or edit this analysis yourself and create a merge request for your changes.

The Analysis 

Update 2021-06-29: The provider informed us that the latest code can be found in a new repository. Apparently the new repository is a fork of the old repository where they changed the license from open source to some look-dont-touch license. For us, both provide the same degree of transparency so we have to revert the last change in verdict. This app does indeed share up to date source code although the git tag and the Play Store version name do differ.

Update 2021-06-27: As pointed out here, the provider stopped updating the public source repository and thus is to be considered closed source. The current version on the Play Store is 4.10.0 from yesterday. The latest version available on their GitHub is 4.9.1.1 from 2021-03-03.

This wallet claims not to be custodial and we found its supposed source code but we found no claim of verifiability and so verification was difficult.

Update: The team reacted quickly to our reach-out after our first analysis via this issue on their GitHub.

Now we find a tag build-3.14.3.3 and can try to compile that:

$ git tag | grep 3.14.3
build-3.14.3.3
$ git checkout build-3.14.3.3
...
HEAD is now at a332b4d5 Merge branch 'pablobu/DROID-1497' into 'release/3.14.3'
$ git submodule update --init --recursive
$ docker run -v $PWD:/mnt -it beevelop/cordova bash
root@e34a31867b99:/tmp# cd /mnt/
root@e34a31867b99:/mnt# yes | $ANDROID_HOME/tools/bin/sdkmanager "platforms;android-28"
root@e34a31867b99:/mnt# ./gradlew :app:assemble
root@e34a31867b99:/mnt# ls app/build/outputs/apk/brd/release/*.apk
brd-release-3.14.2.1.apk  output.json

Now that doesn’t look promising, given we need version 3.14.3 and indeed the diff is huge and goes across many code files.

The content of AboutActivity for example confirms its the wrong version. Many of the differences look harmless like this:

diff -r fromBuild/smali/com/breadwallet/presenter/activities/settings/AboutActivity.smali fromPlayStore/smali/com/breadwallet/presenter/activities/settings/AboutActivity.smali
157c157
<     const-string v4, "3.14.2"
---
>     const-string v4, "3.14.3"

But with these diffs we can’t give it a pass:

Binary files fromBuild/lib/arm64-v8a/libcore.so and fromPlayStore/lib/arm64-v8a/libcore.so differ
Binary files fromBuild/lib/armeabi-v7a/libcore.so and fromPlayStore/lib/armeabi-v7a/libcore.so differ
Binary files fromBuild/lib/x86/libcore.so and fromPlayStore/lib/x86/libcore.so differ
Binary files fromBuild/lib/x86_64/libcore.so and fromPlayStore/lib/x86_64/libcore.so differ

Diffoscope yields user directories in its 397662 lines of diff:

│ ├── readelf --wide --decompress --hex-dump=.rodata {}
│ │ @@ -1,7610 +1,7450 @@
│ │  
│ │  Hex dump of section '.rodata':
│ │ -  0x001622e0 2f557365 72732f61 6a762f64 6576656c /Users/ajv/devel
│ │ -  0x001622f0 2f627265 61647761 6c6c6574 2d616e64 /breadwallet-and
│ │ -  0x00162300 726f6964 2f636f72 652f4a61 76612f43 roid/core/Java/C
│ │ -  0x00162310 6f72652f 7372632f 6d61696e 2f637070 ore/src/main/cpp
│ │ -  0x00162320 2f636f72 652f7375 70706f72 742f4252 /core/support/BR

This looks like NDK being the culprit for part of the diff, apart from it being the wrong version. Hopefully with Docker this can be improved.

Our verdict

We conclude that we hope for a quick resolution of the issues but for now this wallet remains not verifiable.

(lw)

Verdict Explained

We could not verify that the provided code matches the binary!

As part of our Methodology, we ask:

Is the published binary matching the published source code? If not, we tag it Unreproducible! 

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.