This relatively new app currently has more than 1000 downloads, a 4.3 stars rating from 6 users and the latest APK (version 1.7.5) was from 23rd January 2020.
Our analysis was done on 29th January 2020 based on data found in their Playstore description and their website and their source repository. We discuss the issue with verification with the provider here.
We found these ways of contacting the developers:
Help spread awareness for build verifiability
Please help us spread the word, asking Bitcoin Wallet for COINiD to support verifiable builds via their Twitter!
The following 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 bad coding practice. We cannot find and tell you all the dark secrets the wallet providers might have.
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.
This app does not reveal much information on Google Play but
- Complete Control
- Hierarchical Deterministic
sounds like the standard non-custodial wallet.
The FAQ on their website is more explicit:
Do my private key ever leave my device? No, your private key never leaves your device. You are in full control of your private key.
And in the FAQ we find this gem:
Do you provide deterministic builds? Since we need to distribute the app via the App Store that is not possible. The source is however available on our Github so that anyone can review and compile it.
So let’s give it a try anyway …
The current version is
1.7.5. The build instructions in their entirety are:
We are currently not including the secrets.js in the repo. If you want to compile the wallet to test it you need to add the following to src/config/secrets.js.
export const p2pCommonSecret = ''; export const encryptPrivateSalt = ''; export const pinSecret = '';
That is not good but let’s see:
$ git clone email@example.com:COINiD/COINiDWallet.git $ cd COINiDWallet/ $ git tag v1.6.0 v1.7.0 v1.7.2 v1.7.3 v1.7.4 v1.7.5 $ git checkout v1.7.5 $ docker run --volume=$PWD:/mnt --workdir=/mnt --rm -it beevelop/cordova bash root@c0a4b6139564:/mnt# echo "export const p2pCommonSecret = '';export const encryptPrivateSalt = '';export const pinSecret = '';" > src/config/secrets.js root@c0a4b6139564:/mnt# apt update ; apt install python -y root@c0a4b6139564:/mnt# npm install root@c0a4b6139564:/mnt# yes | $ANDROID_HOME/tools/bin/sdkmanager "platforms;android-28" root@c0a4b6139564:/mnt# cd android/ root@c0a4b6139564:/mnt/android# ./gradlew clean :app:assembleRelease ... > Task :app:bundleReleaseJsAndAssets warning: the transform cache was reset. Loading dependency graph, done. error While trying to resolve module `lottie-react-native` from file `/mnt/src/components/CheckBoxSelect.js`, the package `/mnt/node_modules/lottie-react-native/package.json` was successfully found. However, this package itself specifies a `main` module field that could not be resolved (`/mnt/node_modules/lottie-react-native/lib/index.js`. Indeed, none of these files exist: * `/mnt/node_modules/lottie-react-native/lib/index.js(.native||.android.js|.native.js|.js|.android.json|.native.json|.json|.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx)` * `/mnt/node_modules/lottie-react-native/lib/index.js/index(.native||.android.js|.native.js|.js|.android.json|.native.json|.json|.android.ts|.native.ts|.ts|.android.tsx|.native.tsx|.tsx)`. Run CLI with --verbose flag for more details. > Task :app:bundleReleaseJsAndAssets FAILED FAILURE: Build failed with an exception. * What went wrong: Execution failed for task ':app:bundleReleaseJsAndAssets'. > Process 'command 'node'' finished with non-zero exit value 1 * Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights. * Get more help at https://help.gradle.org Deprecated Gradle features were used in this build, making it incompatible with Gradle 6.0. Use '--warning-mode all' to show the individual deprecation warnings. See https://docs.gradle.org/5.1.1/userguide/command_line_interface.html#sec:command_line_warnings BUILD FAILED in 25s 190 actionable tasks: 174 executed, 16 up-to-date
And that’s where we give it up and conclude with the verdict: not verifiable
Not verifiable: The provided Open Source Code could not be verified to match the app released on Google Play
This verdict means that the provider did share some source code but that we could not verify that this source code matches the released app. This might be due to the source being released later than the app or due to the provided instructions on how to compile the app not being sufficient or due to the provider excluding parts from the public source code. In any case, the result is a discrepancy between the app we can create and the app we can find on GooglePlay 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 app 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 app 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 app 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.