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Muun - Bitcoin and Lightning Wallet

latest release: 45.2 last analysed  6th April 2021
Not reproducible from the source provided
4.4 ★★★★★
168 ratings
10thousand
25th April 2017

Published:

Our last analysis is based on data found in their Play Store description and their website and their source repository. We discuss issues with the provider here.
details below 

Older reviews (show 0 of 1 reproducible)

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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.

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The Analysis

Update 2021-04-06: The provider announced that the app is reproducible now. We will have to check that …

So they now have build instructions for reproducible builds. Promising! Let’s see how that goes …

$ sha256sum fromGoogle45.2.apk # just for the record, the apk hash:
292776e270739d37b9307465cbddfc11068813078d9633035d74ae67f322a3b2  fromGoogle45.2.apk
$ cd /tmp/
$ git clone https://github.com/muun/apollo
$ cd apollo/
$ git checkout v45.2
$ mkdir -p apk
$ docker build -f android/Dockerfile -o apk .
...
BUILD SUCCESSFUL in 3m 9s
62 actionable tasks: 60 executed, 1 from cache, 1 up-to-date
Removing intermediate container 9812d21025c9
 ---> d997f192afe8
Step 24/26 : FROM scratch
 ---> 
Step 25/26 : COPY --from=build /src/android/apolloui/build/outputs/apk/prod/release/apolloui-prod-release-unsigned.apk apolloui-prod-release-unsigned.apk
 ---> 5b8f679ee607
Step 26/26 : COPY --from=build /src/android/apolloui/build/outputs/mapping/prodRelease/mapping.txt mapping.txt
 ---> ad2ddc6ce00f
Successfully built ad2ddc6ce00f
$ ls *.apk
$ ls apk/
$

so the apk did not end up where it’s supposed to end up but it should be part of the docker image now:

$ docker images
REPOSITORY                                                 TAG                    IMAGE ID            CREATED             SIZE
<none>                                                     <none>                 ad2ddc6ce00f        31 minutes ago      59.1MB
<none>                                                     <none>                 d997f192afe8        31 minutes ago      10.3GB
...

with some poking around with interactive runs, I found this works:

$ docker run --rm --volume $(pwd)/apk:/apk d997f192afe8 cp ./android/apolloui/build/outputs/apk/prod/release/apolloui-prod-release-unsigned.apk /apk/
$ ls apk/
apolloui-prod-release-unsigned.apk
$ apktool d -o fromBuild apk/apolloui-prod-release-unsigned.apk 
$ apktool d -o fromGoogle fromGoogle45.2.apk 
$ diff --brief --recursive from{Google,Build}
Files fromGoogle/apktool.yml and fromBuild/apktool.yml differ
Only in fromGoogle/original/META-INF: APOLLORE.RSA
Only in fromGoogle/original/META-INF: APOLLORE.SF
Files fromGoogle/original/META-INF/MANIFEST.MF and fromBuild/original/META-INF/MANIFEST.MF differ
Files fromGoogle/res/values/strings.xml and fromBuild/res/values/strings.xml differ

so the only diff of interest is in res/values/strings.xml:

$ diff from{Google,Build}/res/values/strings.xml
76c76
<     <string name="com.crashlytics.android.build_id">79a4d6b75ce84bd6ae254b900862f3a4</string>
---
>     <string name="com.crashlytics.android.build_id">976f51d22fdf4feda23c0dbc83806a9f</string>

That’s almost reproducible. On a subjective level, if somebody reviewed the source code and it is fine then yes, the apk is also fine but as we only allow diffs in the signature part itself, it is too much of a diff for a reproducible verdict. The app is close but still not verifiable.

(lw)

Verdict Explained

Not reproducible from the source provided

The app provider also shares code but we could so far not verify that the published code matches the published app!

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.