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Electrum Bitcoin Wallet

Latest release: ( 7th April 2022 ) 🔍 Last analysed 17th April 2022 . Reproducible when tested
3.6 ★★★★★
2500 ratings
500 thousand
2nd March 2016

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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 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!

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 

With our test script (?) we get:

+ cp contrib/deterministic-build/requirements-build-android.txt contrib/android/
+ docker build -t electrum-android-builder-img contrib/android/
Sending build context to Docker daemon  101.9kB
Step 1/51 : FROM ubuntu:20.04@sha256:86ac87f73641c920fb42cc9612d4fb57b5626b56ea2a19b894d0673fd5b4f2e9
Removing intermediate container e83920d3fae6
 ---> 6609b240a7d9
Step 44/51 : COPY contrib/deterministic-build/requirements-build-base.txt /opt/deterministic-build/
COPY failed: file not found in build context or excluded by .dockerignore: stat contrib/deterministic-build/requirements-build-base.txt: file does not exist
+ mkdir --parents .buildozer/.gradle
+ docker run -it --rm --name electrum-android-builder-cont --volume /tmp/test_org.electrum.electrum/app:/home/user/wspace/electrum --volume /tmp/test_org.electrum.electrum/app/.buildozer/.gradle:/home/user/.gradle --workdir /home/user/wspace/electrum electrum-android-builder-img /bin/bash -c './contrib/android/make_apk release-unsigned;
        echo "CTRL-D to continue";
Unable to find image 'electrum-android-builder-img:latest' locally
docker: Error response from daemon: pull access denied for electrum-android-builder-img, repository does not exist or may require 'docker login': denied: requested access to the resource is denied.

which means something changed how to build this app.

Checking git diff 4.1.5 4.2.1 indeed, the Dockerfile changed in the line of the error:

-COPY requirements-build-android.txt /opt/deterministic-build/
+COPY contrib/deterministic-build/requirements-build-base.txt /opt/deterministic-build/
+COPY contrib/deterministic-build/requirements-build-android.txt /opt/deterministic-build/

the way the Dockerfile was used to build changed:

-sudo docker build \
+docker build \
     -t electrum-android-builder-img \
+    --file "$CONTRIB_ANDROID/Dockerfile" \

and … the build instructions also slightly changed:

-    $ ELECBUILD_COMMIT=HEAD ELECBUILD_NOCACHE=1 ./build.sh release-unsigned
+    $ ELECBUILD_COMMIT=HEAD ELECBUILD_NOCACHE=1 ./build.sh kivy all release-unsigned

Time to update our test script (?) and run it again:

===== Begin Results =====
appId:          org.electrum.electrum
signer:         e543d576fa0f2a33d412bca4c7d61e2301830e956e7d947e75b9052d176027d3
apkVersionCode: 34020100
verdict:        reproducible
appHash:        f7da55a86aca86080884c1864f8db383d29116d9409ed7f37179785514f1ecf0
commit:         90e5984b647eb0211524e604b6fedff08894f6fd

Only in /tmp/fromPlay_org.electrum.electrum_34020100/META-INF: CERT.RSA
Only in /tmp/fromPlay_org.electrum.electrum_34020100/META-INF: CERT.SF
Files /tmp/fromPlay_org.electrum.electrum_34020100/META-INF/MANIFEST.MF and /tmp/fromBuild_org.electrum.electrum_34020100/META-INF/MANIFEST.MF differ

Revision, tag (and its signature):
object 90e5984b647eb0211524e604b6fedff08894f6fd
type commit
tag 4.2.1
tagger ThomasV <thomasv@electrum.org> 1648320121 +0100

===== End Results =====

which looks good. This binary is reproducible.


Verdict Explained

The binary provided was reproducible from the code provided.

As part of our Methodology, we ask:

Does the binary we built differ from what we downloaded? If not, we tag it Reproducible

If we can reproduce the binary we downloaded from the public source code, with all bytes accounted for, we call the product reproducible. This does not mean we audited the code but it’s the precondition to make sure the public code has relevance for the provided binary.

If the provider puts your funds at risk on purpose or by accident, security researchers can see this if they care to look. It also means that inside the company, engineers can verify that the release manager is releasing the product based on code known to all engineers on the team. A scammer would have to work under the potential eyes of security researchers. He would have to take more effort in hiding any exploit.

“Reproducible” does not mean “verified”. There is good reason to believe that security researchers as of today would not detect very blatant backdoors in the public source code before it gets exploited, much less if the attacker takes moderate efforts to hide it. This is especially true for less popular projects.