Some details on this can be found in our documentation at Release Channels and Signing Keys. To make it easier to understand for non-devs, here are the steps in short:
- download https://f-droid.org/F-Droid.apk.asc and https://f-droid.org/F-Droid.apk
- load the public key for
admin@f-droid.org - compare the fingerprint with what the documentation mentioned above states
- verify the file
On Linux, this is what it would look like:
# download the files
wget -q https://f-droid.org/F-Droid.apk.asc
wget -q https://f-droid.org/F-Droid.apk
# load the public key
gpg --keyserver keyserver.ubuntu.com --recv-key 37D2C98789D8311948394E3E41E7044E1DBA2E89
# verify the file
gpg --verify F-Droid.apk.asc F-Droid.apk
The expected output of the last command should look like:
gpg: Signature made Mon 09 Aug 2021 11:17:55 PM CEST
gpg: using RSA key 802A9799016112346E1FEFF47A029E54DD5DCE7A
gpg: Good signature from "F-Droid <admin@f-droid.org>" [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg: There is no indication that the signature belongs to the owner.
Primary key fingerprint: 37D2 C987 89D8 3119 4839 4E3E 41E7 044E 1DBA 2E89
Subkey fingerprint: 802A 9799 0161 1234 6E1F EFF4 7A02 9E54 DD5D CE7A
The date will vary as the client APK is updated, it’s not an issue if it is newer. The warning about the key not being certified with a trusted signature can be ignored. The important part is the indication of a good signature and that it has the same fingerprint that was used to download the key:
37D2 C987 89D8 3119 4839 4E3E 41E7 044E 1DBA 2E89