DroidFS is an alternative way to use encrypted overlay filesystems on Android that uses its own internal file explorer instead of mounting virtual volumes. It currently supports gocryptfs and CryFS (alpha).
DroidFS is provided "as is", without any warranty of any kind. It shouldn't be considered as an absolute safe way to store files. DroidFS cannot protect you from screen recording apps, keyloggers, apk backdooring, compromised root accesses, memory dumps etc. Do not use this app with volumes containing sensitive data unless you know exactly what you are doing.
DroidFS allows you to enable/disable unsafe features to fit your needs between security and comfort. It is strongly recommended to read the documentation of a feature before enabling it.
- Disable the secure flag of DroidFS activities. This will allow you to take screenshots from the app, but will also allow other apps to record the screen while using DroidFS. Note: apps with root access don't care about this flag: they can take screenshots or record the screen of any app without any permissions.
- Decrypt and open file using external apps. These apps could save and send the files thus opened.
- Decrypt and write file to disk (external storage). Any app with storage permissions could access exported files.
- Decrypt and share file with other apps. These apps could save and send the files thus shared.
- Don't close the volume when you leave the app but keep running it in the background. Anyone going back to the activity could have access to the volume.
- Generate an AES-256 GCM key in the Android Keystore (protected by fingerprint authentication), then use it to encrypt the volume password hash and store it to the DroidFS internal storage. This require Android v6.0 . If your device is not encrypted, extracting the encryption key with physical access may be possible.
You can download DroidFS from F-Droid or from the "Releases" section in this repository.
APKs available here are signed with my PGP key available on keyservers:
gpg --keyserver hkps://keyserver.ubuntu.com --recv-keys AFE384344A45E13A
Fingerprint: B64E FE86 CEE1 D054 F082 1711 AFE3 8434 4A45 E13A
Email: Hardcore Sushi <[email protected]>
To verify APKs, save the PGP-signed message to a file and run gpg --verify <the file>
. Don't install any APK if the verification fails !
If the signature is valid, you can compare the SHA256 checksums with:
sha256sum <APK file>
Don't install the APK if the checksums don't match!
F-Droid APKs should be signed with the F-Droid key. More details here.
DroidFS need some permissions to work properly. Here is why:
- Required for creating, opening and modifying volumes and for importing/exporting files to/from volumes.
- Required to encrypt/decrypt password hashes using a fingerprint protected key.
- Needed to take photos & videos directly encrypted inside DroidFS. You can deny this permission if you don't want to use it.
- Required if you want sound on video recorded with DroidFS.
DroidFS works as a wrapper around modified versions of the original encrypted container implementations (libgocryptfs and libcryfs). These programs were designed to run on standard x86 Linux systems: they access the underlying file system with file paths and syscalls. However, on Android, you can't access files from other applications using file paths. Instead, one has to use the ContentProvider API. Obviously, neither Gocryptfs nor CryFS support this API. As a result, DroidFS cannot open volumes provided by other applications (such as cloud storage clients), nor can it allow other applications to access encrypted volumes once opened.
Due to Android's storage restrictions, encrypted volumes located on SD cards must be placed under /Android/data/sushi.hardcore.droidfs/
if you want DroidFS to be able to modify them.
You can follow the instructions in BUILD.md to build DroidFS from source.
Thanks to these open source projects that DroidFS uses:
- Encrypted filesystems (to protect your data):
- libgocryptfs (forked from gocryptfs)
- libcryfs (forked from CryFS)
- libpdfviewer (forked from PdfViewer) to open PDF files
- DoubleTapPlayerView to add double-click controls to the video player
- MaterialFiles for Kotlin natural sorting implementation