From 7e04941bccb2683f8a6e3ee38a99c50129234dd1 Mon Sep 17 00:00:00 2001 From: Lena Date: Thu, 1 Jan 2026 00:00:00 +0000 Subject: rsend: push phone folders to a home SSH host over rsync A small Android app for one-way folder backup, a KISS alternative to Syncthing. It bundles rsync (built from pinned source via the NDK) and a pure-Go SSH transport, both shipped in the APK as lib*.so and run from the native library directory. rsend pins the host key, stores the ed25519 identity Keystore-encrypted, pushes each folder additively or as a mirror, and runs on demand or on a WiFi-only schedule. The build is self-contained and reproducible: make setup provisions the toolchain, make builds rsync, rsh, and the APK. --- metadata/reproducible-builds.md | 46 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 metadata/reproducible-builds.md (limited to 'metadata') diff --git a/metadata/reproducible-builds.md b/metadata/reproducible-builds.md new file mode 100644 index 0000000..9830957 --- /dev/null +++ b/metadata/reproducible-builds.md @@ -0,0 +1,46 @@ +rsend reproducible builds +========================= +How rsend stays reproducible and what F-Droid needs to build it. + + +Pinning +------- +Every tool and source version lives in ./versions: the rsync source and its +sha256, the Go version, the Android NDK, SDK platform, build-tools, Gradle, the +Android Gradle Plugin, and Kotlin. The build never floats a version. + + +Determinism +----------- +- rsh (Go): built with the NDK clang, -trimpath, -ldflags "-s -w -buildid=", + and CGO_CFLAGS=-ffile-prefix-map to drop build paths. +- rsync (C): cross-compiled with -ffile-prefix-map and stripped; optional + dependencies are disabled and zlib and popt come from rsync's bundled copies, + so the binary needs nothing outside Bionic. +- APK: no code shrinking (minifyEnabled false), the Google dependency-metadata + block is dropped (dependenciesInfo off), and native libs use legacy packaging. + +Verify locally by building twice and diffing the native libs: + + make verify-repro + + +F-Droid +------- +The build recipe lives in fdroiddata, not in this repo. F-Droid supplies the +NDK named by the recipe's ndk field and exports ANDROID_NDK_HOME. It pins Go +through the go srclib (the official Go source) and builds it with make.bash, +and installs make and g++ for rsync. The native lib*.so are then built in the +recipe's build step, which runs after F-Droid's source scanner and calls +rsync/build.sh and rsh/build.sh; Gradle then assembles the APK. The release +build is unsigned unless a local keystore.properties is present, so F-Droid +signs the published APK with its own key. + + +All-files access +---------------- +rsend requests MANAGE_EXTERNAL_STORAGE. It is required: backup targets such as +OEM call-recording directories and app-specific media folders live outside the +scoped-media buckets, and rsync needs real filesystem paths rather than SAF +content URIs. The app makes no network access other than the SSH connection to +the host the user configures. -- cgit v1.2.3