Add release APK build script and update README and .gitignore

.gitignore

@@ -15,3 +15,6 @@ local.properties
 
 tmp/
 CLAUDE.local.md
+
+# Release APKs from scripts/build-release-apk.sh
+dist/

README.md

@@ -46,6 +46,23 @@ the core repo (tag + sha256 in `gradle.properties`) and unpacks the
 Pin a newer core release with `scripts/bump-jnilibs.sh <tag>` (rewrites the
 tag, the sha256, and the app version in `gradle.properties`).
 
+CI (`.github/workflows/ci.yml`) runs the tests and uploads the debug APK of
+every push/PR as the `app-debug` workflow artifact.
+
+### Release APK
+
+```bash
+scripts/build-release-apk.sh            # → dist/ezvpn-android-<version>.apk
+scripts/build-release-apk.sh --unsigned # no signing (not installable as is)
+```
+
+The release key is a keystore outside the repo (default
+`~/.config/ezvpn-android/release.jks`, override with `EZVPN_KEYSTORE`;
+password from `EZVPN_KEYSTORE_PASSWORD` or prompted). The script creates it on
+first use — back it up, devices only accept updates signed with the same key.
+A release build cannot be installed over a debug build of the app (different
+signature); uninstall the other one first.
+
 ### Local FFI development
 
 To run against a local build of the core instead of the pinned release, build

app/build.gradle.kts

@@ -94,9 +94,26 @@ android {
         versionName = providers.gradleProperty("ezvpn.versionName").get()
     }
 
+    // Release signing comes from the environment (scripts/build-release-apk.sh
+    // sets it up): EZVPN_KEYSTORE (path), EZVPN_KEYSTORE_PASSWORD, optional
+    // EZVPN_KEY_ALIAS (default "ezvpn") and EZVPN_KEY_PASSWORD (defaults to the
+    // keystore password). Without EZVPN_KEYSTORE, assembleRelease produces an
+    // unsigned APK (app-release-unsigned.apk) that no device will install.
+    val releaseKeystore = System.getenv("EZVPN_KEYSTORE")?.takeIf { it.isNotBlank() }
+    if (releaseKeystore != null) {
+        signingConfigs.create("release") {
+            storeFile = file(releaseKeystore)
+            storePassword = System.getenv("EZVPN_KEYSTORE_PASSWORD")?.takeIf { it.isNotEmpty() }
+                ?: error("EZVPN_KEYSTORE is set but EZVPN_KEYSTORE_PASSWORD is not")
+            keyAlias = System.getenv("EZVPN_KEY_ALIAS")?.takeIf { it.isNotBlank() } ?: "ezvpn"
+            keyPassword = System.getenv("EZVPN_KEY_PASSWORD")?.takeIf { it.isNotEmpty() } ?: storePassword
+        }
+    }
+
     buildTypes {
         release {
             isMinifyEnabled = false
+            signingConfig = signingConfigs.findByName("release")
         }
     }
 

scripts/build-release-apk.sh

@@ -0,0 +1,97 @@
+#!/usr/bin/env bash
+#
+# Build a signed release APK locally.
+#
+# The signing key lives outside the repo in a keystore (default
+# ~/.config/ezvpn-android/release.jks, override with EZVPN_KEYSTORE). On the
+# first run the keystore is created with keytool; the password is taken from
+# EZVPN_KEYSTORE_PASSWORD or prompted for. Keep the keystore and password safe:
+# a device only accepts updates signed with the same key, and there is no way
+# to recover a lost keystore.
+#
+# The APK is written to app/build/outputs/apk/release/app-release.apk and copied
+# to dist/ezvpn-android-<versionName>.apk. The core (libezvpn.so) comes from the
+# pinned ezvpn release unless EZVPN_LOCAL_JNILIBS=1 (see README).
+#
+# Usage:
+#   scripts/build-release-apk.sh             # signed release APK
+#   scripts/build-release-apk.sh --unsigned  # skip signing (app-release-unsigned.apk)
+#   EZVPN_KEYSTORE=/path/to/key.jks EZVPN_KEYSTORE_PASSWORD=... scripts/build-release-apk.sh
+#
+# Note: a release-signed build cannot be installed over a debug build of the
+# same applicationId (and vice versa); uninstall the other one first.
+#
+set -euo pipefail
+
+cd "$(dirname "${BASH_SOURCE[0]}")/.."
+
+SIGN=1
+for arg in "$@"; do
+  case "$arg" in
+    --unsigned) SIGN=0 ;;
+    -h|--help) sed -n '2,23p' "$0"; exit 0 ;;
+    *) echo "unknown option: $arg" >&2; exit 1 ;;
+  esac
+done
+
+if [ "$SIGN" = 1 ]; then
+  keystore="${EZVPN_KEYSTORE:-$HOME/.config/ezvpn-android/release.jks}"
+  alias="${EZVPN_KEY_ALIAS:-ezvpn}"
+  password="${EZVPN_KEYSTORE_PASSWORD:-}"
+
+  keytool=keytool
+  if [ -n "${JAVA_HOME:-}" ] && [ -x "$JAVA_HOME/bin/keytool" ]; then
+    keytool="$JAVA_HOME/bin/keytool"
+  fi
+
+  if [ ! -f "$keystore" ]; then
+    echo "== no keystore at $keystore; creating one"
+    if [ -z "$password" ]; then
+      read -r -s -p "New keystore password (min 6 chars): " password; echo
+      read -r -s -p "Repeat password: " again; echo
+      [ "$password" = "$again" ] || { echo "passwords do not match" >&2; exit 1; }
+    fi
+    [ "${#password}" -ge 6 ] || { echo "password must be at least 6 characters" >&2; exit 1; }
+    mkdir -p "$(dirname "$keystore")"
+    (umask 077 && "$keytool" -genkeypair -keystore "$keystore" -alias "$alias" \
+      -keyalg RSA -keysize 4096 -validity 10000 \
+      -dname "CN=ezvpn-android" \
+      -storepass "$password" -keypass "$password" >/dev/null)
+    echo "   created $keystore (alias $alias) — back it up, it cannot be regenerated"
+  elif [ -z "$password" ]; then
+    read -r -s -p "Password for $keystore: " password; echo
+  fi
+
+  export EZVPN_KEYSTORE="$keystore" EZVPN_KEYSTORE_PASSWORD="$password" EZVPN_KEY_ALIAS="$alias"
+  apk=app/build/outputs/apk/release/app-release.apk
+else
+  unset EZVPN_KEYSTORE EZVPN_KEYSTORE_PASSWORD
+  apk=app/build/outputs/apk/release/app-release-unsigned.apk
+fi
+
+echo "== building release APK"
+./gradlew :app:assembleRelease --console=plain
+[ -f "$apk" ] || { echo "expected $apk after assembleRelease" >&2; exit 1; }
+
+if [ "$SIGN" = 1 ]; then
+  # Verify with apksigner from the newest installed build-tools, if any.
+  sdk="${ANDROID_HOME:-${ANDROID_SDK_ROOT:-}}"
+  if [ -z "$sdk" ] && [ -f local.properties ]; then
+    sdk="$(sed -n 's/^sdk\.dir=//p' local.properties)"
+  fi
+  apksigner="$(ls -d "$sdk"/build-tools/*/apksigner 2>/dev/null | sort -V | tail -n1 || true)"
+  if [ -n "$apksigner" ]; then
+    echo "== verifying signature"
+    "$apksigner" verify --print-certs "$apk" | grep -E 'certificate (DN|SHA-256)'
+  fi
+fi
+
+version="$(sed -n 's/^ezvpn\.versionName=//p' gradle.properties)"
+mkdir -p dist
+if [ "$SIGN" = 1 ]; then
+  out="dist/ezvpn-android-$version.apk"
+else
+  out="dist/ezvpn-android-$version-unsigned.apk"
+fi
+cp "$apk" "$out"
+echo "== $out"