fix(android): treat a blank signing secret as absent, not as the password

The Android jobs failed with "Get Key failed: Given final block not properly
padded" once the store password was corrected - the keystore opened, but the
KEY could not be decrypted.

Cause: GitHub Actions substitutes an empty string, not an unset variable, for
a secret that does not exist. ANDROID_KEY_PASSWORD is deliberately not set (our
keystore is PKCS12, where the key password cannot differ from the store
password), so OSTP_KEY_PASSWORD arrived as "". Kotlin's elvis operator only
falls back on null, so `getenv(...) ?: storePassword` kept the empty string and
used it as the literal key password.

signingSetting() now maps blank to null, so the documented fallback actually
happens. Applies to every signing field, not just the key password - the same
trap would have hit any of them.

.github/workflows/release.yml

@@ -378,7 +378,15 @@ jobs:
             ~/.cargo/registry/cache/
             ~/.cargo/git/db/
             target/
+            ostp-gui/src-tauri/target/
           key: cargo-windows-gui-${{ matrix.target }}-${{ hashFiles('**/Cargo.lock') }}
+          # Without a prefix fallback this cache NEVER restored on a release:
+          # cutting a release rewrites every Cargo.lock (version bump), which
+          # changes hashFiles(), which misses the exact key — so each release
+          # rebuilt every dependency from scratch. That is why the GUI jobs ran
+          # 2-4x longer than the plain release targets, which had this all along.
+          restore-keys: |
+            cargo-windows-gui-${{ matrix.target }}-
 
       - name: Download wintun
         shell: pwsh
@@ -460,7 +468,10 @@ jobs:
             ~/.cargo/registry/cache/
             ~/.cargo/git/db/
             target/
+            ostp-gui/src-tauri/target/
           key: cargo-linux-gui-${{ matrix.target }}-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: |
+            cargo-linux-gui-${{ matrix.target }}-
 
       - name: Build Tauri App
         working-directory: ostp-gui
@@ -522,7 +533,10 @@ jobs:
             ~/.cargo/registry/cache/
             ~/.cargo/git/db/
             target/
+            ostp-gui/src-tauri/target/
           key: cargo-macos-gui-${{ matrix.target }}-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: |
+            cargo-macos-gui-${{ matrix.target }}-
 
       - name: Build Tauri App
         working-directory: ostp-gui
@@ -587,27 +601,107 @@ jobs:
         with:
           ndk-version: r26b
 
-      - name: Install cargo-ndk
-        run: cargo install cargo-ndk
+      # The Android jobs had no Rust caching at all, so every release recompiled
+      # the whole ostp-jni dependency graph from scratch — the main reason these
+      # were among the slowest jobs in the matrix.
+      - name: Cache cargo
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry/index/
+            ~/.cargo/registry/cache/
+            ~/.cargo/git/db/
+            target/
+          key: cargo-android-${{ matrix.arch }}-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: |
+            cargo-android-${{ matrix.arch }}-
+
+      # cargo-ndk was built from source on every run. Cache the binary the same
+      # way the cross-compilation jobs already cache `cross`.
+      - name: Restore cargo-ndk binary cache
+        id: cargo-ndk-cache
+        uses: actions/cache@v4
+        with:
+          path: ~/.cargo/bin/cargo-ndk
+          key: cargo-ndk-bin-${{ runner.os }}-v1
+
+      - name: Install cargo-ndk (if not cached)
+        if: steps.cargo-ndk-cache.outputs.cache-hit != 'true'
+        run: cargo install cargo-ndk --locked
 
       - name: Build Android APK
         shell: bash
         working-directory: ostp-flutter
+        env:
+          OSTP_KEYSTORE_B64: ${{ secrets.ANDROID_KEYSTORE_BASE64 }}
+          OSTP_KEYSTORE_PASSWORD: ${{ secrets.ANDROID_KEYSTORE_PASSWORD }}
+          OSTP_KEY_ALIAS: ${{ secrets.ANDROID_KEY_ALIAS }}
+          OSTP_KEY_PASSWORD: ${{ secrets.ANDROID_KEY_PASSWORD }}
         run: |
-          # 1. Compile JNI
+          set -euo pipefail
+
+          # 1. Materialise the upload keystore from secrets. Android keys an app
+          #    by applicationId + signing key and refuses to update across a key
+          #    change, so every published build MUST use this one key. Releases
+          #    used to fall through to the per-machine debug keystore, which on
+          #    ephemeral CI runners meant a different random key every build -
+          #    hence "App not installed" on upgrade.
+          if [ -z "${OSTP_KEYSTORE_B64:-}" ]; then
+            echo "::error::ANDROID_KEYSTORE_BASE64 secret is not set. Refusing to publish a"
+            echo "::error::debug-signed APK: users could not update over it and the key is"
+            echo "::error::not reproducible. See docs for the one-time keystore setup."
+            exit 1
+          fi
+          export OSTP_KEYSTORE_PATH="$RUNNER_TEMP/ostp-upload.jks"
+          # Strip any stray CR/LF before decoding: the secret is pasted from a
+          # shell whose line endings we don't control, and a single trailing \r
+          # is enough to corrupt the decode.
+          printf '%s' "$OSTP_KEYSTORE_B64" | tr -d '\r\n' | base64 -d > "$OSTP_KEYSTORE_PATH"
+
+          # Verify the keystore opens BEFORE spending four minutes on Gradle only
+          # to fail at the packaging step. The size/SHA-256 are safe to print (a
+          # hash reveals nothing) and let the operator compare against the local
+          # file to tell a transport problem apart from a wrong password.
+          echo "keystore: $(stat -c%s "$OSTP_KEYSTORE_PATH") bytes, sha256 $(sha256sum "$OSTP_KEYSTORE_PATH" | cut -d' ' -f1)"
+          if ! keytool -list -keystore "$OSTP_KEYSTORE_PATH" \
+                 -storepass "$OSTP_KEYSTORE_PASSWORD" >/dev/null 2>&1; then
+            echo "::error::The keystore did not open with ANDROID_KEYSTORE_PASSWORD."
+            echo "::error::If the SHA-256 above matches your local ostp-upload.jks, the file"
+            echo "::error::arrived intact and the password secret itself is wrong - note that"
+            echo "::error::PowerShell expands \$ inside double quotes, so a password containing"
+            echo "::error::one gets mangled unless it was set with single quotes."
+            exit 1
+          fi
+          if ! keytool -list -keystore "$OSTP_KEYSTORE_PATH" \
+                 -storepass "$OSTP_KEYSTORE_PASSWORD" -alias "$OSTP_KEY_ALIAS" >/dev/null 2>&1; then
+            echo "::error::Keystore opened, but it has no key under ANDROID_KEY_ALIAS."
+            echo "::error::Aliases present in the keystore:"
+            keytool -list -keystore "$OSTP_KEYSTORE_PATH" -storepass "$OSTP_KEYSTORE_PASSWORD" \
+              | grep -i "PrivateKeyEntry" || true
+            exit 1
+          fi
+
+          # 2. Compile JNI
           mkdir -p android/app/src/main/jniLibs/${{ matrix.arch }}
 
           cd ../ostp-jni
           cargo ndk -t ${{ matrix.arch }} -o "../ostp-flutter/android/app/src/main/jniLibs" build --release
           cd ../ostp-flutter
 
-
-          
           # 3. Build Flutter APK
           flutter build apk --release --target-platform ${{ matrix.flutter_target }}
 
-          # 4. Copy to output
-          cp build/app/outputs/flutter-apk/app-release.apk ostp-android-${{ matrix.arch }}.apk
+          # 4. Fail loudly if the APK somehow still came out debug-signed, rather
+          #    than shipping another un-updatable build.
+          APK=build/app/outputs/flutter-apk/app-release.apk
+          if "$ANDROID_HOME"/build-tools/*/apksigner verify --print-certs "$APK" 2>/dev/null \
+               | grep -qi "CN=Android Debug"; then
+            echo "::error::APK is signed with the Android debug certificate - aborting."
+            exit 1
+          fi
+
+          # 5. Copy to output
+          cp "$APK" ostp-android-${{ matrix.arch }}.apk
 
       - name: Upload to GitHub Release
         uses: softprops/action-gh-release@v2

.gitignore

@@ -26,6 +26,13 @@ test_route.ps1
 config.json
 wintun.dll
 
+# Android signing keys. The upload keystore is the ONE key every published APK
+# must be signed with (Android refuses to update an app across a key change),
+# so losing or leaking it is unrecoverable — it can never be committed.
+*.jks
+*.keystore
+key.properties
+
 # Server runtime cache (public IP autodetect) — must never be committed,
 # it's regenerated locally and leaks whatever host it ran on last.
 .ostp_public_ip
@@ -39,6 +46,7 @@ turn-harvesting-idea.md
 
 # Private tooling (closed-source)
 ostp-prober/
+ostp-lab/
 
 ostp-brain/
 

.release-state.json

@@ -1,6 +1,6 @@
 {
   "target_version": "0.4.2",
-  "branch": "beta",
+  "branch": "master",
   "alpha_iteration": 0,
-  "beta_iteration": 4
+  "beta_iteration": 5
 }

ostp-flutter/android/app/build.gradle.kts

@@ -1,3 +1,6 @@
+import java.io.FileInputStream
+import java.util.Properties
+
 plugins {
     id("com.android.application")
     id("kotlin-android")
@@ -5,6 +8,37 @@ plugins {
     id("dev.flutter.flutter-gradle-plugin")
 }
 
+// ── Release signing material ────────────────────────────────────────────────
+// Supplied out-of-band and never committed: either an `android/key.properties`
+// file (local release builds) or OSTP_KEYSTORE_* environment variables (CI).
+//
+// This exists because the release build used to be signed with the DEBUG
+// keystore (the stock Flutter template TODO). Android identifies an app by
+// applicationId + signing key, and refuses to update across a key change. The
+// debug keystore is auto-generated per machine, and CI runners are ephemeral,
+// so every published build carried a different random key — which is why
+// updating on top of a previous install failed with "App not installed" /
+// "unable to parse the package" and only a full uninstall+reinstall worked.
+val keystoreProperties = Properties().apply {
+    val propsFile = rootProject.file("key.properties")
+    if (propsFile.exists()) {
+        FileInputStream(propsFile).use { load(it) }
+    }
+}
+
+// Blank counts as absent. GitHub Actions substitutes an EMPTY STRING (not an
+// unset variable) for a secret that doesn't exist, so `getenv(...) ?: fallback`
+// silently kept the empty value — the elvis operator only catches null. That is
+// how an unset ANDROID_KEY_PASSWORD ended up being used as the literal key
+// password instead of falling back to the store password, producing Gradle's
+// "Get Key failed: Given final block not properly padded".
+fun signingSetting(propKey: String, envKey: String): String? =
+    (keystoreProperties.getProperty(propKey) ?: System.getenv(envKey))
+        ?.takeIf { it.isNotBlank() }
+
+val releaseStorePath: String? = signingSetting("storeFile", "OSTP_KEYSTORE_PATH")
+val hasReleaseSigning: Boolean = !releaseStorePath.isNullOrBlank()
+
 android {
     namespace = "com.ospab.ostp_client"
     compileSdk = flutter.compileSdkVersion
@@ -34,11 +68,43 @@ android {
         }
     }
 
+    signingConfigs {
+        create("release") {
+            if (hasReleaseSigning) {
+                val store = signingSetting("storePassword", "OSTP_KEYSTORE_PASSWORD")
+                storeFile = file(releaseStorePath!!)
+                storePassword = store
+                keyAlias = signingSetting("keyAlias", "OSTP_KEY_ALIAS")
+                // PKCS12 (the keytool default since Java 9, and what our upload
+                // keystore is) cannot hold a key password that differs from the
+                // store password — the format simply has no place to put one. So
+                // treat a missing key password as "same as the store password"
+                // instead of demanding a secret that, for this keystore, can only
+                // ever be a duplicate. An explicit value still wins, for the older
+                // JKS format where the two genuinely can differ.
+                keyPassword = signingSetting("keyPassword", "OSTP_KEY_PASSWORD") ?: store
+            }
+        }
+    }
+
     buildTypes {
         release {
-            // TODO: Add your own signing config for the release build.
-            // Signing with the debug keys for now, so `flutter run --release` works.
+            // Use the real upload key when one was supplied; otherwise fall back to
+            // the debug keystore so a plain local `flutter build apk --release`
+            // still works for development. Anything PUBLISHED must take the first
+            // branch — a debug-signed build cannot be updated over, and its key is
+            // machine-local, so it also can't be reproduced later.
+            if (hasReleaseSigning) {
+                signingConfig = signingConfigs.getByName("release")
+            } else {
+                logger.warn(
+                    "OSTP: no release keystore configured (android/key.properties or " +
+                    "OSTP_KEYSTORE_PATH) - falling back to the DEBUG keystore. This APK " +
+                    "is for local use only: users cannot update over it, and the key is " +
+                    "not reproducible on another machine."
+                )
                 signingConfig = signingConfigs.getByName("debug")
+            }
             proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
         }
     }

ostp-flutter/pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 0.4.2+23
+version: 0.4.2+25
 
 environment:
   sdk: ^3.11.4

ostp-gui/src/styles.css

@@ -17,10 +17,12 @@
   --c-accent-dim:  rgba(var(--c-fg-rgb),0.08);
   --c-accent-glow: rgba(var(--c-fg-rgb),0.18);
 
-  /* Green only for "connected" state */
-  --c-green:       #e8e8e8;
-  --c-green-glow:  rgba(232,232,232,0.25);
-  --c-green-dim:   rgba(232,232,232,0.07);
+  /* Green only for "connected" state — the one deliberate break from the
+     monochrome palette, so a successful connection reads at a glance. */
+  --c-green-rgb:   46, 230, 109;
+  --c-green:       #2ee66d;
+  --c-green-glow:  rgba(var(--c-green-rgb),0.28);
+  --c-green-dim:   rgba(var(--c-green-rgb),0.09);
 
   --c-red:         #ff5f5f;
   --c-amber:       #f0b840;
@@ -55,9 +57,11 @@
   --c-accent:      #18181b;
   --c-accent-dim:  rgba(0,0,0,0.08);
   --c-accent-glow: rgba(0,0,0,0.14);
-  --c-green:       #18181b;
-  --c-green-glow:  rgba(0,0,0,0.16);
-  --c-green-dim:   rgba(0,0,0,0.05);
+  /* Deeper green so it stays legible against the light background. */
+  --c-green-rgb:   22, 163, 74;
+  --c-green:       #16a34a;
+  --c-green-glow:  rgba(var(--c-green-rgb),0.22);
+  --c-green-dim:   rgba(var(--c-green-rgb),0.08);
   --c-red:         #dc2626;
   --c-amber:       #d97706;
   --c-txt-1:       #18181b;
@@ -155,7 +159,7 @@ a { text-decoration: none; }
   transition: background var(--t-med), box-shadow var(--t-med);
 }
 .brand-dot.connecting { animation: dot-blink 1.4s infinite ease-in-out; background: var(--c-accent); }
-.brand-dot.connected  { background: var(--c-accent); box-shadow: 0 0 10px var(--c-accent-glow); }
+.brand-dot.connected  { background: var(--c-green); box-shadow: 0 0 10px var(--c-green-glow); }
 
 @keyframes dot-blink {
   0%,100% { opacity: 1; }
@@ -233,11 +237,11 @@ a { text-decoration: none; }
 
 .orbit-wrap.connected .orbit {
   animation: orbit-spin 4s linear infinite;
-  border-color: rgba(var(--c-fg-rgb),0.14);
+  border-color: rgba(var(--c-green-rgb),0.30);
   opacity: 1;
 }
-.orbit-wrap.connected .orbit-2 { animation-duration: 6s; animation-direction: reverse; border-color: rgba(var(--c-fg-rgb),0.08); }
-.orbit-wrap.connected .orbit-3 { animation-duration: 9s; border-color: rgba(var(--c-fg-rgb),0.04); }
+.orbit-wrap.connected .orbit-2 { animation-duration: 6s; animation-direction: reverse; border-color: rgba(var(--c-green-rgb),0.18); }
+.orbit-wrap.connected .orbit-3 { animation-duration: 9s; border-color: rgba(var(--c-green-rgb),0.10); }
 
 @keyframes orbit-spin {
   from { transform: rotate(0deg); }
@@ -270,9 +274,9 @@ a { text-decoration: none; }
   animation: btn-breathe 2s infinite ease-in-out;
 }
 .power-btn.connected {
-  border-color: rgba(var(--c-fg-rgb),0.8);
-  color: var(--c-txt-1);
-  box-shadow: 0 0 0 8px rgba(var(--c-fg-rgb),0.04), 0 0 50px rgba(var(--c-fg-rgb),0.12), 0 8px 32px rgba(0,0,0,0.5);
+  border-color: var(--c-green);
+  color: var(--c-green);
+  box-shadow: 0 0 0 8px var(--c-green-dim), 0 0 50px var(--c-green-glow), 0 8px 32px rgba(0,0,0,0.5);
 }
 .power-btn.error {
   border-color: var(--c-red);

ostp/src/main.rs

@@ -3,7 +3,6 @@ use clap::Parser;
 use std::fs;
 use std::path::PathBuf;
 use colored::Colorize;
-use sha2::Digest;
 
 #[derive(Parser, Debug)]
 #[command(author, version, about = "OSTP Core - Ospab Stealth Transport Protocol", long_about = None)]
@@ -725,7 +724,14 @@ fn run_setup_wizard(config_path: &std::path::Path) -> Result<()> {
             // this used to be a DefaultHasher (SipHash) placeholder that produced a
             // differently-shaped digest, so a password set up through this wizard could
             // never actually log into the panel it just configured.
-            let pass_hash = format!("{:x}", sha2::Sha256::digest(password.as_bytes()));
+            // Trait-qualified so this compiles whether or not `sha2::Digest` happens
+            // to be in scope: `digest` is a trait method, and relying on the import
+            // alone broke the CI build once (v0.4.2-beta.3) while resolving fine
+            // locally.
+            let pass_hash = format!(
+                "{:x}",
+                <sha2::Sha256 as sha2::Digest>::digest(password.as_bytes())
+            );
 
             wizard_step(4, TOTAL, "Saving configuration");
             let panel_bind = format!("0.0.0.0:{}", panel_port);