Only enable telemetry in Mihon production apps (#1976)

telemetry/src/firebase/kotlin/mihon/telemetry/PackageInfo.kt

@@ -0,0 +1,46 @@
+package mihon.telemetry
+
+import android.content.pm.PackageInfo
+import android.content.pm.PackageManager
+import android.content.pm.Signature
+import android.os.Build
+import java.security.MessageDigest
+
+internal fun PackageInfo.getCertificateFingerprints(): List<String> {
+    return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+        val signingInfo = signingInfo!!
+        if (signingInfo.hasMultipleSigners()) {
+            signingInfo.apkContentsSigners
+        } else {
+            signingInfo.signingCertificateHistory
+        }
+    } else {
+        @Suppress("DEPRECATION")
+        signatures
+    }
+        ?.map(Signature::getCertificateFingerprint)
+        ?.toList()
+        ?: emptyList()
+}
+
+internal val SignatureFlags = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+    PackageManager.GET_SIGNING_CERTIFICATES
+} else {
+    @Suppress("DEPRECATION")
+    PackageManager.GET_SIGNATURES
+}
+
+@OptIn(ExperimentalStdlibApi::class)
+private val CertificateFingerprintHexFormat = HexFormat {
+    upperCase = true
+    bytes {
+        byteSeparator = ":"
+    }
+}
+
+@OptIn(ExperimentalStdlibApi::class)
+private fun Signature.getCertificateFingerprint(): String {
+    return MessageDigest.getInstance("SHA-256")
+        .digest(toByteArray())
+        .toHexString(CertificateFingerprintHexFormat)
+}

telemetry/src/firebase/kotlin/mihon/telemetry/TelemetryConfig.kt

@@ -6,20 +6,35 @@ import com.google.firebase.analytics.FirebaseAnalytics
 import com.google.firebase.crashlytics.FirebaseCrashlytics
 
 object TelemetryConfig {
-    private lateinit var analytics: FirebaseAnalytics
+    private var analytics: FirebaseAnalytics? = null
-    private lateinit var crashlytics: FirebaseCrashlytics
+    private var crashlytics: FirebaseCrashlytics? = null
 
     fun init(context: Context) {
+        // To stop forks/test builds from polluting our data
+        if (!context.isMihonProductionApp()) return
+
         analytics = FirebaseAnalytics.getInstance(context)
         FirebaseApp.initializeApp(context)
         crashlytics = FirebaseCrashlytics.getInstance()
     }
 
     fun setAnalyticsEnabled(enabled: Boolean) {
-        analytics.setAnalyticsCollectionEnabled(enabled)
+        analytics?.setAnalyticsCollectionEnabled(enabled)
     }
 
     fun setCrashlyticsEnabled(enabled: Boolean) {
-        crashlytics.isCrashlyticsCollectionEnabled = enabled
+        crashlytics?.isCrashlyticsCollectionEnabled = enabled
+    }
+
+    private fun Context.isMihonProductionApp(): Boolean {
+        if (packageName !in MIHON_PACKAGES) return false
+
+        return packageManager.getPackageInfo(packageName, SignatureFlags)
+            .getCertificateFingerprints()
+            .any { it == MIHON_CERTIFICATE_FINGERPRINT }
     }
 }
+
+private val MIHON_PACKAGES = hashSetOf("app.mihon", "app.mihon.debug")
+private const val MIHON_CERTIFICATE_FINGERPRINT =
+    "9A:DD:65:5A:78:E9:6C:4E:C7:A5:3E:F8:9D:CC:B5:57:CB:5D:76:74:89:FA:C5:E7:85:D6:71:A5:A7:5D:4D:A2"

telemetry/src/main/AndroidManifest.xml

@@ -2,6 +2,10 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools">
 
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.WAKE_LOCK" />
+
     <!-- Remove unnecessary permissions from Firebase dependency -->
     <uses-permission
         android:name="android.permission.ACCESS_ADSERVICES_AD_ID"