Display the app signer in the about bottom sheet

application/resources/src/main/res/values/strings.xml

@@ -293,6 +293,7 @@
     <string name="about_license_text" translatable="false"></string>
     <string name="vlc_authors">and VLC Authors.</string>
     <string name="is_compiled_by">Compiled by</string>
+    <string name="is_signed_by">Signed by</string>
     <string name="sources">Source code</string>
     <string name="libraries">Libraries</string>
     <string name="feedback_forum">Feedback forum</string>

application/vlc-android/res/layout/dialog_about_version.xml

@@ -105,6 +105,17 @@
                     app:layout_constraintStart_toStartOf="parent"
                     app:layout_constraintTop_toTopOf="@+id/compiled_by" />
 
+            <TextView
+                    android:id="@+id/textView31"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginStart="16dp"
+                    android:text="@string/is_signed_by"
+                    android:textColor="?attr/font_light"
+                    app:layout_constraintBottom_toBottomOf="@+id/signed_by"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toTopOf="@+id/signed_by" />
+
             <View
                     android:id="@+id/divider"
                     android:layout_width="0dp"
@@ -113,7 +124,7 @@
                     android:background="?attr/default_divider"
                     app:layout_constraintEnd_toEndOf="parent"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@+id/compiled_by" />
+                    app:layout_constraintTop_toBottomOf="@+id/signed_by" />
 
             <TextView
                     android:id="@+id/textView29"
@@ -219,6 +230,18 @@
                     app:layout_constraintTop_toBottomOf="@+id/revision"
                     tools:text="Gitlab runner" />
 
+            <TextView
+                    android:id="@+id/signed_by"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_marginStart="24dp"
+                    android:layout_marginTop="4dp"
+                    android:textColor="?attr/font_default"
+                    app:layout_constraintEnd_toEndOf="parent"
+                    app:layout_constraintStart_toEndOf="@+id/compilation_barrier"
+                    app:layout_constraintTop_toBottomOf="@+id/compiled_by"
+                    tools:text="VideoLAN" />
+
             <TextView
                     android:id="@+id/remote_access_version"
                     android:layout_width="0dp"

application/vlc-android/src/org/videolan/vlc/gui/dialogs/AboutVersionDialog.kt

@@ -21,7 +21,10 @@
  */
 package org.videolan.vlc.gui.dialogs
 
+import android.content.pm.PackageManager
+import android.os.Build
 import android.os.Bundle
+import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
@@ -29,6 +32,8 @@ import com.google.android.material.bottomsheet.BottomSheetBehavior.STATE_EXPANDE
 import org.videolan.vlc.BuildConfig
 import org.videolan.vlc.R
 import org.videolan.vlc.databinding.DialogAboutVersionBinding
+import java.security.MessageDigest
+
 
 /**
  * Dialog showing the info of the current version
@@ -77,6 +82,45 @@ class AboutVersionDialog : VLCBottomSheetDialogFragment() {
             whatsNewDialog.show(requireActivity().supportFragmentManager, "fragment_whats_new")
             dismiss()
         }
+
+
+        val signatures =
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) requireActivity().packageManager.getPackageInfo(
+                requireActivity().packageName,
+                PackageManager.GET_SIGNATURES
+            ).signatures
+            else
+                requireActivity().packageManager.getPackageInfo(
+                    requireActivity().packageName,
+                    PackageManager.GET_SIGNING_CERTIFICATES
+                ).signingInfo.apkContentsSigners
+        var signer = requireActivity().getString(R.string.unknown)
+        signatures.forEach {
+            try {
+                val md = MessageDigest.getInstance("SHA1")
+                md.update(it.toByteArray())
+
+                val digest = md.digest()
+                val toRet = java.lang.StringBuilder()
+                for (i in digest.indices) {
+                    if (i != 0) toRet.append(":")
+                    val b = digest[i].toInt() and 0xff
+                    val hex = Integer.toHexString(b)
+                    if (hex.length == 1) toRet.append("0")
+                    toRet.append(hex)
+                }
+                when (toRet.toString().uppercase()) {
+                    "AC:5A:BC:F1:99:AC:86:61:6A:79:65:CB:84:59:94:89:A5:A7:3F:86" -> signer = "VideoLAN nightly"
+                    "4D:D5:44:A7:51:D3:D5:4C:17:D8:7E:1D:D3:60:F0:C6:40:A5:C1:50" -> signer = "Google"
+                    "EE:FB:C9:81:42:83:43:BB:DD:FF:F6:B2:3B:6B:D8:71:73:51:41:0C" -> signer = "VideoLAN"
+                    "40:80:86:F9:AE:A6:52:A8:61:44:70:4F:11:79:9A:CA:BA:31:C7:A0" -> signer = "F-Droid"
+                }
+                Log.i(this::class.java.simpleName, "Found signature. Fingerprint: $toRet")
+            } catch (e: Exception) {
+                Log.e("Signature",e.message, e)
+            }
+        }
+        binding.signedBy.text = signer
     }