Implement system signature spoofing

app/build.gradle.kts

@@ -63,6 +63,7 @@ android {
 
 dependencies {
     implementation("org.lsposed.libcxx:libcxx:27.0.12077973")
+    implementation("org.lsposed.hiddenapibypass:hiddenapibypass:4.3")
 }
 
 tasks.register("copyFiles") {

app/proguard-rules.pro

@@ -1,3 +1,4 @@
 -keep class es.chiteroman.playintegrityfix.EntryPoint {public <methods>;}
 -keep class es.chiteroman.playintegrityfix.CustomProvider
 -keep class es.chiteroman.playintegrityfix.CustomKeyStoreSpi
+-keep class es.chiteroman.playintegrityfix.CustomPackageInfoCreator

app/src/main/java/es/chiteroman/playintegrityfix/CustomPackageInfoCreator.java

@@ -0,0 +1,41 @@
+package es.chiteroman.playintegrityfix;
+
+import android.content.pm.PackageInfo;
+import android.content.pm.Signature;
+import android.os.Build;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+public class CustomPackageInfoCreator implements Parcelable.Creator<PackageInfo> {
+    private final Parcelable.Creator<PackageInfo> originalCreator;
+    private final Signature spoofedSignature;
+
+    public CustomPackageInfoCreator(Parcelable.Creator<PackageInfo> originalCreator, Signature spoofedSignature) {
+        this.originalCreator = originalCreator;
+        this.spoofedSignature = spoofedSignature;
+    }
+
+    @Override
+    public PackageInfo createFromParcel(Parcel source) {
+        PackageInfo packageInfo = originalCreator.createFromParcel(source);
+        if (packageInfo.packageName.equals("android")) {
+            if (packageInfo.signatures != null && packageInfo.signatures.length > 0) {
+                packageInfo.signatures[0] = spoofedSignature;
+            }
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+                if (packageInfo.signingInfo != null) {
+                    Signature[] signaturesArray = packageInfo.signingInfo.getApkContentsSigners();
+                    if (signaturesArray != null && signaturesArray.length > 0) {
+                        signaturesArray[0] = spoofedSignature;
+                    }
+                }
+            }
+        }
+        return packageInfo;
+    }
+
+    @Override
+    public PackageInfo[] newArray(int size) {
+        return originalCreator.newArray(size);
+    }
+}

app/src/main/java/es/chiteroman/playintegrityfix/EntryPoint.java

@@ -1,12 +1,21 @@
 package es.chiteroman.playintegrityfix;
 
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.Signature;
 import android.os.Build;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.util.Base64;
 import android.util.JsonReader;
 import android.util.Log;
 
+import org.lsposed.hiddenapibypass.HiddenApiBypass;
+
 import java.io.IOException;
 import java.io.StringReader;
 import java.lang.reflect.Field;
+import java.lang.reflect.Method;
 import java.security.KeyStore;
 import java.security.KeyStoreException;
 import java.security.KeyStoreSpi;
@@ -18,6 +27,34 @@ import java.util.Map;
 public final class EntryPoint {
     private static Integer verboseLogs = 0;
 
+    private static final String signatureData = "MIIFyTCCA7GgAwIBAgIVALyxxl+zDS9SL68SzOr48309eAZyMA0GCSqGSIb3DQEBCwUAMHQxCzAJ\n" +
+            "BgNVBAYTAlVTMRMwEQYDVQQIEwpDYWxpZm9ybmlhMRYwFAYDVQQHEw1Nb3VudGFpbiBWaWV3MRQw\n" +
+            "EgYDVQQKEwtHb29nbGUgSW5jLjEQMA4GA1UECxMHQW5kcm9pZDEQMA4GA1UEAxMHQW5kcm9pZDAg\n" +
+            "Fw0yMjExMDExODExMzVaGA8yMDUyMTEwMTE4MTEzNVowdDELMAkGA1UEBhMCVVMxEzARBgNVBAgT\n" +
+            "CkNhbGlmb3JuaWExFjAUBgNVBAcTDU1vdW50YWluIFZpZXcxFDASBgNVBAoTC0dvb2dsZSBJbmMu\n" +
+            "MRAwDgYDVQQLEwdBbmRyb2lkMRAwDgYDVQQDEwdBbmRyb2lkMIICIjANBgkqhkiG9w0BAQEFAAOC\n" +
+            "Ag8AMIICCgKCAgEAsqtalIy/nctKlrhd1UVoDffFGnDf9GLi0QQhsVoJkfF16vDDydZJOycG7/kQ\n" +
+            "ziRZhFdcoMrIYZzzw0ppBjsSe1AiWMuKXwTBaEtxN99S1xsJiW4/QMI6N6kMunydWRMsbJ6aAxi1\n" +
+            "llVq0bxSwr8Sg/8u9HGVivfdG8OpUM+qjuV5gey5xttNLK3BZDrAlco8RkJZryAD40flmJZrWXJmc\n" +
+            "r2HhJJUnqG4Z3MSziEgW1u1JnnY3f/BFdgYsA54SgdUGdQP3aqzSjIpGK01/vjrXvifHazSANjvl\n" +
+            "0AUE5i6AarMw2biEKB2ySUDp8idC5w12GpqDrhZ/QkW8yBSa87KbkMYXuRA2Gq1fYbQx3YJraw0U\n" +
+            "gZ4M3fFKpt6raxxM5j0sWHlULD7dAZMERvNESVrKG3tQ7B39WAD8QLGYc45DFEGOhKv5Fv8510h5\n" +
+            "sXK502IvGpI4FDwz2rbtAgJ0j+16db5wCSW5ThvNPhCheyciajc8dU1B5tJzZN/ksBpzne4Xf9gO\n" +
+            "LZ9ZU0+3Z5gHVvTS/YpxBFwiFpmL7dvGxew0cXGSsG5UTBlgr7i0SX0WhY4Djjo8IfPwrvvA0QaC\n" +
+            "FamdYXKqBsSHgEyXS9zgGIFPt2jWdhaS+sAa//5SXcWro0OdiKPuwEzLgj759ke1sHRnvO735dYn\n" +
+            "5whVbzlGyLBh3L0CAwEAAaNQME4wDAYDVR0TBAUwAwEB/zAdBgNVHQ4EFgQUU1eXQ7NoYKjvOQlh\n" +
+            "5V8jHQMoxA8wHwYDVR0jBBgwFoAUU1eXQ7NoYKjvOQlh5V8jHQMoxA8wDQYJKoZIhvcNAQELBQAD\n" +
+            "ggIBAHFIazRLs3itnZKllPnboSd6sHbzeJURKehx8GJPvIC+xWlwWyFO5+GHmgc3yh/SVd3Xja/k\n" +
+            "8Ud59WEYTjyJJWTw0Jygx37rHW7VGn2HDuy/x0D+els+S8HeLD1toPFMepjIXJn7nHLhtmzTPlDW\n" +
+            "DrhiaYsls/k5Izf89xYnI4euuOY2+1gsweJqFGfbznqyqy8xLyzoZ6bvBJtgeY+G3i/9Be14HseS\n" +
+            "Na4FvI1Oze/l2gUu1IXzN6DGWR/lxEyt+TncJfBGKbjafYrfSh3zsE4N3TU7BeOL5INirOMjre/j\n" +
+            "VgB1YQG5qLVaPoz6mdn75AbBBm5a5ahApLiKqzy/hP+1rWgw8Ikb7vbUqov/bnY3IlIU6XcPJTCD\n" +
+            "b9aRZQkStvYpQd82XTyxD/T0GgRLnUj5Uv6iZlikFx1KNj0YNS2T3gyvL++J9B0Y6gAkiG0EtNpl\n" +
+            "z7Pomsv5pVdmHVdKMjqWw5/6zYzVmu5cXFtR384Ti1qwML1xkD6TC3VIv88rKIEjrkY2c+v1frh9\n" +
+            "fRJ2OmzXmML9NgHTjEiJR2Ib2iNrMKxkuTIs9oxKZgrJtJKvdU9qJJKM5PnZuNuHhGs6A/9gt9Oc\n" +
+            "cetYeQvVSqeEmQluWfcunQn9C9Vwi2BJIiVJh4IdWZf5/e2PlSSQ9CJjz2bKI17pzdxOmjQfE0JS\n" +
+            "F7Xt\n";
+
     private static final Map<String, String> map = new HashMap<>();
 
     public static Integer getVerboseLogs() {
@@ -28,6 +65,7 @@ public final class EntryPoint {
         verboseLogs = level;
         if (verboseLogs > 99) logFields();
         spoofProvider();
+        spoofPackageManager();
         spoofDevice();
     }
 
@@ -78,6 +116,63 @@ public final class EntryPoint {
         }
     }
 
+    private static void spoofPackageManager() {
+        Signature spoofedSignature = new Signature(Base64.decode(signatureData, Base64.DEFAULT));
+        Parcelable.Creator<PackageInfo> originalCreator = PackageInfo.CREATOR;
+        Parcelable.Creator<PackageInfo> customCreator = new CustomPackageInfoCreator(originalCreator, spoofedSignature);
+
+        try {
+            Field creatorField = findField(PackageInfo.class, "CREATOR");
+            creatorField.setAccessible(true);
+            creatorField.set(null, customCreator);
+        } catch (Exception e) {
+            LOG("Couldn't replace PackageInfoCreator: " + e);
+        }
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+            HiddenApiBypass.addHiddenApiExemptions("Landroid/os/Parcel;", "Landroid/content/pm", "Landroid/app");
+        }
+
+        try {
+            Field cacheField = findField(PackageManager.class, "sPackageInfoCache");
+            cacheField.setAccessible(true);
+            Object cache = cacheField.get(null);
+            Method clearMethod = cache.getClass().getMethod("clear");
+            clearMethod.invoke(cache);
+        } catch (Exception e) {
+            LOG("Couldn't clear PackageInfoCache: " + e);
+        }
+
+        try {
+            Field creatorsField = findField(Parcel.class, "mCreators");
+            creatorsField.setAccessible(true);
+            Map<?, ?> mCreators = (Map<?, ?>) creatorsField.get(null);
+            mCreators.clear();
+        } catch (Exception e) {
+            LOG("Couldn't clear Parcel mCreators: " + e);
+        }
+
+        try {
+            Field creatorsField = findField(Parcel.class, "sPairedCreators");
+            creatorsField.setAccessible(true);
+            Map<?, ?> sPairedCreators = (Map<?, ?>) creatorsField.get(null);
+            sPairedCreators.clear();
+        } catch (Exception e) {
+            LOG("Couldn't clear Parcel sPairedCreators: " + e);
+        }
+    }
+
+    private static Field findField(Class<?> currentClass, String fieldName) throws NoSuchFieldException {
+        while (currentClass != null && !currentClass.equals(Object.class)) {
+            try {
+                return currentClass.getDeclaredField(fieldName);
+            } catch (NoSuchFieldException e) {
+                currentClass = currentClass.getSuperclass();
+            }
+        }
+        throw new NoSuchFieldException("Field '" + fieldName + "' not found in class hierarchy of " + currentClass.getName());
+    }
+
     private static boolean classContainsField(Class className, String fieldName) {
         for (Field field : className.getDeclaredFields()) {
             if (field.getName().equals(fieldName)) return true;