Device Profile Simulation & System Integrity Guide

This document details the offline partition-level device profile simulation engine and Play Integrity verification mechanisms provided by KuyFox.

💡 Core Architecture: Offline Partition Simulation

Unlike runtime frameworks (Magisk modules, KernelSU, LSPosed) that alter device properties in-memory while the Android OS is active, KuyFox operates directly on physical disk partitions offline within Custom Recovery.

Key Advantages of Offline Partition Testing:

1. Pure & Isolated Test Environment: Leaves zero resident background daemons, hooks, or non-standard binaries inside the active Android OS, guaranteeing unpolluted test results.
2. Persistent Across Test Cycles: Configurations are committed directly to partition images, maintaining steady consistency across reboots until baseline restoration.
3. Verified Boot & System Integrity Compliance: Enforces verified boot state (green), verity mode (enforcing), and standard encryption parameters aligned with certified device requirements.

🧩 Simulated Profile Components

1. Multi-Partition System Property Files (build.prop & Modern DLKM)

KuyFox reads and updates build.prop across all relevant physical partitions:

• /system/build.prop (Master System Identity)
• /vendor/build.prop (Vendor Hardware Specification)
• /product/build.prop (Product Customization)
• /system_ext/build.prop (System Extensions)
• /odm/etc/build.prop (Original Device Manufacturer)
• /system/system_dlkm/etc/build.prop (System DLKM - Android 13+ GKI)
• /vendor/odm_dlkm/etc/build.prop (ODM DLKM)
• /vendor/vendor_dlkm/etc/build.prop (Vendor DLKM)

!NOTESafe Skip: If the target device does not have DLKM partitions, KuyFox automatically skips them without throwing errors or interrupting other partitions.

Synchronized attributes include:

• Brand & Model: Authentic pairings (e.g., samsung SM-S928B Galaxy S24 Ultra or google Pixel 8 Pro).
• Official Build Fingerprints: Authentic release fingerprints registered in the Google Play certified catalog.
• Dynamic Android Release: Dynamically selectable OS releases spanning Android 10 through Android 17.
• Security Patch Date: Validated patch release dates logically matched to the target OS release.
• Builder Host & Timestamps: Realistic compilation timestamps (UTC/date math) and build machine hostnames.
• System Integrity & Verified Boot Compliance:

  ro.boot.verifiedbootstate=green
  ro.boot.flash.locked=1
  ro.boot.veritymode=enforcing
  ro.boot.warranty_bit=0
  

2. Data Storage Identity (/data)

• Android ID: Generates a randomized 16-character hexadecimal Android ID directly into settings_secure.xml.
• SSAID (Per-App Unique ID): Resets the settings_ssaid.xml table so each installed application receives a fresh, isolated test ID upon first launch.
• Device & Bluetooth Name: Updates the commercial marketing device name in settings_global.xml and Bluetooth configuration bt_config.conf.
• Wi-Fi SoftAP SSID: Syncs default hotspot broadcast names with the target test profile.

3. Hardware Serial Number (Kernel Level)

• A standardized KUY random serial number (KUYxxxxxxxx) is written to /system/etc/kuy_serial.
• Custom kernels configured to read this path will automatically adopt the new hardware serial in About Phone and hardware diagnostic apps like AIDA64.

4. Cache Reset & Clean Test Environment

During a comprehensive test profile application, KuyFox cleans stale cache and session states:

• Google Services Framework (GSF): Clears local GSF registration tokens and cached account databases (accounts.db, accounts_ce.db).
• Widevine DRM Cache: Clears DRM caches to prevent media licensing or identifier collisions.
• Dalvik / ART Cache: Clears compiled DEX runtime caches, allowing Android to regenerate them smoothly against the new device profile.

🚀 How to Apply Device Test Profiles

Method 1: Interactive Terminal Menu (TUI)

1. Open Recovery Terminal and run kuyfox.
2. Option 2 Random Test Profile (Recommended):
   • Randomly selects an authentic device profile from the 19 certified brand databases.
   • Automatically applies Android ID, SSAID, serial, and multi-partition build.prop.
   • Executes cache reset and clean test environment setup in a single click.
3. Option 3 Select Device Profile:
   • Choose your desired brand (Samsung, Google, Xiaomi, Motorola, Sony, OnePlus, etc.).
   • Select a specific model from the curated list for targeted compatibility testing.

Method 2: Fast CLI Commands (Automation)

KuyFox commands can be invoked directly from the shell or automation scripts:

# Comprehensive profile simulation (build.prop + Android ID + SSAID + Reset State)
kuyfox --bypass

# Search and apply a specific model profile directly (e.g., Pixel 8)
kuyfox -m "Pixel 8"

# Patch build.prop properties only (without resetting data)
kuyfox --props

# Reset cache and clean the testing environment only
kuyfox --wipe

🔄 How to Restore Baseline Factory Identity

KuyFox includes Dual-Layer Protection:

1. On its very first run, your stock, untouched build.prop files are backed up to:
   • Local partition: /system/build.prop.kuyfox.bak
   • Storage directory: /sdcard/KuyFox/backup_prop/
2. These backup files are permanently write-protected and will never be overwritten by subsequent testing sessions.

Steps to Restore:

• Via TUI Menu: Select [5] Backup & Restore Original build.prop -> Choose [2] Restore Original.
• Via CLI Command:
  Terminal

  kuyfox --restore
  

KuyFox will restore all original partitions, hosts file, and clear the kernel serial override back to 100% stock factory condition.