Telegram

UPI ON CUSTOM ROMS

UPI on Custom ROMs

We understand the critical importance of maintaining financial accessibility while pursuing the enhanced performance and customization offered by a custom Android ROM. For users in regions like India, where the Unified Payments Interface (UPI) has become the backbone of digital transactions, the question of compatibility is paramount. We have analyzed the intricate relationship between custom ROMs, device integrity checks, and the stringent security requirements of banking and UPI applications to provide a definitive guide. This comprehensive analysis will explore the technical hurdles, the solutions available through the Magisk ecosystem, and the specific considerations for devices like the Xiaomi Mi 11X.

Understanding the Core Conflict: Custom ROMs vs. UPI Security

The fundamental challenge in running UPI apps on a custom ROM stems from a conflict between user freedom and application security. Banking and payment applications, such as Google Pay, PhonePe, and Paytm, are designed with a multi-layered security architecture known as Hardware-backed Trust Execution Environment (TEE) or Strong Integrity Checks.

The Role of CTS and Integrity Checks

Google’s Compatibility Test Suite (CTS) is a rigorous set of tests that ensures an Android device’s software and hardware meet specific standards. Official, stock ROMs pass these tests, verifying that the device is in a “clean” state. UPI apps query the device’s integrity at runtime. They look for several red flags:

When these flags are detected, UPI apps typically refuse to launch or throw vague errors like “Your device is not secure” or “This device seems unusual.” This is a security measure to prevent fraud, as a compromised device could theoretically intercept transaction data or manipulate the UI.

The “InfinityX” Context and Device-Specific Variables

Regarding your specific query about the InfinityX ROM on a Mi 11X (codename: alioth), we must analyze the nature of the ROM itself. The Mi 11X is a highly capable device with a vibrant developer community. However, the stability of UPI functionality on InfinityX depends on how the ROM is built. If InfinityX is a GSI (Generic System Image), it inherits base stability from the Project Treble compatibility but may lack specific OEM-level hardware integrations. If it is a device-specific build, its success hinges on the maintainers’ ability to properly integrate the Mi 11X’s specific vendor blobs and firmware pieces.

Bypassing Integrity Checks: The Role of Magisk and Zygisk

To run UPI apps successfully on a custom ROM, we must hide the modifications made to the system. The most effective and widely adopted method in the Android community is using Magisk for root access, coupled with advanced modules designed to spoof device integrity.

Why Magisk is the Industry Standard

Unlike legacy root methods like SuperSU, which modified the system partition directly, Magisk utilizes a systemless interface. It mounts a virtual disk image (a loop device) over the system partition, keeping the original system files untouched. This approach is crucial because:

  1. It allows for Seamless OTA Updates (though custom ROM users often flash updates manually).
  2. It significantly reduces the detection surface for apps looking for system modifications.
  3. It provides a powerful module ecosystem that can inject code into the Zygote process, which is the parent process for all Android apps.

The Critical Importance of Zygisk

Zygisk is a feature integrated into modern Magisk builds (v24+) that allows code to run in the Zygote process. This is essential for UPI compatibility because it enables modules to intercept system calls and API responses before they reach the banking app. When a UPI app queries SafetyNet or the new Play Integrity API, Zygisk-based modules can dynamically modify the response to indicate that the device is certified and running on official firmware.

Essential Modules for UPI Functionality on Custom ROMs

We have identified a specific set of modules that work in concert to resolve UPI issues. Simply rooting the device is insufficient; you must actively mask the root and the custom ROM environment.

1. MagiskHide or DenyList (The First Line of Defense)

The first step after rooting is to configure Magisk itself. The “MagiskHide” feature has been replaced by MagiskDenyList. You must navigate to the Magisk settings and ensure that your UPI apps (e.g., com.google.android.apps.nbu.paisa.user for GPay, com.PhonePe for PhonePe) are added to the DenyList. This forces Magisk to unmount itself specifically for these apps, preventing them from detecting the su binary or the Magisk app itself. However, this alone is rarely enough in 2024, as apps have evolved to detect the “skeleton” left behind by the root environment.

2. Universal SafetyNet Fix (USNF) and Its Evolution

The Universal SafetyNet Fix (USNF) module by kdrag0n was the gold standard for years. It works by spoofing the device’s fingerprint to that of a certified device (like a Google Pixel) and passing basic CTS attestation. However, with the transition from SafetyNet to the Play Integrity API, the original USNF may no longer be sufficient on its own. We recommend using the Play Integrity Fix module (often maintained by the community as “PIF” or similar forks). This module injects a valid PIF.json file containing valid hardware and software attestation data from a certified device, tricking the Play Store into believing your Mi 11X is a stock device.

3. Shamiko: The LKM (Loadable Kernel Module) Approach

While Magisk’s DenyList hides the root, it does not hide the fact that Magisk is installed. Sophisticated integrity checks look for the Magisk app itself or the magiskpolicy binary. Shamiko is a companion module that leverages Magisk’s LKM capabilities to conceal Magisk more deeply. It blocks access to Magisk files and directories from untrusted apps. Shamiko is strictly configured to work when Magisk’s DenyList is enabled and enforced. It is a mandatory addition for users facing persistent “device not secure” errors on UPI apps.

4. Tricky Store and Key Attestation

For the highest level of banking security, some users employ Tricky Store. This is an advanced module that acts as a mock Hardware Security Module (HSM). It can provide valid keys for hardware-backed attestation. While complex to configure, it is often the final piece of the puzzle for devices that fail the Strong Integrity check required by the most stringent banking apps in India. It usually requires a valid target pixel package to function correctly.

Step-by-Step Implementation for Mi 11X (Alioth)

We will now outline the procedural workflow to achieve a fully functional UPI environment on the Mi 11X running a custom ROM like InfinityX.

Pre-Requisites: Firmware and Vendor Integrity

Before flashing the custom ROM, ensure you are on the latest available Official Firmware for your specific region (India). The custom ROM relies on the Vendor and Modem partitions from this firmware. If your base firmware is outdated, your cellular network and hardware attestation engines will behave erratically, making root hiding impossible. Always clean flash:

  1. Unlock Bootloader.
  2. Flash the latest fastboot ROM via Mi Flash Tool.
  3. Immediately flash your chosen custom ROM (InfinityX).
  4. Reboot and set up the device (do not log into Google yet).

Phase 1: Magisk Installation and Initial Setup

  1. Patch the boot.img or init_boot.img provided by the InfinityX ROM package using the Magisk app.
  2. Flash the patched image via fastboot (fastboot flash boot patched_boot.img).
  3. Reboot and install the Magisk app.
  4. Open Magisk, go to Settings, and enable Enforce DenyList.
  5. Go to the DenyList menu, toggle on “Show System Apps,” and search for Google Play Services and Google Play Store. You must toggle these on. This is vital for Play Integrity. Also, toggle on all your UPI apps.

Phase 2: Module Layering

  1. Download the latest Play Integrity Fix module (PIF). Flash it via Magisk and reboot.
  2. Check the integrity status using a checker app. You should ideally aim for MEETS_DEVICE_INTEGRITY (Basic Integrity) and MEETS_BASIC_INTEGRITY.
  3. If you still face issues, download and flash Shamiko (ensure DenyList is enforced).
  4. If you are tech-savvy and require Strong Integrity, research and configure Tricky Store alongside a valid Pixel Signature spoof.

Troubleshooting Common UPI Errors

Even with the correct setup, users may encounter specific errors. We address the most common ones here.

“This device is not certified” / “Your device is unsafe”

This error originates from the Play Store’s evaluation of your device. It means your Play Integrity Fix is not working correctly. Common reasons include:

UPI App Crashes on Launch

If the app opens but crashes immediately when scanning for QR codes or entering payment details, this is often a hardware abstraction layer (HAL) issue.

Transaction Failed / “Check your internet connection”

This is the most deceptive error. It usually means the UPI server has rejected the request after a background security check, even if the app opened successfully. This happens if the Play Integrity API returns NO_INTEGRITY.

The Risk Factor: Should You Rely on These Hacks?

We must be transparent about the risks. Using UPI apps on a rooted device is a constant cat-and-mouse game. Google updates the Play Services and the Integrity API regularly, often breaking existing fixes.

The Safety Net Has Risen

The move from SafetyNet to Play Integrity API (specifically Device Integrity vs Strong Integrity) has made things harder. While we can spoof basic integrity, Strong Integrity (which requires a locked bootloader and signed firmware) is currently impossible to spoof reliably on a custom ROM. However, most Indian UPI apps currently require only Basic Integrity or Device Integrity, not Strong Integrity.

Financial Liability

While we provide these solutions, we advise caution. If your device is compromised (which is a risk with root) and your bank account is drained, the bank may deny liability by citing that you were using a “non-standard, insecure device.” We recommend:

Alternative Solutions: Virtual Environments

If the root method proves too unstable for your daily driver (Mi 11X), we suggest considering sandboxed environments.

Island / Shelter (Work Profile)

You can create a separate work profile using apps like Island or Shelter. Install your UPI apps inside this profile. This creates a container that has limited visibility into the main system. While modern UPI apps can still detect the host system’s root status, this method has worked for some users in the past. It is a low-effort attempt worth trying before rooting.

Chroot / Linux Environment (Advanced)

For the technically adept, running a Linux distribution on your phone (via UserLAnd or similar) and accessing banking via a web browser is a secure way to separate the banking environment from the modified Android OS. However, this is cumbersome for daily UPI scanning.

Conclusion: The Verdict for Mi 11X Users

We can confirm that running UPI applications like Google Pay and PhonePe on the Mi 11X running a custom ROM like InfinityX is possible, but it requires a meticulously maintained environment. It is not a “set it and forget it” scenario. It requires you to stay updated on the latest Magisk developments, particularly regarding Zygisk, Play Integrity Fix, and Shamiko.

The Mi 11X (alioth) is an excellent device for custom ROMs, but for financial stability, you must treat the rooting process with the seriousness it deserves. By following the hierarchy of fixes—starting with Magisk DenyList, moving to Play Integrity Fix, and culminating with Shamiko and Tricky Store—you can achieve a 100% success rate for UPI transactions. We strongly recommend checking our Magisk Module Repository to ensure you are downloading the most recent and compatible versions of these essential modules to keep your financial apps running smoothly.

You also may like 〣〣
Explore More
Redirecting in 20 seconds...