How to Install Peter Twrp recovery 3.3.1-6 for Redmi Note 7 Pro (Violet) by PeterCxy (Encrption)

This is the unofficial TWRP recovery for Xiaomi Redmi Note 7 Pro (Violet) by PeterCxy. This ROM is a little bit different from the official Twrp recovery for Violet.

Differences between official Twrp and PeterCxy Twrp for Redmi Note 7 Pro:

• Supports CAF-based wrappedkey encryption (decryption) properly (tested with MIUI 10.3.5.0)
• Supports decrypting devices that have screen lock set up after Android 9 May update, which introduced a new key derivation function.
• Mounts the system partition at /system_root as per AOSP standards. This makes the auto-backup scripts (e.g. GApps / Magisk survival script) work properly during updates, and you no longer need any 'patch' to flash GApps / Magisk properly. However, this may break some existing ROMs. See below FAQ section for details.
• Appended DTBO to the recovery image so it doesn't depend on the dtbo partition. No standalone DTBO image required.

Requirements:

• Unlocked bootloader:  check how to unlock bootloader Here
• Adb/Fastboot Driver: Check download link and guide Here
• PeterCxy unofficial Twrp Recovery for Violet: Download Here
• Dm-verity and Forced Encryption Disabler: Download Here.

How to Install:

• Download the DM verity disabler and copy it to your phone's internal storage.
• Download the Twrp from the link above and rename it to twrp.img
• Copy the downloaded twrp image to the adb folder on your computer
• Reboot your phone to fastboot by holding down the power button and volume down (-) at the same time 
• connect the phone to your PC 
• Enter the fastboot command below

                fastboot flash recovery twrp.img

• After flashing, disconnect your phone and hold both the power button and volume up(+) simultaneously to boot to recovery.
• Click on install and select the DM verity file.
• After installing that, reboot to system.

Note:

• DO NOT try to reboot to recovery by running the command 'fastboot boot recovery.img', as it won't work.
• You have to format the data partition if and ONLY IF:

            1) You were not encrypted, now going to an encrypted state, or vice-versa OR

            2) You were on a ROM other than MIUI that does not support "wrappedkey"                                         (ROMs would often state it supports wrappedkey if it does), now going to                                              a ROM that supports it

• The restore zip created by the Migrate app is NOT compatible with this recovery. It's a problem of the Migrate app, not this recovery. Please DO NOT try to flash the restore zip created by Migrate.

Frequently Asked Questions (FAQ):

> Q: Do I need any specific DTBO image to make this recovery working?

- A: Nope. It is appended to the recovery image so it will work with any DTBO.

> Q: What is wrappedkey?

- A: It's a different mode of FBE implemented in CAF, the Qualcomm branch of AOSP.

> Q: This cannot install ROM X, why?

- A: Because it mounts the system partition at /system_root, which is AOSP standard behavior for A-only system_as_root devices, but is broken in some custom ROMs currently (MIUI should work though). 

> Q: Decryption doesn't work with ROM X, why?

- A: Decryption should work for most ROMs based on the CAF branch (not AOSP). CAF ROMs (including official MIUI) use a different scheme for key storage, which is why TWRP hasn't supported it till now. I have ported the CAF encryption changes (wrappedkey) to TWRP, but unfortunately this will break ROMsthat do not support the CAF wrappedkey mode of encryption. 

Credit:

• PeterCxy
• XDAThread