Repack with AES crypto

How do I repack a UE4.27.2 .pak (game: [REDACTED]) with UnrealPak using AES encryption?
I have game AES (which worked for unpacking with FModel tool), but every time I trie to repack with AES I get errors or seems to use a wrong key....
I put the AES key in Crypto.json, like this:

{
   "$types":{
      "UnrealBuildTool.EncryptionAndSigning+CryptoSettings, UnrealBuildTool, Version=4.0.0.0, Culture=neutral, PublicKeyToken=null":"1",
      "UnrealBuildTool.EncryptionAndSigning+EncryptionKey, UnrealBuildTool, Version=4.0.0.0, Culture=neutral, PublicKeyToken=null":"2",
      "UnrealBuildTool.EncryptionAndSigning+SigningKeyPair, UnrealBuildTool, Version=4.0.0.0, Culture=neutral, PublicKeyToken=null":"3",
      "UnrealBuildTool.EncryptionAndSigning+SigningKey, UnrealBuildTool, Version=4.0.0.0, Culture=neutral, PublicKeyToken=null":"4"
   },
   "$type":"1",
   "EncryptionKey":{
      "$type":"2",
      "Name":"null",
      "Guid":"null",
      "Key":"0x1958456F8B54A02D25DF32327C57C9D20DFCF7E948967D08CFB48E8EBC65BEEB"
   },
   "SigningKey": false,
   "bEnablePakSigning":true,
   "bEnablePakIndexEncryption":true,
   "bEnablePakIniEncryption":true,
   "bEnablePakUAssetEncryption":true,
   "bEnablePakFullAssetEncryption":false,
   "bDataCryptoRequired":true,
   "PakEncryptionRequired":true,
   "PakSigningRequired":true,
   "SecondaryEncryptionKeys":[

   ]
}

but fails miserably:

C:\Users\Luca\Documents\Lavori in corso\Traduzioni - tools\UE\UnrealPakTool>UnrealPak.exe "D:\Epic Games\Redacted\Redacted\Content\Paks\pakchunk0-WindowsNoEditor1.pak" -Create="Lista.txt" -Encrypt -Cryptokeys="Crypto.json" -projectdir="C:\Users\user\Documents\Lavori in corso\Traduzioni - tools\UE\UnrealPakTool"
LogInit: Display: Loading text-based GConfig....
LogPakFile: Display: Parsing crypto keys from a crypto key cache file
LogWindows: Error: === Critical error: ===
LogWindows: Error:
LogWindows: Error: Assertion failed: Key.Num() == sizeof(FAES::FAESKey::Key) [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Public\Misc/KeyChainUtilities.h] [Line: 81]
LogWindows: Error:
LogWindows: Error: [Callstack] 0x00007ffc5f407dc7 UnrealPak-Core.dll!FDebug::CheckVerifyFailedImpl() []
LogWindows: Error: [Callstack] 0x00007ffcb417cad6 UnrealPak-PakFileUtilities.dll!KeyChainUtilities::LoadKeyChainFromFile() []
LogWindows: Error: [Callstack] 0x00007ffcb417b665 UnrealPak-PakFileUtilities.dll!LoadKeyChain() []
LogWindows: Error: [Callstack] 0x00007ffcb416ebd4 UnrealPak-PakFileUtilities.dll!ExecuteUnrealPak() []
LogWindows: Error: [Callstack] 0x00007ff7dae6b037 UnrealPak.exe!wmain() []
LogWindows: Error: [Callstack] 0x00007ff7dae6be18 UnrealPak.exe!__scrt_common_main_seh() []
LogWindows: Error: [Callstack] 0x00007ffd323ae8d7 KERNEL32.DLL!UnknownFunction []
LogWindows: Error: [Callstack] 0x00007ffd3376c53c ntdll.dll!UnknownFunction []
LogWindows: Error:
LogWindows: Error:
LogWindows: Error:
LogWindows: Error:

So I tried using Base64 key in the JSON above, no error, but seems to use generic AES key 00000000000000000000000000000000 (???) now:

C:\Users\Luca\Documents\Lavori in corso\Traduzioni - tools\UE\UnrealPakTool>UnrealPak.exe "D:\Epic Games\Redacted\Redacted\Content\Paks\pakchunk0-WindowsNoEditor1.pak" -Create="Lista.txt" -Encrypt -Cryptokeys="Crypto.json" -projectdir="C:\Users\user\Documents\Lavori in corso\Traduzioni - tools\UE\UnrealPakTool"
LogInit: Display: Loading text-based GConfig....
LogPakFile: Display: Parsing crypto keys from a crypto key cache file
LogPakFile: Display: Loading response file Lista.txt
LogPakFile: Display: Added 1 entries to add to pak file.
LogPakFile: Display: Collecting files to add to pak file...
LogPakFile: Display: Collected 1 files in 0.00s.
LogPakFile: Display: Creating pak D:\Epic Games\Redacted\Redacted\Content\Paks\pakchunk0-WindowsNoEditor1.pak.
LogPakFile: Display: Using encryption key 'Default' [00000000000000000000000000000000]
LogPakFile: Display: CompressionFormats in priority order: Zlib
LogDerivedDataCache: Display: Performance to ../../../Engine/DerivedDataCache: Latency=0.00ms. RandomReadSpeed=999.00MBs, RandomWriteSpeed=999.00MBs. Assigned SpeedClass 'Local'
LogPakFile: Display: CompressionFormat 0 [Zlib] : 0 files, 0 -> 0 bytes
LogPakFile: Display: CompressionFormat 1 [None] : 1 files, 1738362 -> 1738362 bytes
LogPakFile: Display: Added 1 files, 1738860 bytes total, time 0.01s.
LogPakFile: Display: PrimaryIndex size: 164 bytes
LogPakFile: Display: PathHashIndex size: 20 bytes
LogPakFile: Display: FullDirectoryIndex size: 34 bytes
LogPakFile: Display: Encryption - ENABLED
LogPakFile: Display:   Files: 1
LogPakFile: Display:   Index: Unencrypted
LogPakFile: Display:   Total: 1738368 bytes (1.66MB)
LogPakFile: Display: Unreal pak executed in 0.015542 seconds

How does it work this AES encryption? What am I doing wrong...? There is no help on the net and in other forums...

Edited February 4Feb 4 by hexaae