How to convert Unity.Collections.NativeArray byte[] array toString?

[IceBear1226]

I've been practicing with this library for dynamic analysis. Thanks to vfsfitvnm , there was a lot of progress . But I have faced this problem.

So, an instance I've found with iIl2CPP.method return value :
Unity.Collections.NativeArray`1[[System.Byte, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] .

I know it's a metadata because field.value couldn't interpret it.

I'm sure this is a bytearray to deliver certain Strings because the class of this instance is UploadHandler from Unity Engine.

the Codes I tried : I got a help from GPT, but maybe this hexadump thing is not a valid thing for UTF-8 decoding. Nontheless, I got a positive result. i could read Strings I wanted to see. But it throws error at some point.

var bufferField = targetData.tryField("m_Buffer")?.value;  // 0x7fff01d6a3e0
const buffer = bufferField as NativePointer
const lengthField = targetData.tryField("m_Length")?.value;   //366;

// I found these two value by the instance's field value.

var trans = bufferField as Native Pointer
var data = bufferField.readbyteArray

if (data !== null) {
    console.log(hexdump(data, { ansi: true })); 
} else {
    console.log('Failed to read memory.');

NativeArray Data Dump:
           0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F  0123456789ABCDEF
00000000  7b 22 6d 61 69 6c 49 64 73 22 3a 5b 22 70 3a 63  {"mailIds":["p:c
00000010  75 38 73 62 6f 31 68 6d 73 65 34 73 34 75 39 75  u8sbo1hmse4s74uu
00000020  33 61 67 22 5d 2c 22 75 73 65 72 49 64 22 3a 22  3ag"],"userId":"
00000030  31 35 32 33 38 34 38 37 22 2c 22 63 6c 69 65 6e  15238477","clien
00000040  74 44 61 74 61 22 3a 7b 22 70 72 6f 74 6f 63 6f  tData":{"protoco
00000050  6c 56 65 72 73 69 6f 6e 22 3a 22 22 2c 22 61 70  lVersion":"","ap
00000060  70 4c 61 6e 67 75 61 67 65 22 3a 22 6b 6f 22 2c  pLanguage":"en",
00000070  22 64 65 76 69 63 65 49 64 22 3a 22 65 66 63 62  "deviceId":"efcb
00000080  33 65 66 31 36 62 33 61 62 34 30 37 34 62 34 34  3ef16b3ab4074b44
00000090  63 30 30 35 34 38 64 35 65 33 62 37 22 2c 22 61  c00548d5e3b7","a
000000a0  70 70 56 65 72 73 69 6f 6e 22 3a 22 31 2e 34 2e  ppVersion":"1.4.
000000b0  31 22 2c 22 6f 73 56 65 72 73 69 6f 6e 22 3a 22  1","osVersion":"
000000c0  41 6e 64 72 6f 69 64 20 4f 53 20 39 20 2f 20 41  Android OS 9 / A
000000d0  50 49 2d 32 38 20 28 50 51 33 42 2e 31 39 30 38  PI-28 (PQ3B.1908
000000e0  30 31 2e 31 30 31 30 31 38 34 36 2f 47 39 36 35  01.10101846/G965
000000f0  30 5a 48 55 32 41 52 43 36 29 22 2c 22 73 79 73  0ZHU2ARC6)","sys
00000100  74 65 6d 4c 61 6e 67 75 61 67 65 22 3a 22 4b 6f  temLanguage":"En
00000110  72 65 61 6e 22 2c 22 61 70 70 42 75 6e 64 6c 65  rean","appBundle
00000120  22 3a 22 63 6f 6d 2e 68 61 62 62 79 2e 63 61 70  ":"com.haiib.bot
00000130  79 62 61 72 61 22 2c 22 64 65 76 69 63 65 4d 6f    game","deviceMo
00000140  64 65 6c 22 3a 22 73 61 6d 73 75 6e 67 20 53 4d  del":"samsung SM
00000150  2d 4e 39 38 31 30 22 2c 22 6f 73 22 3a 32 2c 22  -N9801","os":2,"
00000160  63 68 61 6e 6e 65 6c 49 64 22 3a 32 7d 7d        channelId":2}}
Error: can't decode byte 0xa4 in position 1

at <anonymous> (frida/runtime/core.js:145)

I tried to find the class for NativeArray in UnityEngine.Module
But it was a struct, not a class. So I couldn't use IL2CPP.domain.assembly().image.class to get the methods of it.
I hope I could use ToArray or CopyTo methods of NativeArray , sadly I can't

    const lengthField = targetData.tryField("m_Length")?.value;   //366;
    var bufferField = targetData.tryField("m_Buffer")?.value;  // 0x7fff01d6a3e0
    const buffer = bufferField as NativePointer
    buffer.readByteArray(length)  

Using this way throws TypeError : not a function error.

I read #117 discussion, but It looks like code below doesn't work anymore.

 const arr = Il2Cpp.Array.from(SystemByte, [0x68, 0x65, 0x6c, 0x6c, 0x6f]);
  console.log(arr);

Another try was to make the array as il2CPP.Object, and get the native pointer of it by .handle  like below. it's similar with the thing I've tried, but it was grasping at straws. 

const buffertest = bufferField as Il2Cpp.Object;
const bufferttest2 = buffertest.handle;
let resultobj = new Il2Cpp.Array(bufferttest2)

After days I practiced this tool , I thought I have a grasp of the basic use of the tool, but I'm feeling hopeless again. Does anyone know how to turnNativa byte array into String[] ini il2cpp-bridge?