Error reading BigInt pointer

[alorodri]

Hello!

In this code, it fails to read the memory from the first pointer, when it sums the offset and tries to readMemory again the new address. Elden Ring is a x64 game, I compiled memoryjs with build64 and I had no problem getting the first ptr value. The problem comes with the second readMemory call, because the first returns a BigInt, then when I call again I must pass an address that is a BigInt, and then it shows me that error:

C:\Users\alope\source\repos\electronTestWindows\node_modules\memoryjs\index.js:49
    return memoryjs.readMemory(handle, address, dataType.toLowerCase());
                    ^

Error: Error in native callback
    at Object.readMemory (C:\Users\alope\source\repos\electronTestWindows\node_modules\memoryjs\index.js:49:21)
    at readMemory (C:\Users\alope\source\repos\electronTestWindows\test.js:16:26)
    at Object.<anonymous> (C:\Users\alope\source\repos\electronTestWindows\test.js:24:1)
    at Module._compile (node:internal/modules/cjs/loader:1256:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1310:10)
    at Module.load (node:internal/modules/cjs/loader:1119:32)
    at Module._load (node:internal/modules/cjs/loader:960:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:23:47

Node.js v18.17.1

Some useful data:

Object process

{
  dwSize: 304,
  th32ProcessID: 30796,
  cntThreads: 97,
  th32ParentProcessID: 32248,
  pcPriClassBase: 8,
  szExeFile: 'eldenring.exe',
  handle: 564,
  modBaseAddr: 2061870039768
}

That's my code:

const memoryjs = require("memoryjs");

function readMemory() {
  const processName = "eldenring.exe";
  const offset1 = 0x3cd4d88;
  const offset2 = 0x94;

  const processObject = memoryjs.openProcess(processName);
  const baseAddress = processObject.modBaseAddr;
  const ptrToValue = memoryjs.readMemory(
    processObject.handle,
    baseAddress + offset1,
    memoryjs.PTR
  );

  const value = memoryjs.readMemory(
    processObject.handle,
    ptrToValue + BigInt(offset2),
    memoryjs.INT64
  );
  console.log(value);
}

readMemory();

Thanks in advance!

[Danovich]

Hey @alorodri,

I have the same error, did you manage to figure it out? If I pass BigInt to func it fails even though it should support it @Rob-- .

all functions that accept an address also accept the address as a BigInt

[alorodri]

Hey @alorodri,

I have the same error, did you manage to figure it out? If I pass BigInt to func it fails even though it should support it @Rob-- .

all functions that accept an address also accept the address as a BigInt

Hey @Danovich ! Besides idk if it's the correct solution, I've been able to manage it casting the address to Number before passing it again to the readMemory function.

[Danovich]

@alorodri and the data you get from readMemory is correct? Converting bigint to number is sketchy as you can go over the MAX_SAFE_INTEGER and lose accuracy...

[alorodri]

@alorodri and the data you get from readMemory is correct? Converting bigint to number is sketchy as you can go over the MAX_SAFE_INTEGER and lose accuracy...

In my case it worked and I got the value I was searching for, but seems it loses accuracy and can result in errors if the Number is > 2^54 or something like that.

[Danovich]

@Rob-- any updates on this issue?

[Rob--]

Hi, will fix this soon.