Tetstack

So for the string "abcde" the number is "734". Try it and it works

Had to use a calculator

Give me a bit of time I am done with a and to go for the rest ....

example 6-5 =1 and 1 is less than 5 ...

as 6 or 7, 8, 9, 10 -5 are in range and true on the 5 < (local_70 -5U)

the range is 5 to 10

so wait

this underflows to a huge number, which is >5, so the real condition is local_70 >5

ghidra did unsigned substraction so .... local_70 is the string length, the expression length_70 - 5U is unsigned

so wait

time to try it

the check sum is this the comments for simplification ...

so I finalized it to this code that's the logic I suppose if you enter any character longer than 5 it exits with that message and then the next one is the number you type must be equal to the checksum of your string..

undefined8 FUN_001011f0(void) {
  int iVar1;
  ostream *poVar2;
  long in_FS_OFFSET;
  int local_7c;
  undefined1 *local_78;
  long local_70;
  undefined1 local_68 [16];
  string local_58 [40];
  long local_30;
  
  local_30 = *(long *)(in_FS_OFFSET + 0x28);
  local_78 = local_68;
  local_68[0] = 0;
  local_70 = 0;
  poVar2 = std::operator<<((ostream *)std::cout,"Enter a string of characters (no spaces): ");
  FUN_00101430(poVar2);
  std::operator>>((istream *)std::cin,(string *)&local_78);
  if (5 < local_70 - 5U) {
    std::operator<<((ostream *)std::cout,"Bro, what are you trying to do?");
    FUN_00101430();
                    /* WARNING: Subroutine does not return */
    exit(0);
  }
  poVar2 = std::operator<<((ostream *)std::cout,"Enter correct number (no spaces): ");
  FUN_00101430(poVar2);
  std::istream::operator>>((istream *)std::cin,&local_7c);
  std::__cxx11::string::string(local_58,(string *)&local_78);
  iVar1 = FUN_001014b0(local_58);
  std::__cxx11::string::_M_dispose();
  if (local_7c == iVar1) {
    poVar2 = std::operator<<((ostream *)std::cout,"OMG! You did it! :3");
  }
  else {
    poVar2 = std::operator<<((ostream *)std::cout,"Send help pls.");
  }
  FUN_00101430(poVar2);
  std::__cxx11::string::_M_dispose();
  if (local_30 == *(long *)(in_FS_OFFSET + 0x28)) {
    return 0;
  }
                    /* WARNING: Subroutine does not return */
  __stack_chk_fail();
}

so which means I missed smthing here

so still this only computes number from whatever string I typed

                                                                   DAT_00104020                                                                                    XREF[2]:               FUN_001014b0:001014c4(*), 
                                                                                                                                                                                                                 FUN_001014b0:001014d5(R)  
                   00104020  04 00 00 00               undefined4      00000004h
                                                                   DAT_00104024                                                                                    XREF[1]:               FUN_001014b0:001014d5(R)  
                   00104024  4f 00 00 00                undefined4      0000004Fh
                   00104028  81                                db                      81h
                   00104029  00                                ??                       00h
                   0010402a  00                                ??                       00h
                   0010402b  00                                ??                       00h
                   0010402c  ab                                ??                       ABh
                   0010402d  00                                ??                       00h
                   0010402e  00                                ??                       00h
                    0010402f  00                                ??                       00h

But there are 2 XREF sooo wait ...

So okay that maths is this, which mathematically would work but idk

so after checking the table is not an array of char but an array of unit(4 bit each) they are 32-bit integers

00104028 81 db 81h 00104029 00 ?? 00h 0010402a 00 ?? 00h 0010402b 00 ?? 00h 0010402c ab ?? ABh 0010402d 00 ?? 00h 0010402e 00 ?? 00h 0010402f 00 ?? 00h 00104030 fe ?? FEh 00104031 00 ?? 00h 00104032 00 ?? 00h 00104033 00 ?? 00h 00104034 7b ?? 7Bh { 00104035 00 ?? 00h 00104036 00 ?? 00h so this are the first 15 byte now gotta find a way

param_1[0] = pointer to the string's character buffer param_1[1]=lenght of the string