[?]code snippet meaning

[abbas]

hi all 

can some one please tell me what does this code do?

private boolean d(String paramString) {
    boolean bool = false;
    byte[] arrayOfByte = paramString.getBytes();
    if (arrayOfByte.length == 26) {
      byte b1 = 0;
      byte b2 = 0;
      while (b1 < 24) {
        b2 = (byte)(b2 ^ arrayOfByte[b1]);
        b1++;
      } 
      if ((b2 & 0xF) == -65 + arrayOfByte[25] && (0xF & b2 >> 4) == -65 + arrayOfByte[24])
        bool = true; 
    } 
    return bool;
  }

 

[CodeExplorer]

if ((b2 & 0xF) == -65 + arrayOfByte[25] && (0xF & b2 >> 4) == -65 + arrayOfByte[24]) bool = true;

This will check first hex byte tetrade from b2 variable and second hex byte tetrade;
my recommendation is to generate random bytes from index 0 to 24,
from those bytes we get a byte value for b2:
just copy paste the first part of that algorithm:
then just fix arrayOfByte[25] and arrayOfByte[24] so it will return true:
arrayOfByte[25] = (b2 & 0xF) + 65
arrayOfByte[24] = (0xF & b2 >> 4)+ 65

 

Edited February 17, 2020 by CodeExplorer

[abbas]

16 hours ago, CodeExplorer said:

 

 

hi

thnx for reply

i calculated AXXabcXYUJKXXXXPOLKJXQWEDN which is correct for this func

but clearly there another func at start up cause its not accepted in the next launch

are you familiar with android studio debugging? if not what debugger do you use?

Edited February 18, 2020 by abbas