change a clipper code to bypass authentication of a old program

Question

Hi a friend of mine asked me to recover a password of a program written in clipper back in 1994. I got myself a decompiler (Valkyrie 5) and decompiled the EXE-file. I located a procedure called USERLOGIN. The problem is that i dont know how to program in clipper. I would be very thankfull if someone could edit the procedure so it won't ask for authentication anymore.

#include "common.ch"
#include "inkey.ch"

********************************
Function USERLOGON

   Local Local1:= -1, Local2:= .F., Local3, Local4, Local5:= 3, ;
      Local6:= 3, Local7:= 7, Local8:= 41, Local9, Local10, Local11, ;
      Local12, Local13, Local14, Local15
   Local3:= 1
   Local9:= {}
   Local13:= setcursor()
   If (!netuse(diskname() + ":" + dirname() + "\" + "sinusr.dbf", ;
         "users"))
      Return Local1
   EndIf
   dbSetFilter({ || users->valid })
   Local14:= box(Local5, Local6, Local7, Local8, Nil, ;
      coltonum("GR+/B"))
   Do While (!Local2)
      Local10:= Space(12)
      Local11:= Space(10)
      setcursor(1)
      If (!Empty(n_shellver()))
         Local10:= padr(nnetwhoami(), 12)
      EndIf
      wininfo(Local14, @Local5, @Local6, @Local7, @Local8)
      @ Local5 + 1, Local6 + 5 Say "User............." Color "GR+/B"
      SetPos(Row(), Col() + 1)
      AAdd(Local9, __Get({ |_1| IIf(ISNIL(_1), Local10, Local10:= ;
         _1) }, "cUName", "@K!", Nil, Nil):display())
      @ Local5 + 2, Local6 + 5 Say "Password........." Color "GR+/B"
      SetPos(Row(), Col() + 1)
      AAdd(Local9, __Get({ |_1| IIf(ISNIL(_1), Local11, Local11:= ;
         _1) }, "cUPass", "@K!", Nil, Nil):display())
      Local9[2]:reader({ |_1| gt_grpassw(_1) })
      wreadmodal(Local9, 0)
      Local11:= Local9[2]:cargo()
      Local9:= {}
      If (LastKey() == K_ESC .OR. !winisinuse(Local14))
         If (winisinuse(Local14))
            winclose(Local14)
         EndIf
         Return Local1
      EndIf
      Local10:= alltrim(Local10)
      Local12:= {}
      Locate For Local10 == alltrim(users->emri)
      Do While (Found())
         AAdd(Local12, users->id)
         Continue
      EndDo
      For Local4:= 1 To Len(Local12)
         If ((Local15:= upass(Local12[Local4])) != Nil)
            If (alltrim(Local11) == Local15)
               Local2:= .T.
               Exit
            EndIf
         EndIf
      Next
   EndDo
   If (users->id != Local12[Local4])
      users->(dbGoTop())
      Locate For Local12[Local4] == users->id
      If (!Found())
         msg("Fatal error in user's file !", 3)
         Return -1
      EndIf
   EndIf
   For Local4:= 1 To MaxCol()
      winchgpos(0, 3)
   Next
   boxc(Local14)
   setcursor(Local13)
   If (users->in)
      tone(500, 10)
      Local4:= al_box("User " + Trim(users->emri) + ;
         " is already IN;" + "Do You Want to Jump In ?", 2, ;
         {" Yes ", " No  "}, 2, "WARNING")
      If (Local4 == 1)
         msg("More than One User with the same Name might cause Trouble !", ;
            3)
      Else
         Close
         Return -1
      EndIf
   ElseIf (netrlock())
      Replace users->in With .T.
      Unlock
      dbcommit()
   Else
      Close
      Return -1
   EndIf
   Static148[1]:= users->id
   Static148[2]:= alltrim(users->emri)
   Static148[3]:= alltrim(users->dirpriv)
   Static148[4]:= users->gjuha1
   Static148[5]:= users->gjuha2
   Static148[6]:= alltrim(users->emriiplote)
   Local1:= Static148[1]
   Close
   Return Local1

* EOF

Answer 1

This is partially guesswork, but here's my interpretation:

Read the user's password from the console into Local9[2]:

@ Local5 + 2, Local6 + 5 Say "Password........." Color "GR+/B"
...
Local9[2]:reader({ |_1| gt_grpassw(_1) })
wreadmodal(Local9, 0)

Put the password into Local11:

Local11:= Local9[2]:cargo()

Fetch all user ids into Local12 via Local10:

Locate For Local10 == alltrim(users->emri)
Do While (Found())
    AAdd(Local12, users->id)
    Continue
EndDo

Get each user's password into Local15, and if the password's present and matches the password in Local11, verify the user:

For Local4:= 1 To Len(Local12)
    If ((Local15:= upass(Local12[Local4])) != Nil)
        If (alltrim(Local11) == Local15)
            Local2:= .T.
            Exit
        EndIf
    EndIf
Next

The fix

Just remove the password check code. Not being certain about the purpose of all the rest of the code, I'd recommend leaving it alone. I've preserved the retrieval of the user's password, as maybe there's a good reason not to log in a user who has no password at all (perhaps that's how an account is disabled. The last block above could be changed to this:

For Local4:= 1 To Len(Local12)
    If ((Local15:= upass(Local12[Local4])) != Nil)
        Local2:= .T.
    EndIf
Next