CP/M/CPM_CDROM.iso/cpm/rcpm/wheel.asm

Assembly Source File | 1994-07-13 | 10.0 KB | 387 lines

; WHEEL.ASM  -    Password access for ZCPR/ZCMD systems  -  05/20/86
;
;          copyrighted by Irv Hoff W6FFC
;
;
    ASEG            ; For M80 and RMAC ignore error with MAC
;
; This program permits the SYSOP to activate the WHEEL byte.  This kicks
; in the drives and user areas set for the Sysop in place of those set
; for the remote user.
;
; There are several ways to change these allocations:
;
;    1) Using ZCMD or ZCPR without BYE5 for remote use
;    2) Using ZCMD or ZCPR with BYE5 for remote use
;    3) Using ZCMD or ZCPR with/without BYE5 with external flow path
;
; All of these cases are covered.  In the case of an external flow path
; be sure to set the EXTPATH equate below.
;
; This program is placed in A0: so the Sysop can request it without the
; WHEEL byte being activated.  Since any user could do the same, several
; levels of security are included:
;
;    1) Go to the 'special attention' area below and:
;        a) add your own password at PSSWD (use only upper-case)
;        b) select remote user's max drive/user
;        c) select Sysop's max drive/user
;        d) select external path (if used in ZCMD or ZCPR)
;
;    2) Assemble and load to get WHEEL.COM
;    3) Rename program for additional security, instead of WHEEL.COM
;    4) Place on A0: and 'hide' with STAT.COM as a .SYS file
;
;        A0>STAT    IRV.COM    $SYS    ; (So the name can't be seen)
;
;    5) Assuming for the example "HOFF" was chosen for a password:
;
;        A0>IRV HOFF    ; To enable the wheel byte mode
;        A0>IRV -    ; Resets for remote user, types msg.
;        A0>IRV
;           Password:    ; Requests password, which is not
;                ; displayed so nobody can see what you
;                ; are using
;
;-----------------------------------------------------------------------
;
; IRV.COM would be the first level of security.  Hiding it as a system
; file on A0: prevents others from knowing the initial program's name.
; HOFF in this case would be the second level of security.  Even if you
; type:  A0>IRV <ret> when some remote user is watching, and they see
; the request for a password, they will not see your answer.  If it is
; wrong, it wipes out the 'Password: ' and replaces it with the name of
; the program with a '?' as though CP/M doesn't know what you are asking
; for and there is no such program - another mild form of security.
;
; If some twit does attempt to find your initial password (name of pgm)
; and uses the correct name (IRV in this case), it resets for remote
; user (without displaying any message) and then shows IRV? indicating
; no such file exists.    (It really does, but this is an additional level
; of security to discourage twits.)
;
; SUMMARY:
; =======
;    There may be other programs existing with similar features but
;    none I ran across have as much security as this program, which
;    is why I wrote it.  I use it with ZCMD2x, BYE5 and KMD on two
;    different systems, one having a BBS and one without.  This is
;    also useful for giving friends access to your system when you
;    do not have a BBS that automatically asks their name and kicks
;    them in as a Sysop.  The primary use though, is so the Sysop
;    can kick in his own capability whenever he wishes, perhaps on
;    some occasion a particular user is on his system and the Sysop
;    needs more capability than the remote user is normally given.
;
;                    - Notes by Irv Hoff
    ORG    0100H
;
    JMP    START
;
;
;=======================================================================
;        (start of special attention area)
;
; NOTE: Set the following four values for your system's normal use:
;
RDRIVE    EQU    2        ; Number of drives available to user
RUSER    EQU    12        ; # of highest area for remote users
SDRIVE    EQU    2        ; Number of drives available to SYSOP
SUSER    EQU    15        ; # of highest area for SYSOP (0-15)
;.....
;
;
; Put your password here, end it with a '0', can be 15 characters or
; less, not including the 0.
;
PSSWRD:    DB    'PASS'        ; Up to 15 characters, end with 0 below
    DB    0
;
;
; If using an external path, set the following equate YES and check the
; address of the external path in the line following that, usually 40h.
;
EXTPATH    EQU    0        ; 0 = NO, 1 = YES
PATHADR    EQU    40H        ; Change if needed
;
;        (end of special attention items)
;=======================================================================
;
; Tells the SYSOP the WHEEL byte is now activated
;
WHLMSG:    DB    0DH,0AH,'   WHEEL is on',0DH,0AH,'$'
WHLOFF:    DB    0DH,0AH,'   WHEEL is off',0DH,0AH,'$'
;.....
;
;
; Equates
;
BDOS    EQU    0005H        ; BDOS location
CR    EQU    0DH        ; Carriage return character
DIRCON    EQU    0006H        ; Direct console call
LF    EQU    0AH        ; Line feed character
FCB    EQU    005CH        ; File control block
DRVMAX    EQU    003DH        ; Location of MAXDRV byte
PRINT    EQU    09H        ; BDOS print a string
USRMAX    EQU    003FH        ; Location of MAXUSER byte
WHEEL    EQU    003EH        ; Location of wheel byte
WRCON    EQU    02H        ; Display a character on CRT
;
;
START:    LDA    FCB+1        ; See what we are supposed to do
    CPI    ' '
    JZ    ASKFOR        ; Nothing typed, ignore request
    CPI    '-'        ; Disable wheel mode
    JZ    DISABLE
;
CHECK:    LXI    H,FCB+1        ; Set up all the pointers
    LXI    D,PSSWRD    ; Location of password buffer
;
CHECK1:    LDAX    D        ; Actual password in 'A' register
    ORA    A
    JZ    OK        ; If zero, checks ok
    CMP    M        ; Characters match?
    JNZ    ABORT        ; No check, exit with no changes
    INX    H        ; Address of next password address
    INX    D        ; Address of next password typed entry
    JMP    CHECK1        ; If not zero, check another character
;
OK:    JMP    ENABLE
;
;
;-----------------------------------------------------------------------
;              subroutines
;-----------------------------------------------------------------------
;
; Aborts if a person happens to type to correct filename, reprints the
; name to throw him off, then resets the system for a remote user, as an
; added level of security.
;
ABORT:    MVI    C,PRINT
    LXI    D,ABTCLR
    CALL    BDOS
;
    LDA    0002H        ; MSP of BIOS address
    SUI    22
    MOV    H,A
    MVI    L,8        ; Index into buffer
;
ABORT1:    MOV    A,M        ; Get the character there
    ORA    A        ; See if finished
    JZ    ABORT2
    CPI    ' '
    JZ    ABORT2
    CALL    SHOW
    INX    H        ; Next location
    JMP    ABORT1
;
ABORT2:    MVI    A,'?'
    CALL    SHOW
    MVI    A,LF
    CALL    SHOW
;
ABORT3:    JMP    DISAB0        ; Go disable the drives
;...
;
;
ABTCLR:    DB    CR,'                ',CR,'$' ; wipes out 'Password: '
;.....
;
;
; Asks for a password if none was given, allows typing so nobody can
; see what it is.  (Just the local typist.)
;
ASKFOR:    MVI    C,PRINT
    LXI    D,ASKPAS
    CALL    BDOS
    LXI    D,FCB+1        ; Location to put password for compare
;
ASK1:    PUSH    D
    MVI    C,6        ; Direct console I/O
    MVI    E,0FFH        ; Ask for character
    CALL    BDOS
    POP    D        ; Get the address back
    ORA    A
    JZ    ASK1
;
    CPI    'a'        ; Make sure character is upper case
    JC    ASK2
    CPI    'z'+1
    JNC    ASK2
    ANI    5FH        ; Change to upper-case
;
ASK2:    CPI    CR
    JZ    CHECK
    STAX    D
    INX    D
    JMP    ASK1
;...
;
;
ASKPAS:    DB    '   Password is: ','$'
;.....
;
;
; Change the external path from Sysop to remote or vice versa
;
CHANGE:    MVI    C,7
;
CHANG1:    LDAX    D
    MOV    M,A
    INX    D
    INX    H
    DCR    C
    JNZ    CHANG1
    RET
;.....
;
;
; See if BYE5 is active
;
CKBYE:    MVI    C,32
    MVI    E,0F1H
    CALL    BDOS
    CPI    4DH
    RET
;.....
;
;
; Intentional disable shows the WHEEL is off, then resets the system
; for a normal remote user again.
;
DISABLE:MVI    C,PRINT        ; WHEEL "OFF" message
    LXI    D,WHLOFF
    CALL    BDOS
;
DISAB0:    XRA    A        ; Turn the WHEEL byte off
    STA    WHEEL
    CALL    CKBYE        ; See if BYE5 is active
    JNZ    DISAB1        ; If yes exit
;...
;
;
; BYE5 is in use, so set things through it.  First get the BYE5 address
; and then increment into the program to the location of max user (+12_
; and max drive (+13).
;
    CALL    SETBYE
;
; Now have the max user address
;
    LDA    RUSER+1
    MOV    M,A
    INX    H        ; Address of max drive
    LDA    RDRIVE
    MOV    M,A
;
;
; No BYE5 in use, assume ZCMD or ZCPR is setting max drive and max user.
;
DISAB1:    MVI    A,RUSER+1    ; Sysop maximum user area
    STA    USRMAX
    MVI    A,RDRIVE-1    ; Sysop number of drives
    STA    DRVMAX
    STA    DRVMAX
;
     IF    EXTPATH
    LXI    D,RPATH        ; Remote user external path, prevents
    LXI    H,PATHADR    ;   his using A15:
    CALL    CHANGE
     ENDIF            ; EXTPATH
;
    JMP    EXIT
;.....
;
;
; Set the WHEEL, max user, max drive but first check to see if BYE is
; active and handle accordingly.
;
ENABLE:    MVI    A,0FFH        ; Turn the WHEEL byte on
    STA    WHEEL
;
    MVI    C,PRINT        ; WHEEL in use message
    LXI    D,WHLMSG
    CALL    BDOS
    CALL    CKBYE        ; See if BYE5 is active
    JNZ    ENAB1        ; Exit if BYE5 is in use
;
;
; BYE5 is in use, so set things through it.  First get the BYE5 address
; and then increment into the program to the location of max user (+12_
; and max drive (+13).
;
    CALL    SETBYE
;
; Now have the max user address
;
    LDA    SUSER+1
    MOV    M,A
    INX    H        ; Address of max drive
    LDA    SDRIVE
    MOV    M,A
;
;
; No BYE5 in use, assume ZCMD or ZCPR is setting max drive and max user.
;
ENAB1:    MVI    A,SUSER+1    ; Sysop maximum user area
    STA    USRMAX
    MVI    A,SDRIVE-1    ; Sysop number of drives
    STA    DRVMAX
;
     IF    EXTPATH
    LXI    D,SPATH        ; Sysop external path (includes user 15)
    LXI    H,PATHADR
    CALL    CHANGE
     ENDIF            ; EXTPATH
;...
;
;
EXIT:    RET            ; Jump back to original address
;.....
;
;
; Remote user's external path flow - WHEEL off - if any paths are added,
; alter the value at CHANGE: above.
;
RPATH:    DB    '$','$'        ; Current drive, user area
    DB    1,0        ; 'A' drive, 0 user area
    DB    0,0        ; Skips additional checks
    DB    0        ; Finished
;.....
;
;
; Sysop's external path flow - WHEEL off - if any paths are added,
; alter the value at CHANGE: above.
;
SPATH:    DB    '$','$'        ; Current drive, user area
    DB    1,0        ; 'A' drive, 0 user area
    DB    1,15        ; 'A' drive, 15 user area
    DB    0        ; Finished
;.....
;
;
SETBYE:    LHLD    0000H+1        ; Warm boot vector address
    DCX    H        ; MSP of cold boot vector
    MOV    D,M        ; Put into 'D' register
    DCX    H        ; LSP of cold boot vector
    MOV    E,M        ; Put into the 'E' register
;
; Now have the BYE5 MCBOOT location, add 6 to find max user location.
;
    LXI    H,6
    DAD    D        ; Add to MCBOOT location
    RET
;.....
;
;
SHOW:    PUSH    H
    MOV    E,A
    MVI    C,WRCON
    CALL    BDOS
    POP    H
    RET
;.....
;
;
    END