Ìåõàíèçì äåéñòâèÿ S-áëîêîâ
Ïðåîáðàçîâàíèå, ñ ïîìîùüþ êîòîðîãî 48-ðàçðÿäíûé áëîê ïðåîáðàçóåòñÿ â 32-ðàçðÿäíûé, ñâîäèòñÿ ê âûáîðêå âîñüìè òåòðàä èç 8 òàáëèö (S-áëîêîâ) ðàçìåðîì 4 ´ 16 (òàáë. 18.7). Èç êàæäîãî S-áëîêà âûáèðàåòñÿ îäíà òåòðàäà. Äëÿ ýòîãî 48-ðàçðÿäíûé áëîê äåëèòñÿ ïîñëåäîâàòåëüíî íà 8 êîìáèíàöèé ïî 6 áèò êàæäàÿ. Ïåðâàÿ êîìáèíàöèÿ (ñëåâà) ÿâëÿåòñÿ âõîäîì â ïåðâûé S-áëîê, âòîðàÿ — âî âòîðîé è ò.ä. Ïðè ýòîì ïåðâûé è ïîñëåäíèé áèòû êîìáèíàöèè çàäàþò íîìåð ñòðîêè, à îñòàëüíûå 4 áèòà — íîìåð ñòîëáöà S-áëîêà, íà ïåðåñå÷åíèè êîòîðûõ ðàñïîëîæåíà ñîîòâåòñòâóþùàÿ òåòðàäà. Êîíêðåòíûå çíà÷åíèÿ Si (i = 1, …, 8) ïðåäñòàâëåíû â òàáë. 18.7.
Òàáëèöà 18.7. Òàáëèöû S -áëîêîâ äëÿ DES
| S1 | 0 | 1 | 2 | 3
| 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | |||||||||||||||||
| 0 | 14 | 4 | 13 | 1 | 2 | 15 | 11 | 8 | 3 | 10 | 6 | 12 | 5 | 9 | 0 | 7 | |||||||||||||||||
| 1 | 0 | 15 | 7 | 4 | 14 | 2 | 13 | 1 | 10 | 6 | 12 | 11 | 9 | 5 | 3 | 8 | |||||||||||||||||
| 2 | 4 | 1 | 14 | 8 | 13 | 6 | 2 | 11 | 15 | 12 | 9 | 7 | 3 | 10 | 5 | 0 | |||||||||||||||||
| 3 | 15 | 12 | 8 | 2 | 4 | 9 | 1 | 7 | 5 | 11 | 3 | 14 | 10 | 0 | 6 | 13 | |||||||||||||||||
| S2 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | |||||||||||||||||
| 0 | 15 | 1 | 8 | 14 | 6 | 11 | 3 | 4 | 9 | 7 | 2 | 13 | 12 | 0 | 5 | 10 | |||||||||||||||||
| 1 | 3 | 13 | 4 | 7 | 15 | 2 | 8 | 14 | 12 | 0 | 1 | 10 | 6 | 9 | 11 | 5 | |||||||||||||||||
| 2 | 0 | 14 | 7 | 11 | 10 | 4 | 13 | 1 | 5 | 8 | 12 | 6 | 9 | 3 | 2 | 15 | |||||||||||||||||
| 3 | 13 | 8 | 10 | 1 | 3 | 15 | 4 | 2 | 11 | 6 | 7 | 12 | 0 | 5 | 14 | 9 | |||||||||||||||||
| S3 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | |||||||||||||||||
| 0 | 10 | 0 | 9 | 14 | 6 | 3 | 15 | 5 | 1 | 13 | 12 | 7 | 11 | 4 | 2 | 8 | |||||||||||||||||
| 1 | 13 | 7 | 0 | 9 | 3 | 4 | 6 | 10 | 2 | 8 | 5 | 14 | 12 | 11 | 15 | 1 | |||||||||||||||||
| 2 | 13 | 6 | 4 | 9 | 8 | 15 | 3 | 0 | 11 | 1 | 2 | 12 | 5 | 10 | 14 | 7 | |||||||||||||||||
| 3 | 1 | 10 | 13 | 0 | 6 | 9 | 8 | 7 | 4 | 15 | 14 | 3 | 11 | 5 | 2 | 12 | |||||||||||||||||
| S4 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | |||||||||||||||||
| 0 | 7 | 13 | 14 | 3 | 0 | 6 | 9 | 10 | 1 | 2 | 8 | 5 | 11 | 12 | 4 | 15 | |||||||||||||||||
| 1 | 13 | 8 | 11 | 5 | 6 | 15 | 0 | 3 | 4 | 7 | 2 | 12 | 1 | 10 | 14 | 9 | |||||||||||||||||
| 2 | 10 | 6 | 9 | 0 | 12 | 11 | 7 | 13 | 15 | 1 | 3 | 14 | 5 | 2 | 8 | 4 | |||||||||||||||||
| 3 | 3 | 15 | 0 | 6 | 10 | 1 | 13 | 8 | 9 | 4 | 5 | 11 | 12 | 7 | 2 | 14 | |||||||||||||||||
| S5 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | |||||||||||||||||
| 0 | 2 | 12 | 4 | 1 | 7 | 10 | 11 | 6 | 8 | 5 | 3 | 15 | 13 | 0 | 14 | 9 | |||||||||||||||||
| 1 | 14 | 11 | 2 | 12 | 4 | 7 | 13 | 1 | 5 | 0 | 15 | 10 | 3 | 9 | 8 | 6 | |||||||||||||||||
| 2 | 4 | 2 | 1 | 11 | 10 | 13 | 7 | 8 | 15 | 9 | 12 | 5 | 6 | 3 | 0 | 14 | |||||||||||||||||
| 3 | 11 | 8 | 12 | 7 | 1 | 14 | 2 | 13 | 6 | 15 | 0 | 9 | 10 | 4 | 5 | 3 | |||||||||||||||||
| S6 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | |||||||||||||||||
| 0 | 12 | 1 | 10 | 15 | 9 | 2 | 6 | 8 | 0 | 13 | 3 | 4 | 14 | 7 | 5 | 11 | |||||||||||||||||
| 1 | 10 | 15 | 4 | 2 | 7 | 12 | 9 | 5 | 6 | 1 | 13 | 14 | 0 | 11 | 3 | 8 | |||||||||||||||||
| 2 | 9 | 14 | 15 | 5 | 2 | 8 | 12 | 3 | 7 | 0 | 4 | 10 | 1 | 13 | 11 | 6 | |||||||||||||||||
| 3 | 4 | 3 | 2 | 12 | 9 | 5 | 15 | 10 | 11 | 14 | 1 | 7 | 6 | 0 | 8 | 13 |
Îêîí÷àíèå òàáëèöû 18.7
|
S7 |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
|
0 |
4 |
11 |
2 |
14 |
15 |
0 |
8 |
13 |
3 |
32 |
9 |
7 |
5 |
10 |
6 |
1 |
|
1 |
13 |
0 |
11 |
7 |
4 |
9 |
1 |
10 |
14 |
3 |
5 |
12 |
2 |
15 |
8 |
6 |
|
2 |
1 |
4 |
11 |
13 |
12 |
3 |
7 |
14 |
10 |
15 |
6 |
8 |
0 |
5 |
9 |
2 |
|
3 |
6 |
11 |
13 |
8 |
1 |
4 |
10 |
7 |
9 |
5 |
0 |
15 |
14 |
2 |
3 |
12 |
|
S8 |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 |
14 |
15 |
|
0 |
13 |
2 |
8 |
4 |
6 |
15 |
11 |
1 |
10 |
9 |
3 |
14 |
5 |
0 |
12 |
7 |
|
1 |
1 |
15 |
13 |
8 |
10 |
3 |
7 |
4 |
12 |
5 |
6 |
11 |
0 |
14 |
9 |
2 |
|
2 |
7 |
11 |
4 |
1 |
9 |
12 |
14 |
2 |
0 |
6 |
10 |
13 |
15 |
3 |
5 |
8 |
|
3 |
2 |
1 |
14 |
7 |
4 |
10 |
8 |
13 |
15 |
12 |
9 |
0 |
3 |
5 |
6 |
11 |
Ëèñòèíã 18.3. Ïðèìåð ðåàëèçàöèè
àëãîðèòìà DES íà ÿçûêå Basic äëÿ øèôðîâàíèÿ ôàéëîâ
$CPU 80386
$FLOAT NPX
$OPTIMIZE SPEED
$LIB ALL-
$OPTION CNTLBREAK ON
DECLARE FUNCTION MYBIN$ (n%)
DECLARE FUNCTION desalg$ (a$)
DECLARE SUB f (i%, a%(), x%())
DECLARE SUB transpose (datax%(), T%(), n%)
DECLARE SUB mrotate (keyx%())
DECLARE SUB stob (a$, mbits%())
DECLARE SUB btos (mbits%(), a$)
DECLARE SUB letbe (target%(), source%(), LAST%)
DECLARE SUB init (x() AS INTEGER, n%)
DECLARE SUB sboxinit (b() AS INTEGER)
DECLARE SUB xtob (a$, mbits%())
DIM s(1 TO 8, 1 TO 64) AS shared INTEGER
Ïðîäîëæåíèå ëèñòèíãà 18.3
' Èíèöèàëèçàöèÿ
RESTORE InitialTrl
DIM InitialTr(1 TO 64) AS shared INTEGER
init InitialTr(), 64
RESTORE FinalTrl
DIM FinalTr( 1 TO 64) AS shared INTEGER
init FinalTr(), 64
RESTORE swappyl
DIM swappy(1 TO 64) AS shared INTEGER
init swappy(), 64
RESTORE KeyTr1l
DIM KeyTr1(1 TO 56) AS shared INTEGER
init KeyTr1(), 56
RESTORE KeyTr2l
DIM KeyTr2(1 TO 48) AS shared INTEGER
init KeyTr2(), 48
RESTORE etrl
DIM etr(1 TO 48) AS shared INTEGER
init etr(), 48
RESTORE ptrl
DIM ptr(1 TO 32) AS shared INTEGER
init ptr(), 32
sboxinit s()
RESTORE rotsl
DIM rots(1 TO 16) AS shared INTEGER
init rots(), 16
DIM XR(1 TO 56) AS shared INTEGER
DIM EF(1 TO 64) AS shared INTEGER
DIM ikeyf(1 TO 64) AS shared INTEGER
DIM yf(1 TO 64) AS shared INTEGER
Ïðîäîëæåíèå ëèñòèíãà 18.3
DIM ades(1 TO 64) AS shared INTEGER
DIM bdes(1 TO 64) AS shared INTEGER
DIM xdes(1 TO 64) AS shared INTEGER
DIM XT(1 TO 64) AS shared INTEGER
DIM P2(1 TO 64) AS shared INTEGER
' Ãëàâíàÿ ïðîãðàììà
main:
CLS
parm$ = ltrim$(rtrim$(COMMAND$))+" "
IF LEN(parm$) > 1 THEN
Plainf$ = LTRIM$(RTRIM$(LEFT$(parm$, INSTR(parm$, " "))))
PRINT "Èñõîäíûé ôàéë : "; Plainf$
ELSE
INPUT "Èñõîäíûé ôàéë : ", plainf$
END IF
if len(plainf$)=0 then
print : print "ÑÁÎÉ: ââåäèòå èìÿ ôàéëà!"
system
end if
OPEN plainf$ FOR RANDOM AS 1
lof1& = LOF(1)
IF lof1& = 0 THEN
CLOSE #1
KILL plainf$
PRINT : PRINT "Ôàéë íå íàéäåí!";
SYSTEM
ELSE
IF lof1& > 9999999 THEN PRINT : PRINT "Èñõîäíûé ôàéë ñëèøêîì âåëèê!": SYSTEM
CLOSE #1
OPEN plainf$ for binary access read as #1
END IF
cipherf$ = ""
sp0% = 0: sp% = 0
DO
sp0% = sp%
sp% = INSTR(sp% + 1, plainf$, "\")
Ïðîäîëæåíèå ëèñòèíãà 18.3
LOOP WHILE sp% > 0
bplainf$ = RIGHT$(plainf$, LEN(plainf$) - (sp0%))
PRINT "Ñîõðàíÿåìîå èìÿ ôàéëà: "; bplainf$
pp% = INSTR(sp0% + 1, plainf$, ".")
IF pp% = 0 THEN
dcipherf$ = plainf$ + ".DES"
ELSE
dcipherf$ = LEFT$(plainf$, pp% - 1) + ".DES"
END IF
PRINT " Ïî óìîë÷àíèþ : "; dcipherf$
INPUT "Âûõîäíîé ôàéë : ", cipherf$
IF cipherf$ = "" THEN cipherf$ = dcipherf$
OPEN cipherf$ FOR RANDOM AS 2
IF LOF(2) > 0 THEN
CLOSE #2
PRINT : PRINT "Âûõîäíîé ôàéë óæå ñóùåñòâóåò!"
SYSTEM
ELSE
CLOSE #2
OPEN cipherf$ FOR binary AS 2
END IF
PW$ = ""
LOCATE 9, 1
INPUT ; " Ïàðîëü : ", PW$
IF (LEN(PW$) < 8) THEN PW$ = PW$ + STRING$(8 - LEN(PW$), 0)
IF len(pw$) = 16 then
LOCATE 9, 8: PRINT "Ïàðîëü : "; STRING$(16, 15); STRING$(10, " ")
PW$ = ucase$(PW$)
xtob PW$, P2()
ELSE
LOCATE 9, 8: PRINT "Ïàðîëü : "; STRING$(8, 15); STRING$(10, " ")
PW$ = LEFT$(PW$, 8)
stob PW$, P2()
end IF
Ïðîäîëæåíèå ëèñòèíãà 18.3
transpose P2(), KeyTr1(), 56
ciphertekst$ = ""
blocks& = lof1& \ 256
w = RND(-INT(TIMER))
anything$ = ""
FOR i% = 1 TO 12
anything$ = anything$ + CHR$(128 + INT(127 * RND(1)))
NEXT i%
header$ = "#" + LTRIM$(STR$(lof1&))
header$ = "DES" + LEFT$(anything$, 8 - LEN(header$)) + header$
header$ = header$ + RIGHT$(anything$, 12 - LEN(bplainf$)) +
"#" + bplainf$
cheader$=desalg$(left$(header$,8))+desalg$(MID$(header$,9,8))+desalg$(right$(header$,8))
put$ #2, cheader$
LOCATE 10, 8: PRINT ; "Øèôðîâàíèå: 0 %";
inblock$=space$(256)
FOR n& = 1 TO blocks&
get$ #1,256,inblock$
outblock$=""
for b%=1 to 256 step 8
outblock$ = outblock$+desalg$(mid$(inblock$,b%,8))
next
Put$ #2, outblock$
LOCATE 10, 19: PRINT ; USING "###"; (n& / blocks&) * 100;
NEXT n&
rest1 = lof1& MOD 256
rest2 = lof1& MOD 8
rest = rest1-rest2
IF rest1 > 0 THEN
outblock$=""
get$ #1,rest1,inblock$
Ïðîäîëæåíèå ëèñòèíãà 18.3
if rest2 > 0 then
inblock$=inblock$+left$(anything$,(8-rest2))
end if
for b%=1 to len(inblock$) step 8
outblock$ = outblock$+desalg$(mid$(inblock$,b%,8))
next
Put$ #2, outblock$
END IF
CLOSE
LOCATE 10, 19: PRINT "100 % çàâåðøåíî"
PRINT : PRINT "Øèôðîâàíèå ïî àëãîðèòìó DES çàâåðøåíî."
SYSTEM
' Äàííûå è ôóíêöèè
InitialTrl:
DATA 58,50,42,34,26,18,10,02,60,52,44,36,28,20,12,04
DATA 62,54,46,38,30,22,14,06,64,56,48,40,32,24,16,08
DATA 57,49,41,33,25,17,09,01,59,51,43,35,27,19,11,03
DATA 61,53,45,37,29,21,13,05,63,55,47,39,31,23,15,07
FinalTrl:
DATA 40,08,48,16,56,24,64,32,39,07,47,15,55,23,63,31
DATA 38,06,46,14,54,22,62,30,37,05,45,13,53,21,61,29
DATA 36,04,44,12,52,20,60,28,35,03,43,11,51,19,59,27
DATA 34,02,42,10,50,18,58,26,33,01,41,09,49,17,57,25
swappyl:
DATA 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48
DATA 49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64
DATA 01,02,03,04,05,06,07,08,09,10,11,12,13,14,15,16
DATA 17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32
KeyTr1l:
DATA 57,49,41,33,25,17,09,01,58,50,42,34,26,18,10,02
DATA 59,51,43,35,27,19,11,03,60,52,44,36
DATA 63,55,47,39,31,23,15,07,62,54,46,38,30,22,14,06
DATA 61,53,45,37,29,21,13,05,28,20,12,04
Ïðîäîëæåíèå ëèñòèíãà 18.3
KeyTr2l:
DATA 14,17,11,24,01,05,03,28,15,06,21,10,23,19,12,04
DATA 26,08,16,07,27,20,13,02,41,52,31,37,47,55,30,40
DATA 51,45,33,48,44,49,39,56,34,53,46,42,50,36,29,32
etrl:
DATA 32,01,02,03,04,05,04,05,06,07,08,09,08,09,10,11
DATA 12,13,12,13,14,15,16,17,16,17,18,19,20,21,20,21
DATA 22,23,24,25,24,25,26,27,28,29,28,29,30,31,32,01
ptrl:
DATA 16,07,20,21,29,12,28,17,01,15,23,26,05,18,31,10
DATA 02,08,24,14,32,27,03,09,19,13,30,06,22,11,04,25
sboxesl:
DATA 14,04,13,01,02,15,11,08,03,10,06,12,05,09,00,07
DATA 00,15,07,04,14,02,13,01,10,06,12,11,09,05,03,08
DATA 04,01,14,08,13,06,02,11,15,12,09,07,03,10,05,00
DATA 15,12,08,02,04,09,01,07,05,11,03,14,10,00,06,13
DATA 15,01,08,14,06,11,03,04,09,07,02,13,12,00,05,10
DATA 03,13,04,07,15,02,08,14,12,00,01,10,06,09,11,05
DATA 00,14,07,11,10,04,13,01,05,08,12,06,09,03,02,15
DATA 13,08,10,01,03,15,04,02,11,06,07,12,00,05,14,09
DATA 10,00,09,14,06,03,15,05,01,13,12,07,11,04,02,08
DATA 13,07,00,09,03,04,06,10,02,08,05,14,12,11,15,01
DATA 13,06,04,09,08,15,03,00,11,01,02,12,05,10,14,07
DATA 01,10,13,00,06,09,08,07,04,15,14,03,11,05,02,12
DATA 07,13,14,03,00,06,09,10,01,02,08,05,11,12,04,15
DATA 13,08,11,05,06,15,00,03,04,07,02,12,01,10,14,09
DATA 10,06,09,00,12,11,07,13,15,01,03,14,05,02,08,04
DATA 03,15,00,06,10,01,13,08,09,04,05,11,12,07,02,14
DATA 02,12,04,01,07,10,11,06,08,05,03,15,13,00,14,09
DATA 14,11,02,12,04,07,13,01,05,00,15,10,03,09,08,06
DATA 04,02,01,11,10,13,07,08,15,09,12,05,06,03,00,14
DATA 11,08,12,07,01,14,02,13,06,15,00,09,10,04,05,03
Ïðîäîëæåíèå ëèñòèíãà 18.3
DATA 12,01,10,15,09,02,06,08,00,13,03,04,14,07,05,11
DATA 10,15,04,02,07,12,09,05,06,01,13,14,00,11,03,08
DATA 09,14,15,05,02,08,12,03,07,00,04,10,01,13,11,06
DATA 04,03,02,12,09,05,15,10,11,14,01,07,06,00,08,13
DATA 04,11,02,14,15,00,08,13,03,12,09,07,05,10,06,01
DATA 13,00,11,07,04,09,01,10,14,03,05,12,02,15,08,06
DATA 01,04,11,13,12,03,07,14,10,15,06,08,00,05,09,02
DATA 06,11,13,08,01,04,10,07,09,05,00,15,14,02,03,12
DATA 13,02,08,04,06,15,11,01,10,09,03,14,05,00,12,07
DATA 01,15,13,08,10,03,07,04,12,05,06,11,00,14,09,02
DATA 07,11,04,01,09,12,14,02,00,06,10,13,15,03,05,08
DATA 02,01,14,07,04,10,08,13,15,12,09,00,03,05,06,11
rotsl:
DATA 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
SUB btos (mbits() AS INTEGER, a$)
a$ = ""
FOR i% = 1 TO 8
w% = 0
FOR j% = 1 TO 8
w% = w% + ((mbits(((i% - 1) * 8) + j%)) * (2 ^ (8 - j%)))
NEXT j%
a$ = a$ + CHR$(w%)
NEXT i%
END SUB
FUNCTION desalg$ (a$)
temp$ = ""
stob a$, ades()
transpose ades(), InitialTr(), 64
FOR i% = 1 TO 16
letbe bdes(), ades(), 64
FOR j% = 1 TO 32
ades(j%) = bdes(j% + 32)
NEXT j%
f i%, ades(), xdes()
FOR j% = 1 TO 32
ades(j% + 32) = (bdes(j%) + xdes(j%)) MOD 2
Ïðîäîëæåíèå ëèñòèíãà 18.3
NEXT j%
NEXT i%
transpose ades(), swappy(), 64
transpose ades(), FinalTr(), 64
btos ades(), temp$
desalg$ = temp$
END FUNCTION
SUB f (i%, a() AS INTEGER, x() AS INTEGER)
h% = i%: letbe EF(), a(), 64
transpose EF(), etr(), 48
FOR j% = 1 TO rots(h%)
mrotate P2()
NEXT j%
letbe ikeyf(), P2(), 64: transpose ikeyf(), KeyTr2(), 48
FOR j% = 1 TO 48
yf(j%) = (EF(j%) + ikeyf(j%)) MOD 2
NEXT j%
FOR k% = 1 TO 8
k6% = 6 * k%: k4% = 4 * k%
r% = (32 * yf(k6% - 5)) + (16 * yf(k6%)) + (8 * yf(k6% - 4)) + (4 * yf(k6% - 3)) + (2 * yf(k6% - 2)) + yf(k6% - 1) + 1
x(k4% - 3) = (s(k%, r%) \ 8) MOD 2: x(k4% - 2) = (s(k%, r%) \ 4) MOD 2
x(k4% - 1) = (s(k%, r%) \ 2) MOD 2: x(k4%) = s(k%, r%) MOD 2
NEXT k%
transpose x(), ptr(), 32
END SUB
SUB init (x() AS INTEGER, n%)
FOR i% = 1 TO n%
READ x(i%)
NEXT i%
END SUB
SUB letbe (target() AS INTEGER, source() AS INTEGER, LAST%)
FOR i% = 1 TO LAST%
target(i%) = source(i%)
NEXT i%
END SUB
Ïðîäîëæåíèå ëèñòèíãà 18.3
FUNCTION MYBIN$ (n%)
LOCAL ST$
p% = n%
ST$=""
FOR i% = 1 TO 8
IF (p% MOD 2) THEN
ST$ = "1" + ST$
ELSE
ST$ = "0" + ST$
END IF
p% = p% \ 2
NEXT i%
MYBIN$ = ST$
END FUNCTION
SUB mrotate (keyr() AS INTEGER)
letbe XR(), keyr(), 56
FOR i% = 1 TO 55
XR(i%) = XR(i% + 1)
NEXT i%
XR(28) = keyr(1): XR(56) = keyr(29)
letbe keyr(), XR(), 56
END SUB
SUB sboxinit (b() AS INTEGER)
RESTORE sboxesl
FOR i% = 1 TO 8
FOR j% = 1 TO 64
READ b(i%, j%)
NEXT j%
NEXT i%
END SUB
SUB stob (a$, mbits() AS INTEGER)
FOR i% = 1 TO 8
b$ = MYBIN$(ASC(MID$(a$, i%, 1)))
FOR j% = 1 TO 8
mbits(((i% - 1) * 8) + j%) = ASC(MID$(b$, j%, 1)) - 48
NEXT j%
NEXT i%
END SUB
Ïðîäîëæåíèå ëèñòèíãà 18.3
SUB transpose (datax() AS INTEGER, T() AS INTEGER, n%)
letbe XT(), datax(), 64
FOR i% = 1 TO n%
datax(i%) = XT(T(i%))
NEXT i%
END SUB
SUB xtob (a$, mbits() AS INTEGER)
LOCAL X$,NIBBLE$
FOR i% = 1 to 16
X$ = MID$(a$,i%,1)
SELECT CASE X$
CASE "0"
NIBBLE$ = "0000"
CASE "1"
NIBBLE$ = "0001"
CASE "2"
NIBBLE$ = "0010"
CASE "3"
NIBBLE$ = "0011"
CASE "4"
NIBBLE$ = "0100"
CASE "5"
NIBBLE$ = "0101"
CASE "6"
NIBBLE$ = "0110"
CASE "7"
NIBBLE$ = "0111"
CASE "8"
NIBBLE$ = "1000"
CASE "9"
NIBBLE$ = "1001"
CASE "A"
NIBBLE$ = "1010"
CASE "B"
NIBBLE$ = "1011"
CASE "C"
NIBBLE$ = "1100"
CASE "D"
NIBBLE$ = "1101"
CASE "E"
Îêîí÷àíèå ëèñòèíãà 18.3
NIBBLE$ = "1110"
CASE "F"
NIBBLE$ = "1111"
CASE ELSE
Print "Íå ÿâëÿåòñÿ 16-ðè÷íûì çíà÷åíèåì!"
SYSTEM
END SELECT
FOR j% = 1 to 4
mbits(((i% - 1) * 4) + j%) = ASC(MID$(NIBBLE$, j%, 1)) - 48
NEXT j%
NEXT i%
END SUB
Ëèñòèíã 18.4. Ïðèìåð ðåàëèçàöèè àëãîðèòìà
DES íà ÿçûêå Basic äëÿ ðàñøèôðîâûâàíèÿ ôàéëîâ
$CPU 80386
$FLOAT NPX
$OPTIMIZE SPEED
$LIB ALL-
$OPTION CNTLBREAK ON
DECLARE FUNCTION MYBIN$ (n%)
DECLARE FUNCTION desalg$ (a$)
DECLARE SUB f (i%, a%(), x%())
DECLARE SUB transpose (datax%(), T%(), n%)
DECLARE SUB mrotate (keyx%())
DECLARE SUB stob (a$, mbits%())
DECLARE SUB btos (mbits%(), a$)
DECLARE SUB letbe (target%(), source%(), last%)
DECLARE SUB init (x() AS INTEGER, n%)
DECLARE SUB sboxinit (b() AS INTEGER)
DECLARE SUB xtob (a$, mbits%())
DIM s(1 TO 8, 1 TO 64) AS shared INTEGER
' Èíèöèàëèçàöèÿ
RESTORE InitialTrl
Ïðîäîëæåíèå ëèñòèíãà 18.4
DIM InitialTr(1 TO 64) AS shared INTEGER
init InitialTr(), 64
RESTORE FinalTrl
DIM FinalTr(1 TO 64) AS shared INTEGER
init FinalTr(), 64
RESTORE swappyl
DIM swappy(1 TO 64) AS shared INTEGER
init swappy(), 64
RESTORE KeyTr1l
DIM KeyTr1(1 TO 56) AS shared INTEGER
init KeyTr1(), 56
RESTORE KeyTr2l
DIM KeyTr2(1 TO 48) AS shared INTEGER
init KeyTr2(), 48
RESTORE etrl
DIM etr(1 TO 48) AS shared INTEGER
init etr(), 48
RESTORE ptrl
DIM ptr(1 TO 32) AS shared INTEGER
init ptr(), 32
sboxinit s()
RESTORE rotsl
DIM rots(1 TO 16) AS shared INTEGER
init rots(), 16
DIM XR(1 TO 56) AS shared INTEGER
DIM EF(1 TO 64) AS shared INTEGER
DIM ikeyf(1 TO 64) AS shared INTEGER
DIM yf(1 TO 64) AS shared INTEGER
DIM ades(1 TO 64) AS shared INTEGER
DIM bdes(1 TO 64) AS shared INTEGER
Ïðîäîëæåíèå ëèñòèíãà 18.4
DIM xdes(1 TO 64) AS shared INTEGER
DIM XT(1 TO 64) AS shared INTEGER
DIM P2(1 TO 64) AS shared INTEGER
main:
CLS
parm$ = ltrim$(rtrim$(COMMAND$))+" "
IF LEN(parm$) > 1 THEN
cipherf$ = LTRIM$(RTRIM$(LEFT$(parm$, INSTR(parm$, " "))))
PRINT "Èìÿ çàøèôðîâàííîãî ôàéëà : "; cipherf$
ELSE
INPUT "Èìÿ ðàñøèôðîâàííîãî ôàéëà : ", cipherf$
END IF
if len(cipherf$)=0 then
print : print "ÑÁÎÉ: ââåäèòå èìÿ ôàéëà!"
system
end if
OPEN cipherf$ FOR RANDOM AS 1
lof1& = LOF(1)
IF lof1& = 0 THEN
CLOSE #1
KILL cipherf$
PRINT : PRINT "Ôàéë íå íàéäåí!";
SYSTEM
ELSE
CLOSE #1
OPEN cipherf$ for binary access read as #1
END IF
PW$ = ""
LOCATE 6, 1
INPUT " Ïàðîëü : ", PW$
IF (LEN(PW$) < 8) THEN PW$ = PW$ + STRING$(8 - LEN(PW$), 0)
IF len(pw$) = 16 then
LOCATE 6, 1: PRINT " Ïàðîëü : ";
STRING$(16, 15); STRING$(10, " ")
Ïðîäîëæåíèå ëèñòèíãà 18.4
PW$ = ucase$(PW$)
xtob PW$, P2()
ELSE
LOCATE 6, 1: PRINT " Ïàðîëü : ";
STRING$(8, 15); STRING$(10, " ")
PW$ = LEFT$(PW$, 8)
stob PW$, P2()
END IF
PRINT " Ïðîâåðêà ïàðîëÿ : ";
transpose P2(), KeyTr1(), 56
get$ #1,24,cheader$
header$ = desalg$(LEFT$(cheader$, 8))
IF NOT (LEFT$(header$, 3) = "DES") THEN
PRINT "Íåâåðåí!": PRINT : PRINT "Íåïðàâèëüíûé ïàðîëü èëè ";
cipherf$; " íå ÿâëÿåòñÿ çàøèôðîâàííûì ôàéëîì!"
SYSTEM
ELSE
PRINT "Âåðåí!"
END IF
PRINT " Ïðîâåðêà äëèíû ôàéëà :";
header$ = header$ + desalg$(MID$(cheader$, 9, 8))
header$ = header$ + desalg$(RIGHT$(cheader$, 8))
pl% = INSTR(header$, "#")
le$ = MID$(header$, pl% + 1, (11 - pl%))
lf& = VAL(le$)
ev& = lf& + 24
IF (ev& MOD 8) THEN ev& = ev& + 8 - (ev& MOD 8)
rescue% = 0
IF (ev& <> lof1&) THEN
PRINT "Íåâåðíà!! (âîçìîæíà ïîòåðÿ äàííûõ)"
PRINT " Äëèíà èñõîäíîãî ôàéëà :"; lf&
PRINT " Äëèíà óêàçàííîãî ôàéëà :"; lof1&
PRINT " Äëèíà ôàéëà äîëæíà áûòü :"; ev&
INPUT ; "Ïîïûòàòüñÿ âîññòàíîâèòü? (y/n) : ", q$:
IF (INSTR(q$, "N") OR (INSTR(q$, "n"))) THEN SYSTEM
rescue% = 4: PRINT
ELSE
PRINT lf&; ", Âåðíà!"
END IF
Ïðîäîëæåíèå ëèñòèíãà 18.4
pl% = INSTR(12, header$, "#")
oldplainf$ = RIGHT$(header$, 24 - pl%)
PRINT " Èìÿ èñõîäíîãî ôàéëà : "; oldplainf$;
OPEN oldplainf$ FOR RANDOM AS 2
IF INSTR(oldplainf$, ".") THEN
PRINT " ([*.*] ";
ELSE
PRINT " ([*] ";
END IF
IF LOF(2) > 0 THEN PRINT "óæå åñòü â êàòàëîãå";
PRINT ")"
CLOSE #2
plainf$ = ""
INPUT " Èìÿ âûõîäíîãî ôàéëà : ", plainf$
IF plainf$ = "" THEN plainf$ = oldplainf$
plainf$ = RTRIM$(LTRIM$(plainf$))
IF INSTR(plainf$, "*.") THEN
IF INSTR(oldplainf$, ".") THEN
plainf$ = LEFT$(plainf$, INSTR(plainf$, "*.") - 1) + LEFT$(oldplainf$, INSTR(oldplainf$, ".")) + RIGHT$(plainf$, LEN(plainf$) - INSTR(plainf$, "*.") - 1)
ELSE
plainf$ = LEFT$(plainf$, INSTR(plainf$, "*.") - 1) + oldplainf$ + RIGHT$(plainf$, LEN(plainf$) - INSTR(plainf$, "*."))
END IF
END IF
IF (RIGHT$(plainf$, 1) = "*") THEN
IF plainf$ = "*" THEN
plainf$ = oldplainf$
ELSE
IF (MID$(plainf$, LEN(plainf$) - 1, 1) = ".") THEN
plainf$ = LEFT$(plainf$, INSTR(plainf$, ".") - 1) +
RIGHT$(oldplainf$, LEN(oldplainf$) -
INSTR(oldplainf$, ".") + 1)
ELSE
plainf$ = LEFT$(plainf$, LEN(plainf$) - 1) + oldplainf$
END IF
END IF
END IF
IF RIGHT$(plainf$, 1) = "\" THEN plainf$ = plainf$ + oldplainf$
Ïðîäîëæåíèå ëèñòèíãà 18.4
OPEN plainf$ FOR RANDOM AS 2
IF LOF(2) > 0 THEN
CLOSE #2
PRINT : PRINT "Óæå åñòü ôàéë ñ òàêèì èìåíåì!"
SYSTEM
ELSE
CLOSE #2
OPEN plainf$ FOR BINARY AS 2
END IF
plaintekst$ = ""
blocks& = (LOF(1) \ 8) - 3
LOCATE rescue% + 11, 21: PRINT ; "Ðàñøèôðîâûâàíèå : 0 %";
bigblocks&=(blocks&-1) \ 32
large$=space$(256)
FOR m& = 1 TO bigblocks&
outblock$=""
get$ #1,256,large$
for o%=1 to 256 step 8
outblock$=outblock$+desalg$(mid$(large$,o%,8))
next
put$ #2,outblock$
LOCATE rescue% + 11, 32: PRINT ; USING "###"; (m& / (bigblocks&+1)) * 100;
next
FOR n& = (bigblocks&*32)+1 TO blocks& - 1
GET$ #1,8,ciphertekst$
plaintekst$ = desalg$(ciphertekst$)
PUT$ #2, plaintekst$
LOCATE rescue% + 11, 32: PRINT ; USING "###"; (n& / blocks&) * 100;
NEXT n&
get$ #1,8,ciphertekst$
if len(ciphertekst$) > 0 then
plaintekst$ = desalg$(ciphertekst$)
IF rescue% THEN
last$ = plaintekst$
ELSE
Ïðîäîëæåíèå ëèñòèíãà 18.4
last$ = LEFT$(plaintekst$, lf& + 32 - LOF(1))
END IF
IF LEN(last$) > 0 THEN
PUT$ #2, last$
END IF
end if
CLOSE
LOCATE 11 + rescue%, 32: PRINT "100 % ãîòîâî": PRINT
IF rescue% THEN
PRINT " Ïîïûòàéòåñü äðóãèì ñïîñîáîì ðàñøèôðîâàòü ýòîò ôàéë."
ELSE
PRINT "Ðàñøèôðîâûâàíèå ïî àëãîðèòìó DES çàâåðøåíî."
END IF
SYSTEM
' Äàííûå è ôóíêöèè
InitialTrl:
DATA 58,50,42,34,26,18,10,02,60,52,44,36,28,20,12,04
DATA 62,54,46,38,30,22,14,06,64,56,48,40,32,24,16,08
DATA 57,49,41,33,25,17,09,01,59,51,43,35,27,19,11,03
DATA 61,53,45,37,29,21,13,05,63,55,47,39,31,23,15,07
FinalTrl:
DATA 40,08,48,16,56,24,64,32,39,07,47,15,55,23,63,31
DATA 38,06,46,14,54,22,62,30,37,05,45,13,53,21,61,29
DATA 36,04,44,12,52,20,60,28,35,03,43,11,51,19,59,27
DATA 34,02,42,10,50,18,58,26,33,01,41,09,49,17,57,25
swappyl:
DATA 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48
DATA 49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64
DATA 01,02,03,04,05,06,07,08,09,10,11,12,13,14,15,16
DATA 17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32
KeyTr1l:
DATA 57,49,41,33,25,17,09,01,58,50,42,34,26,18,10,02
DATA 59,51,43,35,27,19,11,03,60,52,44,36
DATA 63,55,47,39,31,23,15,07,62,54,46,38,30,22,14,06
DATA 61,53,45,37,29,21,13,05,28,20,12,04
Ïðîäîëæåíèå ëèñòèíãà 18.4
KeyTr2l:
DATA 14,17,11,24,01,05,03,28,15,06,21,10,23,19,12,04
DATA 26,08,16,07,27,20,13,02,41,52,31,37,47,55,30,40
DATA 51,45,33,48,44,49,39,56,34,53,46,42,50,36,29,32
etrl:
DATA 32,01,02,03,04,05,04,05,06,07,08,09,08,09,10,11
DATA 12,13,12,13,14,15,16,17,16,17,18,19,20,21,20,21
DATA 22,23,24,25,24,25,26,27,28,29,28,29,30,31,32,01
ptrl:
DATA 16,07,20,21,29,12,28,17,01,15,23,26,05,18,31,10
DATA 02,08,24,14,32,27,03,09,19,13,30,06,22,11,04,25
sboxesl:
DATA 14,04,13,01,02,15,11,08,03,10,06,12,05,09,00,07
DATA 00,15,07,04,14,02,13,01,10,06,12,11,09,05,03,08
DATA 04,01,14,08,13,06,02,11,15,12,09,07,03,10,05,00
DATA 15,12,08,02,04,09,01,07,05,11,03,14,10,00,06,13
DATA 15,01,08,14,06,11,03,04,09,07,02,13,12,00,05,10
DATA 03,13,04,07,15,02,08,14,12,00,01,10,06,09,11,05
DATA 00,14,07,11,10,04,13,01,05,08,12,06,09,03,02,15
DATA 13,08,10,01,03,15,04,02,11,06,07,12,00,05,14,09
DATA 10,00,09,14,06,03,15,05,01,13,12,07,11,04,02,08
DATA 13,07,00,09,03,04,06,10,02,08,05,14,12,11,15,01
DATA 13,06,04,09,08,15,03,00,11,01,02,12,05,10,14,07
DATA 01,10,13,00,06,09,08,07,04,15,14,03,11,05,02,12
DATA 07,13,14,03,00,06,09,10,01,02,08,05,11,12,04,15
DATA 13,08,11,05,06,15,00,03,04,07,02,12,01,10,14,09
DATA 10,06,09,00,12,11,07,13,15,01,03,14,05,02,08,04
DATA 03,15,00,06,10,01,13,08,09,04,05,11,12,07,02,14
DATA 02,12,04,01,07,10,11,06,08,05,03,15,13,00,14,09
DATA 14,11,02,12,04,07,13,01,05,00,15,10,03,09,08,06
DATA 04,02,01,11,10,13,07,08,15,09,12,05,06,03,00,14
DATA 11,08,12,07,01,14,02,13,06,15,00,09,10,04,05,03
Ïðîäîëæåíèå ëèñòèíãà 18.4
DATA 12,01,10,15,09,02,06,08,00,13,03,04,14,07,05,11
DATA 10,15,04,02,07,12,09,05,06,01,13,14,00,11,03,08
DATA 09,14,15,05,02,08,12,03,07,00,04,10,01,13,11,06
DATA 04,03,02,12,09,05,15,10,11,14,01,07,06,00,08,13
DATA 04,11,02,14,15,00,08,13,03,12,09,07,05,10,06,01
DATA 13,00,11,07,04,09,01,10,14,03,05,12,02,15,08,06
DATA 01,04,11,13,12,03,07,14,10,15,06,08,00,05,09,02
DATA 06,11,13,08,01,04,10,07,09,05,00,15,14,02,03,12
DATA 13,02,08,04,06,15,11,01,10,09,03,14,05,00,12,07
DATA 01,15,13,08,10,03,07,04,12,05,06,11,00,14,09,02
DATA 07,11,04,01,09,12,14,02,00,06,10,13,15,03,05,08
DATA 02,01,14,07,04,10,08,13,15,12,09,00,03,05,06,11
rotsl:
DATA 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
SUB btos (mbits() AS INTEGER, a$)
a$ = ""
FOR i% = 1 TO 8
w% = 0
FOR j% = 1 TO 8
w% = w% + ((mbits(((i% - 1) * 8) + j%)) * (2 ^ (8 - j%)))
NEXT j%
a$ = a$ + CHR$(w%)
NEXT i%
END SUB
FUNCTION desalg$ (a$)
temp$ = "": stob a$, ades()
transpose ades(), InitialTr(), 64
transpose ades(), swappy(), 64
FOR i% = 16 TO 1 STEP -1
letbe bdes(), ades(), 64
f i%, bdes(), xdes()
FOR j% = 1 TO 32
ades(j%) = (bdes(j% + 32) + xdes(j%)) MOD 2
NEXT j%
FOR j% = 33 TO 64
ades(j%) = bdes(j% - 32)
Ïðîäîëæåíèå ëèñòèíãà 18.4
NEXT j%
NEXT i%
transpose ades(), FinalTr(), 64
btos ades(), temp$
desalg$ = temp$
END FUNCTION
SUB f (i%, a() AS INTEGER, x() AS INTEGER)
h% = i%: letbe EF(), a(), 64
transpose EF(), etr(), 48
letbe ikeyf(), P2(), 64
transpose ikeyf(), KeyTr2(), 48
FOR j% = 1 TO rots(h%)
mrotate P2()
NEXT j%
FOR j% = 1 TO 48
yf(j%) = (EF(j%) + ikeyf(j%)) MOD 2
NEXT j%
FOR k% = 1 TO 8
k6% = 6 * k%: k4% = 4 * k%
r% = (32 * yf(k6% - 5)) + (16 * yf(k6%)) + (8 * yf(k6% - 4)) + (4 * yf(k6% - 3)) + (2 * yf(k6% - 2)) + yf(k6% - 1) + 1
x(k4% - 3) = (s(k%, r%) \ 8) MOD 2: x(k4% - 2) = (s(k%, r%) \ 4) MOD 2
x(k4% - 1) = (s(k%, r%) \ 2) MOD 2: x(k4%) = s(k%, r%) MOD 2
NEXT k%
transpose x(), ptr(), 32
END SUB
SUB init (x() AS INTEGER, n%)
FOR i% = 1 TO n%
READ x(i%)
NEXT i%
END SUB
SUB letbe (target() AS INTEGER, source() AS INTEGER, last%)
FOR il% = 1 TO last%
target(il%) = source(il%)
NEXT il%
END SUB
Ïðîäîëæåíèå ëèñòèíãà 18.4
FUNCTION MYBIN$ (n%)
STS$ = ""
p% = n%
FOR i% = 1 TO 8
IF (p% MOD 2) THEN
ST$ = "1" + ST$
ELSE
ST$ = "0" + ST$
END IF
p% = p% \ 2
NEXT i%
MYBIN$ = ST$
END FUNCTION
SUB mrotate (keyr() AS INTEGER)
letbe XR(), keyr(), 56
FOR ir% = 56 TO 2 STEP -1
XR(ir%) = XR(ir% - 1)
NEXT ir%
XR(1) = keyr(28): XR(29) = keyr(56)
letbe keyr(), XR(), 56
END SUB
SUB sboxinit (b() AS INTEGER)
RESTORE sboxesl
FOR i% = 1 TO 8
FOR j% = 1 TO 64
READ b(i%, j%)
NEXT j%
NEXT i%
END SUB
SUB stob (a$, mbits() AS INTEGER)
FOR i% = 1 TO 8
b$ = MYBIN$(ASC(MID$(a$, i%, 1)))
FOR j% = 1 TO 8
mbits(((i% - 1) * 8) + j%) = ASC(MID$(b$, j%, 1)) - 48
NEXT j%
NEXT i%
END SUB
Ïðîäîëæåíèå ëèñòèíãà 18.4
SUB transpose (datax() AS INTEGER, T() AS INTEGER, nt%)
letbe XT(), datax(), 64
FOR i% = 1 TO nt%
datax(i%) = XT(T(i%))
NEXT i%
END SUB
SUB xtob (a$, mbits() AS INTEGER)
LOCAL X$,NIBBLE$
FOR i% = 1 to 16
X$ = MID$(a$,i%,1)
SELECT CASE X$
CASE "0"
NIBBLE$ = "0000"
CASE "1"
NIBBLE$ = "0001"
CASE "2"
NIBBLE$ = "0010"
CASE "3"
NIBBLE$ = "0011"
CASE "4"
NIBBLE$ = "0100"
CASE "5"
NIBBLE$ = "0101"
CASE "6"
NIBBLE$ = "0110"
CASE "7"
NIBBLE$ = "0111"
CASE "8"
NIBBLE$ = "1000"
CASE "9"
NIBBLE$ = "1001"
CASE "A"
NIBBLE$ = "1010"
CASE "B"
NIBBLE$ = "1011"
CASE "C"
NIBBLE$ = "1100"
CASE "D"
NIBBLE$ = "1101"
CASE "E"
Îêîí÷àíèå ëèñòèíãà 18.4
NIBBLE$ = "1110"
CASE "F"
NIBBLE$ = "1111"
CASE ELSE
Print "Íå ÿâëÿåòñÿ 16-ðè÷íûì çíà÷åíèåì!"
SYSTEM
END SELECT
FOR j% = 1 to 4
mbits(((i% - 1) * 4) + j%) = ASC(MID$(NIBBLE$, j%, 1)) - 48
NEXT j%
NEXT i%
END SUB
