Использование современных симметрических DES и асимметрических RSA алгоритмов шифрования (стр. 5 из 5)
B_tekst_32:odnom_1_32;
begin
TextVBinarn (Ish_tekst_bykv,Ish_tekst_64_binar);
Perestanovka_IP (Ish_tekst_64_binar);
//Delim na levyju i na pravyju 4asti
j:=0;
for i:=1 to 64 do
if i<33 then
levaja[1,i]:=Ish_tekst_64_binar[i]
else
begin
j:=j+1;
pravaja[1,j]:=Ish_tekst_64_binar[i];
end;
//16 rayndov wifrovanija
for i:=2 to 17 do
begin
for j:=1 to 32 do
levaja[i,j]:=pravaja[i-1,j];
Perestanovka_E(i-1,pravaja,Tekst_48_posle_raswirenija);
for j:=1 to 48 do
Tekst_48_posle_raswirenija[j]:=Tekst_48_posle_raswirenija[j] xor podklu4i[i-1,j];
s_blok(Tekst_48_posle_raswirenija,B_tekst_32);
Perestanovka_P(B_tekst_32);
for j:=1 to 32 do
pravaja[i,j]:=levaja[i-1,j] xor B_tekst_32[j];
end;
//!!!
//Menjaem mestami
for i:=1 to 32 do
begin
j:= pravaja[17][i];
pravaja[17][i] := levaja[17][i];
levaja[17][i] := j;
end;
//Skladivanie levoi i pravoi
j:=0;
for i:=1 to 64 do
if i<33 then
Ish_tekst_64_binar[i]:=levaja[17,i]
else
begin
j:=j+1;
Ish_tekst_64_binar[i]:=pravaja[17,j];
end;
Perestanovka_IP_1(Ish_tekst_64_binar);
BinarnVText(Ish_tekst_64_binar,Ish_tekst_bykv);
kodirovat:= Ish_tekst_bykv;
end;
function Raskodirovat(Wifr_tekst_bykv:string):string;
var Wifr_tekst_64_binar:odnom_1_64;
i,j:integer;
levaja,pravaja:dvym_1_17_1_32;
Tekst_48_posle_raswirenija:odnom_1_48;
B_tekst_32:odnom_1_32;
begin
TextVBinarn (Wifr_tekst_bykv,Wifr_tekst_64_binar);
Perestanovka_IP (Wifr_tekst_64_binar);
//Delim na levyju i na pravyju 4asti
j:=0;
for i:=1 to 64 do
if i<33 then
levaja[17,i]:=Wifr_tekst_64_binar[i]
else
begin
j:=j+1;
pravaja[17,j]:=Wifr_tekst_64_binar[i];
end;
//!!!!!!!!
//Menjaem mestami
for i:=1 to 32 do
begin
j:= pravaja[17][i];
pravaja[17][i]:=levaja[17][i];
levaja[17][i]:=j;
end;
//16 raundov wifrovanija
for i:=17 downto 2 do
begin
for j:=1 to 32 do
pravaja[i-1,j]:=levaja[i,j];
Perestanovka_E(i,levaja,Tekst_48_posle_raswirenija);
for j:=1 to 48 do
Tekst_48_posle_raswirenija[j]:=Tekst_48_posle_raswirenija[j] xor podklu4i[i-1,j];
s_blok(Tekst_48_posle_raswirenija,B_tekst_32);
Perestanovka_P(B_tekst_32);
for j:=1 to 32 do
levaja[i-1,j]:=pravaja[i,j] xor B_tekst_32[j];
end;
//Skladivanie levoi i pravoi
j:=0;
for i:=1 to 64 do
if i<33 then
Wifr_tekst_64_binar[i]:=levaja[1,i]
else
begin
j:=j+1;
Wifr_tekst_64_binar[i]:=pravaja[1,j];
end;
Perestanovka_IP_1(Wifr_tekst_64_binar);
BinarnVText(Wifr_tekst_64_binar,Wifr_tekst_bykv);
Raskodirovat:=Wifr_tekst_bykv;
end;
end.
unit Podkluchi_unit;
interface
uses DES_unit;
var
podklu4i:dvym_1_16_1_48;
matrica_PC1:array[1..56] of byte=(57, 49, 41, 33, 25, 17, 09,
01, 58, 50, 42, 34, 26, 18,
10, 02, 59, 51, 43, 35, 27,
19, 11, 03, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15,
07, 62, 54, 46, 38, 30, 22,
14, 06, 61, 53, 45, 37, 29,
21, 13, 05, 28, 20, 12, 04);
matrica_PC2:array[1..48] of byte=(14, 17, 11, 24, 01, 05,
03, 28, 15, 06, 21, 10,
23, 19, 12, 04, 26, 08,
16, 07, 27, 20, 13, 02,
41, 52, 31, 37, 47, 55,
30, 40, 51, 45, 33, 48,
44, 49, 39, 56, 34, 53,
46, 42, 50, 36, 29, 32);
matrica_sdvigov:array[1..16] of byte=(1,1,2,2,
2,2,2,2,
1,2,2,2,
2,2,2,1);
procedure Formirovanie_16_podklju4ei(Klju4_64:string);
implementation
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++
procedure Perestanovka_PC1(Klju4_64_do_PC1: odnom_1_64; var Klju4_64_posle_PC1:odnom_1_56);
var i:integer;
begin
for i:=1 to 56 do
Klju4_64_posle_PC1[i]:=Klju4_64_do_PC1[matrica_PC1[i]];
end;
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++
procedure Perestanovka_PC2(Klju4_56_do_PC2:odnom_1_56; k:integer);
var i:integer;
begin
for i:=1 to 48 do
podklu4i[k][i]:=Klju4_56_do_PC2[matrica_PC2[i]];
end;
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++
procedure Formirovanie_16_podklju4ei(Klju4_64:string);
var
i,j,k:integer;
c_vrem,d_vrem: dvym_1_17_1_28;
c: dvym_1_17_1_28;
d: dvym_1_17_1_28;
c_d: odnom_1_56;
Klju4ik_64:odnom_1_64;
Klju4ik_56:odnom_1_56;
begin
TextVBinarn (Klju4_64,Klju4ik_64);//ключиз 64 в 64
Perestanovka_PC1(Klju4ik_64,Klju4ik_56);//битовыйключ 64, битовыйключ 56
//Razbivaem na c i d
j:=0;
for i:=1 to 56 do
if i<29 then
c[1,i]:=Klju4ik_56[i]
else
begin
j:=j+1;
d[1,j]:=Klju4ik_56[i];
end;
//Kopiryem с i d vo vremennie c_vrem i d_vrem
for j:=1 to 28 do
begin
c_vrem[1,j]:=c[1,j];
d_vrem[1,j]:=d[1,j];
end;
//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//Delaem sdvigi LSi
for i:=2 to 17 do
begin
k:=0;
for j:=1 to 28 do
if j+matrica_sdvigov[i-1]>28 then
begin
k:=k+1;
c[i,j]:=c_vrem[i-1,k];
d[i,j]:=d_vrem[i-1,k];
c_vrem[i,j]:=c[i,j];
d_vrem[i,j]:=d[i,j];
end
else
begin
c[i,j]:=c_vrem[i-1,j+matrica_sdvigov[i-1]];
d[i,j]:=d_vrem[i-1,j+matrica_sdvigov[i-1]];
c_vrem[i,j]:=c[i,j];
d_vrem[i,j]:=d[i,j];
end;
end;
//Sobiraem с i d vmeste
for i:=2 to 17 do
begin
k:=0;
for j:=1 to 28 do
begin
k:=k+1;
c_d[k]:=c[i,j];
end;
for j:=1 to 28 do
begin
k:=k+1;
c_d[k]:=d[i,j];
end;
Perestanovka_PC2(c_d,i-1);
end;
end;
end.
unit RSA_unit;
interface
function NOD(a{3}:int64;b{fi}:int64;var x:int64;var y:int64):int64;
function Nomer_v_alfavite(a:char):byte;
function Vozvedenie_po_modylju(osnovanie:int64; stepen:int64;modyl:int64):int64;
procedure Wifrovanie_RSA(Ka:int64; P:int64; Q:int64; nazv_ish_f:string;nazv_vih_f:string;var Kb:int64);
procedure RasWifrovanie_RSA(Kb:int64; P:int64; Q:int64; nazv_ish_f:string;nazv_vih_f:string);
var
alf:string;
implementation
function Vozvedenie_v_stepen(osnovanie:int64; stepen:int64):int64;
var
rez:longint;
i:longint;
begin
rez:=1;
for i:= 1 to stepen do
rez := rez*osnovanie;
Vozvedenie_v_stepen:= rez;
end;
function Vozvedenie_po_modylju(osnovanie:int64; stepen:int64;modyl:int64):int64;
var
rez:int64;
i:longint;
t:int64;//osnovanie vo vremennoi stepeni
begin
rez:=1;
t:=osnovanie;
while(stepen<> 0) do
begin
if(stepen mod 2 = 1) then
rez := (rez * t) mod modyl;
t:=(t*t) mod modyl;
stepen:= stepen div 2;
end;
Vozvedenie_po_modylju:=rez;
end;
//Vozvrawaet nomer bykvi v alfavite
function Nomer_v_alfavite(a:char):byte;
var
i:byte;
begin
i:=0;
while( (i<=Length(alf)) and (alf[i+1] <> a) ) do
i:=i+1;
Nomer_v_alfavite:= i;
end;
//Naibolwii obwii delitel
function NOD(a{3}:int64;b{fi}:int64;var x:int64;var y:int64):int64;
var
x1,y1:longint;
x2,y2:longint;
q:longint;
r:longint;
begin
if(b=0)then
begin
NOD:=a;
x:=1;
y:=0;
end
else
begin
x2:=1;
x1:=0;
y2:=0;
y1:=1;
while (b>0)do
begin
q:=a div b;
r:=a-q*b;
x:=x2-q*x1;
y:=y2-q*y1;
a:=b;
b:=r;
x2:=x1;
x1:=x;
y2:=y1;
y1:=y;
end;
NOD:=a;
x:=x2;
y:=y2;
end;
end;
//RSA wifrovanie failov
procedure Wifrovanie_RSA(Ka:int64; P:int64; Q:int64; nazv_ish_f:string;nazv_vih_f:string;var Kb:int64);
var
N:int64;
M,C:int64;
f:int64;//4islo vzaimnoprostih 4isel s N
i:integer;
ish_text,vihod_text:string;
bykva:char;
ish_f,vihod_f:TextFile;
begin
N := Q*P; //Nahodim N
f := (P-1)*(Q-1); //Nahodin 4islo vzaimnoprostih 4isel s N
NOD(Ka,f,Kb,M); //Nahodim Kb
while(Kb < 0) do
Kb:= Kb + f; //Esli Kb otricatelno to yveli4ivaem ego
assignfile(ish_f,nazv_ish_f);
reset(ish_f);
assignfile(vihod_f,nazv_vih_f);
rewrite(vihod_f);
while not EOF(ish_f) do
begin
read(ish_f,bykva);
C := Nomer_v_alfavite(bykva);
C:=Vozvedenie_po_modylju(C,Ka,N);
writeln(vihod_f,C);
end;
closefile(ish_f);
closefile(vihod_f);
end;
//RSA raswifrovanie failov
procedure RasWifrovanie_RSA(Kb:int64; P:int64; Q:int64; nazv_ish_f:string;nazv_vih_f:string);
var
N:int64;
M,C:int64;
f:int64;//4islo vzaimnoprostih 4isel s N
i:integer;
ish_text,vihod_text:string;
bykva:char;
ish_f,vihod_f:TextFile;
begin
N := Q*P; //Nahodim N
f := (P-1)*(Q-1); //Nahodin 4islo vzaimnoprostih 4isel s N
assignfile(ish_f,nazv_ish_f);
reset(ish_f);
assignfile(vihod_f,nazv_vih_f);
rewrite(vihod_f);
while not EOF(ish_f) do
begin
readln(ish_f,C);
C:=Vozvedenie_po_modylju(C,Kb,N);
bykva:= alf[C+1];
write(vihod_f,bykva);
end;
closefile(ish_f);
closefile(vihod_f);
end;
end.
Зашифрованный и разшифрованный текст записывается в директорию с исходным файлом.
В результате выполнения данной работы были получены практические навыки использования современных как симметрических (DES), так и асимметрических (RSA) алгоритмов шифрования.