public static string GiaiMaTinyDES(char charcangiaima, string khoanhapvao)
{
char kitucangiama = charcangiaima;
int sodecima = Convert.ToInt32(kitucangiama);
string chuoinhiphan = Convert.ToString(sodecima, 2);
chuoinhiphan = ChuyenThanhDecima8KiTu(chuoinhiphan);
string L3 = chuoinhiphan.Substring(0, 4);
string R3 = chuoinhiphan.Substring(4);
string khoa = khoanhapvao;
string KL3 = khoa.Substring(0, 4);
string KR3 = khoa.Substring(4);
string P = "";
//Giải mã
for (int i = 1; i <= 3; i++)
{
string R2 = L3;
string KL2, KR2;
string expandR2 = GiaiThuatTinyDES.Expand(R2);
if (i == 2)
{
KL2 = GiaiThuatTinyDES.DichVongTruoc(KL3, 2);
KR2 = GiaiThuatTinyDES.DichVongTruoc(KR3, 2);
}
else
{
KL2 = GiaiThuatTinyDES.DichVongTruoc(KL3, 1);
KR2 = GiaiThuatTinyDES.DichVongTruoc(KR3, 1);
}
string K3 = GiaiThuatTinyDES.Compress(KL3, KR3);
string xorexpandR2K3 = GiaiThuatTinyDES.Xor2Chuoi(expandR2, K3);
string sbox = GiaiThuatTinyDES.Sbox(xorexpandR2K3);
string F3 = GiaiThuatTinyDES.Pbox(sbox);
string L2 = GiaiThuatTinyDES.Xor2Chuoi(R3, F3);
P = L2 + R2;
L3 = L2;
R3 = R2;
KL3 = KL2;
KR3 = KR2;
}
int soketquagiaima = Convert.ToInt32(P, 2);
char kituketqua = Convert.ToChar(soketquagiaima);
return(kituketqua.ToString());
}
public static string GiaiMaTinyDesTest(string chuoinhiphan, string khoanhapvao)
{
string khoa = khoanhapvao;
string L3 = chuoinhiphan.Substring(0, 4);
string R3 = chuoinhiphan.Substring(4);
string KL3 = khoa.Substring(0, 4);
string KR3 = khoa.Substring(4);
string P = "";
//Giải mã
for (int i = 1; i <= 3; i++)
{
string R2 = L3;
string KL2, KR2;
string expandR2 = GiaiThuatTinyDES.Expand(R2);
if (i == 2)
{
KL2 = GiaiThuatTinyDES.DichVongTruoc(KL3, 2);
KR2 = GiaiThuatTinyDES.DichVongTruoc(KR3, 2);
}
else
{
KL2 = GiaiThuatTinyDES.DichVongTruoc(KL3, 1);
KR2 = GiaiThuatTinyDES.DichVongTruoc(KR3, 1);
}
string K3 = GiaiThuatTinyDES.Compress(KL3, KR3);
string xorexpandR2K3 = GiaiThuatTinyDES.Xor2Chuoi(expandR2, K3);
string sbox = GiaiThuatTinyDES.Sbox(xorexpandR2K3);
string F3 = GiaiThuatTinyDES.Pbox(sbox);
string L2 = GiaiThuatTinyDES.Xor2Chuoi(R3, F3);
P = L2 + R2;
L3 = L2;
R3 = R2;
KL3 = KL2;
KR3 = KR2;
}
return(P);
}
