Des encryption and decryption in script language

<Script language = "JavaScript">

// By liuminghua at 2005.1.10

VaR g_ip = new array (// initial IP address replacement
,
);

VaR g_invip = new array (// reverse initial IP address replacement
,
);

VaR g_e = new array (// e select table
, 28, 29, 28, 29, 30, 31, 32, 31
);

VaR g_p = new array (// P-bit table

);

VaR G_s = new array (// 8 s combination
,,
,,
,,
,,
,,
,,
,,
,
);

VaR g_keyout = new array (768 );

Function initkey (str_key)
{
VaR pC1 = new array (// replace 64-bit keys with 56-bit
,
);
VaR PC2 = new array (// obtain the 48-bit key for the 64-bit shift.
, 34,53, 46,42, 50 ,36, 29,32
);
VaR NLS = new array );

VaR B _array_key = new array (64 );
For (n = I = 0; I <8; I ++)
B _array_key [n ++] = str_key.charcodeat (I)> I & 0x01; // obtain binary

VaR Cd = new array (56 );
VaR c = new array (28 );
VaR d = new array (28 );
 
For (I = 0; I <56; I ++)
CD [I] = B _array_key [pC1 [I]-1];
For (I = 0; I <28; I ++ ){
C [I] = CD [I];
D [I] = CD [I + 28]; // separate c, d
}
For (CNT = 0; CNT <16; CNT ++ ){
For (I = 0; I <NLS [CNT]; I ++ ){
C = lshift (C );
D = lshift (d );
}
For (I = 0; I <28; I ++ ){
CD [I] = C [I];
CD [28 + I] = d [I];
}
For (I = 0; I <48; I ++ ){
G_keyout [CNT * 48 + I] = CD [PC2 [I]-1];
}
}
}
Function lshift (p_array) // shifts one position left in a loop
{
VaR tmp_array = new array (28 );
For (I = 0; I <27; I ++) tmp_array [I] = p_array [I + 1];
Tmp_array [27] = p_array [0];
Return tmp_array;

}

Function frk (p_array_r, CNT)
{
VaR B _array_fout = new array (32 );
VaR B _array_expand = new array (48 );
VaR array_pout = new array (48 );
 
For (I = 0; I <48; I ++) {// convert 32-bit to 48-bit
B _array_expand [I] = p_array_r [g_e [I]-1];
}
VaR B _array_dor = new array (48 );
For (I = 0; I <48; I ++) {// bitwise OR with the key Ki, 8 groups, each with 6 bits
B _array_dor [I] = B _array_expand [I] ^ g_keyout [CNT * 48 + I];
}
For (SCNT = n = 0; SCNT <8; SCNT ++ ){
Row = (B _array_dor [SCNT * 6 + 0] <1) + B _array_dor [SCNT * 6 + 5];
Col = (B _array_dor [SCNT * 6 + 1] <3) + (B _array_dor [SCNT * 6 + 2] <2) + (B _array_dor [SCNT * 6 + 3] <1) + B _array_dor [SCNT * 6 + 4]
VaR sout = new array (8 );
Sout [SCNT] = G_s [SCNT * 64 + (row <4) + Col];
For (I = 3; I> = 0; I --){
Array_pout [N] = sout [SCNT]> I;
Sout [SCNT] = sout [SCNT]-(array_pout [n ++] <I );
}
}
For (I = 0; I <32; I ++)
B _array_fout [I] = array_pout [g_p [I]-1];

Return B _array_fout;
}
Function des_encrypt (str_input) // Encrypt
{
// Initkey ("454554454"); // only test, here
 
VaR B _array_input = new array (64 );
VaR B _array_lr = new array (64 );
VaR B _array_l = new array (32 );
VaR B _array_r = new array (32 );
VaR B _array_fn = new array (32 );
 
For (n = I = 0; I <8; I ++)
For (j = 0; j <8; j ++)
B _array_input [n ++] = str_input.charcodeat (I)> J & 0x01; // obtain binary
 
For (I = 0; I <64; I ++ ){
B _array_lr [I] = B _array_input [g_ip [I]-1];
If (I <32) B _array_l [I] = B _array_lr [I];
Else B _array_r [i-32] = B _array_lr [I]; // separate L, R
}
 
For (CNT = 0; CNT <16; CNT ++)
{
B _array_fn = frk (B _array_r, CNT );
For (I = 0; I <32; I ++ ){
J = B _array_r [I];
B _array_r [I] = B _array_l [I] ^ B _array_fn [I];
B _array_l [I] = J;
}
}
 
For (I = 0; I <32; I ++ ){
B _array_lr [I] = B _array_r [I];
B _array_lr [I + 32] = B _array_l [I];
}
 
VaR fout = new array (64 );
For (I = 0; I <64; I ++) fout [I] = B _array_lr [g_invip [I]-1];
VaR Strout = "";
For (I = 0; I <8; I ++ ){
Sum = 0;
For (j = 0; j <8; j ++ ){
Sum + = (fout [I * 8 + J] <j );
}
Strout + = string. fromcharcode (SUM );
// Document. Write (string. fromcharcode (SUM ));
}
 
Return Strout;

}
Function des_decrypt (str_input) // decrypt
{
VaR B _array_input = new array (64 );
VaR B _array_lr = new array (64 );
VaR B _array_l = new array (32 );
VaR B _array_r = new array (32 );
VaR B _array_fn = new array (32 );
 
For (n = I = 0; I <8; I ++)
For (j = 0; j <8; j ++)
B _array_input [n ++] = str_input.charcodeat (I)> J & 0x01; // obtain binary
 
For (I = 0; I <64; I ++ ){
B _array_lr [I] = B _array_input [g_ip [I]-1];
If (I <32) B _array_l [I] = B _array_lr [I];
Else B _array_r [i-32] = B _array_lr [I]; // separate L, R
}
 
For (CNT = 15; CNT> = 0; CNT --)
{
B _array_fn = frk (B _array_r, CNT );
For (I = 0; I <32; I ++ ){
J = B _array_r [I];
B _array_r [I] = B _array_l [I] ^ B _array_fn [I];
B _array_l [I] = J;
}
}
 
For (I = 0; I <32; I ++ ){
B _array_lr [I] = B _array_r [I];
B _array_lr [I + 32] = B _array_l [I];
}
 
VaR fout = new array (64 );
For (I = 0; I <64; I ++) fout [I] = B _array_lr [g_invip [I]-1];
VaR Strout = "";
For (I = 0; I <8; I ++ ){
Sum = 0;
For (j = 0; j <8; j ++ ){
Sum + = (fout [I * 8 + J] <j );
}
Strout + = string. fromcharcode (SUM );
}
Return Strout;
}
</SCRIPT>