small help converting c++ to vb6

hi mates. i have this c++ code:

Code:

---

#include <string.h>

static unsigned char table1[ ][ 16 ] = {
        { 0x0C, 0x2D, 0x22, 0x43, 0x17, 0x02, 0x13, 0x0A, 0x0F, 0x63, 0x4C, 0x2D, 0x5B, 0x03, 0x37, 0x3B },
        { 0x05, 0x17, 0x43, 0x4C, 0x0C, 0x16, 0x4E, 0x13, 0x59, 0x32, 0x2B, 0x38, 0x56, 0x0B, 0x0F, 0x63 }
        };

static unsigned int table2[ ][ 4 ] = {
        { 0x1E2D3E1F, 0xF5E6F798, 0x9E0D1DFF, 0x3E4D5A3E },
        { 0x7A8E9E0D, 0xB1E2D3A4, 0x5A6E7E8D, 0x9E0F2E3D }
        };

static unsigned int table3[] =        {
        0x9E3779B9,
        0x6F55A634
        };

void Vitel_calc( char *imei, char type, char *code )
{
        unsigned int x, y = 0;
        unsigned int dest[ 8 ];
        unsigned char IMEI[ 17 ];
        int i, j;

        strncpy( (char *)IMEI, imei, 14 );
        IMEI[14] = '0';
        IMEI[15] = '0';
        IMEI[16] = 0;


For I = 0 To 7
DEST(I) = (TABLE1(Vitel_Type)(I Xor &HF) * (IMEI(&H10 - I) - &H30)) - ((IMEI(I) + IMEI(I Xor &HF)) Mod 9) + &H39
next I


        for( i = 0; i < 8; i++ )
        {
dest[ i ] = ( table1[ type ][ i ^ 0x0F ] * ( IMEI[ 0x10 - i ] - 0x30 )) - (( IMEI[ i ] + IMEI[ i ^ 0x0F ] ) % 9 ) + 0x39;
        }

        for( i = 0; i < 0x10; i++ )
                y += IMEI[ i ];

        for( i = 0; i < 8; i++ )
        {
                for( j = 0; j < 4; j++ )
                {
                        x = table1[ type ][ ( i ^ 7 ) + j ];
                        dest[ i ^ 7 ] += (( x << 5 ) ^ ( x << 4 )) + table2[ type ][ j ^ 3 ];
                }
                dest[ i ^ 7 ] += ( y + table3[ type ] * ( i + 1 )) << 2;
        }

        for( i = 0; i < 8; i++ )
        {
                y = dest[ ( i + y ) % 6 ];
                code[ i ] = (char)( 0x39 - ( y % 10 ));
        }
        code[ 8 ] = 0;
}

---

and i am trying to convert it to vb6

i already got this:

Code:

---

Private Sub Command1_Click()
Dim x, y, i, j, dest(8), Imei(21) As Integer
Dim Vitel_Type
Dim code(10) As Integer

For i = 0 To 15
    Imei(i) = Val(Mid(Text2.Text, i + 1, 1)) + 48
Next i

y = 0
Imei(14) = 0
table1 = Array(Array(&HC, &H2D, &H22, &H43, &H17, &H2, &H13, &HA, &HF, &H63, &H4C, &H2D, &H5B, &H3, &H37, &H3B), Array(&H5, &H17, &H43, &H4C, &HC, &H16, &H4E, &H13, &H59, &H32, &H2B, &H38, &H56, &HB, &HF, &H63))
table2 = Array(Array(&H1E2D3E1F, &HF5E6F798, &H9E0D1DFF, &H3E4D5A3E), Array(&H7A8E9E0D, &HB1E2D3A4, &H5A6E7E8D, &H9E0F2E3D))
table3 = Array(&H9E3779B9, &H6F55A634)
Vitel_Type = Text1.Text

For i = 0 To 7
    dest(i) = (table1(Vitel_Type)(i Xor &HF) * (Imei(&H10 - i) - &H30)) - ((Imei(i) + Imei(i Xor &HF)) Mod 9) '+ &H39
Next i

For i = 0 To &H10
    y = y + Imei(i)
Next i

For i = 0 To 7
    For j = 0 To 3
        x = table1(Vitel_Type)((i Xor 7) + j)
        dest(i Xor 7) = dest(i Xor 7) + (CInt(x / (2 ^ 5)) Xor CInt(x / (2 ^ 4)) + table2(Vitel_Type)(j Xor 3))
    Next j
    dest(i Xor 7) = (dest(i Xor 7) + (y + table3(Vitel_Type) * (i + 1))) / (2 ^ 2)
Next i

For i = 0 To 7
    y = dest((i + y) Mod 6)
    code(i) = y Mod 10
Next i
code(8) = 0

MsgBox code(0) + code(1) + code(2) + code(3) + code(4) + code(5) + code(6) + code(7) + code(8)
End Sub

---

but it is not working yet.

this was supposed to calculate a code.

for example:


if i enter the number
123456789012347


it should calculate me this 2 codes depending if i enter 0 or 1 in text1.text:

21477487
91315163

but i was not successfull to convert this.

i am waiting for your help. thanks in advance mates.

where did the edit button go? :s

anyway, this is the most updated codew in vb6 i have

not working yet

Code:

---

Private Sub Command1_Click()
Dim x, y, i, j, dest(8), Imei(21) As Integer
Dim Vitel_Type
Dim code(10) As Integer

For i = 0 To 15
    Imei(i) = Val(Mid(Text2.Text, i + 1, 1)) + 48
Next i

y = 0
Imei(14) = 0
table1 = Array(Array(&HC, &H2D, &H22, &H43, &H17, &H2, &H13, &HA, &HF, &H63, &H4C, &H2D, &H5B, &H3, &H37, &H3B), Array(&H5, &H17, &H43, &H4C, &HC, &H16, &H4E, &H13, &H59, &H32, &H2B, &H38, &H56, &HB, &HF, &H63))
table2 = Array(Array(&H1E2D3E1F, &HF5E6F798, &H9E0D1DFF, &H3E4D5A3E), Array(&H7A8E9E0D, &HB1E2D3A4, &H5A6E7E8D, &H9E0F2E3D))
table3 = Array(&H9E3779B9, &H6F55A634)
Vitel_Type = Text1.Text

For i = 0 To 7
    dest(i) = (table1(Vitel_Type)(i Xor &HF) * (Imei(&H10 - i) - &H30)) - ((Imei(i) + Imei(i Xor &HF)) Mod 9) '+ &H39
Next i

For i = 0 To 15
    y = y + Imei(i)
Next i

For i = 0 To 7
    For j = 0 To 3
        x = table1(Vitel_Type)((i Xor 7) + j)
        dest(i Xor 7) = dest(i Xor 7) + (CInt(x * (2 ^ 5)) Xor CInt(x * (2 ^ 4)) + table2(Vitel_Type)(j Xor 3))
    Next j
    dest(i Xor 7) = (dest(i Xor 7) + (y + table3(Vitel_Type) * (i + 1))) * (2 ^ 2)
Next i

For i = 0 To 7
    y = dest((i + y) Mod 6)
    code(i) = y Mod 10
Next i
code(8) = 0

MsgBox code(0) + code(1) + code(2) + code(3) + code(4) + code(5) + code(6) + code(7) + code(8)
End Sub

---

The C++ arrays are unsigned integers. This datatype is a 32 bit unsigned integer, while the Long datatype is a signed 32 bit integer. Unfortunately there are no unsigned variants of Integer and Long in VB. (Not sure whether Byte is unsigned or not.)

There are a couple of other errors as well. The << operator is the left shift operator. It shifts bits to the left. If you need to use it in VB, then you need to multiply a number with 2^(number to shift).
(The >> operator, right shift, not present here, does the opposite. If you use it, make sure you're doing an integer division.)
When trying to convert the left shift operator, make sure your resulting number doesn't accidentally turn into a double when it grows too large, since the binary information will be modified then. (It's more likely that an overflow error will occur)
It's better to use precalculated values, instead of calculating 2^5 and 2^4 all the time. (Powers, not Xor.).
Also, CInt, will cut off the calculated values to 16 bits, so the 16 most significant bits are discarded.

My suggestion to you if you want to "translate" this code: make sure that you understand the algorithm. The code is a mere representation of the algorithm, so that it can be compiled into executable code. Your VB code might look quite much after the C++ code, but it's impossible to do an 1:1 translation.

When I first read this, I thought a worthwhile move might be to shift this to .NET. I guess I might as well make that suggestion now. .NET allows for 64bit integers, so the unsigned ints can be turned into those.

If you want the code to get a VB alternative, you should give more example results. It is impossible to code an alternative with just one, at easiest you could just do:

VB Code:

'in a module
Public Function GetCode(ByVal CodeString As String, CodeMode As Boolean) As String
    Dim Code(15) As Byte, IMEI() As Byte
    Dim A As Long, B As Long
    
    IMEI = CodeString
    If Not(UBound(IMEI) = 31) Then ReDim Preserve IMEI(31)
    
    For A = 0 To 30 Step 2
        If IMEI(A) > 47 Then IMEI(A) = IMEI(A) - 48
    Next A
    
    B = IMEI(0) Xor IMEI(2) Xor IMEI(4) Xor IMEI(6) Xor IMEI(8) Xor IMEI(10) Xor IMEI(12) Xor IMEI(14) Xor IMEI(16) Xor IMEI(18) Xor IMEI(20) Xor IMEI(22) Xor IMEI(24) Xor IMEI(26) Xor IMEI(28) Xor IMEI(30)
    
    Select Case CodeMode
        Case False
            Code(0) = B + 48
            Code(2) = (B Xor 3) + 48
            Code(4) = (B Xor 6) + 48
            Code(6) = (B Xor 5) + 48
            Code(8) = (B Xor 5) + 48
            Code(10) = (B Xor 6) + 48
            Code(12) = (B Xor 10) + 48
            Code(14) = (B Xor 5) + 48
        Case True
            Code(0) = (B Xor 11) + 48
            Code(2) = (B Xor 3) + 48
            Code(4) = (B Xor 1) + 48
            Code(6) = (B Xor 3) + 48
            Code(8) = (B Xor 7) + 48
            Code(10) = (B Xor 3) + 48
            Code(12) = (B Xor 4) + 48
            Code(14) = (B Xor 1) + 48
    End Select
    
    GetCode = Code
End Function

Which gives a correct result to the only example you gave. But for other input it gives all wrong results (I'm 100% sure about this, nobody can write that complex code to do such a simple thing as this code above does).

In the other hand, coding an alternative might just end up near impossible. In which code you should just make a VB compatible DLL and call the C code that way.

well mates. it is not working very well yet.
but here goes some more valid codes:

000000000000000
04840604
59575151

111111111111119
22995885
11010511

222222222222228
70099570
68778676

333333333333337
68966588
19131299


thanks mates