Convert Routine from VB to C#

Posted on 2009-04-02
Last Modified: 2013-12-17
I need to convert the two method below from VB to C#. The method generates a simple Hash.
I am not a VB Programmer and do not understand exactely what the programmer did...

The goal shoud be that the VB and C# Code generates the same Values.

Hope anyone can help me here...
Public Function get_output_simplehash() As String
Dim fdata As String
Dim HashVal As String, hash As String
Dim hbytes(16) As Byte
Dim dbyte As Byte
Dim l As Long
Dim bb As Long
Dim p As Integer, i As Integer
Dim fs As Object, ts As Object
get_output_simplehash = ""
For i = 1 To 16
    hbytes(i) = 0
Next i
l = 0
For bb = 1 To bufferanz
    fdata = buffer(bb)
    l = l + Len(fdata)
    For i = 1 To Len(fdata)
        dbyte = CByte(Asc(Mid(fdata, i, 1)))
        p = i Mod 16 + 1
        hbytes(p) = hbytes(p) Xor dbyte
    Next i
Next bb
HashVal = ""
For i = 1 To 16
    HashVal = HashVal & " " & Right("0" & Hex(CInt(hbytes(i))), 2)
Next i
get_output_simplehash = Trim(HashVal)
End Function
Public Function get_output_md5hash() As String
Dim fs As Object, f As Object, ts As Object
Dim i As Integer
Dim fdata As String
Dim sContainer As String, sDescription As String, sProvider As String, lHCryptprov As Long
Dim lHHash As Long, lResult As Long, lSignatureLen As Long
Dim hdata(24) As Byte
Dim lDataLen As Long
Dim p As Integer
Dim HashVal As String
get_output_md5hash = ""
'Get handle to the default provider.
sContainer = vbNullChar
sProvider = MS_DEF_PROV & vbNullChar
If Not CBool(CryptAcquireContext(lHCryptprov, ByVal sContainer, ByVal sProvider, PROV_RSA_FULL, 0)) Then
    GoTo ReleaseHandles:
End If
'Create a hash object.
If Not CBool(CryptCreateHash(lHCryptprov, CALG_MD5, 0, 0, lHHash)) Then
    GoTo ReleaseHandles:
End If
For i = 1 To bufferanz
    fdata = buffer(i)
    If Not CBool(CryptHashData(lHHash, fdata, Len(fdata), 0)) Then
        'MsgBox ("Error " & CStr(GetLastError) & " during CryptHashData!")
        GoTo ReleaseHandles:
    End If
Next i
lDataLen = Len(hdata(0)) * (UBound(hdata) + 1)
If Not CBool(CryptGetHashParam(lHHash, HP_HASHVAL, hdata(0), lDataLen, 0)) Then
    GoTo ReleaseHandles:
End If
p = LBound(hdata)
While p <= UBound(hdata)
    If hdata(p) <> 0 Then
        HashVal = HashVal & " " & Right("0" & Hex$(hdata(p)), 2)
        p = UBound(hdata)
    End If
    p = p + 1
get_output_md5hash = Trim(HashVal)
'Destroy hash object.
If lHHash Then lResult = CryptDestroyHash(lHHash)
'Release provider handle.
If lHCryptprov Then lResult = CryptReleaseContext(lHCryptprov, 0)
End Function

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Question by:schubduese
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LVL 21

Expert Comment

ID: 24058544
Here it is:

 public string get_output_simplehash() {
        string fdata;
        string HashVal;
        string hash;
        byte[,] hbytes;
        byte dbyte;
        long l;
        long bb;
        int p;
        int i;
        object fs;
        object ts;
        get_output_simplehash = "";
        for (i = 1; (i <= 16); i++) {
            hbytes[i] = 0;
        l = 0;
        for (bb = 1; (bb <= bufferanz); bb++) {
            fdata = buffer(bb);
            l = (l + fdata.Length);
            for (i = 1; (i <= fdata.Length); i++) {
                dbyte = byte.Parse(Asc(fdata.Substring((i - 1), 1)));
                p = ((i % 16) 
                            + 1);
                hbytes[p] = hbytes[p];
        HashVal = "";
        for (i = 1; (i <= 16); i++) {
            HashVal = (HashVal + (" " + ("0" + Hex(int.Parse(hbytes[i]))).Substring((("0" + Hex(int.Parse(hbytes[i]))).Length - 2))));
        return HashVal.Trim();
    public string get_output_md5hash() {
        object fs;
        object f;
        object ts;
        int i;
        string fdata;
        string sContainer;
        string sDescription;
        string sProvider;
        long lHCryptprov;
        long lHHash;
        long lResult;
        long lSignatureLen;
        byte[,] hdata;
        long lDataLen;
        int p;
        string HashVal;
        get_output_md5hash = "";
        sContainer = vbNullChar;
        sProvider = (MS_DEF_PROV + vbNullChar);
        if (!bool.Parse(CryptAcquireContext(lHCryptprov, sContainer, sProvider, PROV_RSA_FULL, 0))) {
            goto ReleaseHandles;
        // Create a hash object.
        if (!bool.Parse(CryptCreateHash(lHCryptprov, CALG_MD5, 0, 0, lHHash))) {
            goto ReleaseHandles;
        for (i = 1; (i <= bufferanz); i++) {
            fdata = buffer(i);
            if (!bool.Parse(CryptHashData(lHHash, fdata, fdata.Length, 0))) {
                // MsgBox ("Error " & CStr(GetLastError) & " during CryptHashData!")
                goto ReleaseHandles;
        lDataLen = (hdata[0].Length 
                    * (UBound(hdata) + 1));
        if (!bool.Parse(CryptGetHashParam(lHHash, HP_HASHVAL, hdata[0], lDataLen, 0))) {
            goto ReleaseHandles;
        p = LBound(hdata);
        while ((p <= UBound(hdata))) {
            if ((hdata[p] != 0)) {
                HashVal = (HashVal + (" " + ("0" + Hex(hdata[p])).Substring((("0" + Hex(hdata[p])).Length - 2))));
            else {
                p = UBound(hdata);
            p = (p + 1);
            get_output_md5hash = HashVal.Trim();
            if (lHHash) {
                lResult = CryptDestroyHash(lHHash);
            // Release provider handle.
            if (lHCryptprov) {
                lResult = CryptReleaseContext(lHCryptprov, 0);

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LVL 21

Expert Comment

ID: 24058547
I used to translate this.

just google "vb to c#"

Author Comment

ID: 24059198
MogalManic, thanks for your reply

I will test it asap
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Author Comment

ID: 24059228
My Code is from a VB6 Application, I have seen, that the Translator works between VB.NET and C#.
I think this does not work with VB6!?
LVL 96

Assisted Solution

by:Bob Learned
Bob Learned earned 200 total points
ID: 24061678
You need to translate from VB6 to VB.NET, and then to C#.  You might also want to look at the process, and see if it can be reworked in C#, with the classes that are in the .NET framework...
LVL 21

Accepted Solution

MogalManic earned 300 total points
ID: 24062139
TheLearnedOne is right.  The code I converted depends on many functions that were part of the VB6 library but were converted to Object methods by the .Net class libary.  For example, if you want to get the character at string position i, instead of
  Mid(fdata, i, 1)
all you need is:
  char ch=fdata[i];

Also the routine uses the dreaded "GOTO" which, while works, is not recommended for writing maintainable code. (see

If all that you want is the MD5 hash value, then you can use built in .net classes to do this:
public string GetMD5Hash(string input)
    System.Security.Cryptography.MD5CryptoServiceProvider x = new System.Security.Cryptography.MD5CryptoServiceProvider();
    byte[] bs = System.Text.Encoding.UTF8.GetBytes(input);
    bs = x.ComputeHash(bs);
    System.Text.StringBuilder s = new System.Text.StringBuilder();
    foreach (byte b in bs)
    string password = s.ToString();
    return password;

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