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Hash a file and append the filename to the hash in VB.NET

Hi experts!

I want to hash a file with MD5 and compare it to another file's MD5 hash. According to the SDK this is how it's done in PHP:
/*function getGiantsModMD5Hash($modFile)
{
$info = pathinfo($modFile);
// Add mod zip data
$fileContent = file_get_contents($modFile);
// Add basefile name string without extension
$fileContent .= basename($modFile, '.' . $info['extension']);
return md5($fileContent);
}

That returns a correct hash, but now i want to do this in VB.NET and this is the code that i found do hash a file:
Public Class FileChecksum
Private Const BUF_SIZE As Integer = 65536
''' <summary>
''' Returns the file integrity checksum hash, otherwise an empty string.
''' </summary>
Public Shared Function IntegrityCheck(ByVal filePath As String) As String
Dim dataBuffer(BUF_SIZE - 1) As Byte
Dim dataBufferDummy(BUF_SIZE - 1) As Byte
Dim dataBytesRead As Integer = 0
Dim hashResult As String = String.Empty
Dim hashAlg As HashAlgorithm = Nothing
Dim fs As FileStream = Nothing

Try
hashAlg = New MD5CryptoServiceProvider ' or New SHA1CryptoServiceProvider
fs = New FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.None, BUF_SIZE)
Do
dataBytesRead = fs.Read(dataBuffer, 0, BUF_SIZE)
hashAlg.TransformBlock(dataBuffer, 0, dataBytesRead, dataBufferDummy, 0)
Loop Until dataBytesRead = 0
hashAlg.TransformFinalBlock(dataBuffer, 0, 0)
hashResult = BitConverter.ToString(hashAlg.Hash).Replace("-", "").ToLower
Catch ex As IOException
MsgBox(ex.Message, MsgBoxStyle.Critical, "IntegrityCheck")
Catch ex As UnauthorizedAccessException
MsgBox(ex.Message, MsgBoxStyle.Critical, "IntegrityCheck")
Finally
If Not fs Is Nothing Then
fs.Close()
fs.Dispose()
fs = Nothing
End If
If Not hashAlg Is Nothing Then
hashAlg.Clear() 'Dispose()
hashAlg = Nothing
End If
End Try
Return hashResult
End Function

However, as you can the in the PHP example, i must also append the filename whiteout the extension to the end before i calculate the MD5 hash. How in the world do i do that? I've been trying to solve this for the last two days now. :/

David Johnson, CD

Microsoft .net has done most of the heavy lifting for you.
System.Security.Cryptography supports many hash algorithms
MD5, RIPEMD160, SHA1, SHA256, SHA384, SHA512

you basically open a file stream, set the pointer to 0 (beginning of file)
have the hasher read the file and return the value.

http://us.informatiweb.net/programmation/36--generate-hashes-md5-sha-1-and-sha-256-of-a-file.html
https://msdn.microsoft.com/en-us/library/xa627k19%28v=vs.110%29.aspx?cs-save-lang=1&cs-lang=vb#code-snippet-2

Imports System
Imports System.IO
Imports System.Security.Cryptography
Imports System.Windows.Forms

Public Class HashDirectory

    Public Shared Sub Main(ByVal args() As String)
        Dim directory As String 
        If args.Length < 1 Then 
            Dim fdb As New FolderBrowserDialog
            Dim dr As DialogResult = fdb.ShowDialog()
            If (dr = DialogResult.OK) Then
                directory = fdb.SelectedPath
            Else
                Console.WriteLine("No directory selected")
                Return 
            End If 
        Else
            directory = args(0)
        End If 
        Try 
            ' Create a DirectoryInfo object representing the specified directory. 
            Dim dir As New DirectoryInfo(directory)
            ' Get the FileInfo objects for every file in the directory. 
            Dim files As FileInfo() = dir.GetFiles()
            ' Initialize a RIPE160 hash object. 
            Dim myRIPEMD160 As RIPEMD160 = RIPEMD160Managed.Create()
            Dim hashValue() As Byte 
            ' Compute and print the hash values for each file in directory. 
            Dim fInfo As FileInfo
            For Each fInfo In files
                ' Create a fileStream for the file. 
                Dim fileStream As FileStream = fInfo.Open(FileMode.Open)
                ' Be sure it's positioned to the beginning of the stream.
                fileStream.Position = 0
                ' Compute the hash of the fileStream.
                hashValue = myRIPEMD160.ComputeHash(fileStream)
                ' Write the name of the file to the Console.
                Console.Write(fInfo.Name + ": ")
                ' Write the hash value to the Console.
                PrintByteArray(hashValue)
                ' Close the file.
                fileStream.Close()
            Next fInfo
            Return 
        Catch DExc As DirectoryNotFoundException
            Console.WriteLine("Error: The directory specified could not be found.")
        Catch IOExc As IOException
            Console.WriteLine("Error: A file in the directory could not be accessed.")
        End Try 

    End Sub 

    ' Print the byte array in a readable format. 
    Public Shared Sub PrintByteArray(ByVal array() As Byte)
        Dim i As Integer 
        For i = 0 To array.Length - 1
            Console.Write(String.Format("{0:X2}", array(i)))
            If i Mod 4 = 3 Then
                Console.Write(" ")
            End If 
        Next i
        Console.WriteLine()

    End Sub 'PrintByteArray
End Class

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Robberbaron (robr)

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