[Source] Hash My File - Printable Version

Code:

Public Class Form1



    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Try

            With odlgFile



                ' Check to ensure that the selected file exists.  

                ' Dialog box displays a warning otherwise.

                .CheckFileExists = True



                ' Check to ensure that the selected path exists.  Dialog box displays 

                ' a warning otherwise.

                .CheckPathExists = True



                ' Return the file referenced by a link? If False, simply returns the selected link

                ' file. If True, returns the file linked to the LNK file.

                .DereferenceLinks = True



                .Multiselect = False



                ' Restore the original directory when done selecting

                ' a file? If False, the current directory changes

                ' to the directory in which you selected the file.

                ' Set this to True to put the current folder back

                ' where it was when you started.

                ' The default is False.

                .RestoreDirectory = True



                ' Show the Help button and Read-Only checkbox?

                .ShowHelp = False

                .ShowReadOnly = False



                ' Start out with the read-only check box checked?

                ' This only make sense if ShowReadOnly is True.

                .ReadOnlyChecked = False



                .Title = "Select a file to open"



                ' Only accept valid Win32 file names?

                .ValidateNames = True



                If .ShowDialog = Windows.Forms.DialogResult.OK Then

                    Try

                        TextBox1.Text = odlgFile.FileName



                        Dim path As String = TextBox1.Text

                        TextBox2.Text = MD5CalcFile(path)

                        TextBox3.Text = getSHA1Hash(path)

                        TextBox4.Text = getSHA256Hash(path)

                        TextBox5.Text = GetCRC32(path)



                    Catch fileException As Exception

                        Throw fileException

                    End Try

                End If



            End With

        Catch ex As Exception

            MsgBox(ex.Message, MsgBoxStyle.Exclamation, Me.Text)

        End Try



    End Sub



End Class

Code:

Imports System.Security.Cryptography

Imports System.Text

Imports System.IO



Module Module1



    Public Function GetCRC32(ByVal sFileName As String) As String

        Try

            Dim FS As FileStream = New FileStream(sFileName, FileMode.Open, FileAccess.Read, FileShare.Read, 8192)

            Dim CRC32Result As Integer = &HFFFFFFFF

            Dim Buffer(4096) As Byte

            Dim ReadSize As Integer = 4096

            Dim Count As Integer = FS.Read(Buffer, 0, ReadSize)

            Dim CRC32Table(256) As Integer

            Dim DWPolynomial As Integer = &HEDB88320

            Dim DWCRC As Integer

            Dim i As Integer, j As Integer, n As Integer



            'Create CRC32 Table

            For i = 0 To 255

                DWCRC = i

                For j = 8 To 1 Step -1

                    If (DWCRC And 1) Then

                        DWCRC = ((DWCRC And &HFFFFFFFE) \ 2&) And &H7FFFFFFF

                        DWCRC = DWCRC Xor DWPolynomial

                    Else

                        DWCRC = ((DWCRC And &HFFFFFFFE) \ 2&) And &H7FFFFFFF

                    End If

                Next j

                CRC32Table(i) = DWCRC

            Next i



            'Calcualting CRC32 Hash

            Do While (Count > 0)

                For i = 0 To Count - 1

                    n = (CRC32Result And &HFF) Xor Buffer(i)

                    CRC32Result = ((CRC32Result And &HFFFFFF00) \ &H100) And &HFFFFFF

                    CRC32Result = CRC32Result Xor CRC32Table(n)

                Next i

                Count = FS.Read(Buffer, 0, ReadSize)

            Loop

            Return Hex(Not (CRC32Result))

        Catch ex As Exception

            Return ""

        End Try

    End Function



    Public Function MD5CalcFile(ByVal filepath As String) As String

        Try

            Using reader As New System.IO.FileStream(filepath, IO.FileMode.Open, IO.FileAccess.Read)

                Using md5 As New System.Security.Cryptography.MD5CryptoServiceProvider

                    Dim hash() As Byte = md5.ComputeHash(reader)

                    Return ByteArrayToString(hash)

                End Using

            End Using

        Catch ex As Exception

            Return ""

        End Try

    End Function



    Public Function ByteArrayToString(ByVal arrInput() As Byte) As String

        Try

            Dim sb As New System.Text.StringBuilder(arrInput.Length * 2)

            For i As Integer = 0 To arrInput.Length - 1

                sb.Append(arrInput(i).ToString("X2"))

            Next

            Return sb.ToString().ToLower

        Catch ex As Exception

            Return ""

        End Try

    End Function



    'Imports System.Security.Cryptography



    Function getSHA1Hash(ByVal strToHash As String) As String

        Try

            Dim sha1Obj As New Security.Cryptography.SHA1CryptoServiceProvider

            Dim bytesToHash() As Byte = System.Text.Encoding.ASCII.GetBytes(strToHash)

            bytesToHash = sha1Obj.ComputeHash(bytesToHash)

            Dim strResult As String = ""

            For Each b As Byte In bytesToHash

                strResult += b.ToString("x2")

            Next

            Return strResult

        Catch ex As Exception

            Return ""

        End Try

    End Function



    'Imports System.Security.Cryptography



    Function getSHA256Hash(ByVal Txt As String) As String

        Try

            Dim sha As New SHA256Managed()

            Dim ae As New ASCIIEncoding()

            Dim Hash() As Byte = sha.ComputeHash(ae.GetBytes(Txt))

            Dim sb As New StringBuilder(Hash.Length * 2)

            Dim ndx As Integer

            For ndx = 0 To Hash.Length - 1

                sb.Append(Right("0" & Hex(Hash(ndx)), 2))

            Next

            Return sb.ToString

        Catch ex As Exception

            Return ""

        End Try

    End Function

End Module