Keskustelu: Koodit: VB.NET: SHA1-tiiviste

Imports System.Security.Cryptography
Imports System.io
'
'..........................................
'
Function LaskeTiiviste(ByVal filename As String) As String
        '******************************************************************
        '   SHA1 tarkistussumman (160 bit)laskenta tiedostolle
        '   palauttaa hex stringin, jossa väliviivat joka neljännen jälkeen
        '   by TNB 2005
        '******************************************************************
        'oliko tiedosto olemassa
        If File.Exists(filename) = False Then Return "File not exists" 'palaa jos ei tiedostoa
        'alustetaan
        Dim fs As FileStream = New FileStream(filename, FileMode.Open, FileAccess.Read) 'tiedosto auki
        Dim tiiviste1 As New SHA1Managed 'SHA1 luokkasta instanssi
        Dim tiivisteData() As Byte ' tilaa tulokselle byteinä
        'lasketaan SHA1 tiiviste
        tiivisteData = tiiviste1.ComputeHash(fs)
        'vapautetaan resurssit
        fs.Close()
        tiiviste1.Clear()
        'muutetaan hex-tekstiksi, väliviiva
        Dim i As Integer : Dim str As String
        For i = 0 To UBound(tiivisteData)
            If (i Mod 2 = 0) And i <> 0 Then str = str & "-"
            If tiivisteData(i) < 16 Then
                str = str & "0" & Hex(tiivisteData(i))
            Else
                str = str & Hex(tiivisteData(i))
            End If
        Next
        Return str 'paluu
    End Function

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    ' AVAA TIEDOSTO
    'tarkistettavan tiedoston nimi selbville
    Dim openFileDialog1 As New OpenFileDialog
    Dim st As String 'tila tiedostonimelle
    openFileDialog1.InitialDirectory = "c:\"
    openFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"
    openFileDialog1.FilterIndex = 2
    openFileDialog1.RestoreDirectory = True
    TextBox1.Clear()
    If openFileDialog1.ShowDialog() = DialogResult.OK Then
        st = openFileDialog1.FileName
        If File.Exists(st) Then
            TextBox1.Text = LaskeTiiviste(st)
        End If
    End If
    'vertailu oikeaksi tunnettuun arvoon
    If TextBox1.Text = TextBox2.Text Then
        Label3.Text = "OK"
    Else
        Label3.Text = "VIRHE"
    End If

End Sub

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.
    'Do not modify it using the code editor.
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents OpenFileDialog1 As System.Windows.Forms.OpenFileDialog
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents Label3 As System.Windows.Forms.Label
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Button1 = New System.Windows.Forms.Button
        Me.OpenFileDialog1 = New System.Windows.Forms.OpenFileDialog
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.Label1 = New System.Windows.Forms.Label
        Me.TextBox2 = New System.Windows.Forms.TextBox
        Me.Label2 = New System.Windows.Forms.Label
        Me.Label3 = New System.Windows.Forms.Label
        Me.SuspendLayout()
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(16, 24)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(104, 32)
        Me.Button1.TabIndex = 0
        Me.Button1.Text = "Avaa tiedosto"
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(144, 32)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(368, 20)
        Me.TextBox1.TabIndex = 1
        Me.TextBox1.Text = ""
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(144, 16)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(104, 16)
        Me.Label1.TabIndex = 2
        Me.Label1.Text = "Sha1Sum:"
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(144, 80)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.Size = New System.Drawing.Size(368, 20)
        Me.TextBox2.TabIndex = 3
        Me.TextBox2.Text = ""
        '
        'Label2
        '
        Me.Label2.Location = New System.Drawing.Point(144, 64)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(176, 16)
        Me.Label2.TabIndex = 4
        Me.Label2.Text = "Vertailu summa (oikeaksi tiedetty)"
        '
        'Label3
        '
        Me.Label3.Font = New System.Drawing.Font("Microsoft Sans Serif", 15.75!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label3.Location = New System.Drawing.Point(24, 72)
        Me.Label3.Name = "Label3"
        Me.Label3.Size = New System.Drawing.Size(96, 40)
        Me.Label3.TabIndex = 5
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(536, 134)
        Me.Controls.Add(Me.Label3)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.TextBox2)
        Me.Controls.Add(Me.Label1)
        Me.Controls.Add(Me.TextBox1)
        Me.Controls.Add(Me.Button1)
        Me.Name = "Form1"
        Me.Text = "Sha1Sum"
        Me.ResumeLayout(False)

    End Sub

#End Region