Tugas Praktikum Kriptografi

Public Class Form1

    Private Sub CaesarChiperToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Caesar.Click

        Caesar.Show()

    End Sub

    Private Sub GransfieldChiperToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles GransfieldChiperToolStripMenuItem.Click

        DesChiper.Show()

    End Sub

    Private Sub VernamChiperToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles VernamChiperToolStripMenuItem.Click

        Vernam.Show()

    End Sub

    Private Sub VigenereChiperToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles VigenereChiperToolStripMenuItem.Click

        Vigenere.Show()

    End Sub

    Private Sub DesChiperToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DesChiperToolStripMenuItem.Click

        RC4.Show()

    End Sub

    Private Sub KeluarToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles KeluarToolStripMenuItem.Click

        Dim i As MsgBoxResult

        i = MsgBox("Apa anda ingin keluar?", MsgBoxStyle.Information + MsgBoxStyle.YesNo, "Perhatian")

        If i = MsgBoxResult.Yes Then

            Close()

        End If

    End Sub

End Class

Public Class Caesar_Chiper

    Private Sub Caesar_Chiper_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Plaintext.Text = ""

        Chipertext.Text = ""

    End Sub

    Private Sub Btnenkripsi_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btnenkripsi.Click

        Dim jumlah As Double = Len(Plaintext.Text)

        Dim x As String

        Dim xkalimat As String = ""

        Dim i As Double

        Dim bil As Integer

        For i = 1 To jumlah

            x = Mid(Plaintext.Text, i, 1)

            bil = Asc(x) + 3

            x = Chr(bil)

            xkalimat = xkalimat + x

        Next i

        Chipertext.Text = xkalimat

    End Sub

End Class

 

Public Class Vernam_chiper

    Private Sub Vernam_chiper_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        plaintext.Text = ""

        kunci.Text = ""

        chipertext.Text = ""

    End Sub

    Private Sub btnenkripsi_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnenkripsi.Click

        Dim j As Integer

        Dim jum As Integer

        Dim sKey As String

        Dim nKata As Integer

        Dim nKunci As Integer

        Dim sKata As String

        Dim sPlain As String = ""

        Dim nEnc As Integer

        j = 0

        sKata = plaintext.Text

        jum = Len(sKata)

        sKey = kunci.Text

        For i = 1 To jum

            If j = Len(sKey) Then

                j = 1

            Else

                j = j + 1

            End If

            nKata = Asc(Mid(sKata, i, 1)) - 65

            nKunci = Asc(Mid(sKey, j, 1)) - 65

            nEnc = ((nKata + nKunci) Mod 26)

            sPlain = sPlain & Chr((nEnc) + 65)

        Next i

        chipertext.Text = sPlain

    End Sub

    Private Sub kunci_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles kunci.KeyPress

        e.KeyChar = UCase(e.KeyChar)

        Dim tombol As Integer = Asc(e.KeyChar)

        If Not (((tombol >= 65) And (tombol <= 90)) Or (tombol = 8)) Then

            e.Handled = True

        End If

    End Sub

    Private Sub plaintext_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles plaintext.KeyPress

        e.KeyChar = UCase(e.KeyChar)

        Dim tombol As Integer = Asc(e.KeyChar)

        If Not (((tombol >= 65) And (tombol <= 90)) Or (tombol = 8)) Then

            e.Handled = True

        End If

    End Sub

    Private Sub hapus_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles hapus.Click

        plaintext.Text = ""

        kunci.Text = ""

        chipertext.Text = ""

    End Sub

    Private Sub keluar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles keluar.Click

        Me.Close()

    End Sub

End Class

Public Class vigenere

    Private Sub enkripsi_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles enkripsi.Click

        chipertext.Text = Eenkripsi(plaintext.Text, kunci.Text)

    End Sub

    Function Eenkripsi(ByVal Teks As String, ByVal Kunci As String) As String

        Dim j As Integer

        Dim jum As Integer

        Dim sKey As String

        Dim nKata As Integer

        Dim nKunci As Integer

        Dim sKata As String

        Dim sPlain As String

        Dim nEnc As Integer

        j = 0

        jum = Len(Teks)

        sPlain = ""

        sKey = Kunci

        sKata = Teks

        For i = 1 To jum

            If j = Len(sKey) Then

                j = 1

            Else

                j = j + 1

            End If

            nKata = Asc(Mid(sKata, i, 1))

            nKunci = Asc(Mid(sKey, j, 1))

            nEnc = ((nKata + nKunci) Mod 256)

            sPlain = sPlain & Chr((nEnc))

        Next i

        Eenkripsi = sPlain

    End Function

    Private Sub hapus_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles hapus.Click

        plaintext.Text = ""

        kunci.Text = ""

        chipertext.Text = ""

    End Sub

    Private Sub keluar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles keluar.Click

        Me.Close()

    End Sub

End Class

Public Class RC4

    Private Sub RC4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        plaintext.Text = ""

        kunci.Text = ""

        chipertext.Text = ""

    End Sub

    Private Function AutokeyEncipher(ByVal strPlaintext As String, ByRef strKey AsString) As String

        Dim i As Long

        Dim j As Long

        Dim c1 As Integer

        Dim strPlaintext2 As String

        Dim strKey2 As String

        Dim strCiphertext As String

        Dim strCiphertext2 As String

        Dim diffKeyLen As Integer

        Dim pAlphabet As Integer

        Dim cAlphabet As Integer

        Dim nShift As Integer

        '1. Hilangkan semua karakter yang bukan alfabet dari strPlaintext

        ' dan simpan sebagai strPlaintext2

        strPlaintext2 = ""

        For i = 1 To strPlaintext.Length

            c1 = Asc(Mid(strPlaintext, i, 1))

            If (c1 >= 65 And c1 <= 90) Then

                strPlaintext2 = strPlaintext2 & Chr(c1)

            End If

        Next i

        '2. Hilangkan semua karakter yang bukan alfabet dari strKey

        ' dan simpan sebagai strKey2

        strKey2 = ""

        For i = 1 To strKey.Length

            c1 = Asc(Mid(strKey, i, 1))

            If (c1 >= 65 And c1 <= 90) Then

                strKey2 = strKey2 & Chr(c1)

            End If

        Next i

        '3. Susun kunci baru strKey2 berdasarkan kunci awal strKey kemudian

        ' ditambah plaintext

        'perbedaan antara panjang plaintext dan kunci

        diffKeyLen = strPlaintext2.Length - strKey2.Length

        For i = 1 To diffKeyLen

            'c1 = Asc(Mid(strPlaintext2, i, 1))

            strKey2 = strKey2 & Mid(strPlaintext2, i, 1)

        Next i

        '4. Geser masing-masing huruf pada plaintext

        ' dengan huruf yang terkait pada key

        strCiphertext = ""

        For i = 1 To strPlaintext2.Length

            c1 = Asc(Mid$(strPlaintext2, i, 1))

            nShift = Asc(Mid$(strKey2, i, 1)) - 65

            If ((c1 >= 65) And (c1 <= 90)) Then

                pAlphabet = c1 - 65 ' get the alphabet sequence

                cAlphabet = (pAlphabet + nShift) Mod 26 ' shifted alphabet

                c1 = cAlphabet + 65 ' get character in 65 ... 90

            End If

            strCiphertext = strCiphertext & Chr(c1)

        Next i

        '5. Susun strCiphertext sesuai dengan urutan strPlaintext

        strCiphertext2 = ""

        strKey = ""

        j = 1

        For i = 1 To strPlaintext.Length

            c1 = Asc(Mid$(strPlaintext, i, 1))

            If ((c1 >= 65) And (c1 <= 90)) Then

                strCiphertext2 = strCiphertext2 & Mid(strCiphertext, j, 1)

                strKey = strKey & Mid(strKey2, j, 1)

                j = j + 1

            Else

                strCiphertext2 = strCiphertext2 & Chr(c1)

                strKey = strKey & " "

            End If

        Next i

        Return strCiphertext2

    End Function

    Private Sub hapus_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles hapus.Click

        plaintext.Text = ""

        kunci.Text = ""

        chipertext.Text = ""

    End Sub

    Private Sub keluar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles keluar.Click

        Me.Close()

    End Sub

    Private Sub enkripsi_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles enkripsi.Click

        chipertext.Text = AutokeyEncipher(plaintext.Text, kunci.Text)

    End Sub

End Class

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