Coding
frmCryptoViewer
Import the following namespaces:
'Cryptography NameSpace
Imports System.Security.Cryptography
'For File Input & Output
Imports System.IO
Declare the following variables in General Declarations:
'Original TextBox Text
Private OrigText As String
'New Text Entered
Private NewText As String
'Contents Have Changed
Private FileTextChanged As Boolean
'File Name To Open
Private strFileName As String
Sub Procedures and Functions:
'''
''' Creates The Encrypted File, With The Specified Password
''' On The Speciffied File
'''
'''
'''
'''
'''
Private Sub ApplyCrypt(ByVal strInFileName As String, ByVal strOutFileName As String, _
ByVal strPassword As String)
'If TextBox Text Changed
If FileTextChanged Then
'Create Password Key
Dim TestValueBytes As Byte() = _
System.Text.Encoding.ASCII.GetBytes("This Is A Test")
Dim PassKey As Rfc2898DeriveBytes = New _
Rfc2898DeriveBytes(strPassword, TestValueBytes)
'Create Algorithm And Specify The Key And Pass
Dim rmAlgo As RijndaelManaged = New RijndaelManaged
rmAlgo.Key = PassKey.GetBytes(rmAlgo.KeySize / 8)
rmAlgo.IV = PassKey.GetBytes(rmAlgo.BlockSize / 8)
'Read Unencrypted File
Dim strSourceFile As FileStream = _
New FileStream(strInFileName, FileMode.Open, FileAccess.Read)
'Store Its Data
Dim strData(strSourceFile.Length) As Byte
strSourceFile.Read(strData, 0, CType(strSourceFile.Length, Integer))
'Create ICryptoTransform And CryptoStream Objects
Dim ictEncryptor As ICryptoTransform = rmAlgo.CreateEncryptor
'Get Output File
Dim strDestFile As FileStream = New _
FileStream(strOutFileName, FileMode.OpenOrCreate, FileAccess.Write)
'Write The Encryption
Dim csEncryptStream As CryptoStream = _
New CryptoStream(strDestFile, ictEncryptor, CryptoStreamMode.Write)
csEncryptStream.Write(strData, 0, strData.Length)
'Close All File Handles
csEncryptStream.Close()
strSourceFile.Close()
strDestFile.Close()
End If
End Sub
'''
''' Gets The Encrypted File And Loads
''' Contents If Correct Details Were Supplied
'''
'''
'''
'''
'''
Private Sub LoadCrypt(ByVal strInFileName As String, ByVal strOutFileName As String, _
ByVal strPassword As String)
Try
'Create Password Key
Dim TestValueBytes As Byte() = _
System.Text.Encoding.ASCII.GetBytes("This Is A Test")
Dim PassKey As Rfc2898DeriveBytes = New _
Rfc2898DeriveBytes(strPassword, TestValueBytes)
'Create Algorithm And Specify The Key And Pass
Dim rmAlgo As RijndaelManaged = New RijndaelManaged
rmAlgo.Key = PassKey.GetBytes(rmAlgo.KeySize / 8)
rmAlgo.IV = PassKey.GetBytes(rmAlgo.BlockSize / 8)
Dim ictDecryptor As ICryptoTransform = rmAlgo.CreateDecryptor
'Read Encrypted File
Dim strSourceFile As FileStream = _
New FileStream(strInFileName, FileMode.Open, FileAccess.Read)
'Load Encryption
Dim csDecryptStream As CryptoStream = _
New CryptoStream(strSourceFile, ictDecryptor, CryptoStreamMode.Read)
'Store Its Data
Dim fileData(strSourceFile.Length) As Byte
csDecryptStream.Read(fileData, 0, CType(strSourceFile.Length, Integer))
'Get Destination File
Dim strDestFile As FileStream = New FileStream(strOutFileName, _
FileMode.OpenOrCreate, FileAccess.Write)
'Write To destination File
strDestFile.Write(fileData, 0, fileData.Length)
'Close All File Handles
csDecryptStream.Close()
strSourceFile.Close()
strDestFile.Close()
'Load File Into TextBox
txtCrypto.Text = File.ReadAllText(strOutFileName)
txtCrypto.SelectionLength = 0
txtCrypto.SelectionStart = 0
'Detect Changes To Original Text
OrigText = txtCrypto.Text
NewText = txtCrypto.Text
FileTextChanged = False
'Wrong Password Supplied
Catch ex As Exception
MessageBox.Show("Wrong Password And / Or FileName Entered", "Crypto", _
MessageBoxButtons.OK, MessageBoxIcon.Stop)
End Try
End Sub
'''
''' Converts Normal Text To Hexadecimal
'''
'''
'''
'''
Public Function ToHexStr(ByVal strNormal As String) As String
'Get Text To Convert
Dim arrBytes As Integer() = ConvertCharsToBytes(strNormal)
'Creates New StringBuilder Object
Dim sbHexBuilder As System.Text.StringBuilder = New System.Text.StringBuilder
'Loop Through Characters
'And Convert To Hex
For i As Integer = 0 To arrBytes.Length - 1
sbHexBuilder.Append(String.Format("{0:x2}", Hex(arrBytes(i))))
Next
'Return Hex String
Return sbHexBuilder.ToString()
End Function
'''
''' Convert Normal Characters To Byte Objects
'''
'''
'''
'''
Private Function ConvertCharsToBytes(ByVal strInput As String) As Integer()
'Convert Each Normal Character To a Char Object
Dim c As Char() = strInput.ToCharArray()
'Create A Byte Array
Dim arrBytes As Integer()
'Store Character's Bytes Into Array
ReDim arrBytes(c.Length() - 1)
For i As Integer = 0 To c.Length() - 1
arrBytes(i) = System.Convert.ToByte(c(i))
Next
'Return Byte Object
Return arrBytes
End Function
'''
''' Convert Hexadecimal To Normal Text
'''
'''
'''
'''
Private Function HexToStr(ByVal HexStr As String) As String
'Create Objects
Dim strCurrentChar As String
Dim strASCII As Integer
Dim strOutput As String
'Loop Through Each Character
Do While Len(HexStr) > 0
'Get The Next Hex Number
strCurrentChar = HexStr.Substring(0, 2)
'Store It
HexStr = HexStr.Substring(2)
'Convert To Decimal
strASCII = CInt(Val("&H" & strCurrentChar))
'Convert To Normal Character
strOutput &= Chr(strASCII)
Loop
'Return Decoded String
Return strOutput
End Function
Add the following Form events:
Private Sub frmCryptoViewer_FormClosing(ByVal sender As Object, ByVal e _
As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
'If Output.txt Exists Delete It
If File.Exists("Output.txt") Then File.Delete("Output.txt")
End Sub
Private Sub frmCryptoViewer_Load(ByVal sender As System.Object, ByVal e _
As System.EventArgs) Handles MyBase.Load
btnSave.Enabled = False 'Disable Save
End Sub
Add the following code for the btnLoadFile button:
Private Sub btnLoadFile_Click(ByVal sender As System.Object, ByVal e _
As System.EventArgs) Handles btnLoadFile.Click
If ofdCrypt.ShowDialog = Windows.Forms.DialogResult.OK Then
'Get FileName Entered
strFileName = ofdCrypt.FileName
strFileName = ToHexStr(strFileName) 'Convert To Hex
Dim frmCryptoPass As New frmPass
If frmCryptoPass.ShowDialog = Windows.Forms.DialogResult.OK Then
'If Correct Password Supplied Load File
LoadCrypt("Encrypted.enc", "Output.txt", frmCryptoPass.CryptoPass)
End If
End If
End Sub
Add the following code for btnCopy:
Private Sub btnCopy_Click(ByVal sender As System.Object, ByVal e _
As System.EventArgs) Handles btnCopy.Click
Clipboard.SetText(txtCrypto.SelectedText) 'Copy Selected Text
End Sub
btnSave should look like the following:
Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e _
As System.EventArgs) Handles btnSave.Click
'Save To Output.txt
File.WriteAllText("Output.txt", txtCrypto.Text)
Dim frmCryptoPass As New frmPass 'Launch Password Box
If frmCryptoPass.ShowDialog = Windows.Forms.DialogResult.OK Then
'Set Password For File
ApplyCrypt("Output.txt", "Encrypted.enc", frmCryptoPass.CryptoPass)
End If
End Sub
btnExit:
Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e _
As System.EventArgs) Handles btnExit.Click
Me.Close() 'Exit
End Sub
Last but not least,ad the folowing event for txtCrypto:
Private Sub txtCrypto_LostFocus(ByVal sender As Object, ByVal e _
As System.EventArgs) Handles txtCrypto.LostFocus
'Determine TextBox Text Change
If Not String.Compare(OrigText, NewText) Then
FileTextChanged = True
End If
End Sub
Private Sub txtCrypto_TextChanged(ByVal sender As Object, ByVal e _
As System.EventArgs) Handles txtCrypto.TextChanged
'Determine TextBox Text Change
If Not String.Compare(OrigText, NewText) Then
'If Text Changed We Can Save
btnSave.Enabled = True
End If
End Sub
frmPass
Declare the following variables:
Public CryptoPass As String 'Holds Password
Add the following Form events:
Private Sub frmPass_Load(ByVal sender As System.Object, ByVal e _
As System.EventArgs) Handles MyBase.Load
Dim btnAscii As Button 'Declare New Button Object
Dim btnAsciiLeft As Integer = 10 'New Button's Left
Dim btnAsciiTop As Integer = 10 'New Button's Top
'Create Buttons Ranging From "Space" To "~"
'This Would Allow Us To Work All Keyboard Buttons
For i As Integer = Asc(" ") To Asc("~")
btnAscii = New Button 'Initialise
With btnAscii 'Set Properties
.Name = "btn_" & Chr(i) 'Set Name
.Text = Chr(i) 'Set Text
.Size = New Size(25, 25) 'Set Size
'Set Pos
.Location = New Point(btnAsciiLeft, btnAsciiTop)
.Tag = Chr(i) 'Set Tag
'Shift Buttons To The Right
btnAsciiLeft = btnAsciiLeft + 30
If Chr(i) = "0" Then 'If At 0 Start New Line
btnAsciiTop = btnAsciiTop + 50
btnAsciiLeft = 10
End If
If Chr(i) = "A" Then 'If At A Start New Line
btnAsciiTop = btnAsciiTop + 50
btnAsciiLeft = 10
End If
If Chr(i) = "R" Then 'If At R Start New Line
btnAsciiTop = btnAsciiTop + 50
btnAsciiLeft = 10
End If
If Chr(i) = "c" Then 'If At c Start At New Line
btnAsciiTop = btnAsciiTop + 50
btnAsciiLeft = 10
End If
If Chr(i) = "t" Then 'If At t Start New Line
btnAsciiTop = btnAsciiTop + 50
btnAsciiLeft = 10
End If
'If At u Shift Buttons To The Right
If Chr(i) = "u" Then
btnAsciiLeft = btnAsciiLeft + 105
btnAsciiTop = btnAsciiTop
End If
'If At } Shift Last Button To The Right
If Chr(i) = "}" Then
btnAsciiLeft = btnAsciiLeft + 105
btnAsciiTop = btnAsciiTop
End If
.Visible = True 'Make Visible
End With
Me.Controls.Add(btnAscii) 'Add To Form
'Create Event
AddHandler btnAscii.Click, AddressOf btnAscii_click
Next
End Sub
Add the btnAscii event like this:
Private Sub btnAscii_click(ByVal sender As System.Object, ByVal e _
As System.EventArgs)
'Store Clicked Button(s) In String Variable
CryptoPass = (DirectCast(sender, Button).Text)
End Sub
btnDone:
Private Sub btnDone_Click(ByVal sender As System.Object, ByVal e _
As System.EventArgs) Handles btnDone.Click
Me.Dispose() 'Dispose This Form
End Sub
