Ben's Encryption codes

Hi this page will contain some of my little snippets of encryption codes this is my first try it a basic encryption using XOR and random function it also uses a function to get a hash coded from your password hope you like this first example. comments and suggestions welcome.


Sniplet 1 XOR using random encryption for strings.

vbnet Code:

Public Class Form1
 
    Private Function GetHash(ByVal source As String) As Integer
        Dim hash As Integer = 0
        'Add some random hex codes add more if you want.
        Dim Magic = {&H3FEE, &H3A9B, &H3977, &H37A4, &H3583, &H3019, &H2F86, &H2E55, &H554}
        'Build hash code.
        For x As Integer = 0 To source.Length - 1
            hash = (hash >> 2) Xor Asc(source(x)) + Magic(x And &H8)
        Next x
 
        Return hash
 
    End Function
 
    Private Function EncryptString(ByVal source As String, ByVal Password As String) As String
        Dim Hash As Integer = 0
        Dim sb As New System.Text.StringBuilder()
        'Get hash of password.
        Hash = GetHash(Password)
 
        Rnd(-3)
        'Random hash
        Randomize(hash)
 
        For x As Integer = 0 To source.Length - 1
            Dim b As Byte = Asc(source(x)) Xor Int(Rnd() * Hash) Mod 256
            'Append chars.
            sb.Append(Chr(b))
        Next x
 
        'Return string
        Return sb.ToString
    End Function
 
    Private Sub cmdTest_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdTest.Click
        Dim src As String = "hello,hello,hello world"
 
        Dim en As String = EncryptString(src, "secret")
        Dim de As String = EncryptString(en, "secret")
 
        'Show encrypted string.
        MessageBox.Show("Encrypted string: " & en, "Encrypt1", MessageBoxButtons.OK, MessageBoxIcon.Information)
        'Show decrypted string.
        MessageBox.Show("Decrypted string: " & de, "Encrypt1", MessageBoxButtons.OK, MessageBoxIcon.Information)
    End Sub
 
End Class

Hi this is my second example this example shows you how to use XOR to encrypt and decrypt a file using a password.
suggestions and comments welcome hope you like the example.

Class code cXorFile

vbnet Code:

'A simple to use XOR File encrypter / Decrypter
'By Ben Jones use this code as you like it's yours.
 
Option Explicit On
Imports System.IO
 
Public Class cXorFile
 
    Private m_Password As String = vbNullString
    Private m_Source As String = vbNullString
    Private m_Output As String = vbNullString
 
    Public Property SourceFile As String
        Get
            Return m_Source
        End Get
        Set(ByVal value As String)
            m_Source = value
        End Set
    End Property
 
    Public Property OutputFile As String
        Get
            Return m_Output
        End Get
        Set(ByVal value As String)
            m_Output = value
        End Set
    End Property
 
    Public Property Password As String
        Get
            Return m_Password
        End Get
        Set(ByVal value As String)
            m_Password = value
        End Set
    End Property
 
    Public Sub EncryptDecrypt()
        Dim br As BinaryReader = Nothing
        Dim bw As BinaryWriter = Nothing
        Dim KeyHash As Integer = 0
 
        'Generate hash from password.
        For x As Integer = 0 To 256
            KeyHash += Asc(Password(x Mod Len(Password))) << 8
        Next x
 
        Rnd(-1)
        'Set random seed.
        Randomize(KeyHash)
 
        'Check that source file is found.
        If Not File.Exists(SourceFile) Then
            Throw New FileNotFoundException
            Exit Sub
        End If
 
        Try
            'Open files for reading and writeing.
            br = New BinaryReader(File.OpenRead(SourceFile))
            bw = New BinaryWriter(File.OpenWrite(OutputFile))
 
            'Loop though the file xor each byte and write to output file.
            For x As Integer = 0 To br.BaseStream.Length - 1
                'Xor byte
                Dim b As Byte = br.ReadByte Xor Int(Rnd() * KeyHash) Mod 256
                'Write byte.
                bw.Write(b)
            Next x
 
            bw.Close() 'Close output file.
            br.Close() 'Close input file.
        Catch ex As Exception
            Throw New ArgumentException(ex.Message)
        End Try
 
    End Sub
 
End Class

Example code

vbnet Code:

Private Sub cmdGo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdGo.Click
        Dim MyCrypt As New cXorFile()
 
        With MyCrypt
            'Set password.
            .Password = "idkfa65"
            'Source filename.
            .SourceFile = "C:\out\data\test.txt"
            'Output filename.
            .OutputFile = "C:\out\data\test.dat"
 
            Try
                'Do the encryption or decryption.
                .EncryptDecrypt()
            Catch ex As Exception
                'Display error message.
                MessageBox.Show(ex.Message, "Error",
                                MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try
        End With
    End Sub

Here is some code I found on one of my old backup dvds I made years ago in QBasic it is a simple encryption and decryption I thought I place it here with the rest of my examples.
Anyway this example uses a key value to encrypt and decrypt. comments and suggestions welcome.

vbnet Code:

Private Sub EncryptFile(ByVal Input As String, ByVal Output As String, ByVal MagicKey As Byte)
        Dim br As BinaryReader = Nothing
        Dim bw As BinaryWriter
        Dim bKey As Integer = 0
 
        Try
            br = New BinaryReader(File.OpenRead(Input))
        Catch ex As Exception
            Throw New ArgumentException(ex.Message)
        End Try
 
        bw = New BinaryWriter(File.OpenWrite(Output))
        For x As Integer = 0 To br.BaseStream.Length - 1
            'Read byte from file.
            Dim b As Byte = br.ReadByte()
            'Encode key
            bKey = (b + MagicKey)
 
            'If more than 255 minus 255
            If (bKey > 255) Then
                bKey -= 255
            End If
 
            'Write byte to file.
            bw.Write(CByte(bKey))
        Next x
 
        'Close files.
        bw.Close()
        br.Close()
 
    End Sub
 
    Private Sub DecryptFile(ByVal Input As String, ByVal Output As String, ByVal MagicKey As Byte)
        Dim br As BinaryReader
        Dim bw As BinaryWriter
        Dim bKey As Integer = 0
 
        Try
            br = New BinaryReader(File.OpenRead(Input))
        Catch ex As Exception
            Throw New ArgumentException(ex.Message)
        End Try
 
        bw = New BinaryWriter(File.OpenWrite(Output))
 
        For x As Integer = 0 To br.BaseStream.Length - 1
            'Read byte from file.
            Dim b As Byte = br.ReadByte()
 
            'Decrypt key
            bKey = (b - MagicKey)
 
            'If less than 0 plus 255
            If (bKey < 0) Then
                bKey += 255
            End If
 
            'Write byte to file.
            bw.Write(CByte(bKey))
        Next x
 
        'Close files.
        bw.Close()
        br.Close()
    End Sub
 
    Private Sub cmdGo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdGo.Click
        'Do the encryption and decryption.
        EncryptFile("C:\out\data\test.txt", "C:\out\data\out.txt", 128)
        DecryptFile("C:\out\data\out.txt", "C:\out\data\new.txt", 128)
    End Sub

Hi all this is a new example this uses the built in TripleDES functions in VB.NET this example has a class and an example. The class allows you to encrypt decrypt files with a password.
It also has two string functions for encrypting and decrypting strings.
Hope you find this of some use. comments and suggestions welcome.

class code cDes.vb

vbnet Code:

'TripleDES encrypter / Decrypter for files and strings.
'This example is part of Bens Jones encryption codes use as you like.
 
Option Explicit On
 
Imports System.Security.Cryptography
Imports System.Text
Imports System.IO
 
Public Class cDes
 
    'Class variables.
    Private m_Input As String = vbNullString
    Private m_Output As String = vbNullString
    Private m_Password As String = vbNullString
 
    Public Property InputFile As String
        Get
            Return m_Input
        End Get
        Set(ByVal value As String)
            m_Input = value
        End Set
    End Property
 
    Public Property OutputFile As String
        Get
            Return m_Output
        End Get
        Set(ByVal value As String)
            m_Output = value
        End Set
    End Property
 
    Public Property Password As String
        Get
            Return m_Password
        End Get
        Set(ByVal value As String)
            m_Password = value
        End Set
    End Property
 
    Public Sub DecryptFile()
        'Decrypt file.
        DoAction(False)
    End Sub
 
    Public Sub EncryptFile()
        'Encrypt file.
        DoAction(True)
    End Sub
 
    Public Function EncryptString(ByVal source As String, ByVal Password As String) As String
        Dim Bytes() As Byte
 
        Dim Des As New TripleDESCryptoServiceProvider()
        Dim Hash As New MD5CryptoServiceProvider()
        Dim EnTransForm As ICryptoTransform = Nothing
 
        Try
            'Create encrypter.
            Des.Key = Hash.ComputeHash(Encoding.ASCII.GetBytes(Password))
            Des.Mode = CipherMode.ECB
            EnTransForm = Des.CreateEncryptor()
            'Get bytes from string.
            Bytes = Encoding.ASCII.GetBytes(source)
            'Return base64 string.
            Return Convert.ToBase64String(EnTransForm.TransformFinalBlock(Bytes, 0, Bytes.Length))
        Catch ex As Exception
            Throw New ArgumentException(ex.Message)
        End Try
    End Function
 
    Public Function DecryptString(ByVal source As String, ByVal Password As String) As String
        Dim Bytes() As Byte
 
        Dim Des As New TripleDESCryptoServiceProvider()
        Dim Hash As New MD5CryptoServiceProvider()
        Dim EnTransForm As ICryptoTransform = Nothing
 
        Try
            'Create decrypter.
            Des.Key = Hash.ComputeHash(Encoding.ASCII.GetBytes(Password))
            Des.Mode = CipherMode.ECB
            EnTransForm = Des.CreateDecryptor()
            'Get bytes from string.
            Bytes = Convert.FromBase64String(source)
            'Return string.
            Return Encoding.ASCII.GetString(EnTransForm.TransformFinalBlock(Bytes,0,Bytes.Length))
        Catch ex As Exception
            Throw New ArgumentException(ex.Message)
        End Try
    End Function
 
    Private Sub DoAction(ByVal Encrypt As Boolean)
        Dim br As BinaryReader = Nothing
        Dim bw As BinaryWriter = Nothing
        Dim Bytes() As Byte
 
        Dim Des As New TripleDESCryptoServiceProvider()
        Dim Hash As New MD5CryptoServiceProvider()
        Dim EnTransForm As ICryptoTransform = Nothing
 
        'Check for password.
        If String.IsNullOrWhiteSpace(Password) Then
            Throw New ArgumentException("No Password Found")
        End If
 
        Try
            br = New BinaryReader(File.OpenRead(InputFile))
            'Create hash from password.
            Des.Key = Hash.ComputeHash(Encoding.ASCII.GetBytes(Password))
            'Set mode.
            Des.Mode = CipherMode.ECB
 
            If Encrypt Then
                'Create encrypter.
                EnTransForm = Des.CreateEncryptor()
            Else
                'Create decrypter.
                EnTransForm = Des.CreateDecryptor()
            End If
 
            'Read bytes from input filename.
            Bytes = br.ReadBytes(br.BaseStream.Length)
            'Encrypt bytes.
            Bytes = EnTransForm.TransformFinalBlock(Bytes, 0, Bytes.Length)
            'Create output filename.
            bw = New BinaryWriter(File.OpenWrite(OutputFile))
            'Write bytes to output file.
            bw.Write(Bytes)
 
            'Close open files.
            bw.Close()
            br.Close()
        Catch ex As Exception
            Throw New ArgumentException(ex.Message)
        End Try
    End Sub
End Class

Examples

vbnet Code:

Public Class Form1
 
    Private Sub cmdTest1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdTest1.Click
        Dim MyDes As New cDes()
 
        With MyDes
            'Set password for encrypting and decrypting.
            .Password = "crimson"
 
            Try
                'Encrypt file.
                .InputFile = "C:\out\data\test.txt"
                .OutputFile = "C:\out\data\out.txt"
                .EncryptFile()
                'Decrypt file.
                .InputFile = "C:\out\data\out.txt"
                .OutputFile = "C:\out\data\new.txt"
                .DecryptFile()
            Catch ex As Exception
                MessageBox.Show(ex.Message, "Error",
                                MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try
        End With
    End Sub
 
    Private Sub cmdTest2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdTest2.Click
        Dim MyDes As New cDes()
        Dim Demo As String = "Hello World"
 
        'Original
        MessageBox.Show("Original: " & Demo, "Demo", MessageBoxButtons.OK, MessageBoxIcon.Information)
 
        'Encrypt string
        Demo = MyDes.EncryptString(Demo, "alpha45")
        MessageBox.Show("Encrypted: " & Demo, "Demo", MessageBoxButtons.OK, MessageBoxIcon.Information)
 
        'Decrypt string
        Demo = MyDes.DecryptString(Demo, "alpha45")
        MessageBox.Show("Decrypted: " & Demo, "Demo", MessageBoxButtons.OK, MessageBoxIcon.Information)
    End Sub
End Class