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^^kev####
Überflieger
Überflieger

Anmeldedatum: 01.05.2008
Beiträge: 476
Wohnort: Haan
Datenverschlüsselungsklasse
Verfasst am: 29.06.2009, 14:16
Beschreibung:
Das ist eine Kryptographieklasse die die Verschlüsselungsalgorithmen aus den .NET Framework
zusammenfasst und in einfach anzuwendenen Funktionen kapselt.

Es gibt für jedes Szenario eine passende Funktion z.B. wenn man eine Datei von der Festplatte direkt in ein Bytearray entschlüsseln will oder wenn man ein Bytearray verschlüsseln will und das Ergebnis in ein anderes Bytearray speichern will.

Das bietet den Vorteil das man nicht ständig temporäre Dateien oder Variablen verwenden muss.

PS: Für die Salzwerte habe ich irgendwelche Werte festgelegt die natürlich verändert werden können oder man benutzt die entsprechende Eigenschaft um eigene Salzwerte zu benutzen.
Ach und wenn man keine oder eine falsche Bitstärke angegeben hat wird automatisch der höchste und richtige Wert ausgewählt.

Funktion:
Visual Basic: [code]Imports System.IO
Imports System.Text
Imports System.Security.Cryptography

'''
''' Das ist eine Kryptographieklasse die die Verschlüsselungsalgorithmen aus den .NET Framework
''' zusammenfasst und in einfach anzuwendenen Funktionen kapselt.
'''
''' Tim Hartwig
Public Class clsCryptography
Private mKeySalt() As Byte = {&HA1, &H41, &HC4, &HF5, &H23, &H70, &HBF, &H52}
Private mIVSalt() As Byte = {&H47, &H80, &H22, &HFF, &H12, &HE7, &HF1, &H39}
Private mBitLen As Integer

Public Event ProgressError(ByVal sender As Object, ByVal ex As Exception)

'''
''' Gibt einen Salt-Wert für das Passwort für die Verschlüsselung an (ab 8 Bytes)
'''
Public Property KeySalt() As Byte()
Get
Return mKeySalt
End Get
Set(ByVal value As Byte())
If value.Length < 8 Then
Throw New Exception("Der Salt-Wert ist zu klein. Der Wert muss >= 8 Bytes sein.")
Else
mKeySalt = value
End If
End Set
End Property

'''
''' Gibt einen Salt-Wert für den InitialisierungsVektor für die Verschlüsselung an (ab 8 Bytes)
'''
Public Property IVSalt() As Byte()
Get
Return mIVSalt
End Get
Set(ByVal value As Byte())
If value.Length < 8 Then
Throw New Exception("Der Salt-Wert ist zu klein. Der Wert muss >= 8 Bytes sein.")
Else
mIVSalt = value
End If
End Set
End Property

'''
''' Gibt die Verschlüsselungsstärke in Bits an:
''' DES = 64; TDES = 128,192; RIJNDAEL = 128,192,256; RC2 = 40 bis 128 (8er Schritte)
'''
Public Property BitLen() As Integer
Get
Return mBitLen * 8
End Get
Set(ByVal value As Integer)
If value Mod 8 = 1 Then Throw New Exception("Es wurde keine gültige Bitstärke für die Verschlüsselung angegeben!")
mBitLen = value / 8
End Set
End Property

Public Enum ALGO As Integer
'''
''' 64 Bit
'''
DES = 0

'''
''' 128 Bit, 192 Bit
'''
TDES = 1

'''
''' 128 Bit, 192 Bit, 256 Bit
'''
RIJNDAEL = 2

'''
''' 40 - 128 Bit
'''
RC2 = 3
End Enum

Private Sub CheckBitLen(ByVal Algorithm As ALGO)
Select Case Algorithm
Case ALGO.DES
If (mBitLen = 0) Or (Not mBitLen = Cool Then mBitLen = 8
Case ALGO.TDES
If (mBitLen = 0) Or (Not mBitLen = 16) Or (Not mBitLen = 24) Then mBitLen = 24
Case ALGO.RIJNDAEL
If (mBitLen = 0) Or (Not mBitLen = 16) Or (Not mBitLen = 24) Or (Not mBitLen = 32) Then mBitLen = 32
Case ALGO.RC2
If (mBitLen < 5) Or (mBitLen > 16) Then mBitLen = 16
End Select
End Sub

'''
''' Diese Funktion verschlüsselt eine Datei und speichert es in eine andere Datei (HDD -> HDD)
'''
Public Overloads Function Encode(ByVal SourceFile As String, ByVal TargetFile As String, ByVal Password As String, ByVal Algorithm As ALGO, Optional ByVal BufferSize As Integer = 4096) As Boolean
Try
Dim InFileStream As New FileStream(SourceFile, FileMode.Open)
Dim OutFileStream As New FileStream(TargetFile, FileMode.Create)
Dim CryptStream As CryptoStream = Nothing

Dim Data(BufferSize - 1) As Byte
Dim Buffer As Long
Dim BufferCount As Long
Dim FileLen As Long = InFileStream.Length

Dim MakeKey As New Rfc2898DeriveBytes(Password, mKeySalt)
Dim MakeIV As New Rfc2898DeriveBytes(Password, mIVSalt)

'Prüfen ob die Bitstärke mit dem gewählten Algorithmus übereinstimmt und evtl. anpassen
CheckBitLen(Algorithm)

Select Case Algorithm
Case ALGO.DES
Dim DES As New DESCryptoServiceProvider
CryptStream = New CryptoStream(OutFileStream, DES.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write) '8
Case ALGO.TDES
Dim TDES As New TripleDESCryptoServiceProvider
CryptStream = New CryptoStream(OutFileStream, TDES.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write) '16,24
Case ALGO.RIJNDAEL
Dim RIJNDAEL As New RijndaelManaged
CryptStream = New CryptoStream(OutFileStream, RIJNDAEL.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write) '16,24,32
Case ALGO.RC2
Dim RC2 As New RC2CryptoServiceProvider
CryptStream = New CryptoStream(OutFileStream, RC2.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write) '5 bis 16
End Select

Do
If BufferCount >= FileLen - BufferSize Then
ReDim Data(FileLen - BufferCount)
Buffer = InFileStream.Read(Data, 0, FileLen - BufferCount)
CryptStream.Write(Data, 0, Buffer)
Exit Do
End If

Buffer = InFileStream.Read(Data, 0, BufferSize)
CryptStream.Write(Data, 0, BufferSize)
BufferCount += Buffer
Loop

InFileStream.Close()
CryptStream.Close()
OutFileStream.Close()
Return True
Catch ex As Exception
RaiseEvent ProgressError(Me, ex)
End Try
End Function

'''
''' Diese Funktion verschlüsselt ein ByteArray und speichert es in eine Datei (RAM -> HDD)
'''
Public Overloads Function Encode(ByRef SourceByte() As Byte, ByVal TargetFile As String, ByVal Password As String, ByVal Algorithm As ALGO, Optional ByVal BufferSize As Integer = 4096) As Boolean
Try
Dim InByteStream As New MemoryStream(SourceByte, False)
Dim OutFileStream As New FileStream(TargetFile, FileMode.Create)
Dim CryptStream As CryptoStream = Nothing

Dim Data(BufferSize - 1) As Byte
Dim Buffer As Long
Dim BufferCount As Long
Dim FileLen As Long = InByteStream.Length

Dim MakeKey As New Rfc2898DeriveBytes(Password, mKeySalt)
Dim MakeIV As New Rfc2898DeriveBytes(Password, mIVSalt)

'Prüfen ob die Bitstärke mit dem gewählten Algorithmus übereinstimmt und evtl. anpassen
CheckBitLen(Algorithm)

Select Case Algorithm
Case ALGO.DES
Dim DES As New DESCryptoServiceProvider
CryptStream = New CryptoStream(OutFileStream, DES.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
Case ALGO.TDES
Dim TDES As New TripleDESCryptoServiceProvider
CryptStream = New CryptoStream(OutFileStream, TDES.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
Case ALGO.RIJNDAEL
Dim RIJNDAEL As New RijndaelManaged
CryptStream = New CryptoStream(OutFileStream, RIJNDAEL.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
Case ALGO.RC2
Dim RC2 As New RC2CryptoServiceProvider
CryptStream = New CryptoStream(OutFileStream, RC2.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
End Select

Do
If BufferCount >= FileLen - BufferSize Then
ReDim Data(FileLen - BufferCount)
Buffer = InByteStream.Read(Data, 0, FileLen - BufferCount)
CryptStream.Write(Data, 0, Buffer)
Exit Do
End If

Buffer = InByteStream.Read(Data, 0, BufferSize)
CryptStream.Write(Data, 0, BufferSize)
BufferCount += Buffer
Loop

InByteStream.Close()
CryptStream.Close()
OutFileStream.Close()
Return True
Catch ex As Exception
RaiseEvent ProgressError(Me, ex)
End Try
End Function

'''
''' Diese Funktion verschlüsselt eine Datei und speichert es in ein ByteArray (HDD -> RAM)
'''
Public Overloads Function Encode(ByVal SourceFile As String, ByRef TargetByte() As Byte, ByVal Password As String, ByVal Algorithm As ALGO, Optional ByVal BufferSize As Integer = 4096) As Boolean
Try
Dim InFileStream As New FileStream(SourceFile, FileMode.Open)
Dim OutByteStream As New MemoryStream
Dim CryptStream As CryptoStream = Nothing

Dim Data(BufferSize - 1) As Byte
Dim Buffer As Long
Dim BufferCount As Long
Dim FileLen As Long = InFileStream.Length

Dim MakeKey As New Rfc2898DeriveBytes(Password, mKeySalt)
Dim MakeIV As New Rfc2898DeriveBytes(Password, mIVSalt)

'Prüfen ob die Bitstärke mit dem gewählten Algorithmus übereinstimmt und evtl. anpassen
CheckBitLen(Algorithm)

Select Case Algorithm
Case ALGO.DES
Dim DES As New DESCryptoServiceProvider
CryptStream = New CryptoStream(OutByteStream, DES.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
Case ALGO.TDES
Dim TDES As New TripleDESCryptoServiceProvider
CryptStream = New CryptoStream(OutByteStream, TDES.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
Case ALGO.RIJNDAEL
Dim RIJNDAEL As New RijndaelManaged
CryptStream = New CryptoStream(OutByteStream, RIJNDAEL.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
Case ALGO.RC2
Dim RC2 As New RC2CryptoServiceProvider
CryptStream = New CryptoStream(OutByteStream, RC2.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
End Select

Do
If BufferCount >= FileLen - BufferSize Then
ReDim Data(FileLen - BufferCount)
Buffer = InFileStream.Read(Data, 0, FileLen - BufferCount)
CryptStream.Write(Data, 0, Buffer)
Exit Do
End If

Buffer = InFileStream.Read(Data, 0, BufferSize)
CryptStream.Write(Data, 0, BufferSize)
BufferCount += Buffer
Loop

InFileStream.Close()
CryptStream.Close()
OutByteStream.Close()

TargetByte = OutByteStream.ToArray
Return True
Catch ex As Exception
RaiseEvent ProgressError(Me, ex)
End Try
End Function

'''
''' Diese Funktion verschlüsselt ein ByteArray und speichert es in ein anders ByteArray (RAM -> RAM)
'''
Public Overloads Function Encode(ByRef SourceByte() As Byte, ByRef TargetByte() As Byte, ByVal Password As String, ByVal Algorithm As ALGO, Optional ByVal BufferSize As Integer = 4096) As Boolean
Try
Dim InByteStream As New MemoryStream(SourceByte, False)
Dim OutByteStream As New MemoryStream
Dim CryptStream As CryptoStream = Nothing

Dim Data(BufferSize - 1) As Byte
Dim Buffer As Long
Dim BufferCount As Long
Dim FileLen As Long = InByteStream.Length

Dim MakeKey As New Rfc2898DeriveBytes(Password, mKeySalt)
Dim MakeIV As New Rfc2898DeriveBytes(Password, mIVSalt)

'Prüfen ob die Bitstärke mit dem gewählten Algorithmus übereinstimmt und evtl. anpassen
CheckBitLen(Algorithm)

Select Case Algorithm
Case ALGO.DES
Dim DES As New DESCryptoServiceProvider
CryptStream = New CryptoStream(OutByteStream, DES.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
Case ALGO.TDES
Dim TDES As New TripleDESCryptoServiceProvider
CryptStream = New CryptoStream(OutByteStream, TDES.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
Case ALGO.RIJNDAEL
Dim RIJNDAEL As New RijndaelManaged
CryptStream = New CryptoStream(OutByteStream, RIJNDAEL.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
Case ALGO.RC2
Dim RC2 As New RC2CryptoServiceProvider
CryptStream = New CryptoStream(OutByteStream, RC2.CreateEncryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Write)
End Select

Do
If BufferCount >= FileLen - BufferSize Then
ReDim Data(FileLen - BufferCount)
Buffer = InByteStream.Read(Data, 0, FileLen - BufferCount)
CryptStream.Write(Data, 0, Buffer)
Exit Do
End If

Buffer = InByteStream.Read(Data, 0, BufferSize)
CryptStream.Write(Data, 0, BufferSize)
BufferCount += Buffer
Loop

InByteStream.Close()
CryptStream.Close()
OutByteStream.Close()

TargetByte = OutByteStream.ToArray
Return True
Catch ex As Exception
RaiseEvent ProgressError(Me, ex)
End Try
End Function

'''
''' Diese Funktion entschlüsselt eine Datei und speichert es in eine andere Datei (HDD -> HDD)
'''
Public Overloads Function Decode(ByVal SourceFile As String, ByVal TargetFile As String, ByVal Password As String, ByVal Algorithm As ALGO, Optional ByVal BufferSize As Integer = 4096) As Boolean
Try
Dim InFileStream As New FileStream(SourceFile, FileMode.Open)
Dim OutFileStream As New FileStream(TargetFile, FileMode.Create)
Dim CryptStream As CryptoStream = Nothing

Dim Data(BufferSize - 1) As Byte
Dim Buffer As Long
Dim BufferCount As Long
Dim FileLen As Long = InFileStream.Length

Dim MakeKey As New Rfc2898DeriveBytes(Password, mKeySalt)
Dim MakeIV As New Rfc2898DeriveBytes(Password, mIVSalt)

'Prüfen ob die Bitstärke mit dem gewählten Algorithmus übereinstimmt und evtl. anpassen
CheckBitLen(Algorithm)

Select Case Algorithm
Case ALGO.DES
Dim DES As New DESCryptoServiceProvider
CryptStream = New CryptoStream(InFileStream, DES.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.TDES
Dim TDES As New TripleDESCryptoServiceProvider
CryptStream = New CryptoStream(InFileStream, TDES.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.RIJNDAEL
Dim RIJNDAEL As New RijndaelManaged
CryptStream = New CryptoStream(InFileStream, RIJNDAEL.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.RC2
Dim RC2 As New RC2CryptoServiceProvider
CryptStream = New CryptoStream(InFileStream, RC2.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
End Select

Do
If BufferCount >= FileLen - BufferSize Then
ReDim Data(FileLen - BufferCount)
Buffer = CryptStream.Read(Data, 0, FileLen - BufferCount)
OutFileStream.Write(Data, 0, Buffer)
Exit Do
End If

Buffer = CryptStream.Read(Data, 0, BufferSize)
OutFileStream.Write(Data, 0, BufferSize)
BufferCount += Buffer
Loop

OutFileStream.Close()
CryptStream.Close()
InFileStream.Close()
Return True
Catch ex As Exception
RaiseEvent ProgressError(Me, ex)
End Try
End Function

'''
''' Diese Funktion entschlüsselt ein ByteArray und speichert es in eine Datei (RAM -> HDD)
'''
Public Overloads Function Decode(ByRef SourceByte() As Byte, ByVal TargetFile As String, ByVal Password As String, ByVal Algorithm As ALGO, Optional ByVal BufferSize As Integer = 4096) As Boolean
Try
Dim InByteStream As New MemoryStream(SourceByte, False)
Dim OutFileStream As New FileStream(TargetFile, FileMode.Create)
Dim CryptStream As CryptoStream = Nothing

Dim Data(BufferSize - 1) As Byte
Dim Buffer As Long
Dim BufferCount As Long
Dim FileLen As Long = InByteStream.Length

Dim MakeKey As New Rfc2898DeriveBytes(Password, mKeySalt)
Dim MakeIV As New Rfc2898DeriveBytes(Password, mIVSalt)

'Prüfen ob die Bitstärke mit dem gewählten Algorithmus übereinstimmt und evtl. anpassen
CheckBitLen(Algorithm)

Select Case Algorithm
Case ALGO.DES
Dim DES As New DESCryptoServiceProvider
CryptStream = New CryptoStream(InByteStream, DES.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.TDES
Dim TDES As New TripleDESCryptoServiceProvider
CryptStream = New CryptoStream(InByteStream, TDES.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.RIJNDAEL
Dim RIJNDAEL As New RijndaelManaged
CryptStream = New CryptoStream(InByteStream, RIJNDAEL.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.RC2
Dim RC2 As New RC2CryptoServiceProvider
CryptStream = New CryptoStream(InByteStream, RC2.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
End Select

Do
If BufferCount >= FileLen - BufferSize Then
ReDim Data(FileLen - BufferCount)
Buffer = CryptStream.Read(Data, 0, FileLen - BufferCount)
OutFileStream.Write(Data, 0, Buffer)
Exit Do
End If

Buffer = CryptStream.Read(Data, 0, BufferSize)
OutFileStream.Write(Data, 0, BufferSize)
BufferCount += Buffer
Loop

OutFileStream.Close()
CryptStream.Close()
InByteStream.Close()
Return True
Catch ex As Exception
RaiseEvent ProgressError(Me, ex)
End Try
End Function

'''
''' Diese Funktion entschlüsselt eine Datei und speichert es in ein ByteArray (HDD -> RAM)
'''
Public Overloads Function Decode(ByVal SourceFile As String, ByRef TargetByte() As Byte, ByVal Password As String, ByVal Algorithm As ALGO, Optional ByVal BufferSize As Integer = 4096) As Boolean
Try
Dim InFileStream As New FileStream(SourceFile, FileMode.Open)
Dim OutByteStream As New MemoryStream
Dim CryptStream As CryptoStream = Nothing

Dim Data(BufferSize - 1) As Byte
Dim Buffer As Long
Dim BufferCount As Long
Dim FileLen As Long = InFileStream.Length

Dim MakeKey As New Rfc2898DeriveBytes(Password, mKeySalt)
Dim MakeIV As New Rfc2898DeriveBytes(Password, mIVSalt)

'Prüfen ob die Bitstärke mit dem gewählten Algorithmus übereinstimmt und evtl. anpassen
CheckBitLen(Algorithm)

Select Case Algorithm
Case ALGO.DES
Dim DES As New DESCryptoServiceProvider
CryptStream = New CryptoStream(InFileStream, DES.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.TDES
Dim TDES As New TripleDESCryptoServiceProvider
CryptStream = New CryptoStream(InFileStream, TDES.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.RIJNDAEL
Dim RIJNDAEL As New RijndaelManaged
CryptStream = New CryptoStream(InFileStream, RIJNDAEL.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.RC2
Dim RC2 As New RC2CryptoServiceProvider
CryptStream = New CryptoStream(InFileStream, RC2.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
End Select

Do
If BufferCount >= FileLen - BufferSize Then
ReDim Data(FileLen - BufferCount)
Buffer = CryptStream.Read(Data, 0, FileLen - BufferCount)
OutByteStream.Write(Data, 0, Buffer)
Exit Do
End If

Buffer = CryptStream.Read(Data, 0, BufferSize)
OutByteStream.Write(Data, 0, BufferSize)
BufferCount += Buffer
Loop

OutByteStream.Close()
CryptStream.Close()
InFileStream.Close()

TargetByte = OutByteStream.ToArray()
Return True
Catch ex As Exception
RaiseEvent ProgressError(Me, ex)
End Try
End Function

'''
''' Diese Funktion entschlüsselt ein ByteArray und speichert es in ein anders ByteArray (RAM -> RAM)
'''
Public Overloads Function Decode(ByRef SourceByte() As Byte, ByRef TargetByte() As Byte, ByVal Password As String, ByVal Algorithm As ALGO, Optional ByVal BufferSize As Integer = 4096) As Boolean
Try
Dim InByteStream As New MemoryStream(SourceByte, False)
Dim OutByteStream As New MemoryStream
Dim CryptStream As CryptoStream = Nothing

Dim Data(BufferSize - 1) As Byte
Dim Buffer As Long
Dim BufferCount As Long
Dim FileLen As Long = InByteStream.Length

Dim MakeKey As New Rfc2898DeriveBytes(Password, mKeySalt)
Dim MakeIV As New Rfc2898DeriveBytes(Password, mIVSalt)

'Prüfen ob die Bitstärke mit dem gewählten Algorithmus übereinstimmt und evtl. anpassen
CheckBitLen(Algorithm)

Select Case Algorithm
Case ALGO.DES
Dim DES As New DESCryptoServiceProvider
CryptStream = New CryptoStream(InByteStream, DES.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.TDES
Dim TDES As New TripleDESCryptoServiceProvider
CryptStream = New CryptoStream(InByteStream, TDES.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.RIJNDAEL
Dim RIJNDAEL As New RijndaelManaged
CryptStream = New CryptoStream(InByteStream, RIJNDAEL.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
Case ALGO.RC2
Dim RC2 As New RC2CryptoServiceProvider
CryptStream = New CryptoStream(InByteStream, RC2.CreateDecryptor(MakeKey.GetBytes(mBitLen), MakeIV.GetBytes(16)), CryptoStreamMode.Read)
End Select

Do
If BufferCount >= FileLen - BufferSize Then
ReDim Data(FileLen - BufferCount)
Buffer = CryptStream.Read(Data, 0, FileLen - BufferCount)
OutByteStream.Write(Data, 0, Buffer)
Exit Do
End If

Buffer = CryptStream.Read(Data, 0, BufferSize)
OutByteStream.Write(Data, 0, BufferSize)
BufferCount += Buffer
Loop

OutByteStream.Close()
CryptStream.Close()
InByteStream.Close()

TargetByte = OutByteStream.ToArray
Return True
Catch ex As Exception
RaiseEvent ProgressError(Me, ex)
End Try
End Function
End Class
[/code]

Quelle: dotnet-snippets.de
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Tags: visual basic, verschlüsselung, verschlüsseln, algorithmus, filelen

  
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