73 lines
2.7 KiB
VB.net
73 lines
2.7 KiB
VB.net
Imports System.Security.Cryptography
|
|
Public Class clsEncryption
|
|
Private TripleDes As New TripleDESCryptoServiceProvider
|
|
Sub New(ByVal key As String)
|
|
' Initialize the crypto provider.
|
|
TripleDes.Key = TruncateHash(key, TripleDes.KeySize \ 8)
|
|
TripleDes.IV = TruncateHash("", TripleDes.BlockSize \ 8)
|
|
End Sub
|
|
|
|
Private Function TruncateHash(
|
|
ByVal key As String,
|
|
ByVal length As Integer) As Byte()
|
|
|
|
Dim sha1 As New SHA1CryptoServiceProvider
|
|
|
|
' Hash the key.
|
|
Dim keyBytes() As Byte =
|
|
System.Text.Encoding.Unicode.GetBytes(key)
|
|
Dim hash() As Byte = sha1.ComputeHash(keyBytes)
|
|
|
|
' Truncate or pad the hash.
|
|
ReDim Preserve hash(length - 1)
|
|
Return hash
|
|
End Function
|
|
Public Function EncryptData(
|
|
ByVal plaintext As String) As String
|
|
|
|
' Convert the plaintext string to a byte array.
|
|
Dim plaintextBytes() As Byte =
|
|
System.Text.Encoding.Unicode.GetBytes("!Didalog35452Heuchelheim=" & plaintext)
|
|
|
|
' Create the stream.
|
|
Dim ms As New System.IO.MemoryStream
|
|
' Create the encoder to write to the stream.
|
|
Dim encStream As New CryptoStream(ms,
|
|
TripleDes.CreateEncryptor(),
|
|
System.Security.Cryptography.CryptoStreamMode.Write)
|
|
|
|
' Use the crypto stream to write the byte array to the stream.
|
|
encStream.Write(plaintextBytes, 0, plaintextBytes.Length)
|
|
encStream.FlushFinalBlock()
|
|
|
|
' Convert the encrypted stream to a printable string.
|
|
Return Convert.ToBase64String(ms.ToArray)
|
|
End Function
|
|
'Entschlüsselt die Zeichenfolge
|
|
Public Function DecryptData(
|
|
ByVal encryptedtext As String) As String
|
|
Try
|
|
' Convert the encrypted text string to a byte array.
|
|
Dim encryptedBytes() As Byte = Convert.FromBase64String(encryptedtext)
|
|
|
|
' Create the stream.
|
|
Dim ms As New System.IO.MemoryStream
|
|
' Create the decoder to write to the stream.
|
|
Dim decStream As New CryptoStream(ms,
|
|
TripleDes.CreateDecryptor(),
|
|
System.Security.Cryptography.CryptoStreamMode.Write)
|
|
|
|
' Use the crypto stream to write the byte array to the stream.
|
|
decStream.Write(encryptedBytes, 0, encryptedBytes.Length)
|
|
decStream.FlushFinalBlock()
|
|
Dim result = System.Text.Encoding.Unicode.GetString(ms.ToArray)
|
|
result = result.Replace("!Didalog35452Heuchelheim=", "")
|
|
' Convert the plaintext stream to a string.
|
|
Return result
|
|
Catch ex As Exception
|
|
Return Nothing
|
|
End Try
|
|
|
|
End Function
|
|
End Class
|