Originariamente inviata da
cavaliere123
Buona sera a tutti
Sto iniziando ad usare Visual Basic 2010 express per piccoli programmini
Vado subito al dunque, essendo neofita del visual basic sto imparando tutto ex novo chiaramente.
Ho visto vari tutorial per criptare del testo e anche questo sito :
http://msdn.microsoft.com/it-it/library/ms172831.aspx
ed ho scelto di seguire tale procedura descritta.
Bene ed allora ecco il codice che ho fatto :
codice:
Imports System.Security.Cryptography
Public Class Class1
Public NotInheritable Class Simple3Des
Private TripleDes As New TripleDESCryptoServiceProvider
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
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
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(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
Public Function DecryptData(
ByVal encryptedtext As String) As String
' 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()
' Convert the plaintext stream to a string.
Return System.Text.Encoding.Unicode.GetString(ms.ToArray)
End Function
End Class
End Class
messo in un modulo classe e poi in un modulo normale :
codice:
Imports prova_pass.Class1
Module Module1
Public risultato As String
Private Property plainText As String
Sub TestEncoding(ByVal scrittura As String)
Dim wrapper As New Simple3Des(scrittura)
Dim cipherText As String = wrapper.EncryptData(scrittura)
risultato = cipherText
End Sub
Sub TestDecoding(ByVal riga As String)
Dim cipherText As String = riga
Dim wrapper As New Simple3Des(riga)
' DecryptData throws if the wrong password is used.
Try
Dim plainText As String = wrapper.DecryptData(cipherText)
MsgBox("The plain text is: " & plainText)
Catch ex As System.Security.Cryptography.CryptographicException
MsgBox("The data could not be decrypted with the password.")
End Try
End Sub
End Module
Nel form invece per la codifica ho scritto e funziona benissimo:
codice:
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim scrivi As System.IO.StreamWriter
Dim scrittura As String
My.Settings.pass = TextBox2.Text
My.Settings.Save()
My.Settings.Reload()
TextBox2.Visible = False
Button2.Visible = False
scrittura = My.Settings.pass
Call TestEncoding(scrittura)
scrivi = IO.File.CreateText("C:\Users\admin\Desktop\ESEMPI VISUAL BASIC\prova pass\prova.text")
scrivi.WriteLine(risultato)
scrivi.Close()
End Sub
e poi per la decodifica invece :
codice:
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim leggi As System.IO.StreamReader
Dim riga As String
leggi = IO.File.OpenText("C:\Users\admin\Desktop\ESEMPI VISUAL BASIC\prova pass\prova.text")
While (leggi.EndOfStream) 'leggi.Peek <> -1
riga = leggi.ReadLine()
End While
leggi.Close()
Call TestDecoding(riga)
MsgBox(risultato)
End Sub
End Class
che invece quest'ultima procedura non mi funziona, mi esce il messaggio della routine TestDecoding che dice : MsgBox("The data could not be decrypted with the password.")
dove sbaglio ??
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