mH_p0rtal
Well-known member
hi
in this little paper we wanna use symmetric encryption. this type of encryption will be divided into 2 parts : stream cipher , block cipher
some of symmetric famous algorithms are : Twofish, Serpent, AES (Rijndael), Blowfish, CAST5, RC4, TDES,IDEA
so for doing this job , we need these stuffs :
one textbox - 3 buttons - & an open file dialog
for the first button we use this code :
i think that this part is easy to understand for all guys,
lets move to further step
this button will encrypt your plain text file & it will save it as .enc extension
we use two major task in this button , first reading plain text by our traditional way & then we use of an instantiated object to encrypt our bytes by DESCryptoServiceProvider
this time we used CreateDecryptor() to read & decrypt encrypted text & write it on a file by Streamwriter
except streamreader & Writer , we used another Stream that is CryptoStream
, for the first time CryptoStream mode is write & in the second time , its on Read mode , actually we use it when we wanna work with cipher streams
have a nice coding
in this little paper we wanna use symmetric encryption. this type of encryption will be divided into 2 parts : stream cipher , block cipher
some of symmetric famous algorithms are : Twofish, Serpent, AES (Rijndael), Blowfish, CAST5, RC4, TDES,IDEA
so for doing this job , we need these stuffs :
one textbox - 3 buttons - & an open file dialog
for the first button we use this code :
VB.NET:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
OpenFileDialog1.ShowDialog()
textbox1.Text = OpenFileDialog1.FileName
End Sub
lets move to further step
VB.NET:
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim encFile As String = textbox1.Text + ".enc"
Dim fs As FileStream = New FileStream(encFile, _
FileMode.Create, FileAccess.Write)
Dim ir As Math
Dim sr As StreamReader = New _
StreamReader(textbox1.Text)
Dim strinput As String = (sr).ReadToEnd()
sr.Close()
Dim bytearrayinput() As Byte = _
Encoding.Default.GetBytes(strinput)
des = New DESCryptoServiceProvider
Dim desencrypt As ICryptoTransform = _
des.CreateEncryptor()
Dim CryptoStream As CryptoStream = _
New CryptoStream(fs, desencrypt, _
CryptoStreamMode.Write)
CryptoStream.Write(bytearrayinput, 0, _
bytearrayinput.Length)
CryptoStream.Close()
fs.Close()
MessageBox.Show("encrypted :p")
End Sub
we use two major task in this button , first reading plain text by our traditional way & then we use of an instantiated object to encrypt our bytes by DESCryptoServiceProvider
VB.NET:
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim fsread As FileStream = _
New FileStream(textbox1.Text, _
FileMode.Open, FileAccess.Read)
Dim desdecrypt As ICryptoTransform = _
des.CreateDecryptor()
Dim cryptostreamDecr As CryptoStream = _
New CryptoStream(fsread, _
desdecrypt, CryptoStreamMode.Read)
Dim decryptedFile As String = New _
StreamReader(cryptostreamDecr).ReadToEnd()
Dim fi As FileInfo = New FileInfo(textbox1.Text)
Dim origionalFile As String = _
textbox1.Text.Substring(0, textbox1.Text.Length _
- fi.Extension.Length)
Dim fileWriter As StreamWriter = New _
StreamWriter(origionalFile)
fileWriter.Write(decryptedFile)
fileWriter.Close()
MessageBox.Show("decrypted :D")
End Sub
except streamreader & Writer , we used another Stream that is CryptoStream
, for the first time CryptoStream mode is write & in the second time , its on Read mode , actually we use it when we wanna work with cipher streams
have a nice coding