Imports System
Imports System.IO
Imports System.Security
Imports System.Security.Cryptography
Imports System.Text
Module Encrypt
Private Const sSecretKey As String = "password"
Public Sub Main()
EncryptFile("c:\temp\test.txt", _
"c:\temp\Encrypted.txt", _
sSecretKey)
DecryptFile("c:\temp\Encrypted.txt", _
"c:\temp\Decrypted.txt", _
sSecretKey)
End Sub
Sub EncryptFile(ByVal sInputFilename As String, _
ByVal sOutputFilename As String, _
ByVal sKey As String)
Dim fsInput As New FileStream(sInputFilename, _
FileMode.Open, FileAccess.Read)
Dim fsEncrypted As New FileStream(sOutputFilename, _
FileMode.Create, FileAccess.Write)
Dim DES As New DESCryptoServiceProvider()
'为DES算法设置安全码.
'必须是64位,8个字节
DES.Key = ASCIIEncoding.ASCII.GetBytes(sKey)
DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey)
'创建DES加密码实例
Dim desencrypt As ICryptoTransform = DES.CreateEncryptor()
'
Dim cryptostream As New CryptoStream(fsEncrypted, _
desencrypt, _
CryptoStreamMode.Write)
'读取文件到数组
Dim bytearrayinput(fsInput.Length - 1) As Byte
fsInput.Read(bytearrayinput, 0, bytearrayinput.Length)
'写到加密文件中
cryptostream.Write(bytearrayinput, 0, bytearrayinput.Length)
cryptostream.Close()
End Sub
Sub DecryptFile(ByVal sInputFilename As String, _
ByVal sOutputFilename As String, _
ByVal sKey As String)
Dim DES As New DESCryptoServiceProvider()
DES.Key() = ASCIIEncoding.ASCII.GetBytes(sKey)
DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey)
'读取加密文件
Dim fsread As New FileStream(sInputFilename, FileMode.Open, FileAccess.Read)
'
Dim desdecrypt As ICryptoTransform = DES.CreateDecryptor()
'
Dim cryptostreamDecr As New CryptoStream(fsread, desdecrypt, CryptoStreamMode.Read)
'输出到解密文件
Dim fsDecrypted As New StreamWriter(sOutputFilename)
fsDecrypted.Write(New StreamReader(cryptostreamDecr).ReadToEnd)
fsDecrypted.Flush()
fsDecrypted.Close()
End Sub
End Module