Question

我已经在vb.net中编写了一个类来加密/解密文件，但是当我解密像图像或拉链或办公文件这样的文件时，它们看起来已经损坏了。但如果我在记事本中打开解密的原始文件，它们就完全一样了。我能做些什么来阻止这个？

Imports System
Imports System.IO
Imports System.Security
Imports System.Security.Cryptography
Imports System.Text

Public Class Encrytion
Shared 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()

    DES.Key = ASCIIEncoding.ASCII.GetBytes(sKey)

    DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey)

    Dim desencrypt As ICryptoTransform = DES.CreateEncryptor()

    Dim cryptostream As New CryptoStream(fsEncrypted, _
                                        desencrypt, _
                                        CryptoStreamMode.Write)


    Dim bytearrayinput(fsInput.Length - 1) As Byte
    fsInput.Read(bytearrayinput, 0, bytearrayinput.Length)

    cryptostream.Write(bytearrayinput, 0, bytearrayinput.Length)
    cryptostream.Close()
End Sub

Shared 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)

    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)

    Dim fsDecrypted As New StreamWriter(sOutputFilename)
    fsDecrypted.Write(New StreamReader(cryptostreamDecr).ReadToEnd)
    fsDecrypted.Flush()
    fsDecrypted.Close()
End Sub

End Class

Answer 1

我找到this answer来解决这个问题。简而言之，在CreateEncryptor / CreateDecryptor调用之外，加密和解密功能应该完全相同：

Shared 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()

    DES.Key = ASCIIEncoding.ASCII.GetBytes(sKey)

    DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey)

    Dim desencrypt As ICryptoTransform = DES.CreateEncryptor(DES.Key, DES.IV)

    Dim cryptostream As New CryptoStream(fsEncrypted, _
                                        desencrypt, _
                                        CryptoStreamMode.Write)


    Dim bytearrayinput(fsInput.Length - 1) As Byte
    fsInput.Read(bytearrayinput, 0, bytearrayinput.Length)

    cryptostream.Write(bytearrayinput, 0, bytearrayinput.Length)
    cryptostream.Flush()

    cryptostream.Close()
End Sub

Shared Sub DecryptFile(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()

    DES.Key = ASCIIEncoding.ASCII.GetBytes(sKey)

    DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey)

    Dim desencrypt As ICryptoTransform = DES.CreateDecryptor(DES.Key, DES.IV)

    Dim cryptostream As New CryptoStream(fsEncrypted, _
                                        desencrypt, _
                                        CryptoStreamMode.Write)


    Dim bytearrayinput(fsInput.Length - 1) As Byte
    fsInput.Read(bytearrayinput, 0, bytearrayinput.Length)

    cryptostream.Write(bytearrayinput, 0, bytearrayinput.Length)
    cryptostream.Flush()

    cryptostream.Close()
End Sub

des文件加密损坏的文件

1 个答案: