在VB.Net中进行简单的加密/解密

Question

我试图找出如何在VB.Net中加密/解密字符串.

我按照这里给出的例子编写了下面的代码(如下).有一个文本框,一个"加密"按钮和一个"解密"按钮.想法是在文本框中键入内容("喜欢'hello world'"),单击"加密",然后在文本框中看到加密版本.单击"解密"应该会将您带回原始字符串.

但是当我尝试加密时,当我尝试"FlushFinalBlock"时出现错误.错误是:"要加密的数据长度无效".

"解密"部分是黑暗中的总镜头,因为上面引用的示例仅涉及加密,而不是解密.我确定这是错的,但由于我无法"加密"工作,我还没有测试过.

谁能告诉我为什么这不起作用？

Imports System.Data.SqlClient
Imports System.IO
Imports System.Security.Cryptography

Public Class Form1

  Private cryptObj As RijndaelManaged
  Private KEY_128 As Byte() = {42, 1, 52, 67, 231, 13, 94, 101, 123, 6, 0, 12, 32, 91, 4, 111, 31, 70, 21, 141, 123, 142, 234, 82, 95, 129, 187, 162, 12, 55, 98, 23}
  Private IV_128 As Byte() = {234, 12, 52, 44, 214, 222, 200, 109, 2, 98, 45, 76, 88, 53, 23, 78}
  Private enc As System.Text.UTF8Encoding = New System.Text.UTF8Encoding()

  Private Sub btnEncrypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEncrypt.Click
    Dim sPlainText As String = Me.TextBox1.Text
    If Not String.IsNullOrEmpty(sPlainText) Then
      Dim bPlainText As Byte() = Me.enc.GetBytes(Me.TextBox1.Text)
      Dim ms As MemoryStream = New MemoryStream()
      Dim cs As CryptoStream = New CryptoStream(ms, cryptObj.CreateEncryptor(), CryptoStreamMode.Write)
      cs.Write(bPlainText, 0, sPlainText.Length)
      cs.FlushFinalBlock()
      Me.TextBox1.Text = Me.enc.GetString(ms.ToArray())
    End If
  End Sub

  Private Sub btnDecrypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDecrypt.Click
    Dim sCipherText = Me.TextBox1.Text
    Dim ms As MemoryStream = New MemoryStream()
    Dim cs As CryptoStream = New CryptoStream(ms, cryptObj.CreateDecryptor(), CryptoStreamMode.Read)
    cs.Read(Me.enc.GetBytes(sCipherText), 0, sCipherText.Length)
    Me.TextBox1.Text = Me.enc.GetString(ms.ToArray())
  End Sub

  Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    Me.cryptObj = New RijndaelManaged()
    Me.cryptObj.BlockSize = 128
    Me.cryptObj.KeySize = 128
    Me.cryptObj.Mode = CipherMode.ECB
    Me.cryptObj.Padding = PaddingMode.None
    Me.cryptObj.Key = KEY_128
    Me.cryptObj.IV = IV_128
  End Sub

End Class

Answer 1

最终我找到了答案:

http://www.obviex.com/samples/Encryption.aspx

他的例子似乎有点过于复杂.我敢肯定它代表了一个更通用和灵活的情况,但我能够取消"saltPhrase","initVector"和"PasswordDeriveBytes"的使用,显然已被弃用了,但我也避免了它被命名为替换:Rfc2898DeriveBytes.

以下内容允许您输入任意长度的字符串,对其进行加密并重新解密.

Imports System.Data.SqlClient
Imports System.IO
Imports System.Security.Cryptography

Public Class Form1

  Private enc As System.Text.UTF8Encoding
  Private encryptor As ICryptoTransform
  Private decryptor As ICryptoTransform

  Private Sub btnEncrypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnEncrypt.Click
    Dim sPlainText As String = Me.TextBox1.Text
    If Not String.IsNullOrEmpty(sPlainText) Then
      Dim memoryStream As MemoryStream = New MemoryStream()
      Dim cryptoStream As CryptoStream = New CryptoStream(memoryStream, Me.encryptor, CryptoStreamMode.Write)
      cryptoStream.Write(Me.enc.GetBytes(sPlainText), 0, sPlainText.Length)
      cryptoStream.FlushFinalBlock()
      Me.TextBox1.Text = Convert.ToBase64String(memoryStream.ToArray())
      memoryStream.Close()
      cryptoStream.Close()
    End If
  End Sub

  Private Sub btnDecrypt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDecrypt.Click
    Dim cypherTextBytes As Byte() = Convert.FromBase64String(Me.TextBox1.Text)
    Dim memoryStream As MemoryStream = New MemoryStream(cypherTextBytes)
    Dim cryptoStream As CryptoStream = New CryptoStream(memoryStream, Me.decryptor, CryptoStreamMode.Read)
    Dim plainTextBytes(cypherTextBytes.Length) As Byte
    Dim decryptedByteCount As Integer = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length)
    memoryStream.Close()
    cryptoStream.Close()
    Me.TextBox1.Text = Me.enc.GetString(plainTextBytes, 0, decryptedByteCount)
  End Sub

  Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    Dim KEY_128 As Byte() = {42, 1, 52, 67, 231, 13, 94, 101, 123, 6, 0, 12, 32, 91, 4, 111, 31, 70, 21, 141, 123, 142, 234, 82, 95, 129, 187, 162, 12, 55, 98, 23}
    Dim IV_128 As Byte() = {234, 12, 52, 44, 214, 222, 200, 109, 2, 98, 45, 76, 88, 53, 23, 78}
    Dim symmetricKey As RijndaelManaged = New RijndaelManaged()
    symmetricKey.Mode = CipherMode.CBC

    Me.enc = New System.Text.UTF8Encoding
    Me.encryptor = symmetricKey.CreateEncryptor(KEY_128, IV_128)
    Me.decryptor = symmetricKey.CreateDecryptor(KEY_128, IV_128)
  End Sub

End Class

Answer 2

这是基于我的NextLevelEncryption库的加密类的示例。

Public Class Encryption
''' <summary>
''' Encrypt text using AES Algorithm
''' </summary>
''' <param name="text">Text to encrypt</param>
''' <param name="password">Password with which to encrypt</param>
''' <returns>Returns encrypted text</returns>
''' <remarks></remarks>
Public Shared Function Encrypt(text As String, password As String) As String
    Dim AES As New System.Security.Cryptography.RijndaelManaged
    Dim Hash_AES As New System.Security.Cryptography.MD5CryptoServiceProvider
    Dim encrypted As String = ""
    Dim hash(31) As Byte
        Dim temp As Byte() = Hash_AES.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(password))
        Array.Copy(temp, 0, hash, 0, 16)
        Array.Copy(temp, 0, hash, 15, 16)
        AES.Key = hash
        AES.Mode = Security.Cryptography.CipherMode.ECB
        Dim DESEncrypter As System.Security.Cryptography.ICryptoTransform = AES.CreateEncryptor
        Dim Buffer As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(text)
        encrypted = Convert.ToBase64String(DESEncrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
        Return encrypted
End Function

''' <summary>
''' Decrypt text using AES Algorithm
''' </summary>
''' <param name="text">Text to decrypt</param>
''' <param name="password">Password with which to decrypt</param>
''' <returns>Returns decrypted text</returns>
''' <remarks></remarks>
Public Shared Function Decrypt(text As String, password As String) As String
    Dim AES As New System.Security.Cryptography.RijndaelManaged
    Dim Hash_AES As New System.Security.Cryptography.MD5CryptoServiceProvider
    Dim decrypted As String = ""
    Dim hash(31) As Byte
        Dim temp As Byte() = Hash_AES.ComputeHash(System.Text.ASCIIEncoding.ASCII.GetBytes(password))
        Array.Copy(temp, 0, hash, 0, 16)
        Array.Copy(temp, 0, hash, 15, 16)
        AES.Key = hash
        AES.Mode = Security.Cryptography.CipherMode.ECB
        Dim DESDecrypter As System.Security.Cryptography.ICryptoTransform = AES.CreateDecryptor
        Dim Buffer As Byte() = Convert.FromBase64String(text)
        decrypted = System.Text.ASCIIEncoding.ASCII.GetString(DESDecrypter.TransformFinalBlock(Buffer, 0, Buffer.Length))
    Return decrypted
End Function
End Class

要使用它，您所要做的就是调用函数Encrypt("Your text to encrypt here","Your password")和Decrypt(""Your text to encrypt here","Your password")。

欲了解更多信息，请访问https://nextlevelencryption.codeplex.com/