我使用这些代码加密 vb2008 中的任何纯文本。
我想在我的 android 应用程序中解密并使用生成的文件。我知道将文件放在资产文件夹中并使用它。
此代码使用 Cryptography 进行加密。我如何在我的 android 应用程序中解密生成的文件。以及我如何在我的 android 应用程序中使用它们。任何想法?
Imports System.Security.Cryptography
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
在我的表单课中
Sub TestEncoding()
Dim plainText As String = InputBox("Enter the plain text:")
Dim password As String = InputBox("Enter the password:")
Dim wrapper As New Simple3Des(password)
Dim cipherText As String = wrapper.EncryptData(plainText)
MsgBox("The cipher text is: " & cipherText)
My.Computer.FileSystem.WriteAllText(My.Computer.FileSystem.SpecialDirectories.Desktop & "\cipherText.txt", cipherText, False)
End Sub