【VB.Net】使用SHA256进行简单的XOR文本加密与解密

Imports System.Security.Cryptography
Namespace Runplus.Utils.Encoder
'************************************************
'* https://www.runplus.studio/Utils/Encoder '* Likun@Runplus.cn
'************************************************
Module XOREncoder
Sub Main()
'示例代码
Dim Ret As String = "" '定义返回参数，以传址方式传入

If Encoder("Hello World!", "12345abcde", Ret) Then
Console.WriteLine(Ret)
Else
Console.WriteLine(Ret)
End If
If Decoder(Ret, "12345abcde", Ret) Then
Console.WriteLine(Ret)
Else
Console.WriteLine(Ret)
End If

Console.ReadLine()

End Sub
Public Function Encoder(Source As String, Key As String, ByRef Ret As String) As Boolean
Try
If Source.Length = 0 Or Key.Length = 0 Then
Ret = "明文或私钥为空，不能进行加密。"
Return False
Else
Dim ArrKey() As Byte = MakeKey(Key)
Dim ArrSource() As Byte = Text.Encoding.UTF8.GetBytes(Source)
For i As Integer = 0 To ArrSource.Length - 1 Step 32
For j As Integer = 0 To 31 Step 1
If i + j = ArrSource.Length Then
Exit For
Else
ArrSource(i + j) = ArrSource(i + j) Xor ArrKey(j)
End If
Next
Next
Ret = ConvertToBase64(ArrSource)
Return True
End If
Catch ex As Exception
Ret = ex.Message
Return False
End Try
End Function

Public Function Decoder(Source As String, key As String, ByRef Ret As String) As Boolean
Try
If Source.Length = 0 Or key.Length = 0 Then
Ret = "明文或私钥为空，不能进行加密。"
Return False
Else
Dim ArrKey() As Byte = MakeKey(key)
Dim ArrSource() As Byte = ConvertFromBase64(Source)
For i As Integer = 0 To ArrSource.Length - 1 Step 32
For j As Integer = 0 To 31 Step 1
If i + j = ArrSource.Length Then
Exit For
Else
ArrSource(i + j) = ArrSource(i + j) Xor ArrKey(j)
End If
Next
Next
Ret = Text.Encoding.UTF8.GetString(ArrSource)
Return True
End If
Catch ex As Exception
Ret = ex.Message
Return False
End Try
End Function
Private Function MakeKey(ByRef Key As String) As Byte()
If Key.Length = 0 Then
Return Nothing
Else
Return SHA256(Text.Encoding.UTF8.GetBytes(Key))
End If
End Function

Private Function SHA256(Source As Byte()) As Byte()
If Source.Length = 0 Then
Return Nothing
Else
Dim shaM As New SHA256Managed
Return shaM.ComputeHash(Source)
End If
End Function
Private Function ConvertToBase64(Source As Byte()) As String
If Source.Length = 0 Then
Return Nothing
Else
Return Convert.ToBase64String(Source).Replace("+", "*").Replace("/", "!")
End If
End Function
Private Function ConvertFromBase64(Source As String) As Byte()
If Source.Length = 0 Then
Return Nothing
Else
Return Convert.FromBase64String(Source.Replace("*", "+").Replace("!", "/"))
End If
End Function
End Module
End Namespace