VB.net Base64 + 异或

Question

所以我想做一个函数，可以加密和解密到Base64，然后用密钥对其进行异或。

到目前为止，这是我的代码：

    Imports System.Text

   Module Module1

    Private key As String = "37526"


    Sub Main()
        Dim test As String = Console.ReadLine
        test = Decrypt(test)
        Console.WriteLine(test)
        Main()

    End Sub

    Public Function Decrypt(CipherText As String) As String

        Dim decoded = Convert.FromBase64String(CipherText)
        Dim dexored = [xor](decoded, key)
        Return Encoding.UTF8.GetString(dexored)

    End Function

    Private Function [xor](text As Byte(), key As String) As Byte()
        Dim res As Byte() = New Byte(text.Length - 1) {}
        For c As Integer = 0 To text.Length - 1
            res(c) = CByte((text(c)) Xor CUInt(Val(c Mod key.Length)))
        Next

        Return res
    End Function


    Public Function Encrypt(Plaintext As String)

        Dim encoded = Encoding.UTF8.GetBytes(Plaintext)
        Dim xored = [xor](encoded, key)
        Return Convert.ToBase64String(xored)

    End Function

End Module

所以这是我的问题：这段代码工作正常，但我正在尝试解密这个字符串 "X1hZXVoCBQY="，该字符串的解密应该是 "lolol123"。不知道是我的代码错了，还是密钥不对。有人可以检查我的代码或给我正确的密钥吗？我试图暴力破解密钥，但这对我来说没有用。如果我尝试解密我没有得到 "lolol123" 的字符串，我会得到“_Y[^^”

Answer 1

xor函数出错了。尝试在一行中做太多事情会使它变得过于复杂，无法立即看到发生了什么，所以我开始重写它，更多地按照我本来应该做的方式进行，并且在我开始查看任何东西之前快速检查表明它可以正常工作否则：

Option Infer On
Option Strict On
' ...
Private Function [xor](text As Byte(), key As String) As Byte()
    Dim res As Byte() = New Byte(text.Length - 1) {}
    Dim keyBytes = Encoding.UTF8.GetBytes(key)

    For c = 0 To text.Length - 1
        res(c) = CByte((text(c)) Xor keyBytes(c Mod keyBytes.Length))
    Next

    Return res

End Function

VB.net Base64 + 异或

VB.net Base64 + XOR

vb.net

encryption

base64

xor