Question

如果可以使用Excel Visual Basic和某些加密服务提供商进行字符串加密/解密，我感兴趣。

我找到了一个演练Encrypting and Decrypting Strings in Visual Basic，但它似乎只适用于独立的Visual Basic。

那么您是否会建议我使用另一种加密方法或显示如何为Excel Visual Basic采用演练？

Answer 1

您提供的链接显示了如何使用VB.NET执行字符串加密和解密，从而使用.NET Framework。

目前，Microsoft Office产品尚未使用Visual Studio Tools for Applications组件，这将使Office产品能够访问.NET框架的BCL（基类库），而BCL又访问基础Windows CSP（加密服务器提供商）并为这些加密/解密功能提供了一个很好的包装。

目前，Office产品仍然使用旧的VBA（Visual Basic for Applications），它基于基于COM的旧版VB6（和更早版本），而不是.NET Framework

由于所有这些，你需要调用Win32 API来访问CSP函数，或者你必须在纯VB6 / VBA代码中“自己动手”加密方法，尽管这是可能不太安全。这完全取决于您希望加密的“安全性”。

如果您想“自己动手”基本字符串加密/解密例程，请查看以下链接以开始使用：

Encrypt a String Easily
Better XOR Encryption with a readable string
vb6 - encryption function
Visual Basic 6 / VBA String Encryption/Decryption Function

如果要访问Win32 API并使用基础Windows CSP（更安全的选项），请参阅以下链接以获取有关如何实现此目的的详细信息：

How to encrypt a string in Visual Basic 6.0
Access to CryptEncrypt (CryptoAPI/WinAPI) functions in VBA

最后一个链接很可能是您想要的链接，并包含一个完整的VBA类模块来“包装”Windows CSP功能。

Answer 2

创建一个名为clsCifrado的类模块：

Option Explicit
Option Compare Binary

Private clsClave As String

Property Get Clave() As String
    Clave = clsClave
End Property

Property Let Clave(value As String)
    clsClave = value
End Property


Function Cifrar(Frase As String) As String

    Dim Cachos() As Byte
    Dim LaClave() As Byte
    Dim i As Integer
    Dim Largo As Integer

    If Frase <> "" Then
        Cachos() = StrConv(Frase, vbFromUnicode)
        LaClave() = StrConv(clsClave, vbFromUnicode)
        Largo = Len(clsClave)

        For i = LBound(Cachos) To UBound(Cachos)
            Cachos(i) = (Cachos(i) Xor LaClave(i Mod Largo)) + 34
        Next i

        Cifrar = StrConv(Cachos(), vbUnicode)
    Else
        Cifrar = ""
    End If

End Function

Function Descifrar(Frase As String) As String

    Dim Cachos() As Byte
    Dim LaClave() As Byte
    Dim i As Integer
    Dim Largo As Integer

    If Frase <> "" Then
        Cachos() = StrConv(Frase, vbFromUnicode)
        LaClave() = StrConv(clsClave, vbFromUnicode)
        Largo = Len(clsClave)

        For i = LBound(Cachos) To UBound(Cachos)
            Cachos(i) = Cachos(i) - 34
            Cachos(i) = (Cachos(i) Xor LaClave(i Mod Largo))
        Next i

        Descifrar = StrConv(Cachos(), vbUnicode)
    Else
        Descifrar = ""
    End If

End Function

现在您可以在代码中使用它：

加密

Private Sub btnCifrar_Click()

    Dim Texto As String
    Dim cCifrado As clsCifrado

    Set cCifrado = New clsCifrado

    '---poner la contraseña
    If tbxClave.Text = "" Then
        MsgBox "The Password is missing"
        End Sub
    Else
        cCifrado.Clave = tbxClave.Text
    End If

    '---Sacar los datos
    Texto = tbxFrase.Text

    '---cifrar el texto
    Texto = cCifrado.Cifrar(Texto)

    tbxFrase.Text = Texto

 End Sub

要解读

Private Sub btnDescifrar_Click()

    Dim Texto As String
    Dim cCifrado As clsCifrado

    Set cCifrado = New clsCifrado

    '---poner la contraseña
    If tbxClave.Text = "" Then
        MsgBox "The Password is missing"
        End Sub
    Else
        cCifrado.Clave = tbxClave.Text
    End If

    '---Sacar los datos
    Texto = tbxFrase.Text

    '---cifrar el texto
    Texto = cCifrado.Descifrar(Texto)

    tbxFrase.Text = Texto
End Sub

Answer 3

这是一个基本的对称加密/解密示例：

Sub testit()
    Dim inputStr As String
    inputStr = "Hello world!"

    Dim encrypted As String, decrypted As String
    encrypted = scramble(inputStr)
    decrypted = scramble(encrypted)
    Debug.Print encrypted
    Debug.Print decrypted
End Sub


Function stringToByteArray(str As String) As Variant
    Dim bytes() As Byte
    bytes = str
    stringToByteArray = bytes
End Function

Function byteArrayToString(bytes() As Byte) As String
    Dim str As String
    str = bytes
    byteArrayToString = str
End Function


Function scramble(str As String) As String
    Const SECRET_PASSWORD As String = "K*4HD%f#nwS%sdf032#gfl!HLKN*pq7"

    Dim stringBytes() As Byte, passwordBytes() As Byte
    stringBytes = stringToByteArray(str)
    passwordBytes = stringToByteArray(SECRET_PASSWORD)

    Dim upperLim As Long
    upperLim = UBound(stringBytes)
    ReDim scrambledBytes(0 To upperLim) As Byte
    Dim idx As Long
    For idx = LBound(stringBytes) To upperLim
        scrambledBytes(idx) = stringBytes(idx) Xor passwordBytes(idx)
    Next idx
    scramble = byteArrayToString(scrambledBytes)
End Function

请注意，如果给定的输入字符串长于SECRET_PASSWORD，则会崩溃。这只是一个开始使用的例子。

Answer 4

您可以通过任何shell脚本调用pipe excel单元格数据。为Excel安装GPL Bert（http://bert-toolkit.com/）R语言界面。使用Excel中的下面的R脚本将单元格数据传输到Bash / perl / gpg / openssl。

 c:\> cat c:\R322\callable_from_excel.R
    CRYPTIT <- function( PLAINTEXT, MASTER_PASS ) {
    system(
      sprintf("bash -c 'echo '%s' |
        gpg --symmetric --cipher-algo blowfish --force-mdc --passphrase '%s' -q  |
        base64 -w 0'",
        PLAINTEXT, MASTER_PASS),
      intern=TRUE)
  }

DECRYPTIT <- function( CRYPTTEXT, MASTER_PASS ) {
    system(
      sprintf("bash -c 'echo '%s'|
        base64 -d |
        gpg --passphrase '%s' -q |
        putclip | getclip' ",CRYPTTEXT,MASTER_PASS),
      intern=TRUE)  
  }

在Excel中，您可以尝试：C1 = CRYPTIT（A1，A2）和C2 = DECRYPTIT（C1，A2）可选：putclip将解密的文本保存在剪贴板中。两种函数类型都是：String - ＆gt;串。关于在单引号字符串中转义单引号的常见警告。

Answer 5

此代码适用于我（3DES加密/解密）：

我将INITIALIZATION_VECTOR和TRIPLE_DES_KEY存储为环境变量（显然与此处发布的值不同）并使用VBA Environ（）函数获取它们，因此VBA代码中的所有敏感数据（密码）都已加密。

Option Explicit

Public Const INITIALIZATION_VECTOR = "zlrs$5kd"  'Always 8 characters

Public Const TRIPLE_DES_KEY = ">tlF8adk=35K{dsa" 'Always 16 characters

Sub TestEncrypt()
    MsgBox "This is an encrypted string: -> " & EncryptStringTripleDES("This is an encrypted string:")
    Debug.Print EncryptStringTripleDES("This is an encrypted string:")
End Sub

Sub TestDecrypt()
    MsgBox "u99CVItCGiMQEVYHf8+S22QbJ5CPQGDXuS5n1jvEIgU= -> " & DecryptStringTripleDES("u99CVItCGiMQEVYHf8+S22QbJ5CPQGDXuS5n1jvEIgU=")
End Sub


Function EncryptStringTripleDES(plain_string As String) As Variant

    Dim encryption_object As Object
    Dim plain_byte_data() As Byte
    Dim encrypted_byte_data() As Byte
    Dim encrypted_base64_string As String

    EncryptStringTripleDES = Null

    On Error GoTo FunctionError

    plain_byte_data = CreateObject("System.Text.UTF8Encoding").GetBytes_4(plain_string)

    Set encryption_object = CreateObject("System.Security.Cryptography.TripleDESCryptoServiceProvider")
    encryption_object.Padding = 3
    encryption_object.key = CreateObject("System.Text.UTF8Encoding").GetBytes_4(TRIPLE_DES_KEY)
    encryption_object.IV = CreateObject("System.Text.UTF8Encoding").GetBytes_4(INITIALIZATION_VECTOR)
    encrypted_byte_data = _
            encryption_object.CreateEncryptor().TransformFinalBlock(plain_byte_data, 0, UBound(plain_byte_data) + 1)

    encrypted_base64_string = BytesToBase64(encrypted_byte_data)

    EncryptStringTripleDES = encrypted_base64_string

    Exit Function

FunctionError:

    MsgBox "TripleDES encryption failed"

End Function

Function DecryptStringTripleDES(encrypted_string As String) As Variant

    Dim encryption_object As Object
    Dim encrypted_byte_data() As Byte
    Dim plain_byte_data() As Byte
    Dim plain_string As String

    DecryptStringTripleDES = Null

    On Error GoTo FunctionError

    encrypted_byte_data = Base64toBytes(encrypted_string)

    Set encryption_object = CreateObject("System.Security.Cryptography.TripleDESCryptoServiceProvider")
    encryption_object.Padding = 3
    encryption_object.key = CreateObject("System.Text.UTF8Encoding").GetBytes_4(TRIPLE_DES_KEY)
    encryption_object.IV = CreateObject("System.Text.UTF8Encoding").GetBytes_4(INITIALIZATION_VECTOR)
    plain_byte_data = encryption_object.CreateDecryptor().TransformFinalBlock(encrypted_byte_data, 0, UBound(encrypted_byte_data) + 1)

    plain_string = CreateObject("System.Text.UTF8Encoding").GetString(plain_byte_data)

    DecryptStringTripleDES = plain_string

    Exit Function

FunctionError:

    MsgBox "TripleDES decryption failed"

End Function


Function BytesToBase64(varBytes() As Byte) As String
    With CreateObject("MSXML2.DomDocument").createElement("b64")
        .DataType = "bin.base64"
        .nodeTypedValue = varBytes
        BytesToBase64 = Replace(.Text, vbLf, "")
    End With
End Function


Function Base64toBytes(varStr As String) As Byte()
    With CreateObject("MSXML2.DOMDocument").createElement("b64")
         .DataType = "bin.base64"
         .Text = varStr
         Base64toBytes = .nodeTypedValue
    End With
End Function

源代码来自此处：https://gist.github.com/motoraku/97ad730891e59159d86c

请注意原始代码与我的代码之间的差异，即附加选项 encryption_object.Padding = 3 ，这会强制VBA 不执行填充。将padding选项设置为3，我得到的结果与DES_ede3_cbc_encrypt算法的C ++实现完全相同，并且与此online tool生成的内容一致。

Answer 6

此代码在VBA中工作正常，可以轻松移动到VB.NET

避免处理不正常＆＃34;正常＆＃34;字符。您在AllowedChars中决定允许使用哪些字符。

Public Function CleanEncryptSTR(MyString As String, MyPassword As String, Encrypt As Boolean) As String
'Encrypts strings chars contained in Allowedchars
'MyString = String to decrypt
'MyPassword = Password
'Encrypt True: Encrypy   False: Decrypt
    Dim i As Integer
    Dim ASCToAdd As Integer
    Dim ThisChar As String
    Dim ThisASC As Integer
    Dim NewASC As Integer
    Dim MyStringEncrypted As String
    Dim AllowedChars As String

    AllowedChars = "&0123456789;ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"

    If Len(MyPassword) > 0 Then
        For i = 1 To Len(MyString)
'            ThisASC = Asc(Mid(MyString, i, 1))
'            ThisASC = IntFromArray(Asc(Mid(MyString, i, 1)), MyVector())

            ThisChar = Mid(MyString, i, 1)
            ThisASC = InStr(AllowedChars, ThisChar)

            If ThisASC > 0 Then
                ASCToAdd = Asc(Mid(MyPassword, i Mod Len(MyPassword) + 1, 1))
                If Encrypt Then
                    NewASC = ThisASC + ASCToAdd
                Else
                    NewASC = ThisASC - ASCToAdd
                End If
                NewASC = NewASC Mod Len(AllowedChars)
                If NewASC <= 0 Then
                    NewASC = NewASC + Len(AllowedChars)
                End If

                MyStringEncrypted = MyStringEncrypted & Mid(AllowedChars, NewASC, 1)
            Else
                MyStringEncrypted = MyStringEncrypted & ThisChar
            End If
        Next i
    Else
        MyStringEncrypted = MyString
    End If

    CleanEncryptSTR = MyStringEncrypted

End Function

在Excel中加密和解密字符串

6 个答案:

此代码在VBA中工作正常，可以轻松移动到VB.NET