文本文件的基础加密

Question

Option Compare Database

Sub WriteSettingsFile()
  Dim db As DAO.Database
  Dim fld As DAO.Field
  Set db = CurrentDb
  
  'Open Setings File name
  Dim filePath As String
  Dim TextFile As Integer
  
  TextFile = FreeFile
  filePath = Application.CurrentProject.Path & "\settings.cfg"
  Open filePath For Output As TextFile
  
  Print #TextFile, szEncryptDecrypt("Hello World")
  
  Close TextFile
End Sub


Sub ReadSettingsFile()
  Dim strFilename As String
  strFilename = Application.CurrentProject.Path & "\settings.cfg"
  Dim strTextLine As String
  Dim iFile As Integer: iFile = FreeFile
  Open strFilename For Input As #iFile
  
  Do Until EOF(1)
    Line Input #1, strTextLine
    MsgBox strTextLine                    'Not Encrypted
    MsgBox szEncryptDecrypt(strTextLine)  'Encrypted
  Loop
  
Close #iFile
End Sub


Function szEncryptDecrypt(ByVal szData As String) As String
  ' This key value can be changed to alter the encryption,
  ' but it must be the same for both encryption and decryption.
  Const KEY_TEXT As String = "asdfghjkl"
  ' The KEY_OFFSET is optional, and may be any value 0-64.
  ' Likewise, it needs to be the same coming/going.
  Const KEY_OFFSET As Long = 0

  Dim bytKey() As Byte
  Dim bytData() As Byte
  Dim lNum As Long
  Dim szKey As String

  For lNum = 1 To ((Len(szData) \ Len(KEY_TEXT)) + 1)
    szKey = szKey & KEY_TEXT
  Next lNum

  bytKey = Left$(szKey, Len(szData))
  bytData = szData

  For lNum = LBound(bytData) To UBound(bytData)
    If lNum Mod 2 Then
      bytData(lNum) = bytData(lNum) Xor (bytKey(lNum) + KEY_OFFSET)
    Else
      bytData(lNum) = bytData(lNum) Xor (bytKey(lNum) - KEY_OFFSET)
    End If
  Next lNum

  szEncryptDecrypt = bytData
End Function


Sub TestEncrypt()
'This sub works fine
 Dim str As String
 str = szEncryptDecrypt("Hello World!")
 MsgBox "Encrypted" & vbNewLine & str
 MsgBox "Decrypted" & vbNewLine & szEncryptDecrypt(str)
End Sub

有更好的加密功能，可与文本文件一起使用？

Yeah，您发现的加密功能非常简单，但很差。它具有简单的Xoring，并具有偏移量。这意味着，如果某人可以让您加密已知的字符串并可以读取输出，则可以计算键。另外，没有链接，因此我们没有

延伸，文本中的重复模式将导致相同的输出，因此可以推断出常见的模式。 我已经使用CBC模式下的AES-128进行了一种复杂的加密方法。但是，所需的代码相当长。它使用

CNGAPI

进行加密。其他人则使用.NET，而.NET又使用CNG，但可能会导致代码较短。我宁愿不这样做，因为这取决于com对象，并且可以覆盖这些对象。 llet从用法开始：很简单。使用

EncryptString(StringToEncrypt, Key)

加密字符串，然后再次解密。它使用base64编码来表示加密的字符串，因此输出应安全存储在仅接受有效Unicode字符串的字段中（与您发现的实现相反）。 then，基本面。 CBC模式下的AES-128是一个块密码，因此它需要一个固定的长度键，并且还需要在整个块中加密128位。为了解决此问题，我们使用SHA1将钥匙缩小到固定长度，并将输入数据的长度存储在加密的字符串中，以忽略任何填充（末尾的其他字符）。

，然后在CBC模式下，它还需要初始化向量（IV）。我们将其随机生成一个，并在字符串结束时无加密（因为我们需要解密）将其存储。由于我们随机生成IV，因此使用相同键进行两次加密同一字符串将导致完全不同的加密字符串，这通常是可取的（如果您加密密码，您不希望某人能够检查谁与您相同的密码）。

该代码还可以放大数据，并将加密的哈希存储在数据中。这意味着它可以轻松检查您的钥匙是否有效，如果没有的话，它将不会返回任何内容。

Answer 1

DecryptString(StringToDecrypt, Key)

在直接的窗口中轻松检查它有效：

Option Compare Binary
Option Explicit

Public Declare PtrSafe Function BCryptOpenAlgorithmProvider Lib "BCrypt.dll" (ByRef phAlgorithm As LongPtr, ByVal pszAlgId As LongPtr, ByVal pszImplementation As LongPtr, ByVal dwFlags As Long) As Long
Public Declare PtrSafe Function BCryptCloseAlgorithmProvider Lib "BCrypt.dll" (ByVal hAlgorithm As LongPtr, ByVal dwFlags As Long) As Long
Public Declare PtrSafe Function BCryptGetProperty Lib "BCrypt.dll" (ByVal hObject As LongPtr, ByVal pszProperty As LongPtr, ByRef pbOutput As Any, ByVal cbOutput As Long, ByRef pcbResult As Long, ByVal dfFlags As Long) As Long
Public Declare PtrSafe Function BCryptSetProperty Lib "BCrypt.dll" (ByVal hObject As LongPtr, ByVal pszProperty As LongPtr, ByRef pbInput As Any, ByVal cbInput As Long, ByVal dfFlags As Long) As Long
Public Declare PtrSafe Function BCryptCreateHash Lib "BCrypt.dll" (ByVal hAlgorithm As LongPtr, ByRef phHash As LongPtr, pbHashObject As Any, ByVal cbHashObject As Long, ByVal pbSecret As LongPtr, ByVal cbSecret As Long, ByVal dwFlags As Long) As Long
Public Declare PtrSafe Function BCryptHashData Lib "BCrypt.dll" (ByVal hHash As LongPtr, pbInput As Any, ByVal cbInput As Long, Optional ByVal dwFlags As Long = 0) As Long
Public Declare PtrSafe Function BCryptFinishHash Lib "BCrypt.dll" (ByVal hHash As LongPtr, pbOutput As Any, ByVal cbOutput As Long, ByVal dwFlags As Long) As Long
Public Declare PtrSafe Function BCryptDestroyHash Lib "BCrypt.dll" (ByVal hHash As LongPtr) As Long
Public Declare PtrSafe Function BCryptGenRandom Lib "BCrypt.dll" (ByVal hAlgorithm As LongPtr, pbBuffer As Any, ByVal cbBuffer As Long, ByVal dwFlags As Long) As Long
Public Declare PtrSafe Function BCryptGenerateSymmetricKey Lib "BCrypt.dll" (ByVal hAlgorithm As LongPtr, ByRef hKey As LongPtr, pbKeyObject As Any, ByVal cbKeyObject As Long, pbSecret As Any, ByVal cbSecret As Long, ByVal dwFlags As Long) As Long
Public Declare PtrSafe Function BCryptEncrypt Lib "BCrypt.dll" (ByVal hKey As LongPtr, pbInput As Any, ByVal cbInput As Long, pPaddingInfo As Any, pbIV As Any, ByVal cbIV As Long, pbOutput As Any, ByVal cbOutput As Long, ByRef pcbResult As Long, ByVal dwFlags As Long) As Long
Public Declare PtrSafe Function BCryptDecrypt Lib "BCrypt.dll" (ByVal hKey As LongPtr, pbInput As Any, ByVal cbInput As Long, pPaddingInfo As Any, pbIV As Any, ByVal cbIV As Long, pbOutput As Any, ByVal cbOutput As Long, ByRef pcbResult As Long, ByVal dwFlags As Long) As Long
Public Declare PtrSafe Function BCryptDestroyKey Lib "BCrypt.dll" (ByVal hKey As LongPtr) As Long

Public Declare PtrSafe Sub RtlMoveMemory Lib "Kernel32.dll" (Destination As Any, Source As Any, ByVal Length As LongPtr)

Const BCRYPT_BLOCK_PADDING  As Long = &H1

Public Type QuadSextet
    s1 As Byte
    s2 As Byte
    s3 As Byte
    s4 As Byte
End Type

Public Function ToBase64(b() As Byte) As String
    Const Base64Table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
    Dim l As Long
    Dim output As String
    Dim UBoundOut As Long
    UBoundOut = UBound(b) + 1
    If UBoundOut Mod 3 <> 0 Then
        UBoundOut = UBoundOut + (3 - UBoundOut Mod 3)
    End If
    UBoundOut = (UBoundOut \ 3) * 4
    output = String(UBoundOut, vbNullChar)
    Dim qs As QuadSextet
    For l = 0 To (UBound(b) - 2) \ 3
        qs = BytesToQuadSextet(b(l * 3), b(l * 3 + 1), b(l * 3 + 2))
        Mid(output, (l * 4) + 1, 1) = Mid(Base64Table, qs.s1 + 1, 1)
        Mid(output, (l * 4) + 2, 1) = Mid(Base64Table, qs.s2 + 1, 1)
        Mid(output, (l * 4) + 3, 1) = Mid(Base64Table, qs.s3 + 1, 1)
        Mid(output, (l * 4) + 4, 1) = Mid(Base64Table, qs.s4 + 1, 1)
    Next
    If UBound(b) + 1 - (l * 3) = 2 Then
        qs = BytesToQuadSextet(b(l * 3), b(l * 3 + 1))
        Mid(output, (l * 4) + 1, 1) = Mid(Base64Table, qs.s1 + 1, 1)
        Mid(output, (l * 4) + 2, 1) = Mid(Base64Table, qs.s2 + 1, 1)
        Mid(output, (l * 4) + 3, 1) = Mid(Base64Table, qs.s3 + 1, 1)
        Mid(output, (l * 4) + 4, 1) = "="
    ElseIf UBound(b) + 1 - (l * 3) = 1 Then
        qs = BytesToQuadSextet(b(l * 3))
        Mid(output, (l * 4) + 1, 1) = Mid(Base64Table, qs.s1 + 1, 1)
        Mid(output, (l * 4) + 2, 1) = Mid(Base64Table, qs.s2 + 1, 1)
        Mid(output, (l * 4) + 3, 2) = "=="
    End If
    ToBase64 = output
End Function

Public Function Base64ToBytes(strBase64 As String) As Byte()
    Dim outBytes() As Byte
    Dim lenBytes As Long
    lenBytes = Len(strBase64) * 3 \ 4
    If Right(strBase64, 1) = "=" Then lenBytes = lenBytes - 1
    If Right(strBase64, 2) = "==" Then lenBytes = lenBytes - 1
    ReDim outBytes(0 To lenBytes - 1)
    Dim l As Long
    Dim qs As QuadSextet
    For l = 0 To lenBytes - 1
        Select Case l Mod 3
            Case 0
                qs = Base64ToQuadSextet(Mid(strBase64, (l \ 3) * 4 + 1, 4))
                outBytes(l) = qs.s1 * 2 ^ 2 + (qs.s2 \ 2 ^ 4)
            Case 1
                outBytes(l) = (qs.s2 * 2 ^ 4 And 255) + qs.s3 \ 2 ^ 2
            Case 2
                outBytes(l) = (qs.s3 * 2 ^ 6 And 255) + qs.s4
        End Select
    Next
    Base64ToBytes = outBytes
End Function

Public Function BytesToQuadSextet(b1 As Byte, Optional b2 As Byte, Optional b3 As Byte) As QuadSextet
    BytesToQuadSextet.s1 = b1 \ 4
    BytesToQuadSextet.s2 = (((b1 * 2 ^ 6) And 255) \ 4) + b2 \ (2 ^ 4)
    BytesToQuadSextet.s3 = (((b2 * 2 ^ 4) And 255) \ 4) + b3 \ (2 ^ 6)
    BytesToQuadSextet.s4 = (((b3 * 2 ^ 2) And 255) \ 4)
End Function

Public Function Base64ToQuadSextet(strBase64 As String) As QuadSextet
    Const Base64Table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
    Base64ToQuadSextet.s1 = InStr(Base64Table, Mid(strBase64, 1, 1)) - 1
    Base64ToQuadSextet.s2 = InStr(Base64Table, Mid(strBase64, 2, 1)) - 1
    Base64ToQuadSextet.s3 = InStr(Base64Table, Mid(strBase64, 3, 1)) - 1
    Base64ToQuadSextet.s4 = InStr(Base64Table, Mid(strBase64, 4, 1)) - 1
End Function

Public Function StringToBase64(str As String) As String
    StringToBase64 = ToBase64(StrConv(str, vbFromUnicode))
End Function

Public Function HashBytes(Data() As Byte, Optional HashingAlgorithm As String = "SHA1") As Byte()
    HashBytes = NGHash(VarPtr(Data(LBound(Data))), UBound(Data) - LBound(Data) + 1, HashingAlgorithm)
End Function

Public Function NGHash(pData As LongPtr, lenData As Long, Optional HashingAlgorithm As String = "SHA1") As Byte()
    'Erik A, 2019
    'Hash data by using the Next Generation Cryptography API
    'Loosely based on https://learn.microsoft.com/en-us/windows/desktop/SecCNG/creating-a-hash-with-cng
    'Allowed algorithms:  https://learn.microsoft.com/en-us/windows/desktop/SecCNG/cng-algorithm-identifiers. Note: only hash algorithms, check OS support
    'Error handling not implemented!
    On Error GoTo VBErrHandler
    Dim errorMessage As String

    Dim hAlg As LongPtr
    Dim algId As String

    'Open crypto provider
    algId = HashingAlgorithm & vbNullChar
    If BCryptOpenAlgorithmProvider(hAlg, StrPtr(algId), 0, 0) Then GoTo ErrHandler
    
    'Determine hash object size, allocate memory
    Dim bHashObject() As Byte
    Dim cmd As String
    cmd = "ObjectLength" & vbNullString
    Dim Length As Long
    If BCryptGetProperty(hAlg, StrPtr(cmd), Length, LenB(Length), 0, 0) <> 0 Then GoTo ErrHandler
    ReDim bHashObject(0 To Length - 1)
    
    'Determine digest size, allocate memory
    Dim hashLength As Long
    cmd = "HashDigestLength" & vbNullChar
    If BCryptGetProperty(hAlg, StrPtr(cmd), hashLength, LenB(hashLength), 0, 0) <> 0 Then GoTo ErrHandler
    Dim bHash() As Byte
    ReDim bHash(0 To hashLength - 1)
    
    'Create hash object
    Dim hHash As LongPtr
    If BCryptCreateHash(hAlg, hHash, bHashObject(0), Length, 0, 0, 0) <> 0 Then GoTo ErrHandler
    
    'Hash data
    If BCryptHashData(hHash, ByVal pData, lenData) <> 0 Then GoTo ErrHandler
    If BCryptFinishHash(hHash, bHash(0), hashLength, 0) <> 0 Then GoTo ErrHandler
    
    'Return result
    NGHash = bHash
ExitHandler:
    'Cleanup
    If hAlg <> 0 Then BCryptCloseAlgorithmProvider hAlg, 0
    If hHash <> 0 Then BCryptDestroyHash hHash
    Exit Function
VBErrHandler:
    errorMessage = "VB Error " & Err.Number & ": " & Err.Description
ErrHandler:
    If errorMessage <> "" Then MsgBox errorMessage
    Resume ExitHandler
End Function

Public Sub NGRandom(pData As LongPtr, lenData As Long, Optional Algorithm As String = "RNG")
    'Erik A, 2019
    'Fills data at pointer with random bytes
    'Error handling not implemented!
    
    Dim hAlg As LongPtr
    Dim algId As String
    
    'Open crypto provider
    algId = Algorithm & vbNullChar
    BCryptOpenAlgorithmProvider hAlg, StrPtr(algId), 0, 0
    
    'Fill bytearray with random data
    BCryptGenRandom hAlg, ByVal pData, lenData, 0
    
    'Cleanup
    BCryptCloseAlgorithmProvider hAlg, 0
End Sub

Public Sub NGRandomW(Data() As Byte, Optional Algorithm As String = "RNG")
    If LBound(Data) = -1 Then Exit Sub
    NGRandom VarPtr(Data(LBound(Data))), UBound(Data) - LBound(Data) + 1, Algorithm
End Sub

Public Function NGEncrypt(pData As LongPtr, lenData As Long, inpIV As LongPtr, inpIVLength As Long, inpSecret As LongPtr, inpSecretLength As Long) As Byte()
    'Encrypt pData using AES encryption, inpIV and inpSecret
    'Input: pData -> mempointer to data. lenData: amount of bytes to encrypt. inpIV: mempointer to IV. inpSecret: mempointer to 128-bits secret.
    'Output: Bytearray containing encrypted data
    Dim errorMessage As String
    On Error GoTo VBErrHandler
    
    Dim hAlg As LongPtr
    Dim algId As String

    'Open algorithm provider
    algId = "AES" & vbNullChar
    BCryptOpenAlgorithmProvider hAlg, StrPtr(algId), 0, 0

    'Allocate memory to hold the KeyObject
    Dim cmd As String
    Dim keyObjectLength As Long
    cmd = "ObjectLength" & vbNullString
    BCryptGetProperty hAlg, StrPtr(cmd), keyObjectLength, LenB(keyObjectLength), 0, 0
    Dim bKeyObject() As Byte
    ReDim bKeyObject(0 To keyObjectLength - 1)

    'Check block length = 128 bits, copy IV
    Dim ivLength As Long
    Dim bIV() As Byte
    cmd = "BlockLength" & vbNullChar
    BCryptGetProperty hAlg, StrPtr(cmd), ivLength, LenB(ivLength), 0, 0
    If ivLength > inpIVLength Then
        Debug.Print
    End If
    ReDim bIV(0 To ivLength - 1)
    RtlMoveMemory bIV(0), ByVal inpIV, ivLength

    'Set chaining mode
    cmd = "ChainingMode" & vbNullString
    Dim val As String
    val = "ChainingModeCBC" & vbNullString
    BCryptSetProperty hAlg, StrPtr(cmd), ByVal StrPtr(val), LenB(val), 0

    'Create KeyObject using secret
    Dim hKey As LongPtr
    BCryptGenerateSymmetricKey hAlg, hKey, bKeyObject(0), keyObjectLength, ByVal inpSecret, inpSecretLength, 0

    'Calculate output buffer size, allocate output buffer
    Dim cipherTextLength As Long
    BCryptEncrypt hKey, ByVal pData, lenData, ByVal 0, bIV(0), ivLength, ByVal 0, 0, cipherTextLength, BCRYPT_BLOCK_PADDING
    Dim bCipherText() As Byte
    ReDim bCipherText(0 To cipherTextLength - 1)

    'Encrypt the data
    Dim dataLength As Long
    BCryptEncrypt hKey, ByVal pData, lenData, ByVal 0, bIV(0), ivLength, bCipherText(0), cipherTextLength, dataLength, BCRYPT_BLOCK_PADDING
    
    'Output the encrypted data
    NGEncrypt = bCipherText
    
ExitHandler:
    'Destroy the key
    If hKey <> 0 Then BCryptDestroyKey hKey
    If hAlg <> 0 Then BCryptCloseAlgorithmProvider hAlg, 0
    Exit Function
VBErrHandler:
    errorMessage = "VB Error " & Err.Number & ": " & Err.Description
ErrHandler:
    If errorMessage <> "" Then MsgBox errorMessage
    Resume ExitHandler
End Function

Public Function NGEncryptW(pData() As Byte, pIV() As Byte, pSecret() As Byte) As Byte()
    NGEncryptW = NGEncrypt(VarPtr(pData(LBound(pData))), UBound(pData) - LBound(pData) + 1, VarPtr(pIV(LBound(pIV))), UBound(pIV) - LBound(pIV) + 1, VarPtr(pSecret(LBound(pSecret))), UBound(pSecret) - LBound(pSecret) + 1)
End Function


Public Function NGDecrypt(pData As LongPtr, lenData As Long, pIV As LongPtr, lenIV As Long, pSecret As LongPtr, lenSecret As Long) As Byte()
    Dim errorMessage As String
    On Error GoTo VBErrHandler
    Dim hAlg As LongPtr
    Dim algId As String

    'Open algorithm provider
    algId = "AES" & vbNullChar
    If BCryptOpenAlgorithmProvider(hAlg, StrPtr(algId), 0, 0) <> 0 Then GoTo ErrHandler

    'Allocate memory to hold the KeyObject
    Dim cmd As String
    Dim keyObjectLength As Long
    cmd = "ObjectLength" & vbNullString
    If BCryptGetProperty(hAlg, StrPtr(cmd), keyObjectLength, LenB(keyObjectLength), 0, 0) <> 0 Then GoTo ErrHandler
    Dim bKeyObject() As Byte
    ReDim bKeyObject(0 To keyObjectLength - 1)

    'Calculate the block length for the IV, resize the IV
    Dim ivLength As Long
    Dim bIV() As Byte
    cmd = "BlockLength" & vbNullChar
    If BCryptGetProperty(hAlg, StrPtr(cmd), ivLength, LenB(ivLength), 0, 0) <> 0 Then GoTo ErrHandler
    ReDim bIV(0 To ivLength - 1)
    RtlMoveMemory bIV(0), ByVal pIV, ivLength

    'Set chaining mode
    cmd = "ChainingMode" & vbNullString
    Dim val As String
    val = "ChainingModeCBC" & vbNullString
    If BCryptSetProperty(hAlg, StrPtr(cmd), ByVal StrPtr(val), LenB(val), 0) <> 0 Then GoTo ErrHandler

    'Create KeyObject using secret
    Dim hKey As LongPtr
    If BCryptGenerateSymmetricKey(hAlg, hKey, bKeyObject(1), keyObjectLength, ByVal pSecret, lenSecret, 0) <> 0 Then GoTo ErrHandler

    'Calculate output buffer size, allocate output buffer
    Dim OutputSize As Long
    If BCryptDecrypt(hKey, ByVal pData, lenData, ByVal 0, bIV(0), ivLength, ByVal 0, 0, OutputSize, BCRYPT_BLOCK_PADDING) <> 0 Then GoTo ErrHandler
    Dim bDecrypted() As Byte
    ReDim bDecrypted(0 To OutputSize - 1)

    'Decrypt the data
    Dim dataLength As Long
    If BCryptDecrypt(hKey, ByVal pData, lenData, ByVal 0, bIV(0), ivLength, bDecrypted(0), OutputSize, dataLength, BCRYPT_BLOCK_PADDING) <> 0 Then GoTo ErrHandler

    NGDecrypt = bDecrypted
    
    'Cleanup
ExitHandler:
    BCryptDestroyKey hKey
    BCryptCloseAlgorithmProvider hAlg, 0
    Exit Function
VBErrHandler:
    errorMessage = "VB Error " & Err.Number & ": " & Err.Description
ErrHandler:
    If errorMessage <> "" Then MsgBox errorMessage
    GoTo ExitHandler
End Function

Public Function NGDecryptW(pData() As Byte, pIV() As Byte, pSecret() As Byte) As Byte()
    NGDecryptW = NGDecrypt(VarPtr(pData(LBound(pData))), UBound(pData) - LBound(pData) + 1, VarPtr(pIV(LBound(pIV))), UBound(pIV) - LBound(pIV) + 1, VarPtr(pSecret(LBound(pSecret))), UBound(pSecret) - LBound(pSecret) + 1)
End Function

Public Function EncryptData(inpData() As Byte, inpKey() As Byte) As Byte()
    'SHA1 the key and data
    Dim keyHash() As Byte
    keyHash = HashBytes(inpKey, "SHA1")
    Dim dataHash() As Byte
    dataHash = HashBytes(inpData, "SHA1")
    Dim dataLength As Long
    dataLength = UBound(inpData) - LBound(inpData) + 1
    Dim toEncrypt() As Byte
    'To encrypt = Long (4 bytes) + dataLength + SHA1 (20 bytes)
    ReDim toEncrypt(0 To dataLength + 23)
    'Append length (in bytes) to start of array
    RtlMoveMemory toEncrypt(0), dataLength, 4
    'Then data
    RtlMoveMemory toEncrypt(4), inpData(LBound(inpData)), dataLength
    'Then hash of data
    RtlMoveMemory toEncrypt(dataLength + 4), dataHash(0), 20
    
    'Generate IV
    Dim IV(0 To 15) As Byte
    NGRandomW IV
    'Encrypt data
    Dim encryptedData() As Byte
    encryptedData = NGEncrypt(VarPtr(toEncrypt(0)), dataLength + 24, VarPtr(IV(0)), 16, VarPtr(keyHash(0)), 16)
    'Deallocate copy made to encrypt
    Erase toEncrypt
    'Extend encryptedData to append IV
    ReDim Preserve encryptedData(LBound(encryptedData) To UBound(encryptedData) + 16)
    'Append IV
    RtlMoveMemory encryptedData(UBound(encryptedData) - 15), IV(0), 16
    'Return result
    EncryptData = encryptedData
End Function

Public Function DecryptData(inpData() As Byte, inpKey() As Byte, outDecrypted() As Byte) As Boolean
    If LBound(inpData) <> 0 Then Exit Function 'Array must start at 0
    Dim arrLength As Long
    arrLength = UBound(inpData) + 1
    'IV = 16 bytes, length = 4 bytes
    If arrLength < 20 Then Exit Function
    'SHA1 the key
    Dim keyHash() As Byte
    keyHash = HashBytes(inpKey, "SHA1")
    'Get the pointer to the IV
    Dim pIV As LongPtr
    pIV = VarPtr(inpData(UBound(inpData) - 15)) 'Last 16 bytes = IV
    'Decrypt the data
    Dim decryptedData() As Byte
    decryptedData = NGDecrypt(VarPtr(inpData(0)), UBound(inpData) - LBound(inpData) - 15, pIV, 16, VarPtr(keyHash(0)), 16)
    'Check we got some data
    If StrPtr(decryptedData) = 0 Then Exit Function ' Weirdly, this checks for uninitialized byte arrays
    If UBound(decryptedData) < 3 Then Exit Function
    'Get the data length
    Dim dataLength As Long
    RtlMoveMemory dataLength, decryptedData(0), 4
    'Check if length is valid, with invalid key length = random data
    If dataLength > (UBound(decryptedData) - 3) Or dataLength < 0 Then Exit Function
    'Hash the decrypted data
    Dim hashResult() As Byte
    hashResult = NGHash(VarPtr(decryptedData(4)), dataLength, "SHA1")
    'Verify the hash
    Dim l As Byte
    For l = 0 To 19
        If hashResult(l) <> decryptedData(l + 4 + dataLength) Then
            'Stored hash not equal to hash with decrypted data, key incorrect or encrypted data tampered with
            'Don't touch output, return false by default
            Exit Function
        End If
    Next

    'Initialize output array
    ReDim outDecrypted(0 To dataLength - 1)
    'Copy data to output array
    RtlMoveMemory outDecrypted(0), decryptedData(4), dataLength
    DecryptData = True
End Function

Public Function EncryptString(inpString As String, inpKey As String) As String
    Dim Data() As Byte
    Data = inpString
    Dim key() As Byte
    key = inpKey
    EncryptString = ToBase64(EncryptData(Data, key))
End Function

Public Function DecryptString(inpEncryptedString As String, inpKey As String) As String
    Dim Data() As Byte
    Data = Base64ToBytes(inpEncryptedString)
    Dim key() As Byte
    key = inpKey
    Dim out() As Byte
    DecryptData Data, key, out
    DecryptString = out
End Function

首先，我当然会推荐Erik的路线，但是，要直接回答您的问题，您的麻烦是，您可以生成具有非ASCII字符的二进制数据。 但是，可以通过使用

Base64

编码/解码来解决。

?EncryptString("Secret data", "Key") 'Returns seemingly random data, changing every call
?DecryptString(EncryptString("Secret data", "Other key"), "Other key")
'Test that long keys and long strings work, returns True since encrypted + decrypted = original
?DecryptString(EncryptString(String(100000, "A"), String(10000, "B")), String(10000, "B")) = String(100000, "A")

这需要两个支持功能，然后您的代码开始堆积一点：

Sub WriteSettingsFile()
    
    Dim db As DAO.Database
    Dim fld As DAO.Field
    Set db = CurrentDb
    
    'Open Setings File name
    Dim FilePath  As String
    Dim TextFile  As Integer
    
    TextFile = FreeFile
    FilePath = Application.CurrentProject.Path & "\settings.cfg"
    
    Open FilePath For Output As #TextFile
    Print #TextFile, Encode64(szEncryptDecrypt("Hello World"))
    Close #TextFile
  
End Sub


Sub ReadSettingsFile()
    
    Dim strFilename As String
    Dim strTextLine As String
    Dim TextFile    As Integer
    
    TextFile = FreeFile
    strFilename = Application.CurrentProject.Path & "\settings.cfg"
    
    Open strFilename For Input As #TextFile
    Do Until EOF(1)
        Line Input #1, strTextLine
        MsgBox strTextLine                              ' Not decrypted
        MsgBox szEncryptDecrypt(Decode64(strTextLine))  ' Decrypted
    Loop
    Close #TextFile
    
End Sub

输出：

Base64不提供任何安全性，任何人都可以解码其输出。

Answer 2