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
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)，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。DecryptString(StringToDecrypt, Key)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。