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rem 在ASP中實現加密與解密,加密方法:根據RSA
rem 聯系:hnsoso@sina.com
Class clsRSA

Public PrivateKey
Public PublicKey
Public Modulus

Public Function Crypt(pLngMessage, pLngKey)
On Error Resume Next
Dim lLngMod
Dim lLngResult
Dim lLngIndex
If pLngKey Mod 2 = 0 Then
lLngResult = 1
For lLngIndex = 1 To pLngKey / 2
lLngMod = (pLngMessage ^ 2) Mod Modulus
' Mod may error on key generation
lLngResult = (lLngMod * lLngResult) Mod Modulus
If Err Then Exit Function
Next
Else
lLngResult = pLngMessage
For lLngIndex = 1 To pLngKey / 2
lLngMod = (pLngMessage ^ 2) Mod Modulus
On Error Resume Next
' Mod may error on key generation
lLngResult = (lLngMod * lLngResult) Mod Modulus
If Err Then Exit Function
Next
End If
Crypt = lLngResult
End Function

Public Function Encode(ByVal pStrMessage)
Dim lLngIndex
Dim lLngMaxIndex
Dim lBytAscii
Dim lLngEncrypted
lLngMaxIndex = Len(pStrMessage)
If lLngMaxIndex = 0 Then Exit Function
For lLngIndex = 1 To lLngMaxIndex
lBytAscii = Asc(Mid(pStrMessage, lLngIndex, 1))
lLngEncrypted = Crypt(lBytAscii, PublicKey)
Encode = Encode & NumberToHex(lLngEncrypted, 4)
Next
End Function

Public Function Decode(ByVal pStrMessage)
Dim lBytAscii
Dim lLngIndex
Dim lLngMaxIndex
Dim lLngEncryptedData
Decode = ""
lLngMaxIndex = Len(pStrMessage)
For lLngIndex = 1 To lLngMaxIndex Step 4
lLngEncryptedData = HexToNumber(Mid(pStrMessage, lLngIndex, 4))
lBytAscii = Crypt(lLngEncryptedData, PrivateKey)
Decode = Decode & Chr(lBytAscii)
Next
End Function

Private Function NumberToHex(ByRef pLngNumber, ByRef pLngLength)
NumberToHex = Right(String(pLngLength, "0") & Hex(pLngNumber), pLngLength)
End Function

Private Function HexToNumber(ByRef pStrHex)
HexToNumber = CLng("&h" & pStrHex)
End Function

End Class

function Encryptstr(Message)
Dim LngKeyE
Dim LngKeyD
Dim LngKeyN
Dim StrMessage
Dim ObjRSA

LngKeyE = "32823"
LngKeyD = "20643"
LngKeyN = "29893"
StrMessage = Message

Set ObjRSA = New clsRSA

ObjRSA.PublicKey = LngKeyE
ObjRSA.Modulus = LngKeyN
Encryptstr = ObjRSA.Encode(StrMessage)
Set ObjRSA = Nothing
end function

function decryptstr(Message)
Dim LngKeyE
Dim LngKeyD
Dim LngKeyN
Dim StrMessage
Dim ObjRSA

LngKeyE = "32823"
LngKeyD = "20643"
LngKeyN = "29893"
StrMessage = Message

Set ObjRSA = New clsRSA

ObjRSA.PrivateKey =LngKeyD
ObjRSA.Modulus=LngKeyN
decryptstr=ObjRSA.Decode(StrMessage)
Set ObjRSA = Nothing
end function

dim last,first
first="3256425"
Response.Write "加密前為:"&first
last=Encryptstr(first)
Response.Write "加密后為"&last
Response.Write "解密后為" &decryptstr(last)
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