A function for encryption and decryption in asp

There are not many decryption methods corresponding to the encryption method in ASP. Now, according to the previous documents, the encryption and decryption functions in asp are sorted out.

Rsa. asp
<%
Rem implements encryption and decryption in ASP. The encryption method is based on RSA
Rem contact: 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
%>

Test. asp
<! -- # Include file = "RSA. asp" -->
<%
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 = "sohu"
Response. Write ":" & first before encryption
Last = Encryptstr (first)
Response. Write "encrypted to" & last
Response. Write "decrypted as" & decryptstr (last)

%>