文章

在Asp中实现rsa加密与解密

本文章有两文件组成
test.asp 测试演示文件
clsrsa.asp 实现rsa加密与解密的vbs类文件
下面是代码:

1. test.asp


<%Option Explicit%>

<%

Dim LngKeyE
Dim LngKeyD
Dim LngKeyN
Dim StrMessage
Dim ObjRSA
If Not Request.Form = "" Then

LngKeyE = Request.Form("KeyE")
LngKeyD = Request.Form("KeyD")
LngKeyN = Request.Form("KeyN")
StrMessage = Request.Form("Message")

Set ObjRSA = New clsRSA

Select Case Request.Form("Action")
Case "Generate Keys"
Call ObjRSA.GenKey()
LngKeyE = ObjRSA.PublicKey
LngKeyD = ObjRSA.PrivateKey
LngKeyN = ObjRSA.Modulus
Case "Encrypt"
ObjRSA.PublicKey = LngKeyE
ObjRSA.Modulus = LngKeyN
StrMessage = ObjRSA.Encode(StrMessage)
Case "Decrypt"
ObjRSA.PrivateKey = LngKeyD
ObjRSA.Modulus = LngKeyN
StrMessage = ObjRSA.Decode(StrMessage)
End Select

Set ObjRSA = Nothing

End If
%>


RSA Cipher Demonstration


RSA Cipher Demonstration



You will first need to generate your public/privage key-pair
before you can encrypt/decrypt messages.























Public Key

Private Key
Modulus

Test Message:











clsrsa.asp

<%


'' RSA Encryption Class
''
'' .PrivateKey
'' Your personal private key. Keep this hidden.
''
'' .PublicKey
'' Key for others to encrypt data with.
''
'' .Modulus
'' Used with both public and private keys when encrypting
'' and decrypting data.
''
'' .GenKey()
'' Creates Public/Private key set and Modulus
''
'' .Crypt(pLngMessage, pLngKey)
'' Encrypts/Decrypts message and returns
'' as a string.
''
'' .Encode(pStrMessage)
'' Encrypts message and returns in double-hex format
''
'' .Decode(pStrMessage)
'' Decrypts message from double-hex format and returns a string
''
Class clsRSA

Public PrivateKey
Public PublicKey
Public Modulus

Public Sub GenKey()
Dim lLngPhi
Dim q
Dim p

Randomize

Do
Do

'' 2 random primary numbers (0 to 1000)
Do
p = Rnd * 1000 \ 1
Loop While Not IsPrime(p)

Do
q = Rnd * 1000 \ 1
Loop While Not IsPrime(q)


'' n = product of 2 primes
Modulus = p * q \ 1

'' random decryptor (2 to n)
PrivateKey = Rnd * (Modulus - 2) \ 1 + 2

lLngPhi = (p - 1) * (q - 1) \ 1
PublicKey = Euler(lLngPhi, PrivateKey)

Loop While PublicKey = 0 Or PublicKey = 1

'' Loop if we can''t crypt/decrypt a byte
Loop While Not TestCrypt(255)

End Sub

Private Function TestCrypt(ByRef pBytData)
Dim lStrCrypted
lStrCrypted = Crypt(pBytData, PublicKey)
TestCrypt = Crypt(lStrCrypted, PrivateKey) = pBytData
End Function

Private Function Euler(ByRef pLngPHI, ByRef pLngKey)

Dim lLngR(3)
Dim lLngP(3)
Dim lLngQ(3)

Dim lLngCounter
Dim lLngResult

Euler = 0

lLngR(1) = pLngPHI: lLngR(0) = pLngKey
lLngP(1) = 0: lLngP(0) = 1
lLngQ(1) = 2: lLngQ(0) = 0

lLngCounter = -1

Do Until lLngR(0) = 0

lLngR(2) = lLngR(1): lLngR(1) = lLngR(0)
lLngP(2) = lLngP(1): lLngP(1) = lLngP(0)
lLngQ(2) = lLngQ(1): lLngQ(1) = lLngQ(0)

lLngCounter = lLngCounter + 1

lLngR(0) = lLngR(2) Mod lLngR(1)
lLngP(0) = ((lLngR(2)\lLngR(1)) * lLngP(1)) + lLngP(2)
lLngQ(0) = ((lLngR(2)\lLngR(1)) * lLngQ(1)) + lLngQ(2)

Loop

lLngResult = (pLngKey * lLngP(1)) - (pLngPHI * lLngQ(1))

If lLngResult > 0 Then
Euler = lLngP(1)
Else
Euler = Abs(lLngP(1)) + pLngPHI
End If

End Function

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

Private Function IsPrime(ByRef pLngNumber)
Dim lLngSquare
Dim lLngIndex
IsPrime = False
If pLngNumber < 2 Then Exit Function
If pLngNumber Mod 2 = 0 Then Exit Function
lLngSquare = Sqr(pLngNumber)
For lLngIndex = 3 To lLngSquare Step 2
If pLngNumber Mod lLngIndex = 0 Then Exit Function
Next
IsPrime = True
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
%>