RSA加密解密算法 asp源码
时间:2009-08-28 13:10:00
它是第一个既能用于数据加密也能用于数字签名的算法。它易于理解和操作,也很流行。算法的名字以发明者的名字命名:Ron Rivest, Adi Shamir 和Leonard Adleman。但RSA的安全性一直未能得到理论上的证明。
它经历了各种攻击,至今未被完全攻破。
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' Compiled by Lewis Edward Moten III
' lewis@moten.com
' http://www.lewismoten.com
' Wednesday, May 09, 2001 05:42 PM GMT +5
' RSA Encryption Class
'
' .KeyEnc
' Key for others to encrypt data with.
'
' .KeyDec
' Your personal private key. Keep this hidden.
'
' .KeyMod
' Used with both public and private keys when encrypting and decrypting data.
'
' .KeyGen
' Used to generate both public and private keys for encrypting and decrypting data.
'
' .Encode(pStrMessage)
' Encrypts message and returns in numeric format
'
' .Decode(pStrMessage)
' Decrypts message and returns a string
'
Class TRSA
Public KeyEnc
Public KeyDec
Private Function Mult(ByVal x, ByVal pg, ByVal m)
dim y : y=1
Do While pg > 0
Do While (pg / 2) = Int((pg / 2))
x = nMod((x * x), m)
pg = pg / 2
Loop
y = nMod((x * y), m)
pg = pg - 1
Loop
Mult = y
End Function
Private Function nMod(x, y)
nMod = 0
if y = 0 then Exit Function End If
nMod = x - (Int(x / y) * y)
End Function
Private Function Euler(E3, PHI3)
'genetates D from (E and PHI) using the Euler algorithm
On Error Resume Next
Dim u1, u2, u3, v1, v2, v3, q
Dim t1, t2, t3, z, vv, inverse
u1 = 1
u2 = 0
u3 = PHI3
v1 = 0
v2 = 1
v3 = E3
Do Until (v3 = 0)
q = Int(u3 / v3)
t1 = u1 - q * v1: t2 = u2 - q * v2: t3 = u3 - q * v3
u1 = v1: u2 = v2: u3 = v3
v1 = t1: v2 = t2: v3 = t3
z = 1
Loop
If (u2 < 0) Then
inverse = u2 + PHI3
Else
inverse = u2
End If
Euler = inverse
End Function
Private Function GCD(nPHI)
On Error Resume Next
Dim nE, y
Const N_UP = 99999999 'set upper limit of random number For E
Const N_LW = 10000000 'set lower limit of random number For E
Randomize
nE = Int((N_UP - N_LW + 1) * Rnd + N_LW)
Do
x = nPHI Mod nE
y = x Mod nE
If y <> 0 And IsPrime(nE) Then
GCD = nE
Exit Function
Else
nE = nE + 1
End If
Loop
End Function
Private Function IsPrime(lngNumber)
On Error Resume Next
Dim lngCount, ngSqr
Dim x
lngSqr = Int(Sqr(lngNumber)) ' Get the int square root
If lngNumber < 2 Then
IsPrime = False
Exit Function
End If
lngCount = 2
IsPrime = True
If lngNumber Mod lngCount = 0 Then
IsPrime = False
Exit Function
End If
lngCount = 3
For x = lngCount To lngSqr Step 2
If lngNumber Mod x = 0 Then
IsPrime = False
Exit Function
End If
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
Public Function Encrypt(ByVal tIp)
Dim encSt, z
Dim strMult
Dim iEnc, iMod
Dim aKey : aKey=Split(KeyEnc,",")
If tIp = "" Then Exit Function End If
iEnc=Int(aKey(0))
iMod=Int(aKey(1))
For z = 1 To Len(tIp)
encSt = encSt & NumberToHex(Mult(CLng(Asc(Mid(tIp, z, 1))), iEnc, iMod),8)
Next
Encrypt = encSt
End Function
Public Function Decrypt(ByVal tIp)
Dim decSt, z
Dim iDec, iMod
Dim aKey : aKey=Split(KeyDec,",")
if Len(tIp) Mod 8 <> 0 then Exit Function End If
iDec=Int(aKey(0))
iMod=Int(aKey(1))
For z = 1 To Len(tIp) Step 8
decSt = decSt + Chr(Mult(HexToNumber(Mid(tIp, z, 8)), iDec, iMod))
Next
Decrypt = decSt
End Function
Public Function genKey()
'Generates the keys for E, D and N
Dim E, D, N, p, q
Const PQ_UP = 9999 'set upper limit of random number
Const PQ_LW = 3170 'set lower limit of random number
Const KEY_LOWER_LIMIT = 10000000 'set For 64bit minimum
p = 0: q = 0
Randomize
Do Until D > KEY_LOWER_LIMIT 'makes sure keys are 64bit minimum
Do Until IsPrime(p) And IsPrime(q) ' make sure q and q are primes
p = clng((PQ_UP - PQ_LW + 1) * Rnd + PQ_LW)
q = clng((PQ_UP - PQ_LW + 1) * Rnd + PQ_LW)
Loop
N = clng(p * q)
PHI = (p - 1) * (q - 1)
E = clng(GCD(PHI))
D = clng(Euler(E, PHI))
Loop
KeyEnc = E & "," & N
KeyDec = D & "," & N
genKey=E & "," & D & "," & N
End Function
Public Function setKey(ByVal a_sKey)
Dim aKeys : aKeys=Split(a_sKey,",")
setKey=false
KeyEnc=null
KeyDec=null
If UBound(aKeys)<2 Then Exit Function End If
KeyEnc=aKeys(0) & "," & aKeys(2)
KeyDec=aKeys(1) & "," & aKeys(2)
setKey=true
End Function
End Class
%><%
' Compiled by Lewis Edward Moten III
' lewis@moten.com
' http://www.lewismoten.com
' Wednesday, May 09, 2001 05:42 PM GMT +5
' RSA Encryption Class
'
' .KeyEnc
' Key for others to encrypt data with.
'
' .KeyDec
' Your personal private key. Keep this hidden.
'
' .KeyMod
' Used with both public and private keys when encrypting and decrypting data.
'
' .KeyGen
' Used to generate both public and private keys for encrypting and decrypting data.
'
' .Encode(pStrMessage)
' Encrypts message and returns in numeric format
'
' .Decode(pStrMessage)
' Decrypts message and returns a string
'
Class TRSA
Public KeyEnc
Public KeyDec
Private Function Mult(ByVal x, ByVal pg, ByVal m)
dim y : y=1
Do While pg > 0
Do While (pg / 2) = Int((pg / 2))
x = nMod((x * x), m)
pg = pg / 2
Loop
y = nMod((x * y), m)
pg = pg - 1
Loop
Mult = y
End Function
Private Function nMod(x, y)
nMod = 0
if y = 0 then Exit Function End If
nMod = x - (Int(x / y) * y)
End Function
Private Function Euler(E3, PHI3)
'genetates D from (E and PHI) using the Euler algorithm
On Error Resume Next
Dim u1, u2, u3, v1, v2, v3, q
Dim t1, t2, t3, z, vv, inverse
u1 = 1
u2 = 0
u3 = PHI3
v1 = 0
v2 = 1
v3 = E3
Do Until (v3 = 0)
q = Int(u3 / v3)
t1 = u1 - q * v1: t2 = u2 - q * v2: t3 = u3 - q * v3
u1 = v1: u2 = v2: u3 = v3
v1 = t1: v2 = t2: v3 = t3
z = 1
Loop
If (u2 < 0) Then
inverse = u2 + PHI3
Else
inverse = u2
End If
Euler = inverse
End Function
Private Function GCD(nPHI)
On Error Resume Next
Dim nE, y
Const N_UP = 99999999 'set upper limit of random number For E
Const N_LW = 10000000 'set lower limit of random number For E
Randomize
nE = Int((N_UP - N_LW + 1) * Rnd + N_LW)
Do
x = nPHI Mod nE
y = x Mod nE
If y <> 0 And IsPrime(nE) Then
GCD = nE
Exit Function
Else
nE = nE + 1
End If
Loop
End Function
Private Function IsPrime(lngNumber)
On Error Resume Next
Dim lngCount, ngSqr
Dim x
lngSqr = Int(Sqr(lngNumber)) ' Get the int square root
If lngNumber < 2 Then
IsPrime = False
Exit Function
End If
lngCount = 2
IsPrime = True
If lngNumber Mod lngCount = 0 Then
IsPrime = False
Exit Function
End If
lngCount = 3
For x = lngCount To lngSqr Step 2
If lngNumber Mod x = 0 Then
IsPrime = False
Exit Function
End If
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
Public Function Encrypt(ByVal tIp)
Dim encSt, z
Dim strMult
Dim iEnc, iMod
Dim aKey : aKey=Split(KeyEnc,",")
If tIp = "" Then Exit Function End If
iEnc=Int(aKey(0))
iMod=Int(aKey(1))
For z = 1 To Len(tIp)
encSt = encSt & NumberToHex(Mult(CLng(Asc(Mid(tIp, z, 1))), iEnc, iMod),8)
Next
Encrypt = encSt
End Function
Public Function Decrypt(ByVal tIp)
Dim decSt, z
Dim iDec, iMod
Dim aKey : aKey=Split(KeyDec,",")
if Len(tIp) Mod 8 <> 0 then Exit Function End If
iDec=Int(aKey(0))
iMod=Int(aKey(1))
For z = 1 To Len(tIp) Step 8
decSt = decSt + Chr(Mult(HexToNumber(Mid(tIp, z, 8)), iDec, iMod))
Next
Decrypt = decSt
End Function
Public Function genKey()
'Generates the keys for E, D and N
Dim E, D, N, p, q
Const PQ_UP = 9999 'set upper limit of random number
Const PQ_LW = 3170 'set lower limit of random number
Const KEY_LOWER_LIMIT = 10000000 'set For 64bit minimum
p = 0: q = 0
Randomize
Do Until D > KEY_LOWER_LIMIT 'makes sure keys are 64bit minimum
Do Until IsPrime(p) And IsPrime(q) ' make sure q and q are primes
p = clng((PQ_UP - PQ_LW + 1) * Rnd + PQ_LW)
q = clng((PQ_UP - PQ_LW + 1) * Rnd + PQ_LW)
Loop
N = clng(p * q)
PHI = (p - 1) * (q - 1)
E = clng(GCD(PHI))
D = clng(Euler(E, PHI))
Loop
KeyEnc = E & "," & N
KeyDec = D & "," & N
genKey=E & "," & D & "," & N
End Function
Public Function setKey(ByVal a_sKey)
Dim aKeys : aKeys=Split(a_sKey,",")
setKey=false
KeyEnc=null
KeyDec=null
If UBound(aKeys)<2 Then Exit Function End If
KeyEnc=aKeys(0) & "," & aKeys(2)
KeyDec=aKeys(1) & "," & aKeys(2)
setKey=true
End Function
End Class
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