RSA加密算法的API函数在VB中怎么用?(Crypto API)

[freedomjim]

现在做网络通讯中数据加密
应用程序使用API进行加密通讯的一般步骤:
1)包含头文件 wincrypt.h
2)调用CryptAcquireContext()函数获取某个CSP模块中的密钥容器的一个句柄
3)发送方使用CryptImportKey()将接收方的证书导入CSP中,获取接收方的公钥
4)发送方用CryptGenKey()随机生成一个会话密钥,用(刚刚的到的接收方公钥)进行加密
用CryptExportKey()将加密后的会话密钥导出并发送给对方
5)接收方收到加密会话密钥后,用自己的私钥调用CryptImportKey(),将会话密钥截取出来
6)发送方用会话密钥调用CryptEncrypt()加密数据,发给对方
7)接收方收到加密后的数据,用会话密钥调用CryptDecrypt(),对数据进行解密
8)通讯完毕,调用CryptDestroyKey()释放任何密钥句柄,再用CryptReleaseContext()释放
最初获取的CSP句柄资源



有谁能把上面的API函数的VB用法告诉我吗?主要是参数类型问题
如果有例子就更好了

[online]

呵呵
前段时间找的一个
你看看
留下email

[Geo_Cra]

寒，原来有API啊……
我还自己写的RSA实现……

[rainstormmaster]

'Paste this code in a Class Module, named clsCryptoFilterBox

Option Explicit
Private Declare Function CryptAcquireContext Lib "advapi32.dll" Alias "CryptAcquireContextA" (phProv As Long, pszContainer As String, pszProvider As String, ByVal dwProvType As Long, ByVal dwFlags As Long) As Long
Private Declare Function CryptCreateHash Lib "advapi32.dll" (ByVal hProv As Long, ByVal Algid As Long, ByVal hKey As Long, ByVal dwFlags As Long, phHash As Long) As Long
Private Declare Function CryptDeriveKey Lib "advapi32.dll" (ByVal hProv As Long, ByVal Algid As Long, ByVal hBaseData As Long, ByVal dwFlags As Long, phKey As Long) As Long
Private Declare Function CryptDestroyHash Lib "advapi32.dll" (ByVal hHash As Long) As Long
Private Declare Function CryptDestroyKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Private Declare Function CryptEncrypt Lib "advapi32.dll" (ByVal hKey As Long, ByVal hHash As Long, ByVal Final As Long, ByVal dwFlags As Long, ByVal pbData As String, pdwDataLen As Long, ByVal dwBufLen As Long) As Long
Private Declare Function CryptDecrypt Lib "advapi32.dll" (ByVal hKey As Long, ByVal hHash As Long, ByVal Final As Long, ByVal dwFlags As Long, ByVal pbData As String, pdwDataLen As Long) As Long
Private Declare Function CryptExportKey Lib "advapi32.dll" (ByVal hKey As Long, ByVal hExpKey As Long, ByVal dwBlobType As Long, ByVal dwFlags As Long, ByVal pbData As String, pdwDataLen As Long) As Long
Private Declare Function CryptGenKey Lib "advapi32.dll" (ByVal hProv As Long, ByVal Algid As Long, ByVal dwFlags As Long, phKey As Long) As Long
Private Declare Function CryptGetProvParam Lib "advapi32.dll" (ByVal hProv As Long, ByVal dwParam As Long, pbData As Any, pdwDataLen As Long, ByVal dwFlags As Long) As Long
Private Declare Function CryptGetUserKey Lib "advapi32.dll" (ByVal hProv As Long, ByVal dwKeySpec As Long, phUserKey As Long) As Long
Private Declare Function CryptHashData Lib "advapi32.dll" (ByVal hHash As Long, ByVal pbData As String, ByVal dwDataLen As Long, ByVal dwFlags As Long) As Long
Private Declare Function CryptReleaseContext Lib "advapi32.dll" (ByVal hProv As Long, ByVal dwFlags As Long) As Long
Private Declare Function CryptSignHash Lib "advapi32.dll" Alias "CryptSignHashA" (ByVal hHash As Long, ByVal dwKeySpec As Long, ByVal sDescription As String, ByVal dwFlags As Long, ByVal pbSignature As String, pdwSigLen As Long) As Long
Private Declare Function CryptVerifySignature Lib "advapi32.dll" Alias "CryptVerifySignatureA" (ByVal hHash As Long, ByVal pbSignature As String, ByVal dwSigLen As Long, ByVal hPubKey As Long, ByVal sDescription As String, ByVal dwFlags As Long) As Long

'API error function
Private Declare Function GetLastError Lib "kernel32" () As Long

'API memory functions
Private Declare Function GlobalAlloc Lib "kernel32" (ByVal wFlags As Long, ByVal dwBytes As Long) As Long
Private Declare Function GlobalFree Lib "kernel32" (ByVal hMem As Long) As Long
Private Declare Function GlobalLock Lib "kernel32" (ByVal hMem As Long) As Long
Private Declare Function GlobalUnlock Lib "kernel32" (ByVal hMem As Long) As Long
Private Declare Sub CpyMemValAdrFromRefAdr Lib "kernel32" Alias "RtlMoveMemory" (ByVal hpvDest As Any, hpvSource As Any, ByVal cbCopy As Long)
Private Declare Sub CpyMemRefAdrFromValAdr Lib "kernel32" Alias "RtlMoveMemory" (hpvDest As Any, ByVal hpvSource As Any, ByVal cbCopy As Long)

'constants for API memory functions
Private Const GMEM_MOVEABLE = &H2
Private Const GMEM_ZEROINIT = &H40
Private Const GHND = (GMEM_MOVEABLE Or GMEM_ZEROINIT)

'constants for Cryptography API functions
Private Const MS_DEF_PROV = "Microsoft Base Cryptographic Provider v1.0"
Private Const PROV_RSA_FULL = 1
Private Const CRYPT_NEWKEYSET = &H8
Private Const PP_CONTAINER = 6
Private Const AT_KEYEXCHANGE = 1
Private Const AT_SIGNATURE = 2

Private Const SIMPLEBLOB = 1

Private Const ALG_CLASS_DATA_ENCRYPT = 24576
Private Const ALG_CLASS_HASH = 32768
Private Const ALG_TYPE_ANY = 0
Private Const ALG_TYPE_BLOCK = 1536
Private Const ALG_TYPE_STREAM = 2048
Private Const ALG_SID_RC2 = 2
Private Const ALG_SID_RC4 = 1
Private Const ALG_SID_MD5 = 3

Private Const CALG_MD5 = ((ALG_CLASS_HASH Or ALG_TYPE_ANY) Or ALG_SID_MD5)
Private Const CALG_RC2 = ((ALG_CLASS_DATA_ENCRYPT Or ALG_TYPE_BLOCK) Or ALG_SID_RC2)
Private Const CALG_RC4 = ((ALG_CLASS_DATA_ENCRYPT Or ALG_TYPE_STREAM) Or ALG_SID_RC4)

'constants from WinErr.h
Private Const NTE_NO_KEY As Long = -2146893811 '0x8009000DL
Private Const NTE_BAD_SIGNATURE As Long = -2146893818

'clsCryptoFilterBox constants
Private Const CFB_BUSY = 0
Private Const CFB_READY = 1
Private Const CFB_VALID = 2

Private Const ENCRYPT_ALGORITHM = CALG_RC4
Private Const ENCRYPT_BLOCK_SIZE = 1

Private Const CRYPT_EXPORTABLE = 1

'private property buffers
Private sInBuffer As String
Private sOutBuffer As String
Private sPassword As String
Private sSignature As String
Private lStatus As Long
Public Property Get InBuffer() As String
InBuffer = sInBuffer
End Property
Public Property Let InBuffer(vNewValue As String)
sInBuffer = vNewValue
End Property
Public Property Get OutBuffer() As String
OutBuffer = sOutBuffer
End Property
Public Property Get Signature() As String
Signature = sSignature
End Property
Public Property Let Signature(vNewValue As String)
sSignature = vNewValue
End Property
Public Sub Sign()
'Create a signature for Inbuffer and place in Signature

Dim sContainer As String, sDescription As String, sProvider As String, lHCryptprov As Long
Dim lHHash As Long, lResult As Long, lSignatureLen As Long

On Error GoTo ErrSign

'switch Status property
lStatus = CFB_BUSY

[rainstormmaster]

'init Signature property
sSignature = ""

'Get handle to the default provider.
sContainer = vbNullChar
sProvider = MS_DEF_PROV & vbNullChar
If Not CBool(CryptAcquireContext(lHCryptprov, ByVal sContainer, ByVal sProvider, PROV_RSA_FULL, 0)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptAcquireContext!")
GoTo ReleaseHandles:
End If

'Create a hash object.
If Not CBool(CryptCreateHash(lHCryptprov, CALG_MD5, 0, 0, lHHash)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptCreateHash!")
GoTo ReleaseHandles:
End If

If Not CBool(CryptHashData(lHHash, sInBuffer, Len(sInBuffer), 0)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptHashData!")
GoTo ReleaseHandles:
End If

'Sign hash object.
'Determine size of signature.
sDescription = vbNullChar
lResult = CryptSignHash(lHHash, AT_SIGNATURE, sDescription, 0, sSignature, lSignatureLen)

sSignature = String(lSignatureLen, vbNullChar)

'Sign hash object (with signature key).
If Not CBool(CryptSignHash(lHHash, AT_SIGNATURE, sDescription, 0, sSignature, lSignatureLen)) Then
MsgBox ("Error " & CStr(GetLastError()) & " during CryptSignHash")
GoTo ReleaseHandles:
End If

ReleaseHandles:
'Destroy hash object.
If lHHash Then lResult = CryptDestroyHash(lHHash)
'Release provider handle.
If lHCryptprov Then lResult = CryptReleaseContext(lHCryptprov, 0)

'switch Status property
lStatus = CFB_READY

Exit Sub

ErrSign:
MsgBox ("ErrSign " & Error$)
GoTo ReleaseHandles
End Sub

Public Sub Validate()
'Validate InBuffer with Signature and assign Status with result
Dim bValid As Boolean, sContainer As String, sDescription As String, sProvider As String
Dim lDataLen As Long, lDataPoint As Long, lHCryptprov As Long, lHHash As Long
Dim lResult As Long, lSignatureLen As Long, lHCryptKey As Long

ReDim aByteData(0) As Byte

On Error GoTo ErrValidate

'switch Status property
lStatus = CFB_BUSY

'init internal valid flag
bValid = True

'Get handle to the default provider.
sContainer = vbNullChar
sProvider = MS_DEF_PROV & vbNullChar
If Not CBool(CryptAcquireContext(lHCryptprov, ByVal sContainer, ByVal sProvider, PROV_RSA_FULL, 0)) Then
bValid = False
MsgBox ("Error " & CStr(GetLastError) & " during CryptAcquireContext!")
GoTo ReleaseHandles:
End If

'Create a hash object.
If Not CBool(CryptCreateHash(lHCryptprov, CALG_MD5, 0, 0, lHHash)) Then
bValid = False
MsgBox ("Error " & CStr(GetLastError) & " during CryptCreateHash!")
GoTo ReleaseHandles:
End If

'Add data to hash object.
If Not CBool(CryptHashData(lHHash, sInBuffer, Len(sInBuffer), 0)) Then
bValid = False
MsgBox ("Error " & CStr(GetLastError) & " during CryptHashData!")
GoTo ReleaseHandles:
End If

'Determine size of signature.
'sDescription = vbNullChar
'lResult = CryptSignHash(lHHash, AT_SIGNATURE, sDescription, 0, 0, lSignatureLen)

'Get handle to signature key.
If Not CBool(CryptGetUserKey(lHCryptprov, AT_SIGNATURE, lHCryptKey)) Then
bValid = False
MsgBox ("Error " & CStr(GetLastError) & " during CryptGetUserKey!")
GoTo ReleaseHandles:
End If

lSignatureLen = Len(sSignature)

'Verify signature.
If Not CBool(CryptVerifySignature(lHHash, sSignature, lSignatureLen, lHCryptKey, sDescription, 0)) Then

If GetLastError = NTE_BAD_SIGNATURE Then
bValid = False
GoTo ReleaseHandles:
Else
bValid = False
MsgBox ("Error " & CStr(GetLastError) & " during CryptVerifySignature!")
GoTo ReleaseHandles:
End If

End If

ReleaseHandles:
'Release signature key.
If lHCryptKey Then lResult = CryptDestroyKey(lHCryptKey)
'Destroy hash object.
If lHHash Then lResult = CryptDestroyHash(lHHash)
'Release provider handle.
If lHCryptprov Then lResult = CryptReleaseContext(lHCryptprov, 0)

Select Case bValid
Case True
lStatus = CFB_VALID
Case Else
lStatus = CFB_READY
End Select

Exit Sub

ErrValidate:
MsgBox ("ErrValidate " & Error$)
Resume

End Sub
Public Sub Encrypt()
'Encrypt InBuffer into OutBuffer

Dim lHExchgKey As Long, lHCryptprov As Long, lHHash As Long, lHkey As Long
Dim lResult As Long, sContainer As String, sProvider As String, sCryptBuffer As String
Dim lCryptLength As Long, lCryptBufLen As Long

On Error GoTo ErrEncrypt

'switch Status property
lStatus = CFB_BUSY

'Get handle to the default provider
sContainer = vbNullChar
sProvider = vbNullChar
sProvider = MS_DEF_PROV & vbNullChar
If Not CBool(CryptAcquireContext(lHCryptprov, ByVal sContainer, ByVal sProvider, PROV_RSA_FULL, 0)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptAcquireContext!")
GoTo Done
End If

'Create a hash object.
If Not CBool(CryptCreateHash(lHCryptprov, CALG_MD5, 0, 0, lHHash)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptCreateHash!")
GoTo Done
End If

'Hash in the password data.
If Not CBool(CryptHashData(lHHash, sPassword, Len(sPassword), 0)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptHashData!")
GoTo Done
End If

[rainstormmaster]

'Derive a session key from the hash object.
If Not CBool(CryptDeriveKey(lHCryptprov, ENCRYPT_ALGORITHM, lHHash, 0, lHkey)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptDeriveKey!")
GoTo Done
End If

'Destroy the hash object.
CryptDestroyHash (lHHash)
lHHash = 0

'Prepare a string buffer for the CryptEncrypt function
lCryptLength = Len(sInBuffer)
lCryptBufLen = lCryptLength * 2
sCryptBuffer = String(lCryptBufLen, vbNullChar)
LSet sCryptBuffer = sInBuffer

'Encrypt data
If Not CBool(CryptEncrypt(lHkey, 0, 1, 0, sCryptBuffer, lCryptLength, lCryptBufLen)) Then
MsgBox ("bytes required:" & CStr(lCryptLength))
MsgBox ("Error " & CStr(GetLastError) & " during CryptEncrypt!")
'GoTo Done
End If

sOutBuffer = Mid$(sCryptBuffer, 1, lCryptLength)

Done:

'Destroy session key.
If (lHkey) Then lResult = CryptDestroyKey(lHkey)

'Release key exchange key handle.
If lHExchgKey Then CryptDestroyKey (lHExchgKey)

'Destroy hash object.
If lHHash Then CryptDestroyHash (lHHash)

'Release provider handle.
If lHCryptprov Then lResult = CryptReleaseContext(lHCryptprov, 0)

'switch Status property
lStatus = CFB_READY

Exit Sub

ErrEncrypt:

MsgBox ("ErrEncrypt " & Error$)
Resume

End Sub
Public Sub Decrypt()
'Decrypt InBuffer into OutBuffer
Dim lHExchgKey As Long, lHCryptprov As Long, lHHash As Long, lHkey As Long
Dim lResult As Long, sContainer As String, sProvider As String
Dim sCryptBuffer As String, lCryptBufLen As Long, lCryptPoint As Long
Dim lPasswordPoint As Long, lPasswordCount As Long

On Error GoTo ErrDecrypt

'switch Status property
lStatus = CFB_BUSY

'Init sOutBuffer
sOutBuffer = ""

'Get handle to the default provider.
sContainer = vbNullChar
sProvider = vbNullChar
sProvider = MS_DEF_PROV & vbNullChar
If Not CBool(CryptAcquireContext(lHCryptprov, ByVal sContainer, ByVal sProvider, PROV_RSA_FULL, 0)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptAcquireContext!")
GoTo Done
End If

'Create a hash object.
If Not CBool(CryptCreateHash(lHCryptprov, CALG_MD5, 0, 0, lHHash)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptCreateHash!")
GoTo Done
End If

'Hash in the password data.
If Not CBool(CryptHashData(lHHash, sPassword, Len(sPassword), 0)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptHashData!")
GoTo Done
End If

'Derive a session key from the hash object.
If Not CBool(CryptDeriveKey(lHCryptprov, ENCRYPT_ALGORITHM, lHHash, 0, lHkey)) Then
MsgBox ("Error " & CStr(GetLastError) & " during CryptDeriveKey!")
GoTo Done
End If

'Destroy the hash object.
CryptDestroyHash (lHHash)
lHHash = 0

'Prepare sCryptBuffer for CryptDecrypt
lCryptBufLen = Len(sInBuffer) * 2
sCryptBuffer = String(lCryptBufLen, vbNullChar)
LSet sCryptBuffer = sInBuffer

'Decrypt data
If Not CBool(CryptDecrypt(lHkey, 0, 1, 0, sCryptBuffer, lCryptBufLen)) Then
MsgBox ("bytes required:" & CStr(lCryptBufLen))
MsgBox ("Error " & CStr(GetLastError) & " during CryptDecrypt!")
GoTo Done
End If

'Apply decrypted string from sCryptBuffer to private buffer for OutBuffer property
sOutBuffer = Mid$(sCryptBuffer, 1, Len(sInBuffer))

Done:

'Destroy session key.
If (lHkey) Then lResult = CryptDestroyKey(lHkey)

'Release key exchange key handle.
If lHExchgKey Then CryptDestroyKey (lHExchgKey)

'Destroy hash object.
If lHHash Then CryptDestroyHash (lHHash)

'Release provider handle.
If lHCryptprov Then lResult = CryptReleaseContext(lHCryptprov, 0)

'switch Status property
lStatus = CFB_READY

Exit Sub

ErrDecrypt:
MsgBox ("ErrDecrypt " & Error$)
GoTo Done

End Sub
Public Property Get Status() As Long
Status = lStatus
End Property
Private Function InitUser() As Long
Dim lHCryptprov As Long, lHCryptKey As Long, avProviderData(1000) As Byte
Dim lProviderDataAddress As Long, lProviderDataLen As Long, lDataSize As Long
Dim lResult As Long, sContainer As String, sProvider As String
Dim sUserName As String, lPoint As Long, lMemHandle As Long
Dim lReturn As Long, sBuffer As String

On Error GoTo ErrInitUser
'prepare string buffers

sContainer = vbNullChar
sProvider = MS_DEF_PROV & vbNullChar

'Attempt to acquire a handle to the default key container.
If Not CBool(CryptAcquireContext(lHCryptprov, ByVal sContainer, ByVal sProvider, PROV_RSA_FULL, 0)) Then

'Create default key container.
If Not CBool(CryptAcquireContext(lHCryptprov, ByVal sContainer, ByVal sProvider, PROV_RSA_FULL, CRYPT_NEWKEYSET)) Then
MsgBox ("Error creating key container! " & CStr(GetLastError))
Exit Function
End If

'Get name of default key container.
lProviderDataLen = Len(avProviderData(0)) * (UBound(avProviderData) + 1)
If Not CBool(CryptGetProvParam(lHCryptprov, PP_CONTAINER, avProviderData(0), lProviderDataLen, 0)) Then
MsgBox ("Error getting user name! " & CStr(GetLastError))
avProviderData(0) = 0
End If

'Get sUserName from avProviderData()
lPoint = LBound(avProviderData)
While lPoint <= UBound(avProviderData)
If avProviderData(lPoint) <> 0 Then
sUserName = sUserName & Chr$(avProviderData(lPoint))
Else
lPoint = UBound(avProviderData)
End If
lPoint = lPoint + 1
Wend

MsgBox ("Create key container " & sUserName)

End If

'Attempt to get handle to signature key
If Not CBool(CryptGetUserKey(lHCryptprov, AT_SIGNATURE, lHCryptKey)) Then
If GetLastError = NTE_NO_KEY Then
MsgBox ("Create key exchange key pair")
If Not CBool(CryptGenKey(lHCryptprov, AT_SIGNATURE, 0, lHCryptKey)) Then
MsgBox ("Error during CryptGenKey! " & CStr(GetLastError))
Exit Function
Else
lResult = CryptDestroyKey(lHCryptprov)
End If
Else
MsgBox ("Error during CryptGetUserKey! " & CStr(GetLastError))
Exit Function
End If
End If

'Attempt to get handle to exchange key
If Not CBool(CryptGetUserKey(lHCryptprov, AT_KEYEXCHANGE, lHCryptKey)) Then
If GetLastError = NTE_NO_KEY Then
MsgBox ("Create key exchange key pair")
If Not CBool(CryptGenKey(lHCryptprov, AT_KEYEXCHANGE, 0, lHCryptKey)) Then
MsgBox ("Error during CryptGenKey! " & CStr(GetLastError))
Exit Function
Else
lResult = CryptDestroyKey(lHCryptprov)
End If
Else
MsgBox ("Error during CryptGetUserKey! " & CStr(GetLastError))
Exit Function
End If
End If

'release handle to provider
lResult = CryptReleaseContext(lHCryptprov, 0)
InitUser = True

Exit Function

ErrInitUser:
MsgBox ("ErrInitUser " & Error$)
Resume

End Function
Private Sub Class_Initialize()
If InitUser = True Then
MsgBox ("InitUser OK")
Else
MsgBox ("InitUser failed")
End If
End Sub
Public Property Get Password() As String
Password = sPassword
End Property
Public Property Let Password(vNewValue As String)
sPassword = vNewValue
End Property

[freedomjim]

////online(龙卷风V2.0--再战江湖)
已经收到
谢谢!

[freedomjim]

////online(龙卷风V2.0--再战江湖)
你好，我的e-mail是：[e-mail]
发给我好吗？
谢谢！

[bluesky23]

学习，呵呵
UP

[raidenzxx]

NB,First
非常不错的回复!

[freedomjim]

////rainstormmaster(暴风雨 v2.0)
你好，经过研究,你的方法主要是用在数字签名方面
当然,对我来说很有帮助了
谢谢!!
不过不知到能不能把该类的使用例子也发给我?
有写初值话的问题我对它搞的不是很清楚
谢谢!

[online]

已经发送
注意查收

[Geo_Cra]

RSA算法例子：

http://www.aivisoft.net/Source/VB_RSA.zip

[freedomjim]

////online(龙卷风V2.0--再战江湖)
////rainstormmaster(暴风雨 v2.0)
我研究过你们的程序
在我研究的过程中总是产生一个问题就是都没说到密钥对的生成
究竟公钥，私钥这两个密钥对是怎么用算法来生成的？
我看过简单的说明，但都没有说到具体的算法

[Geo_Cra]

RSA 原理：

选取两个不同的大素数p、q，并计算N=p*q
选取小素数d，并计算e，使d*e % (p-1)(q-1)=1

对于任意A<N：

若B=A**d % N
则A=B**e % N

可见d、e形成了非对称秘钥关系，加密者用公钥d加密，解密者可用私钥e解密，第
三者即使拦截了密文B、公钥d和N，在不知道p、q的前提下，无法推算出e，从而无
法获得明文A。当N取非常大的值时，将其因式分解成p、q是非常困难的，例如当N
为1024 bit时，据分析，需动用价值数千万美金的大型计算机系统并耗费一年的时
间。

[freedomjim]

本人用 ////Geo_Cra(锺意阿芙洛蒂忒)
提供的例子做个一个dll来调用,速度还可以

但是用微软的API怎么就是不行呢?
而且好像做起来很复杂
有没有那位对它进行一定的封装??

[laozhaoskinny]

ding
好贴收藏之。

[hxy2003]

RSA原理。。。U。

[freedomjim]

RSA 原理：

选取两个不同的大素数p、q，并计算N=p*q
选取小素数d，并计算e，使d*e % (p-1)(q-1)=1

对于任意A<N：

若B=A**d % N
则A=B**e % N

可见d、e形成了非对称秘钥关系，加密者用公钥d加密，解密者可用私钥e解密，第
三者即使拦截了密文B、公钥d和N，在不知道p、q的前提下，无法推算出e，从而无
法获得明文A。当N取非常大的值时，将其因式分解成p、q是非常困难的，例如当N
为1024 bit时，据分析，需动用价值数千万美金的大型计算机系统并耗费一年的时
间。

RSA 密钥的选取和加解密过程都非常简洁，在算法上主要要实现四个问题：

1、如何处理大数运算
2、如何求解同余方程 XY % M = 1
3、如何快速进行模幂运算
4、如何获取大素数

[freedomjim]

问题已经解决
谢谢大家的帮助
只是现在用了vc自己写算法来实现
没有用到微软的api
不过速度还可以
再次谢谢
////online(龙卷风V2.0--再战江湖)
////rainstormmaster(暴风雨 v2.0) ( )
////Geo_Cra(锺意阿芙洛蒂忒) ( )
的帮助

[freedomjim]

以上用用vc写的dll，如果有谁要可以跟我联系 [e-mail]