CryptAPI函数调用实例(修改后)

#include "stdafx.h" #include "CEncrypt.h" #include <stdio.h> //******************************************************************************* // temporary //******************************************************************************* #include "CryptErr.h" //******************************************************************************* // Constructor[s] and Destructor //******************************************************************************* CEncrypt::CEncrypt(LPSTR pCryptContainer, LPSTR pCryptProvider, DWORD dwProviderType, DWORD dwFlags) { BOOL bResult; // set last error flag to success value m_dwLastError = 0L; // set initialization flag m_bInitialized = TRUE; // get specified context provider bResult = ::CryptAcquireContext( &this->m_hCryptProvider, // save the returned handle of CSP provider pCryptContainer, // the appoint key container pCryptProvider, // the CSP provider dwProviderType, // the type of the CSP dwFlags); // conduct a new key container // if cannot do so then error if (!bResult) { this->m_dwLastError = GetLastError(); this->m_bInitialized = FALSE; WhatIsError(TRUE, 0, "CryptAcquireContext Error"); } } CEncrypt::~CEncrypt() { // release context provider if one acquired earlier if (m_bInitialized) { ::CryptReleaseContext(this->m_hCryptProvider, 0); } } //******************************************************************************* // User Initialization & Destruction //******************************************************************************* int CEncrypt::AddUser() { HCRYPTPROV hProv; HCRYPTKEY hKey; CHAR szUserName[100]; DWORD dwUserNameLen = 100; int iReturnCode = ENCRYPT_SUCCESS; // return error if not initialized if (!m_bInitialized) { return(ENCRYPT_NOTINITIALIZED); } // Attempt to acquire a handle to the default key container. if (!::CryptAcquireContext( &hProv, NULL, MS_DEF_PROV, PROV_RSA_FULL, 0)) { // Some sort of error occured. // Create default key container. if(!::CryptAcquireContext( &hProv, NULL, MS_DEF_PROV, PROV_RSA_FULL, CRYPT_NEWKEYSET)) { this->m_dwLastError = GetLastError(); WhatIsError(TRUE, 0, "Error Creating key container"); return(ENCRYPT_CRYPTAPIERROR); } // Get name of default key container. if(!::CryptGetProvParam( hProv, PP_CONTAINER, (BYTE *)szUserName, &dwUserNameLen, 0)) { // Error getting key container name. szUserName[0] = 0; } } // Attempt to get handle to signature key. if(!::CryptGetUserKey(hProv, AT_SIGNATURE, &hKey)) { if(GetLastError() == NTE_NO_KEY) { // Create signature key pair. if(!::CryptGenKey(hProv,AT_SIGNATURE,0,&hKey)) { this->m_dwLastError = GetLastError(); WhatIsError(TRUE, 0, "CryptGenKey Error"); return(ENCRYPT_CRYPTAPIERROR); } else { ::CryptDestroyKey(hKey); } } else { this->m_dwLastError = GetLastError(); WhatIsError(TRUE, 0, "CryptGetUserKey Error"); return(ENCRYPT_CRYPTAPIERROR); } } // Attempt to get handle to exchange key. if(!::CryptGetUserKey(hProv,AT_KEYEXCHANGE,&hKey)) { if(GetLastError()==NTE_NO_KEY) { // Create key exchange key pair. if(!::CryptGenKey(hProv,AT_KEYEXCHANGE,0,&hKey)) { this->m_dwLastError = GetLastError(); WhatIsError(TRUE, 0, "CryptGenKey Error"); return(ENCRYPT_CRYPTAPIERROR); } else { ::CryptDestroyKey(hKey); } } else { this->m_dwLastError = GetLastError(); WhatIsError(TRUE, 0, "CryptGetUserKey Error"); return(ENCRYPT_CRYPTAPIERROR); } } ::CryptReleaseContext(hProv,0); return(iReturnCode); } BOOL CEncrypt::RemoveUser() { HCRYPTPROV hProv; int iReturnCode = ENCRYPT_SUCCESS; // Attempt to delete key set if (!::CryptAcquireContext( &hProv, NULL, MS_DEF_PROV, PROV_RSA_FULL, CRYPT_DELETEKEYSET)) { this->m_dwLastError = GetLastError(); WhatIsError(TRUE, 0, "Error deleting key set"); iReturnCode = ENCRYPT_CRYPTAPIERROR; } return(iReturnCode); } //******************************************************************************* // Encryption & decryption member functions //******************************************************************************* DWORD CEncrypt::RequiredBufferSize(DWORD dwBufferSize) { DWORD dwBufferLen = 0; return(dwBufferLen); } int CEncrypt::EncryptBuffer(LPSTR pBuffer, DWORD dwSize, LPSTR pPassword) { int iReturnCode = ENCRYPT_SUCCESS; // return error if not initialized if (!m_bInitialized) { return(ENCRYPT_NOTINITIALIZED); } return(iReturnCode); } int CEncrypt::DecryptBuffer(LPSTR pBuffer, DWORD dwSize, LPSTR pPassword) { int iReturnCode = ENCRYPT_SUCCESS; // return error if not initialized if (!m_bInitialized) { return(ENCRYPT_NOTINITIALIZED); } return(iReturnCode); } int CEncrypt::EncryptFile(LPSTR pInputFile, LPSTR pOutputFile, LPSTR pPassword) { int iReturnCode = ENCRYPT_SUCCESS; FILE *hSource = NULL; FILE *hDestination = NULL; HCRYPTKEY hKey = 0; // return error if not initialized if (!m_bInitialized) { return(ENCRYPT_NOTINITIALIZED); } // set last error flag to success value this->m_dwLastError = 0L; // Open source and destination files if (this->OpenSrcAndDstFiles(pInputFile, &hSource, pOutputFile, &hDestination) == ENCRYPT_SUCCESS) { // see if password was supplied if (pPassword == NULL) { // Create a random session key. ::CryptGenKey(this->m_hCryptProvider, ENCRYPT_ALGORITHM, CRYPT_EXPORTABLE, &hKey); // export key to file this->PutKeyBlobToFile(hDestination, hKey); } else { // Derive a session key from the hashed password hKey = this->GetKeyFromHashedPassword(this->m_hCryptProvider, pPassword); } // encrypt source file into destionation file ProcessSrcAndDstFiles(hKey, FALSE, &hSource, &hDestination); } // Close files. CloseSrcAndDstFiles(&hSource, &hDestination); // Destroy session key. ::CryptDestroyKey(hKey); return(iReturnCode); } int CEncrypt::DecryptFile(LPSTR pInputFile, LPSTR pOutputFile, LPSTR pPassword) { int iReturnCode = ENCRYPT_SUCCESS; FILE *hSource = NULL; FILE *hDestination = NULL; HCRYPTKEY hKey = 0; // return error if not initialized if (!m_bInitialized) { return(ENCRYPT_NOTINITIALIZED); } // set last error flag to success value this->m_dwLastError = 0L; // Open source and destination files if (this->OpenSrcAndDstFiles(pInputFile, &hSource, pOutputFile, &hDestination) == ENCRYPT_SUCCESS) { // see if password was supplied if(pPassword == NULL) { // Decrypt the file with the saved session key. hKey = this->GetKeyBlobFromFile(hSource); } else { // Decrypt the file with a session key derived from a password. hKey = this->GetKeyFromHashedPassword(this->m_hCryptProvider, pPassword); } // decrypt source file into destionation file ProcessSrcAndDstFiles(hKey, FALSE, &hSource, &hDestination); } // Close files. CloseSrcAndDstFiles(&hSource, &hDestination); // Destroy session key. ::CryptDestroyKey(hKey); return(iReturnCode); } //******************************************************************************* // Key & Password member functions //******************************************************************************* HCRYPTKEY CEncrypt::GetKeyFromHashedPassword(HCRYPTPROV hProv, LPSTR pPassword) { HCRYPTKEY hKey = (HCRYPTKEY)NULL; HCRYPTKEY hHash; // Create a hash object. if (::CryptCreateHash(hProv, CALG_MD5, 0, 0, &hHas