There are basically four methods to run a command in Visual C++. WinExec is provided only for compatibility with 16-bit Windows. Applications should use the CreateProcess function.
· system(), _wsystem() · ShellExecute() or ShellExecuteEx() · CreateProcess() · WinExec()
To get the name of files in a folder,
call the FindFirstFile function to open a search handle and get information about the first file that the file system find in the folder.
call the FindNextFile function to continue listing files from a previous call to FindFirstFile.
WIN32_FIND_DATA FindFileData;
HANDLE hFind;
TCHAR *FilePathBuff = L"C:RequiredFolder";
hFind = FindFirstFile(FilePathBuff, &FindFileData);
if (hFind == INVALID_HANDLE_VALUE) {
printf(TEXT("FindFirstFile failed (%d)n"), GetLastError());
}
else
{
printf(TEXT("The first file is %sn"), FindFileData.cFileName);
while (FindNextFile(hFind, &FindFileData) != 0)
{
printf(TEXT("The next file is %sn"), FindFileData.cFileName);
} FindClose(hFind);
}
Using Win32 API FindFirstFile we can find whether a given file exists in the given path (szFilePath) or not. BOOL IsFileExists( LPCTSTR szFilePath) method shown below serves our purpose.
BOOL IsFileExists( LPCTSTR szFilePath) // szFilePath in | file path
{
BOOL bFileExists;
WIN32_FIND_DATA FindFileData;
HANDLE hFind;
hFind = FindFirstFile(szFilePath, &FindFileData);
if (hFind == INVALID_HANDLE_VALUE)
{
bFileExists = FALSE;
} else {
FindClose(hFind);
bFileExists = TRUE;
}
return bFileExists;
}
Cryptography is the use of codes to convert data so that only a specific recipient will be able to read it. Microsoft provide win32 API to Hash Data/string. The class CHashDataProvider developed to provides simple function HashData(ALG_ID algorithmID, LPCTSTR plainText, LPTSTR hashedText); which takes algorithmID and inputText to convert plainText to hashedText
ALG_ID algorithmID - Algorithm ID to be used LPCTSTR plainText - plainText that to be converted to hashedText LPTSTR hashedText - Hashed Test using the input algorithmID.
CHashDataProvider Code
HashDataProvider.h
#include <wincrypt.h>;
#define BUFFER_SIZE 256
class CHashDataProvider
{
public:
CHashDataProvider(void);
~CHashDataProvider(void);
private:
// Handle to a cryptographic service provider (CSP)
HCRYPTPROV m_hProv;
// Handle to the hash object needed to create a hash.
HCRYPTHASH m_hHash;
// Pointer to the hash.
PBYTE m_pbHash;
private:
void FreeResources();
void InitializeData();
LPTSTR FormatData(PBYTE pbHash, DWORD dwDataLen, LPTSTR hashedText);
public:
bool HashData(ALG_ID algorithmID, LPCTSTR plainText, LPTSTR hashedText);
};
HashDataProvider.cpp
#include "HashDataProvider.h"
CHashDataProvider::CHashDataProvider(void)
{
InitializeData();
}
CHashDataProvider::~CHashDataProvider(void)
{
}
//\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
// des: Hashes data based on the ALG_ID
// return: Hashing of the text is sucessful or not
//\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*
bool
CHashDataProvider::HashData(ALG_ID algorithmID, // in | Algorithm ID (Sha1 or MD5 )
LPCTSTR plainText, // in | Original string to be hashed
LPTSTR hashedText) //out | string to store hashed text
{
InitializeData();
bool rc = true; // Default is success
DWORD dwDataLen = 0; // Length, in bytes, of the hash.
//--------------------------------------------------------------------
// Acquire a handle to the default RSA cryptographic service provider.
if (!CryptAcquireContext(
&m_hProv, // handle of the CSP
NULL, // key container name
NULL, // CSP name
PROV_RSA_FULL, // provider type
CRYPT_VERIFYCONTEXT)) // no key access is requested
{
AfxMessageBox("Error in AcquireContext 0x%08x n", GetLastError());
rc = false;
FreeResources();
}
if (!CryptCreateHash(
m_hProv, // handle of the CSP
algorithmID, // hash algorithm to use
0, // hash key
0, // reserved
&m_hHash)) // address of hash object handle
{
AfxMessageBox("Error in CryptCreateHash 0x%08x n", GetLastError());
rc = false;
FreeResources();
}
if (!CryptHashData(
m_hHash, // handle of the hash object
(const BYTE *) plainText, // text to be hash
_tcslen(plainText)*sizeof(TCHAR), // number of bytes of data
0)) // flags
{
AfxMessageBox("Error in CryptHashData 0x%08x n", GetLastError());
rc = false;
FreeResources();
}
if (!CryptGetHashParam(
m_hHash, // handle of the HMAC hash object
HP_HASHVAL, // query on the hash value
NULL, // pointer to the HMAC hash value
&dwDataLen, // length,in bytes, of the hash
0))
{
AfxMessageBox("Error in CryptGetHashParam 0x%08x n", GetLastError());
rc = false;
FreeResources();
}
m_pbHash = (BYTE\*)malloc(dwDataLen);
if(NULL == m_pbHash)
{
AfxMessageBox("unable to allocate memoryn");
rc = false;
FreeResources();
}
if (!CryptGetHashParam(
m_hHash, // handle of the HMAC hash object
HP_HASHVAL, // query on the hash value
m_pbHash, // pointer to the HMAC hash value
&dwDataLen, // length,in bytes, of the hash
0))
{
AfxMessageBox("Error in CryptGetHashParam 0x%08x n", GetLastError());
rc = false;
FreeResources();
}
hashedText = FormatData(m_pbHash, dwDataLen, hashedText);
FreeResources();
return rc;
}
//Helper functions
void CHashDataProvider::FreeResources()
{
if(m_hHash)
CryptDestroyHash(m_hHash);
if(m_hProv)
CryptReleaseContext(m_hProv, 0);
if(m_pbHash)
free(m_pbHash);
}
void CHashDataProvider::InitializeData()
{
m_hProv = NULL;
m_hHash = NULL;
m_pbHash = NULL;
}
LPTSTR CHashDataProvider::FormatData(PBYTE pbHash, DWORD dwDataLen, LPTSTR hashedText)
{
TCHAR rstData[BUFFER_SIZE]= {0}; // Buffer to receive hashed result
TCHAR tmpBuffer[3] = {0};
for (DWORD i = 0 ; i < dwDataLen ; i++)
{
tmpBuffer[0] = 0;
tmpBuffer[1] = 0;
tmpBuffer[2] = 0;
_stprintf_s(tmpBuffer, _T("%2.2x"), pbHash\[i\]);
_tcscat_s(rstData, tmpBuffer);
}
_tcscpy(hashedText, rstData);
return hashedText;
}