保存用户名密码的另一种方式 CREDENTIALW

        在Windows客户端开发时，如果需要用户进行登录，那么很多时候都需要对用户密码进行保存。尤其是需要自动登录的时候！

        一般来说，可能会使用ini文件进行用户名密码的保存。稍有安全意识的，会对用户名密码进行加密，再保存。下面要介绍的是另一种保存用户名密码的实现方式：windows系统上的PCREDENTIALW（附赠string与wstring互转的代码）。示例代码如下：

#include <Windows.h>#include <wincred.h>#include <string>#include <tchar.h>//s2wsstd::wstring s2ws(const char* pStr, int len, unsigned int CodePage = CP_ACP){std::wstring buf;if(pStr == NULL || (len < 0 && len != -1)){return buf;}// figure out how many wide characters we are going to get int nChars = MultiByteToWideChar( CodePage, 0, pStr, len, NULL, 0 ); if ( len == -1 )--nChars; if ( nChars == 0 )return L"";// convert the narrow string to a wide string // nb: slightly naughty to write directly into the string like thisbuf.resize( nChars ); MultiByteToWideChar( CodePage, 0, pStr, len, const_cast<wchar_t*>(buf.c_str()), nChars ); return buf;}//ws2sstd::string ws2s(const wchar_t* pStr, int len, unsigned int CodePage = CP_ACP){std::string buf;if(pStr == NULL || (len < 0 && len != -1)){return buf;}// figure out how many narrow characters we are going to get int nChars = WideCharToMultiByte( CodePage, 0, pStr, len, NULL, 0, NULL, NULL ); if ( len == -1 )--nChars; if ( nChars == 0 )return "";// convert the wide string to a narrow string// nb: slightly naughty to write directly into the string like thisbuf.resize( nChars );WideCharToMultiByte( CodePage, 0, pStr, len, const_cast<char*>(buf.c_str()), nChars, NULL, NULL ); return buf;}bool WriteAccount(const std::string& username, const std::string& password) {    char password_chars[255] = { 0 };    wchar_t username_wstrs[255] = { 0 };    wchar_t target_name_wstrs[1024] = { 0 };    // password    strcpy(password_chars, password.c_str());    DWORD cbCreds = 1 + strlen(password_chars);    // username    std::wstring username_wstr = s2ws(username.c_str(), strlen(username.c_str()));    wcscpy(username_wstrs, username_wstr.c_str());    // target name    std::wstring target_name_wstr = L"YourAppName";    wcscpy(target_name_wstrs, target_name_wstr.c_str());    CREDENTIALW cred = { 0 };    cred.Type = CRED_TYPE_GENERIC;    cred.TargetName = target_name_wstrs;    cred.CredentialBlobSize = cbCreds;    cred.CredentialBlob = (LPBYTE)password_chars;    cred.Persist = CRED_PERSIST_LOCAL_MACHINE;    cred.UserName = username_wstrs;    return ::CredWriteW(&cred, 0);}bool ReadAccount(std::string& username, std::string& password){wchar_t username_wstrs[255] = { 0 };wchar_t target_name_wstrs[1024] = { 0 };// target namestd::wstring target_name_wstr = L"YourAppName";PCREDENTIALW pcred;BOOL success = false;do {success = ::CredReadW(target_name_wstr.c_str(), CRED_TYPE_GENERIC, 0, &pcred);if (!success){break;}std::wstring wszUserName = std::wstring(pcred->UserName);username = ws2s(wszUserName.c_str(), wcslen(wszUserName.c_str()));std::string pwd((char*)pcred->CredentialBlob, pcred->CredentialBlobSize);password = pwd;::CredFree(pcred);return true;} while (0);return false;}int _tmain(int argc, _TCHAR* argv[]){std::string szUserName = "admin";std::string szPassWord = "helloworld123456";WriteAccount(szUserName, szPassWord);std::string szUserNameOut;std::string szPassWordOut;ReadAccount(szUserNameOut, szPassWordOut);printf("username : %s, password : %s\r\n", szUserNameOut.c_str(), szPassWordOut.c_str());system("pause");return 0;}