学步园

程序启动子进程时，子进程会自动使用当前进程的权限，包括ShellExecute启动的进程，都有这个问题。

当自己制作安装包时，安装包进程，在win7上，当前进程是管理员权限，启动的程序如果也以管理员权限运行，可能有问题，需要降低权限。

此函数的代码可以做到这一点，将当前进程的权限降低之后，再启动其他的进程。

BOOL CreateLowIntegrityProcess(LPCTSTR pszCommandLine)
{
    DWORD dwError = ERROR_SUCCESS;
    HANDLE hToken = NULL;
    HANDLE hNewToken = NULL;
    SID_IDENTIFIER_AUTHORITY MLAuthority = SECURITY_MANDATORY_LABEL_AUTHORITY;
    PSID pIntegritySid = NULL;
    TOKEN_MANDATORY_LABEL tml = { 0 };
    STARTUPINFO si = { sizeof(si) };
    PROCESS_INFORMATION pi = { 0 };

    // Open the primary access token of the process.
    if (!OpenProcessToken(GetCurrentProcess(), TOKEN_DUPLICATE | TOKEN_QUERY |
        TOKEN_ADJUST_DEFAULT | TOKEN_ASSIGN_PRIMARY, &hToken))
    {
        dwError = GetLastError();
        goto Cleanup;
    }

    // Duplicate the primary token of the current process.
    if (!DuplicateTokenEx(hToken, 0, NULL, SecurityImpersonation,
        TokenPrimary, &hNewToken))
    {
        dwError = GetLastError();
        goto Cleanup;
    }

    // Create the low integrity SID.
    if (!AllocateAndInitializeSid(&MLAuthority, 1, SECURITY_MANDATORY_MEDIUM_RID,

        0, 0, 0, 0, 0, 0, 0, &pIntegritySid))
    {
        dwError = GetLastError();
        goto Cleanup;
    }

    tml.Label.Attributes = SE_GROUP_INTEGRITY;
    tml.Label.Sid = pIntegritySid;

    // Set the integrity level in the access token to low.
    if (!SetTokenInformation(hNewToken, TokenIntegrityLevel, &tml,
        (sizeof(tml) + GetLengthSid(pIntegritySid))))
    {
        dwError = GetLastError();
        goto Cleanup;
    }

    // Create the new process at the Low integrity level.
    if (!CreateProcessAsUser(hNewToken, NULL, (LPWSTR) pszCommandLine, NULL, NULL,

        FALSE, 0, NULL, NULL, &si, &pi))
    {
        dwError = GetLastError();
        goto Cleanup;
    }

Cleanup:
    // Centralized cleanup for all allocated resources.
    if (hToken)
    {
        CloseHandle(hToken);
        hToken = NULL;
    }
    if (hNewToken)
    {
        CloseHandle(hNewToken);
        hNewToken = NULL;
    }
    if (pIntegritySid)
    {
        FreeSid(pIntegritySid);
        pIntegritySid = NULL;
    }
    if (pi.hProcess)
    {
        CloseHandle(pi.hProcess);
        pi.hProcess = NULL;
    }
    if (pi.hThread)
    {
        CloseHandle(pi.hThread);
        pi.hThread = NULL;
    }

    if (ERROR_SUCCESS != dwError)
    {
        // Make sure that the error code is set for failure.
        SetLastError(dwError);
        return FALSE;
    }
    else
    {
        return TRUE;
    }
}