CODEWITHSUNDEEP
c++windows
anegru
anegru

Reputation: 1123

Security id structure is invalid error when calling NetLocalGroupAddMembers from WindowsAPI

I want to add a user to local Administrators group using NetLocalGroupAddMembers function from the Windows API. 

    NET_API_STATUS nStatus;
    DWORD dwLevel = 0;
    LOCALGROUP_INFO_0 localGroupInformation;

    localGroupInformation.lgrpi0_name = username;

    nStatus = NetLocalGroupAddMembers(
        NULL,
        TEXT("Administrators"),
        dwLevel,
        (LPBYTE)& localGroupInformation,
        1
    );

However when I use the following command it works:

net localgroup Administrators username /add

Thank you.

Upvotes: 1

Views: 263

Answers (1)

Castorix
Castorix

Reputation: 1545

You must use the User SID and LOCALGROUP_MEMBERS_INFO_0 structure.

Something like this =>

        WCHAR wsName[256] = L"test";
        DWORD dwSidSize = 0;
        DWORD dwDomainSize = 0;
        SID_NAME_USE snu;
        LPWSTR pwszDomain = NULL;
        PSID pSid = NULL;
        LookupAccountName(NULL, wsName, NULL, &dwSidSize, NULL, &dwDomainSize, &snu);
        DWORD dwErr = GetLastError();
        if (dwErr == ERROR_INSUFFICIENT_BUFFER)
        {
            pSid = (PSID)LocalAlloc(LPTR, dwSidSize);
            pwszDomain = (PWSTR)LocalAlloc(LPTR, dwDomainSize * sizeof(WCHAR));
            if (!LookupAccountName(NULL, wsName, pSid, &dwSidSize, pwszDomain, &dwDomainSize, &snu))
            {
                // Handle error
            }
        }
        if (pwszDomain != NULL)
            LocalFree(pwszDomain);
        if (pSid)
        {
            NET_API_STATUS nStatus;
            DWORD dwLevel = 0;
            LOCALGROUP_MEMBERS_INFO_0 localGroupMemberInfo;
            localGroupMemberInfo.lgrmi0_sid = pSid;
            nStatus = NetLocalGroupAddMembers(
                NULL,
                TEXT("Administrators"),
                dwLevel,
                (LPBYTE)&localGroupMemberInfo,
                1
            );
            // Test nStatus...
            LocalFree(pSid);
        }

Upvotes: 1

Related Questions