How to create directory with all rights granted to everyone

Question

I need to programmatically create a directory that grants "Full Control" to the group "Everyone". If I use

CreateDirectory(path, NULL);

This will, according to the Win32 SDK documentation, create a directory that inherits from its parent directory. I do not want to inherit the access rights of the parent directory I need to ensure that "Everyone" has full control over the directory.

Obviously, this will require setting up the SECURITY_ATTRIBUTES structure with the appropriate security descriptor. How do I do that?

Answer 1

I prefer the following code snippet as it creates a folder inheriting default rights - which seems the right thing to do - other software / the user might have setup specific inheritable rights on a directory for a legitimate reason - then adds a Full Control explicit access entry for the built in "Users" group.

BOOL CreateDirectoryWithUserFullControlACL(LPCTSTR lpPath)
{
  if(!CreateDirectory(lpPath,NULL))
    return FALSE;

  HANDLE hDir = CreateFile(lpPath,READ_CONTROL|WRITE_DAC,0,NULL,OPEN_EXISTING,FILE_FLAG_BACKUP_SEMANTICS,NULL);
  if(hDir == INVALID_HANDLE_VALUE)
    return FALSE; 

  ACL* pOldDACL;
  SECURITY_DESCRIPTOR* pSD = NULL;
  GetSecurityInfo(hDir, SE_FILE_OBJECT , DACL_SECURITY_INFORMATION,NULL, NULL, &pOldDACL, NULL, (void**)&pSD);

  PSID pSid = NULL;
  SID_IDENTIFIER_AUTHORITY authNt = SECURITY_NT_AUTHORITY;
  AllocateAndInitializeSid(&authNt,2,SECURITY_BUILTIN_DOMAIN_RID,DOMAIN_ALIAS_RID_USERS,0,0,0,0,0,0,&pSid);

  EXPLICIT_ACCESS ea={0};
  ea.grfAccessMode = GRANT_ACCESS;
  ea.grfAccessPermissions = GENERIC_ALL;
  ea.grfInheritance = CONTAINER_INHERIT_ACE|OBJECT_INHERIT_ACE;
  ea.Trustee.TrusteeType = TRUSTEE_IS_GROUP;
  ea.Trustee.TrusteeForm = TRUSTEE_IS_SID;
  ea.Trustee.ptstrName = (LPTSTR)pSid;

  ACL* pNewDACL = 0;
  DWORD err = SetEntriesInAcl(1,&ea,pOldDACL,&pNewDACL);

  if(pNewDACL)
    SetSecurityInfo(hDir,SE_FILE_OBJECT,DACL_SECURITY_INFORMATION,NULL, NULL, pNewDACL, NULL);

  FreeSid(pSid);
  LocalFree(pNewDACL);
  LocalFree(pSD);
  LocalFree(pOldDACL);
  CloseHandle(hDir);

  return TRUE;
}

Answer 2

Here's one technique that seems to work:

SID_IDENTIFIER_AUTHORITY SIDAuthWorld = SECURITY_WORLD_SID_AUTHORITY;
PSID everyone_sid = NULL;
AllocateAndInitializeSid(&SIDAuthWorld, 1, SECURITY_WORLD_RID, 
   0, 0, 0, 0, 0, 0, 0, &everyone_sid);

EXPLICIT_ACCESS ea;
ZeroMemory(&ea, sizeof(EXPLICIT_ACCESS));
ea.grfAccessPermissions = SPECIFIC_RIGHTS_ALL | STANDARD_RIGHTS_ALL;
ea.grfAccessMode = SET_ACCESS;
ea.grfInheritance = NO_INHERITANCE;
ea.Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea.Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
ea.Trustee.ptstrName  = (LPWSTR)everyone_sid;

PACL acl = NULL;
SetEntriesInAcl(1, &ea, NULL, &acl);

PSECURITY_DESCRIPTOR sd = (PSECURITY_DESCRIPTOR)LocalAlloc(LPTR, 
                                   SECURITY_DESCRIPTOR_MIN_LENGTH);
InitializeSecurityDescriptor(sd, SECURITY_DESCRIPTOR_REVISION);
SetSecurityDescriptorDacl(sd, TRUE, acl, FALSE);

SECURITY_ATTRIBUTES sa;
sa.nLength = sizeof(SECURITY_ATTRIBUTES);
sa.lpSecurityDescriptor = sd;
sa.bInheritHandle = FALSE;

CreateDirectory(path, &sa);

FreeSid(everyone_sid);
LocalFree(sd);
LocalFree(acl);

Note that this sample code has absolutely no error checking -- you'll have to supply that yourself.