I am trying to change file permissions in Windows 10 c:\program files(X86) using SetNamedSecurityInfo() from the MSDN API, but it is returning access denied. The same is wroking in Windows 7, but I am not able to do in Windows 10. Please help me to solve this.
bool GrantOwnership(const char *lpszOwnFile)
{
BOOL bRetval = FALSE;
HANDLE hToken = NULL;
PSID pSIDAdmin = NULL;
PSID pSIDEveryone = NULL;
PACL pACL = NULL;
SID_IDENTIFIER_AUTHORITY SIDAuthWorld =
SECURITY_WORLD_SID_AUTHORITY;
SID_IDENTIFIER_AUTHORITY SIDAuthNT = SECURITY_NT_AUTHORITY;
const int NUM_ACES = 2;
EXPLICIT_ACCESS ea[NUM_ACES];
DWORD dwRes;
LPTSTR str = (LPTSTR)lpszOwnFile;
// Specify the DACL to use.
// Create a SID for the Everyone group.
if (!AllocateAndInitializeSid(&SIDAuthWorld, 1,
SECURITY_WORLD_RID,
0,
0, 0, 0, 0, 0, 0,
&pSIDEveryone))
{
printf("AllocateAndInitializeSid (Everyone) error %u\n",
GetLastError());
goto Cleanup;
}
// Create a SID for the BUILTIN\Administrators group.
if (!AllocateAndInitializeSid(&SIDAuthNT, 2,
SECURITY_BUILTIN_DOMAIN_RID,
DOMAIN_ALIAS_RID_ADMINS,
0, 0, 0, 0, 0, 0,
&pSIDAdmin))
{
printf("AllocateAndInitializeSid (Admin) error %u\n",
GetLastError());
goto Cleanup;
}
ZeroMemory(&ea, NUM_ACES * sizeof(EXPLICIT_ACCESS));
// Set read access for Everyone.
ea[0].grfAccessPermissions = GENERIC_READ;
ea[0].grfAccessMode = SET_ACCESS;
ea[0].grfInheritance = NO_INHERITANCE;
ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[0].Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
ea[0].Trustee.ptstrName = (LPTSTR)pSIDEveryone;
// Set full control for Administrators.
ea[1].grfAccessPermissions = GENERIC_ALL;
ea[1].grfAccessMode = SET_ACCESS;
ea[1].grfInheritance = NO_INHERITANCE;
ea[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[1].Trustee.TrusteeType = TRUSTEE_IS_GROUP;
ea[1].Trustee.ptstrName = (LPTSTR)pSIDAdmin;
if (ERROR_SUCCESS != SetEntriesInAcl(NUM_ACES,
ea,
NULL,
&pACL))
{
printf("Failed SetEntriesInAcl\n");
goto Cleanup;
}
// Try to modify the object's DACL.
dwRes = SetNamedSecurityInfo(
(LPTSTR)lpszOwnFile, // name of the object
SE_FILE_OBJECT, // type of object
DACL_SECURITY_INFORMATION, // change only the object's DACL
NULL, NULL, // do not change owner or group
pACL, // DACL specified
NULL); // do not change SACL
if (ERROR_SUCCESS == dwRes)
{
printf("Successfully changed DACL\n");
bRetval = TRUE;
// No more processing needed.
goto Cleanup;
}
if (dwRes != ERROR_ACCESS_DENIED)
{
printf("First SetNamedSecurityInfo call failed: %u\n",
dwRes);
goto Cleanup;
}
// If the preceding call failed because access was denied,
// enable the SE_TAKE_OWNERSHIP_NAME privilege, create a SID for
// the Administrators group, take ownership of the object, and
// disable the privilege. Then try again to set the object's DACL.
// Open a handle to the access token for the calling process.
if (!OpenProcessToken(GetCurrentProcess(),
TOKEN_ADJUST_PRIVILEGES,
&hToken))
{
printf("OpenProcessToken failed: %u\n", GetLastError());
goto Cleanup;
}
// Enable the SE_TAKE_OWNERSHIP_NAME privilege.
if (!SetPrivilege(hToken, SE_TAKE_OWNERSHIP_NAME, TRUE))
{
printf("You must be logged on as Administrator.\n");
goto Cleanup;
}
// Set the owner in the object's security descriptor.
dwRes = SetNamedSecurityInfo(
(LPTSTR)lpszOwnFile, // name of the object
SE_FILE_OBJECT, // type of object
OWNER_SECURITY_INFORMATION, // change only the object's owner
pSIDAdmin, // SID of Administrator group
NULL,
NULL,
NULL);
if (dwRes != ERROR_SUCCESS)
{
printf("Could not set owner. Error: %u\n", dwRes);
goto Cleanup;
}
// Disable the SE_TAKE_OWNERSHIP_NAME privilege.
if (!SetPrivilege(hToken, SE_TAKE_OWNERSHIP_NAME, FALSE))
{
printf("Failed SetPrivilege call unexpectedly.\n");
goto Cleanup;
}
// Try again to modify the object's DACL,
// now that we are the owner.
dwRes = SetNamedSecurityInfo(
(LPTSTR)lpszOwnFile, // name of the object
SE_FILE_OBJECT, // type of object
DACL_SECURITY_INFORMATION, // change only the object's DACL
NULL, NULL, // do not change owner or group
pACL, // DACL specified
NULL); // do not change SACL
if (dwRes == ERROR_SUCCESS)
{
printf("Successfully changed DACL\n");
bRetval = TRUE;
}
else
{
printf("Second SetNamedSecurityInfo call failed: %u\n",
dwRes);
}
Cleanup:
if (pSIDAdmin)
FreeSid(pSIDAdmin);
if (pSIDEveryone)
FreeSid(pSIDEveryone);
if (pACL)
LocalFree(pACL);
if (hToken)
CloseHandle(hToken);
return bRetval;
}
Related
I'm making an computer management program (that runs only as an admin, of course) that shouldn't be accessible to normal users (only by the SYSTEM user, because my uninstaller will run as this user).
I have been trying to prevent normal users from modifying and deleting my main EXE file, and it works.
The problem is that I want the user to be able to execute it and read it, but it won't let them read/execute the file.
Here is my code:
#include <windows.h>
#include <stdio.h>
#include <accctrl.h>
#include <aclapi.h>
#include <iostream>
#include <cstdio>
#pragma comment(lib, "ntdll.lib")
extern "C" NTSTATUS NTAPI RtlAdjustPrivilege(ULONG Privilege, BOOLEAN Enable, BOOLEAN CurrThread, PBOOLEAN StatusPointer);
BOOL ProtectFile(LPTSTR lpszOwnFile)
{
BOOL bRetval = FALSE;
HANDLE hToken = NULL;
PSID pSIDAdmin = NULL;
PSID pSIDEveryone = NULL;
PACL pACL = NULL;
SID_IDENTIFIER_AUTHORITY SIDAuthWorld = SECURITY_WORLD_SID_AUTHORITY;
SID_IDENTIFIER_AUTHORITY SIDAuthNT = SECURITY_NT_AUTHORITY;
const int NUM_ACES = 2;
EXPLICIT_ACCESS ea[NUM_ACES];
DWORD dwRes;
// Specify the DACL to use.
// Create a SID for the Everyone group.
if (!AllocateAndInitializeSid(&SIDAuthWorld, 1,
SECURITY_WORLD_RID,
0,
0, 0, 0, 0, 0, 0,
&pSIDEveryone))
{
printf("AllocateAndInitializeSid (Everyone) error %u\n",
GetLastError());
}
// Create a SID for the BUILTIN\Administrators group.
if (!AllocateAndInitializeSid(&SIDAuthNT, 2,
SECURITY_BUILTIN_DOMAIN_RID,
DOMAIN_ALIAS_RID_ADMINS,
0, 0, 0, 0, 0, 0,
&pSIDAdmin))
{
printf("AllocateAndInitializeSid (Admin) error %u\n",
GetLastError());
}
ZeroMemory(&ea, NUM_ACES * sizeof(EXPLICIT_ACCESS));
// Set read and execute access for Everyone.
ea[0].grfAccessPermissions = GENERIC_WRITE| GENERIC_EXECUTE | FILE_GENERIC_READ | STANDARD_RIGHTS_READ | STANDARD_RIGHTS_EXECUTE | READ_CONTROL | FILE_EXECUTE| FILE_READ_EA | FILE_CREATE_PIPE_INSTANCE;
ea[0].grfAccessMode = SET_ACCESS;
ea[0].grfInheritance = NO_INHERITANCE;
ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[0].Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
ea[0].Trustee.ptstrName = (LPTSTR) pSIDEveryone;
// Set read and execute access for Administrators.
ea[1].grfAccessPermissions = GENERIC_READ| GENERIC_EXECUTE | FILE_GENERIC_READ | STANDARD_RIGHTS_READ | STANDARD_RIGHTS_EXECUTE | READ_CONTROL | FILE_EXECUTE| FILE_READ_EA | FILE_CREATE_PIPE_INSTANCE ;
ea[1].grfAccessMode = SET_ACCESS;
ea[1].grfInheritance = NO_INHERITANCE;
ea[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[1].Trustee.TrusteeType = TRUSTEE_IS_GROUP;
ea[1].Trustee.ptstrName = (LPTSTR) pSIDAdmin;
// Deny modify and delete access for Everyone.
ea[0].grfAccessPermissions = GENERIC_WRITE| FILE_GENERIC_WRITE | FILE_WRITE_ATTRIBUTES | FILE_WRITE_EA | WRITE_OWNER | DELETE | WRITE_DAC;
ea[0].grfAccessMode = DENY_ACCESS;
ea[0].grfInheritance = NO_INHERITANCE;
ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[0].Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
ea[0].Trustee.ptstrName = (LPTSTR) pSIDEveryone;
// Deny modify and delete access for Administrators.
ea[1].grfAccessPermissions = GENERIC_WRITE| FILE_GENERIC_WRITE | FILE_WRITE_ATTRIBUTES | FILE_WRITE_EA | WRITE_OWNER | DELETE | WRITE_DAC;
ea[1].grfAccessMode = DENY_ACCESS;
ea[1].grfInheritance = NO_INHERITANCE;
ea[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[1].Trustee.TrusteeType = TRUSTEE_IS_GROUP;
ea[1].Trustee.ptstrName = (LPTSTR) pSIDAdmin;
if (ERROR_SUCCESS != SetEntriesInAcl(NUM_ACES,
ea,
NULL,
&pACL))
{
printf("Failed SetEntriesInAcl\n");
}
// Try to modify the object's DACL.
dwRes = SetNamedSecurityInfo(
lpszOwnFile, // name of the object
SE_FILE_OBJECT, // type of object
DACL_SECURITY_INFORMATION, // change only the object's DACL
NULL, NULL, // do not change owner or group
pACL, // DACL specified
NULL); // do not change SACL
if (ERROR_SUCCESS == dwRes)
{
printf("Successfully changed DACL\n");
bRetval = TRUE;
// No more processing needed.
}
if (dwRes != ERROR_ACCESS_DENIED)
{
printf("First SetNamedSecurityInfo call failed: %u\n",
dwRes);
}
// If the preceding call failed because access was denied,
// enable the SE_TAKE_OWNERSHIP_NAME privilege, create a SID for
// the Administrators group, take ownership of the object, and
// disable the privilege. Then try again to set the object's DACL.
// Open a handle to the access token for the calling process.
if (!OpenProcessToken(GetCurrentProcess(),
TOKEN_ADJUST_PRIVILEGES,
&hToken))
{
printf("OpenProcessToken failed: %u\n", GetLastError());
}
//get the take ownership privilege
BOOLEAN PrivilegeState = FALSE;
RtlAdjustPrivilege(9, TRUE, FALSE, &PrivilegeState);
// Set the owner in the object's security descriptor.
dwRes = SetNamedSecurityInfo(
lpszOwnFile, // name of the object
SE_FILE_OBJECT, // type of object
OWNER_SECURITY_INFORMATION, // change only the object's owner
pSIDAdmin, // SID of Administrator group
NULL,
NULL,
NULL);
if (dwRes != ERROR_SUCCESS)
{
printf("Could not set owner. Error: %u\n", dwRes);
}
// Try again to modify the object's DACL,
// now that we are the owner.
dwRes = SetNamedSecurityInfo(
lpszOwnFile, // name of the object
SE_FILE_OBJECT, // type of object
DACL_SECURITY_INFORMATION, // change only the object's DACL
NULL, NULL, // do not change owner or group
pACL, // DACL specified
NULL); // do not change SACL
if (dwRes == ERROR_SUCCESS)
{
printf("Successfully changed DACL\n");
bRetval = TRUE;
}
else
{
printf("Second SetNamedSecurityInfo call failed: %u\n",
dwRes);
}
if (pSIDAdmin)
FreeSid(pSIDAdmin);
if (pSIDEveryone)
FreeSid(pSIDEveryone);
if (pACL)
LocalFree(pACL);
if (hToken)
CloseHandle(hToken);
return bRetval;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
ProtectFile("C:\\Windows\\program.exe");
}
Now, it sets correctly the delete/modify denied access permissions, as you can see right here:
But, when I try to execute the same file, as you can see here, it doesn't work, for some reason.
I'm not sure why it happens, but I think it is because I forgot to put one or multiple access right(s) in the allowed section, or that some access rights needed to read/execute the file are in the denied section.
BTW, here are the pictures of both allow/deny permissions section:
denied permissions section:
allowed permissions section:
Do you have any idea of the permissions I forgot, or that I set wrong? If yes, what are they?
You are denying and allowing Read permissions?
How's that?
If you are denying Read Permissions, how can it be run?
Stop denying Read Permissions.
Here is some info that could help you: How Permissions Work
Here's CreateFile doc.
I want to create a file via CreateFile with SECURITY_ATTRIBUTES, when I create it under a windows account user A, the file shouldn't be accessed by another windows user B.
I found this
Creating a Security Descriptor for a New Object in C++
But still couldn't figure it out how to assgin a certain user.
But still couldn't figure it out how to assgin a certain user.
You need to get the SID of a certain user first.
Here is some steps,
Validate the input parameters.
Create buffers for the SID and the domain name that may be large
enough.
In a loop, call LookupAccountName to retrieve the SID for the
account name supplied. If the buffer for the SID or the buffer for
the domain name is not large enough, the buffer size needed is
returned in cbSid or cchDomainName, respectively, and a new buffer
is allocated before the next call to LookupAccountName. Note that
the information is retrieved on the local system when the
lpSystemName parameter is set to NULL.
Free the memory allocated for the domain name buffer.
Then pass the SID to the SetEntriesInAclA function,
The SetEntriesInAcl function creates a new access control list (ACL)
by merging new access control or audit control information into an
existing ACL structure.
Modified code:
#pragma comment(lib, "advapi32.lib")
#include <windows.h>
#include <stdio.h>
#include <aclapi.h>
#include <tchar.h>
#include <mq.h.>
HRESULT GetSid(
LPCWSTR wszAccName,
PSID* ppSid
)
{
// Validate the input parameters.
if (wszAccName == NULL || ppSid == NULL)
{
return MQ_ERROR_INVALID_PARAMETER;
}
// Create buffers that may be large enough.
// If a buffer is too small, the count parameter will be set to the size needed.
const DWORD INITIAL_SIZE = 32;
DWORD cbSid = 0;
DWORD dwSidBufferSize = INITIAL_SIZE;
DWORD cchDomainName = 0;
DWORD dwDomainBufferSize = INITIAL_SIZE;
WCHAR* wszDomainName = NULL;
SID_NAME_USE eSidType;
DWORD dwErrorCode = 0;
HRESULT hr = MQ_OK;
// Create buffers for the SID and the domain name.
*ppSid = (PSID) new BYTE[dwSidBufferSize];
if (*ppSid == NULL)
{
return MQ_ERROR_INSUFFICIENT_RESOURCES;
}
memset(*ppSid, 0, dwSidBufferSize);
wszDomainName = new WCHAR[dwDomainBufferSize];
if (wszDomainName == NULL)
{
return MQ_ERROR_INSUFFICIENT_RESOURCES;
}
memset(wszDomainName, 0, dwDomainBufferSize * sizeof(WCHAR));
// Obtain the SID for the account name passed.
for (; ; )
{
// Set the count variables to the buffer sizes and retrieve the SID.
cbSid = dwSidBufferSize;
cchDomainName = dwDomainBufferSize;
if (LookupAccountNameW(
NULL, // Computer name. NULL for the local computer
wszAccName,
*ppSid, // Pointer to the SID buffer. Use NULL to get the size needed,
&cbSid, // Size of the SID buffer needed.
wszDomainName, // wszDomainName,
&cchDomainName,
&eSidType
))
{
if (IsValidSid(*ppSid) == FALSE)
{
wprintf(L"The SID for %s is invalid.\n", wszAccName);
dwErrorCode = MQ_ERROR;
}
break;
}
dwErrorCode = GetLastError();
// Check if one of the buffers was too small.
if (dwErrorCode == ERROR_INSUFFICIENT_BUFFER)
{
if (cbSid > dwSidBufferSize)
{
// Reallocate memory for the SID buffer.
wprintf(L"The SID buffer was too small. It will be reallocated.\n");
FreeSid(*ppSid);
*ppSid = (PSID) new BYTE[cbSid];
if (*ppSid == NULL)
{
return MQ_ERROR_INSUFFICIENT_RESOURCES;
}
memset(*ppSid, 0, cbSid);
dwSidBufferSize = cbSid;
}
if (cchDomainName > dwDomainBufferSize)
{
// Reallocate memory for the domain name buffer.
wprintf(L"The domain name buffer was too small. It will be reallocated.\n");
delete[] wszDomainName;
wszDomainName = new WCHAR[cchDomainName];
if (wszDomainName == NULL)
{
return MQ_ERROR_INSUFFICIENT_RESOURCES;
}
memset(wszDomainName, 0, cchDomainName * sizeof(WCHAR));
dwDomainBufferSize = cchDomainName;
}
}
else
{
wprintf(L"LookupAccountNameW failed. GetLastError returned: %d\n", dwErrorCode);
hr = HRESULT_FROM_WIN32(dwErrorCode);
break;
}
}
delete[] wszDomainName;
return hr;
}
void main()
{
PSID sid;
GetSid(L"strives", &sid); // enter a user name
DWORD dwRes, dwDisposition;
PACL pACL = NULL;
PSECURITY_DESCRIPTOR pSD = NULL;
EXPLICIT_ACCESS ea;
SECURITY_ATTRIBUTES sa;
HANDLE lRes = NULL;
// Initialize an EXPLICIT_ACCESS structure for an ACE.
// The ACE will allow Everyone read access to the key.
ZeroMemory(&ea, sizeof(EXPLICIT_ACCESS));
ea.grfAccessPermissions = GENERIC_ALL;
ea.grfAccessMode = SET_ACCESS;
ea.grfInheritance = NO_INHERITANCE;
ea.Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea.Trustee.TrusteeType = TRUSTEE_IS_USER;
ea.Trustee.ptstrName = (LPTSTR)sid;
// Create a new ACL that contains the new ACEs.
dwRes = SetEntriesInAcl(1, &ea, NULL, &pACL);
if (ERROR_SUCCESS != dwRes)
{
_tprintf(_T("SetEntriesInAcl Error %u\n"), GetLastError());
goto Cleanup;
}
// Initialize a security descriptor.
pSD = (PSECURITY_DESCRIPTOR)LocalAlloc(LPTR,
SECURITY_DESCRIPTOR_MIN_LENGTH);
if (NULL == pSD)
{
_tprintf(_T("LocalAlloc Error %u\n"), GetLastError());
goto Cleanup;
}
if (!InitializeSecurityDescriptor(pSD,
SECURITY_DESCRIPTOR_REVISION))
{
_tprintf(_T("InitializeSecurityDescriptor Error %u\n"),
GetLastError());
goto Cleanup;
}
// Add the ACL to the security descriptor.
if (!SetSecurityDescriptorDacl(pSD,
TRUE, // bDaclPresent flag
pACL,
FALSE)) // not a default DACL
{
_tprintf(_T("SetSecurityDescriptorDacl Error %u\n"),
GetLastError());
goto Cleanup;
}
// Initialize a security attributes structure.
sa.nLength = sizeof(SECURITY_ATTRIBUTES);
sa.lpSecurityDescriptor = pSD;
sa.bInheritHandle = FALSE;
// Use the security attributes to set the security descriptor
// when you create a key.
lRes = CreateFile(_T("D:\\File.txt"), GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ,
&sa, OPEN_ALWAYS, 0, NULL);
if (lRes != NULL)
{
_tprintf(_T("Create file success\n"));
}
Cleanup:
if (pACL)
LocalFree(pACL);
if (pSD)
LocalFree(pSD);
if (lRes)
CloseHandle(lRes);
return;
}
You can verify by checking the properties of the file.
I am testing the following code in C using Win32 API, which is intended to create a new file that is accessible for the current user but private (not accessible) for everyone else.
For this this a deny all permissions for everyone SID, then for current's user SID I set up the permissions.
The file is created successfully and the permissions are apparently set up successfully (see screenshots below), however when I try to open the file with notepad, it says "access is denied" (My file explorer is running under the same session), also if I open a command prompt and do "type file_created.txt" the same "access is denied" appear.
I can of course, restore manually the permissions since I am administrator, but the idea is to make it work programmatically.
Image with everyone permissions:
Image with current user permissions:
The code:
#include <windows.h>
#include <AccCtrl.h>
#include <aclapi.h>
#include <stdio.h>
#include <stdexcept>
#include <string>
#undef UNICODE
int GetCurrentUserSid(PSID* pSID)
{
const int MAX_NAME = 256;
DWORD i, dwSize = 0;
HANDLE hToken;
PTOKEN_USER user;
TOKEN_INFORMATION_CLASS TokenClass = TokenUser;
if (!OpenProcessToken(GetCurrentProcess(), TOKEN_READ | TOKEN_QUERY, &hToken))
return GetLastError();
else
wprintf(L"OpenProcessToken() - got the handle to the access token!\n");
if (!GetTokenInformation(hToken, TokenClass, NULL, 0, &dwSize))
{
DWORD dwResult = GetLastError();
if (dwResult != ERROR_INSUFFICIENT_BUFFER)
{
wprintf(L"GetTokenInformation() failed, error %u\n", dwResult);
return FALSE;
}
else
wprintf(L"GetTokenInformation() - have an ample buffer...\n");
}
else
wprintf(L"GetTokenInformation() - buffer for Token group is OK\n");
user = (PTOKEN_USER)LocalAlloc(GPTR, dwSize);
if (!GetTokenInformation(hToken, TokenClass, user, dwSize, &dwSize))
{
wprintf(L"GetTokenInformation() failed, error %u\n", GetLastError());
return FALSE;
}
else
wprintf(L"GetTokenInformation() for getting the TokenGroups is OK\n");
DWORD dw_sid_len = GetLengthSid(user->User.Sid);
*pSID = (SID*)LocalAlloc(GPTR, dw_sid_len);
CopySid(dw_sid_len, *pSID, user->User.Sid);
return 0;
}
DWORD set_file_security(LPSTR filename)
{
PACL pNewDACL = NULL;
PSID current_user = NULL;
DWORD sid_size = SECURITY_MAX_SID_SIZE;
SID everyone_sid;
DWORD dwRes;
if (CreateWellKnownSid(WinWorldSid, NULL, &everyone_sid, &sid_size) ==
FALSE) {
throw std::runtime_error("CreateWellKnownSid() failed: " +
std::to_string(GetLastError()));
}
GetCurrentUserSid(¤t_user);
EXPLICIT_ACCESSA ea[2];
ZeroMemory(&ea, 2 * sizeof(EXPLICIT_ACCESSA));
ea[0].grfAccessPermissions = ACCESS_SYSTEM_SECURITY | READ_CONTROL | WRITE_DAC | GENERIC_ALL;
ea[0].grfAccessMode = GRANT_ACCESS;
ea[0].grfInheritance = NO_INHERITANCE;
ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[0].Trustee.ptstrName = reinterpret_cast<char*>(current_user);
ea[1].grfAccessPermissions = ACCESS_SYSTEM_SECURITY | READ_CONTROL | WRITE_DAC | GENERIC_ALL;
ea[1].grfAccessMode = DENY_ACCESS;
ea[1].grfInheritance = NO_INHERITANCE;
ea[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[1].Trustee.ptstrName = reinterpret_cast<char*>(&everyone_sid);
dwRes = SetEntriesInAclA(2, ea, NULL, &pNewDACL);
if (ERROR_SUCCESS != dwRes) {
printf("SetEntriesInAcl Error %u\n", dwRes);
//TODO: goto Cleanup;
}
PSECURITY_DESCRIPTOR pSD = NULL;
// Initialize a security descriptor.
pSD = (PSECURITY_DESCRIPTOR)LocalAlloc(LPTR,
SECURITY_DESCRIPTOR_MIN_LENGTH);
if (NULL == pSD)
{
_tprintf(_T("LocalAlloc Error %u\n"), GetLastError());
goto Cleanup;
}
if (!InitializeSecurityDescriptor(pSD,
SECURITY_DESCRIPTOR_REVISION))
{
_tprintf(_T("InitializeSecurityDescriptor Error %u\n"),
GetLastError());
goto Cleanup;
}
// Add the ACL to the security descriptor.
if (!SetSecurityDescriptorDacl(pSD,
TRUE, // bDaclPresent flag
pNewDACL,
FALSE)) // not a default DACL
{
_tprintf(_T("SetSecurityDescriptorDacl Error %u\n"),
GetLastError());
goto Cleanup;
}
SECURITY_ATTRIBUTES sa;
// Initialize a security attributes structure.
sa.nLength = sizeof(SECURITY_ATTRIBUTES);
sa.lpSecurityDescriptor = pSD;
sa.bInheritHandle = FALSE;
HANDLE hFile = CreateFileA(filename, GENERIC_ALL, 0, &sa, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, NULL);
CloseHandle(hFile);
//dwRes = SetNamedSecurityInfoA(filename, SE_FILE_OBJECT,
// DACL_SECURITY_INFORMATION, NULL, NULL, pNewDACL, NULL);
//if (ERROR_SUCCESS != dwRes) {
// printf("SetNamedSecurityInfo Error %u\n", dwRes);
// //goto Cleanup;
//}
Cleanup:
if (pNewDACL != NULL)
LocalFree((HLOCAL)pNewDACL);
return dwRes;
}
int main()
{
//return 0;
// Create Everyone SID.
DWORD sid_size = SECURITY_MAX_SID_SIZE;
SID everyone_sid;
if (CreateWellKnownSid(WinWorldSid, NULL, &everyone_sid, &sid_size) ==
FALSE) {
throw std::runtime_error("CreateWellKnownSid() failed: " +
std::to_string(GetLastError()));
}
LPSTR filename = "created_file.txt";
set_file_security(filename);
return 0;
}
NOTE: I realized the code has memory leaks and other issues, I was just quickly hacking to test the idea.
In the Windows OS explicit deny permissions have a precedence over explicit allow permissions. So since "Everyone" group includes your account, access to the file is denied, even if you enabled it for yourself. In fact you don't need deny rule altogether, if access rights are not set in the object ACL for some user, access will be denied by default.
I have to create a folder or modify security attributes if folder already exist. I need to set permissions to folder so that only LocalAccount has full access and other user accounts should not have any access to this folder.
As of now, I'm trying the below code,but couldn't achieve.
Updated: I guess, any existing ACEs causing problem(if folder exist) or Any ACEs which are inherited from parent directory causing problem?
DWORD dwRes;
PSID pEveryoneSID = NULL, pLocalSystemSID = NULL;
PACL pACL = NULL;
PSECURITY_DESCRIPTOR pSD = NULL;
EXPLICIT_ACCESS ea[2];
SID_IDENTIFIER_AUTHORITY SIDAuthWorld =
SECURITY_WORLD_SID_AUTHORITY;
SID_IDENTIFIER_AUTHORITY SIDAuthNT = SECURITY_NT_AUTHORITY;
SECURITY_ATTRIBUTES sa;
// Create a well-known SID for the Everyone group.
if (!AllocateAndInitializeSid(&SIDAuthWorld, 1,
SECURITY_WORLD_RID,
0, 0, 0, 0, 0, 0, 0,
&pEveryoneSID))
{
LOGERROR(_T("AllocateAndInitializeSid Error %u\n"), GetLastError());
goto Cleanup;
}
// Initialize an EXPLICIT_ACCESS structure for an ACE.
// The ACE will deny Everyone GENERIC_ALL to the folder.
ZeroMemory(&ea, 2 * sizeof(EXPLICIT_ACCESS));
ea[0].grfAccessPermissions = GENERIC_ALL;
ea[0].grfAccessMode = DENY_ACCESS;
ea[0].grfInheritance = NO_INHERITANCE;
ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[0].Trustee.TrusteeType = TRUSTEE_IS_WELL_KNOWN_GROUP;
ea[0].Trustee.ptstrName = (LPTSTR)pEveryoneSID;
// Create a SID for the LocalSystem account(A special account used by the operating system) group.
if (!AllocateAndInitializeSid(&SIDAuthNT, 1,
SECURITY_LOCAL_SYSTEM_RID,
0, 0, 0, 0, 0, 0, 0,
&pLocalSystemSID))
{
LOGERROR(_T("AllocateAndInitializeSid Error %u\n"), GetLastError());
goto Cleanup;
}
// Initialize an EXPLICIT_ACCESS structure for an ACE.
// The ACE will allow the LocalSystem full access to the folder
ea[1].grfAccessPermissions = GENERIC_ALL;
ea[1].grfAccessMode = GRANT_ACCESS; // or SET_ACCESS ?
ea[1].grfInheritance = NO_INHERITANCE;
ea[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[1].Trustee.TrusteeType = TRUSTEE_IS_GROUP; //not sure what to use here for localAccount
ea[1].Trustee.ptstrName = (LPTSTR)pLocalSystemSID;
// Create a new ACL that contains the new ACEs.
dwRes = SetEntriesInAcl(2, ea, NULL, &pACL);
if (ERROR_SUCCESS != dwRes)
{
LOGERROR(_T("SetEntriesInAcl Error %u\n"), GetLastError());
goto Cleanup;
}
// Initialize a security descriptor.
pSD = (PSECURITY_DESCRIPTOR)LocalAlloc(LPTR,
SECURITY_DESCRIPTOR_MIN_LENGTH);
if (NULL == pSD)
{
LOGERROR(_T("LocalAlloc Error %u\n"), GetLastError());
goto Cleanup;
}
if (!InitializeSecurityDescriptor(pSD,
SECURITY_DESCRIPTOR_REVISION))
{
LOGERROR(_T("InitializeSecurityDescriptor Error %u\n"),
GetLastError());
goto Cleanup;
}
// Add the ACL to the security descriptor.
if (!SetSecurityDescriptorDacl(pSD,
TRUE, // bDaclPresent flag
pACL,
FALSE)) // not a default DACL
{
LOGERROR(_T("SetSecurityDescriptorDacl Error %u\n"),
GetLastError());
goto Cleanup;
}
// Initialize a security attributes structure.
sa.nLength = sizeof (SECURITY_ATTRIBUTES);
sa.lpSecurityDescriptor = pSD;
sa.bInheritHandle = FALSE;
int rVal = SHCreateDirectoryExW(NULL, m_tcProxyData, &sa);
I was writing a c++ program to add ACE for object access Audit to SASL. Though all the functions return success, When I go and check the properties of the folder manually, I could not see any policy has been set.
Below is my code. I have modified the sample code given in MSDN site at the below link to add to SASL instead of DACL .
https://msdn.microsoft.com/en-us/library/windows/desktop/aa379283(v=vs.85).aspx
BOOL SetPrivilege(
HANDLE hToken, // access token handle
LPCTSTR lpszPrivilege, // name of privilege to enable/disable
BOOL bEnablePrivilege // to enable or disable privilege
)
{
TOKEN_PRIVILEGES tp;
LUID luid;
if (!LookupPrivilegeValue(
NULL, // lookup privilege on local system
lpszPrivilege, // privilege to lookup
&luid)) // receives LUID of privilege
{
printf("LookupPrivilegeValue error: %u\n", GetLastError());
return FALSE;
}
tp.PrivilegeCount = 1;
tp.Privileges[0].Luid = luid;
if (bEnablePrivilege)
tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
else
tp.Privileges[0].Attributes = 0;
// Enable the privilege or disable all privileges.
if (!AdjustTokenPrivileges(
hToken,
FALSE,
&tp,
sizeof(TOKEN_PRIVILEGES),
(PTOKEN_PRIVILEGES)NULL,
(PDWORD)NULL))
{
printf("AdjustTokenPrivileges error: %u\n", GetLastError());
return FALSE;
}
if (GetLastError() == ERROR_NOT_ALL_ASSIGNED)
{
printf("The token does not have the specified privilege. \n");
return FALSE;
}
return TRUE;
}
DWORD AddAceToObjectsSecurityDescriptor(
LPTSTR pszObjName, // name of object
SE_OBJECT_TYPE ObjectType, // type of object
LPTSTR pszTrustee // trustee for new ACE
)
{
DWORD dwRes = 0;
PACL pOldSACL = NULL, pNewSACL = NULL;
PSECURITY_DESCRIPTOR pSD = NULL;
EXPLICIT_ACCESS ea;
HANDLE hToken;
if (NULL == pszObjName)
return ERROR_INVALID_PARAMETER;
// Open a handle to the access token for the calling process.
if (!OpenProcessToken(GetCurrentProcess(),
TOKEN_ADJUST_PRIVILEGES,
&hToken))
{
printf("OpenProcessToken failed: %u\n", GetLastError());
goto Cleanup;
}
// Enable the SE_SECURITY_NAME privilege.
if (!SetPrivilege(hToken, SE_SECURITY_NAME, TRUE))
{
printf("You must be logged on as Administrator.\n");
goto Cleanup;
}
// Get a pointer to the existing SACL.
dwRes = GetNamedSecurityInfo(pszObjName, ObjectType,
SACL_SECURITY_INFORMATION,
NULL, NULL, NULL, &pOldSACL, &pSD);
if (ERROR_SUCCESS != dwRes) {
printf("GetNamedSecurityInfo Error %u\n", dwRes);
goto Cleanup;
}
// Initialize an EXPLICIT_ACCESS structure for the new ACE.
ZeroMemory(&ea, sizeof(EXPLICIT_ACCESS));
//ea.grfAccessPermissions = dwAccessRights;
ea.grfAccessPermissions = GENERIC_ALL;
//ea.grfAccessMode = AccessMode;
ea.grfAccessMode = SET_AUDIT_SUCCESS;
//ea.grfInheritance = dwInheritance;
ea.grfInheritance = INHERIT_ONLY;
//ea.Trustee.TrusteeForm = TrusteeForm;
ea.Trustee.TrusteeForm = TRUSTEE_IS_NAME;
ea.Trustee.ptstrName = pszTrustee;
ea.Trustee.TrusteeType = TRUSTEE_IS_USER;
// Create a new ACL that merges the new ACE
// into the existing SACL.
dwRes = SetEntriesInAcl(1, &ea, pOldSACL, &pNewSACL);
if (ERROR_SUCCESS != dwRes) {
printf("SetEntriesInAcl Error %u\n", dwRes);
goto Cleanup;
}
// Attach the new ACL as the object's SACL.
dwRes = SetNamedSecurityInfo(pszObjName, ObjectType,
SACL_SECURITY_INFORMATION,
NULL, NULL, NULL, pNewSACL);
if (ERROR_SUCCESS != dwRes) {
printf("SetNamedSecurityInfo Error %u\n", dwRes);
goto Cleanup;
}
// Disable the SE_SECURITY_NAME privilege.
if (!SetPrivilege(hToken, SE_SECURITY_NAME, FALSE))
{
printf("You must be logged on as Administrator.\n");
goto Cleanup;
}
Cleanup:
if (pSD != NULL)
LocalFree((HLOCAL)pSD);
if (pNewSACL != NULL)
LocalFree((HLOCAL)pNewSACL);
return dwRes;
}
int _tmain(int argc, _TCHAR* argv[])
{
LPTSTR objstrname = L"C:\\path\\to\\folder\\Test_Folder";
LPTSTR trusteeName = L"UserName"; // I have mentioned username here
AddAceToObjectsSecurityDescriptor(objstrname, SE_FILE_OBJECT, trusteeName);
return 0;
}
Though all the functions return success, I am not able to see any new audit policy is getting set. Might I am setting the parameters wrong, I that case I expect the functions to fail. Please help to resolve the issue.
I believe the problem is that you are setting the wrong inheritance flags.
INHERIT_ONLY means that the ACE should not apply to the object, but only be inherited by child objects.
However, you have not set either CONTAINER_INHERIT_ACE or OBJECT_INHERIT_ACE. So the ACE does not apply to child objects.
Since the ACE applies to neither the parent nor to children, it has no effect, so Windows discards it.