token.c

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/*
 * COPYRIGHT:       See COPYING in the top level directory
 * PROJECT:         ReactOS system libraries
 * FILE:            lib/advapi32/token/token.c
 * PURPOSE:         Token functions
 * PROGRAMMER:      Ariadne (ariadne@xs4all.nl)
 * UPDATE HISTORY:
 *                  Created 01/11/98
 */

#include <advapi32.h>

#include <ndk/setypes.h>

WINE_DEFAULT_DEBUG_CHANNEL(advapi);

/*
 * @implemented
 */
BOOL WINAPI
CheckTokenMembership(IN HANDLE ExistingTokenHandle,
                     IN PSID SidToCheck,
                     OUT PBOOL IsMember)
{
    PISECURITY_DESCRIPTOR SecurityDescriptor = NULL;
    ACCESS_MASK GrantedAccess;
    struct
    {
        PRIVILEGE_SET PrivilegeSet;
        LUID_AND_ATTRIBUTES Privileges[4];
    } PrivBuffer;
    ULONG PrivBufferSize = sizeof(PrivBuffer);
    GENERIC_MAPPING GenericMapping =
    {
        STANDARD_RIGHTS_READ,
        STANDARD_RIGHTS_WRITE,
        STANDARD_RIGHTS_EXECUTE,
        STANDARD_RIGHTS_ALL
    };
    PACL Dacl;
    ULONG SidLen;
    HANDLE hToken = NULL;
    NTSTATUS Status, AccessStatus;

    /* doesn't return gracefully if IsMember is NULL! */
    *IsMember = FALSE;

    SidLen = RtlLengthSid(SidToCheck);

    if (ExistingTokenHandle == NULL)
    {
        Status = NtOpenThreadToken(NtCurrentThread(),
                                   TOKEN_QUERY,
                                   FALSE,
                                   &hToken);

        if (Status == STATUS_NO_TOKEN)
        {
            /* we're not impersonating, open the primary token */
            Status = NtOpenProcessToken(NtCurrentProcess(),
                                        TOKEN_QUERY | TOKEN_DUPLICATE,
                                        &hToken);
            if (NT_SUCCESS(Status))
            {
                HANDLE hNewToken = FALSE;
                BOOL DupRet;

                /* duplicate the primary token to create an impersonation token */
                DupRet = DuplicateTokenEx(hToken,
                                          TOKEN_QUERY | TOKEN_IMPERSONATE,
                                          NULL,
                                          SecurityImpersonation,
                                          TokenImpersonation,
                                          &hNewToken);

                NtClose(hToken);

                if (!DupRet)
                {
                    WARN("Failed to duplicate the primary token!\n");
                    return FALSE;
                }

                hToken = hNewToken;
            }
        }

        if (!NT_SUCCESS(Status))
        {
            goto Cleanup;
        }
    }
    else
    {
        hToken = ExistingTokenHandle;
    }

    /* create a security descriptor */
    SecurityDescriptor = RtlAllocateHeap(RtlGetProcessHeap(),
                                         0,
                                         sizeof(SECURITY_DESCRIPTOR) +
                                             sizeof(ACL) + SidLen +
                                             FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart));
    if (SecurityDescriptor == NULL)
    {
        Status = STATUS_INSUFFICIENT_RESOURCES;
        goto Cleanup;
    }

    Status = RtlCreateSecurityDescriptor(SecurityDescriptor,
                                         SECURITY_DESCRIPTOR_REVISION);
    if (!NT_SUCCESS(Status))
    {
        goto Cleanup;
    }

    /* set the owner and group */
    Status = RtlSetOwnerSecurityDescriptor(SecurityDescriptor,
                                           SidToCheck,
                                           FALSE);
    if (!NT_SUCCESS(Status))
    {
        goto Cleanup;
    }

    Status = RtlSetGroupSecurityDescriptor(SecurityDescriptor,
                                           SidToCheck,
                                           FALSE);
    if (!NT_SUCCESS(Status))
    {
        goto Cleanup;
    }

    /* create the DACL */
    Dacl = (PACL)(SecurityDescriptor + 1);
    Status = RtlCreateAcl(Dacl,
                          sizeof(ACL) + SidLen + FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart),
                          ACL_REVISION);
    if (!NT_SUCCESS(Status))
    {
        goto Cleanup;
    }

    Status = RtlAddAccessAllowedAce(Dacl,
                                    ACL_REVISION,
                                    0x1,
                                    SidToCheck);
    if (!NT_SUCCESS(Status))
    {
        goto Cleanup;
    }

    /* assign the DACL to the security descriptor */
    Status = RtlSetDaclSecurityDescriptor(SecurityDescriptor,
                                          TRUE,
                                          Dacl,
                                          FALSE);
    if (!NT_SUCCESS(Status))
    {
        goto Cleanup;
    }

    /* it's time to perform the access check. Just use _some_ desired access right
       (same as for the ACE) and see if we're getting it granted. This indicates
       our SID is a member of the token. We however can't use a generic access
       right as those aren't mapped and return an error (STATUS_GENERIC_NOT_MAPPED). */
    Status = NtAccessCheck(SecurityDescriptor,
                           hToken,
                           0x1,
                           &GenericMapping,
                           &PrivBuffer.PrivilegeSet,
                           &PrivBufferSize,
                           &GrantedAccess,
                           &AccessStatus);
    if (NT_SUCCESS(Status) && NT_SUCCESS(AccessStatus) && (GrantedAccess == 0x1))
    {
        *IsMember = TRUE;
    }

Cleanup:
    if (hToken != NULL && hToken != ExistingTokenHandle)
    {
        NtClose(hToken);
    }

    if (SecurityDescriptor != NULL)
    {
        RtlFreeHeap(RtlGetProcessHeap(),
                    0,
                    SecurityDescriptor);
    }

    if (!NT_SUCCESS(Status))
    {
        SetLastError(RtlNtStatusToDosError(Status));
        return FALSE;
    }

    return TRUE;
}


/*
 * @implemented
 */
BOOL WINAPI
IsTokenRestricted(HANDLE TokenHandle)
{
    ULONG RetLength;
    PTOKEN_GROUPS lpGroups;
    NTSTATUS Status;
    BOOL Ret = FALSE;

    /* determine the required buffer size and allocate enough memory to read the
       list of restricted SIDs */
    Status = NtQueryInformationToken(TokenHandle,
                                     TokenRestrictedSids,
                                     NULL,
                                     0,
                                     &RetLength);
    if (Status != STATUS_BUFFER_TOO_SMALL)
    {
        SetLastError(RtlNtStatusToDosError(Status));
        return FALSE;
    }

AllocAndReadRestrictedSids:
    lpGroups = (PTOKEN_GROUPS)HeapAlloc(GetProcessHeap(),
                                        0,
                                        RetLength);
    if (lpGroups == NULL)
    {
        SetLastError(ERROR_OUTOFMEMORY);
        return FALSE;
    }

    /* actually read the list of the restricted SIDs */
    Status = NtQueryInformationToken(TokenHandle,
                                     TokenRestrictedSids,
                                     lpGroups,
                                     RetLength,
                                     &RetLength);
    if (NT_SUCCESS(Status))
    {
        Ret = (lpGroups->GroupCount != 0);
    }
    else if (Status == STATUS_BUFFER_TOO_SMALL)
    {
        /* looks like the token was modified in the meanwhile, let's just try again */
        HeapFree(GetProcessHeap(),
                 0,
                 lpGroups);

        goto AllocAndReadRestrictedSids;
    }
    else
    {
        SetLastError(RtlNtStatusToDosError(Status));
    }

    /* free allocated memory */
    HeapFree(GetProcessHeap(),
             0,
             lpGroups);

    return Ret;
}

/*
 * @unimplemented
 */
PSID
WINAPI
GetSiteSidFromToken(IN HANDLE TokenHandle)
{
    PTOKEN_GROUPS RestrictedSids;
    ULONG RetLen;
    UINT i;
    NTSTATUS Status;
    PSID PSiteSid = NULL;
    SID_IDENTIFIER_AUTHORITY InternetSiteAuthority = {SECURITY_INTERNETSITE_AUTHORITY};

    Status = NtQueryInformationToken(TokenHandle,
                                     TokenRestrictedSids,
                                     NULL,
                                     0,
                                     &RetLen);
    if (Status != STATUS_BUFFER_TOO_SMALL)
    {
        SetLastError(RtlNtStatusToDosError(Status));
        return NULL;
    }

    RestrictedSids = (PTOKEN_GROUPS)RtlAllocateHeap(RtlGetProcessHeap(),
                                                    0,
                                                    RetLen);
    if (RestrictedSids == NULL)
    {
        SetLastError(ERROR_OUTOFMEMORY);
        return NULL;
    }

    Status = NtQueryInformationToken(TokenHandle,
                                     TokenRestrictedSids,
                                     RestrictedSids,
                                     RetLen,
                                     &RetLen);
    if (NT_SUCCESS(Status))
    {
        for (i = 0; i < RestrictedSids->GroupCount; i++)
        {
            SID* RSSid = RestrictedSids->Groups[i].Sid;

            if (RtlCompareMemory(&(RSSid->IdentifierAuthority),
                                 &InternetSiteAuthority,
                                 sizeof(SID_IDENTIFIER_AUTHORITY)) ==
                                 sizeof(SID_IDENTIFIER_AUTHORITY))
            {
                PSiteSid = RtlAllocateHeap(RtlGetProcessHeap(),
                                           0,
                                           RtlLengthSid((RestrictedSids->
                                                         Groups[i]).Sid));
                if (PSiteSid == NULL)
                {
                    SetLastError(ERROR_OUTOFMEMORY);
                }
                else
                {
                    RtlCopySid(RtlLengthSid(RestrictedSids->Groups[i].Sid),
                               PSiteSid,
                               RestrictedSids->Groups[i].Sid);
                }

                break;
            }
        }
    }
    else
    {
        SetLastError(RtlNtStatusToDosError(Status));
    }

    RtlFreeHeap(RtlGetProcessHeap(), 0, RestrictedSids);
    return PSiteSid;
}