NTSTATUS
PvfsAccessCheckFile(
PACCESS_TOKEN pToken,
PPVFS_FILE_NAME FileName,
ACCESS_MASK Desired,
ACCESS_MASK *pGranted
)
{
NTSTATUS ntError = STATUS_UNSUCCESSFUL;
ACCESS_MASK AccessMask = 0;
ACCESS_MASK GrantedAccess = 0;
PSECURITY_DESCRIPTOR_ABSOLUTE pSecDesc = NULL;
BYTE pRelativeSecDescBuffer[SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE];
ULONG ulRelativeSecDescLength = SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE;
PSECURITY_DESCRIPTOR_ABSOLUTE pParentSecDesc = NULL;
BYTE pParentRelSecDescBuffer[SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE];
ULONG ulParentRelSecDescLength = SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE;
BOOLEAN bGranted = FALSE;
SECURITY_INFORMATION SecInfo = (OWNER_SECURITY_INFORMATION |
GROUP_SECURITY_INFORMATION |
DACL_SECURITY_INFORMATION |
SACL_SECURITY_INFORMATION);
PSID pOwner = NULL;
BOOLEAN bOwnerDefaulted = FALSE;
BOOLEAN bWantsDelete = FALSE;
BOOLEAN bWantsMaximumAccess = FALSE;
PPVFS_FILE_NAME parentDirectoryName = NULL;
PPVFS_FILE_NAME relativeFileName = NULL;
BAIL_ON_INVALID_PTR(pToken, ntError);
BAIL_ON_INVALID_PTR(pGranted, ntError);
// Check the file object itself
ntError = PvfsGetSecurityDescriptorFilename(
PvfsGetCStringBaseFileName(FileName),
SecInfo,
(PSECURITY_DESCRIPTOR_RELATIVE)((PVOID)pRelativeSecDescBuffer),
&ulRelativeSecDescLength);
BAIL_ON_NT_STATUS(ntError);
ntError = PvfsSecurityAclSelfRelativeToAbsoluteSD(
&pSecDesc,
(PSECURITY_DESCRIPTOR_RELATIVE)((PVOID)pRelativeSecDescBuffer));
BAIL_ON_NT_STATUS(ntError);
// Tests against NTFS/Win2003R2 show that the file/directory object
// owner is always granted FILE_READ_ATTRIBUTE
ntError = RtlGetOwnerSecurityDescriptor(
pSecDesc,
&pOwner,
&bOwnerDefaulted);
BAIL_ON_NT_STATUS(ntError);
if (RtlIsSidMemberOfToken(pToken, pOwner))
{
ClearFlag(Desired, FILE_READ_ATTRIBUTES);
SetFlag(GrantedAccess, FILE_READ_ATTRIBUTES);
}
// Check for access rights. We'll deal with DELETE separately since that
// could be granted by the parent directory security descriptor
if (Desired & DELETE)
{
bWantsDelete = TRUE;
ClearFlag(Desired, DELETE);
}
if (Desired & MAXIMUM_ALLOWED)
{
bWantsMaximumAccess = TRUE;
}
bGranted = RtlAccessCheck(
pSecDesc,
pToken,
Desired,
GrantedAccess,
&gPvfsDriverState.GenericSecurityMap,
&AccessMask,
&ntError);
if (!bGranted)
{
BAIL_ON_NT_STATUS(ntError);
}
GrantedAccess = AccessMask;
// See if the file object security descriptor grants DELETE
// Only continue when checking for MAXIMUM_ALLOWED if we haven't been
// granted DELETE already
if (bWantsDelete ||
(bWantsMaximumAccess && !(GrantedAccess & DELETE)))
{
AccessMask = 0;
bGranted = RtlAccessCheck(
pSecDesc,
pToken,
DELETE,
GrantedAccess,
&gPvfsDriverState.GenericSecurityMap,
&AccessMask,
&ntError);
if (!bGranted)
{
ntError = PvfsSplitFileNamePath(
&parentDirectoryName,
&relativeFileName,
FileName);
BAIL_ON_NT_STATUS(ntError);
ntError = PvfsGetSecurityDescriptorFilename(
PvfsGetCStringBaseFileName(parentDirectoryName),
SecInfo,
(PSECURITY_DESCRIPTOR_RELATIVE)((PVOID)pParentRelSecDescBuffer),
&ulParentRelSecDescLength);
BAIL_ON_NT_STATUS(ntError);
ntError = PvfsSecurityAclSelfRelativeToAbsoluteSD(
&pParentSecDesc,
(PSECURITY_DESCRIPTOR_RELATIVE)((PVOID)pParentRelSecDescBuffer));
BAIL_ON_NT_STATUS(ntError);
AccessMask = 0;
bGranted = RtlAccessCheck(
pParentSecDesc,
pToken,
FILE_DELETE_CHILD,
0,
&gPvfsDriverState.GenericSecurityMap,
&AccessMask,
&ntError);
// This is a hard failure unless we are just trying to determine
// what the maximum allowed access would be
if (!bGranted && !bWantsMaximumAccess)
{
BAIL_ON_NT_STATUS(ntError);
}
AccessMask = DELETE;
}
// Combine directory and file object granted permissions
AccessMask |= GrantedAccess;
}
*pGranted = AccessMask;
ntError = STATUS_SUCCESS;
error:
if (parentDirectoryName)
{
PvfsFreeFileName(relativeFileName);
}
if (relativeFileName)
{
PvfsFreeFileName(parentDirectoryName);
}
if (pParentSecDesc)
{
PvfsFreeAbsoluteSecurityDescriptor(&pParentSecDesc);
}
if (pSecDesc)
{
PvfsFreeAbsoluteSecurityDescriptor(&pSecDesc);
}
return ntError;
}
NTSTATUS
PvfsAccessCheckFileEnumerate(
PPVFS_CCB pCcb,
PCSTR pszRelativeFilename
)
{
NTSTATUS ntError = STATUS_UNSUCCESSFUL;
PACCESS_TOKEN pToken = pCcb->pUserToken;
PSTR pszFilename = NULL;
ACCESS_MASK AccessMask = 0;
ACCESS_MASK GrantedAccess = 0;
PSECURITY_DESCRIPTOR_ABSOLUTE pSecDesc = NULL;
BYTE pRelativeSecDescBuffer[SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE];
ULONG ulRelativeSecDescLength = SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE;
BOOLEAN bGranted = FALSE;
SECURITY_INFORMATION SecInfo = (OWNER_SECURITY_INFORMATION |
GROUP_SECURITY_INFORMATION |
DACL_SECURITY_INFORMATION |
SACL_SECURITY_INFORMATION);
ACCESS_MASK Desired = (FILE_READ_ATTRIBUTES|
FILE_READ_EA|
FILE_READ_DATA|
READ_CONTROL);
PSID pOwner = NULL;
BOOLEAN bOwnerDefaulted = FALSE;
/* Create the absolute path */
ntError = LwRtlCStringAllocatePrintf(
&pszFilename,
"%s/%s",
pCcb->pScb->pOwnerFcb->pszFilename,
pszRelativeFilename);
BAIL_ON_NT_STATUS(ntError);
/* Check the file object itself */
ntError = PvfsGetSecurityDescriptorFilename(
pszFilename,
SecInfo,
(PSECURITY_DESCRIPTOR_RELATIVE)((PVOID)pRelativeSecDescBuffer),
&ulRelativeSecDescLength);
BAIL_ON_NT_STATUS(ntError);
ntError = PvfsSecurityAclSelfRelativeToAbsoluteSD(
&pSecDesc,
(PSECURITY_DESCRIPTOR_RELATIVE)((PVOID)pRelativeSecDescBuffer));
BAIL_ON_NT_STATUS(ntError);
// Tests against NTFS/Win2003R2 show that the file/directory object
// owner is always granted FILE_READ_ATTRIBUTE
ntError = RtlGetOwnerSecurityDescriptor(
pSecDesc,
&pOwner,
&bOwnerDefaulted);
BAIL_ON_NT_STATUS(ntError);
if (RtlIsSidMemberOfToken(pToken, pOwner))
{
ClearFlag(Desired, FILE_READ_ATTRIBUTES);
SetFlag(GrantedAccess, FILE_READ_ATTRIBUTES);
}
/* Now check access */
bGranted = RtlAccessCheck(
pSecDesc,
pToken,
Desired,
GrantedAccess,
&gPvfsDriverState.GenericSecurityMap,
&AccessMask,
&ntError);
if (!bGranted)
{
ntError = STATUS_ACCESS_DENIED;
}
BAIL_ON_NT_STATUS(ntError);
cleanup:
if (pszFilename)
{
LwRtlCStringFree(&pszFilename);
}
if (pSecDesc)
{
PvfsFreeAbsoluteSecurityDescriptor(&pSecDesc);
}
return ntError;
error:
goto cleanup;
}
NTSTATUS
PvfsSetSecurityDescriptorFile(
IN PPVFS_CCB pCcb,
IN SECURITY_INFORMATION SecInfo,
IN PSECURITY_DESCRIPTOR_RELATIVE pSecDesc,
IN ULONG SecDescLength
)
{
NTSTATUS ntError = STATUS_ACCESS_DENIED;
PSECURITY_DESCRIPTOR_RELATIVE pFinalSecDesc = NULL;
ULONG ulFinalSecDescLength = 0;
SECURITY_INFORMATION SecInfoAll = (OWNER_SECURITY_INFORMATION |
GROUP_SECURITY_INFORMATION |
DACL_SECURITY_INFORMATION |
SACL_SECURITY_INFORMATION);
BYTE pCurrentSecDescBuffer[SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE];
ULONG ulCurrentSecDescLength = SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE;
BYTE pNewSecDescBuffer[SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE];
ULONG ulNewSecDescLength = SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE;
PSECURITY_DESCRIPTOR_ABSOLUTE pIncAbsSecDesc = NULL;
union {
TOKEN_OWNER TokenOwnerInfo;
BYTE Buffer[SID_MAX_SIZE];
} TokenOwnerBuffer;
PTOKEN_OWNER pTokenOwnerInformation = (PTOKEN_OWNER)&TokenOwnerBuffer;
ULONG ulTokenOwnerLength = 0;
union {
SID Sid;
BYTE Buffer[SID_MAX_SIZE];
} LocalSystemSidBuffer;
PSID pLocalSystemSid = (PSID)&LocalSystemSidBuffer;
ULONG ulLocalSystemSidLength = sizeof(LocalSystemSidBuffer);
memset(pCurrentSecDescBuffer, 0, SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE);
memset(pNewSecDescBuffer, 0, SECURITY_DESCRIPTOR_RELATIVE_MAX_SIZE);
memset(TokenOwnerBuffer.Buffer, 0, SID_MAX_SIZE);
/* Sanity checks */
if (SecInfo == 0)
{
ntError = STATUS_INVALID_PARAMETER;
BAIL_ON_NT_STATUS(ntError);
}
/* If the new Security Descriptor contains owner or group SID
information, berify that the user's ACCESS_TOKEN contains the
SID as a member */
if (SecInfo & (OWNER_SECURITY_INFORMATION|GROUP_SECURITY_INFORMATION))
{
PSID pOwner = NULL;
PSID pGroup = NULL;
BOOLEAN bDefaulted = FALSE;
ntError = PvfsSecurityAclSelfRelativeToAbsoluteSD(
&pIncAbsSecDesc,
pSecDesc);
BAIL_ON_NT_STATUS(ntError);
ntError = RtlQueryAccessTokenInformation(
pCcb->pUserToken,
TokenOwner,
(PVOID)pTokenOwnerInformation,
sizeof(TokenOwnerBuffer),
&ulTokenOwnerLength);
BAIL_ON_NT_STATUS(ntError);
ntError = RtlCreateWellKnownSid(
WinLocalSystemSid,
NULL,
pLocalSystemSid,
&ulLocalSystemSidLength);
BAIL_ON_NT_STATUS(ntError);
if (SecInfo & OWNER_SECURITY_INFORMATION)
{
ntError = RtlGetOwnerSecurityDescriptor(
pIncAbsSecDesc,
&pOwner,
&bDefaulted);
BAIL_ON_NT_STATUS(ntError);
if (!RtlIsSidMemberOfToken(pCcb->pUserToken, pOwner) &&
!RtlEqualSid(pLocalSystemSid, pTokenOwnerInformation->Owner))
{
ntError = STATUS_ACCESS_DENIED;
BAIL_ON_NT_STATUS(ntError);
}
}
if (SecInfo & GROUP_SECURITY_INFORMATION)
{
ntError = RtlGetGroupSecurityDescriptor(
pIncAbsSecDesc,
&pGroup,
&bDefaulted);
BAIL_ON_NT_STATUS(ntError);
if (!RtlIsSidMemberOfToken(pCcb->pUserToken, pGroup) &&
!RtlEqualSid(pLocalSystemSid, pTokenOwnerInformation->Owner))
{
ntError = STATUS_ACCESS_DENIED;
BAIL_ON_NT_STATUS(ntError);
}
}
}
if (SecInfo == SecInfoAll)
{
/* We already have a fully formed Security Descriptor */
pFinalSecDesc = pSecDesc;
ulFinalSecDescLength = SecDescLength;
}
else
{
/* Retrieve the existing SD and merge with the incoming one */
ntError = PvfsGetSecurityDescriptorFile(
pCcb,
SecInfoAll,
(PSECURITY_DESCRIPTOR_RELATIVE)pCurrentSecDescBuffer,
&ulCurrentSecDescLength);
BAIL_ON_NT_STATUS(ntError);
/* Assume that the new SD is <= the combined size of the current
SD and the incoming one */
ntError = RtlSetSecurityDescriptorInfo(
SecInfo,
pSecDesc,
(PSECURITY_DESCRIPTOR_RELATIVE)pCurrentSecDescBuffer,
(PSECURITY_DESCRIPTOR_RELATIVE)pNewSecDescBuffer,
&ulNewSecDescLength,
&gPvfsFileGenericMapping);
BAIL_ON_NT_STATUS(ntError);
pFinalSecDesc = (PSECURITY_DESCRIPTOR_RELATIVE)pNewSecDescBuffer;
ulFinalSecDescLength = ulNewSecDescLength;
}
/* Save the combined SD */
#ifdef HAVE_EA_SUPPORT
ntError = PvfsSetSecurityDescriptorFileXattr(
pCcb,
pFinalSecDesc,
ulFinalSecDescLength);
#else
ntError = PvfsSetSecurityDescriptorPosix(
pCcb,
pFinalSecDesc,
ulFinalSecDescLength);
#endif
BAIL_ON_NT_STATUS(ntError);
PvfsNotifyScheduleFullReport(
pCcb->pFcb,
FILE_NOTIFY_CHANGE_SECURITY,
FILE_ACTION_MODIFIED,
pCcb->pszFilename);
cleanup:
if (pIncAbsSecDesc)
{
PvfsFreeAbsoluteSecurityDescriptor(&pIncAbsSecDesc);
}
return ntError;
error:
goto cleanup;
}
