void object_tree_modify_access(struct object_tree *root,
uint32_t access)
{
struct object_tree *p;
if (root){
root->remaining_access &= ~access;
}
for (p = root->children; p != NULL; p = p->next)
object_tree_modify_access(p, access);
}
NTSTATUS sec_access_check_ds(const struct security_descriptor *sd,
const struct security_token *token,
uint32_t access_desired,
uint32_t *access_granted,
struct object_tree *tree,
struct dom_sid *replace_sid)
{
uint32_t i;
uint32_t bits_remaining;
struct object_tree *node;
const struct GUID *type;
struct dom_sid self_sid;
dom_sid_parse(SID_NT_SELF, &self_sid);
*access_granted = access_desired;
bits_remaining = access_desired;
/* handle the maximum allowed flag */
if (access_desired & SEC_FLAG_MAXIMUM_ALLOWED) {
access_desired |= access_check_max_allowed(sd, token);
access_desired &= ~SEC_FLAG_MAXIMUM_ALLOWED;
*access_granted = access_desired;
bits_remaining = access_desired;
}
if (access_desired & SEC_FLAG_SYSTEM_SECURITY) {
if (security_token_has_privilege(token, SEC_PRIV_SECURITY)) {
bits_remaining &= ~SEC_FLAG_SYSTEM_SECURITY;
} else {
return NT_STATUS_PRIVILEGE_NOT_HELD;
}
}
/* the owner always gets SEC_STD_WRITE_DAC and SEC_STD_READ_CONTROL */
if ((bits_remaining & (SEC_STD_WRITE_DAC|SEC_STD_READ_CONTROL)) &&
security_token_has_sid(token, sd->owner_sid)) {
bits_remaining &= ~(SEC_STD_WRITE_DAC|SEC_STD_READ_CONTROL);
}
/* TODO: remove this, as it is file server specific */
if ((bits_remaining & SEC_RIGHTS_PRIV_RESTORE) &&
security_token_has_privilege(token, SEC_PRIV_RESTORE)) {
bits_remaining &= ~(SEC_RIGHTS_PRIV_RESTORE);
}
if ((bits_remaining & SEC_RIGHTS_PRIV_BACKUP) &&
security_token_has_privilege(token, SEC_PRIV_BACKUP)) {
bits_remaining &= ~(SEC_RIGHTS_PRIV_BACKUP);
}
/* a NULL dacl allows access */
if ((sd->type & SEC_DESC_DACL_PRESENT) && sd->dacl == NULL) {
*access_granted = access_desired;
return NT_STATUS_OK;
}
if (sd->dacl == NULL) {
goto done;
}
/* check each ace in turn. */
for (i=0; bits_remaining && i < sd->dacl->num_aces; i++) {
struct dom_sid *trustee;
struct security_ace *ace = &sd->dacl->aces[i];
if (ace->flags & SEC_ACE_FLAG_INHERIT_ONLY) {
continue;
}
if (dom_sid_equal(&ace->trustee, &self_sid) && replace_sid) {
trustee = replace_sid;
} else {
trustee = &ace->trustee;
}
if (!security_token_has_sid(token, trustee)) {
continue;
}
switch (ace->type) {
case SEC_ACE_TYPE_ACCESS_ALLOWED:
if (tree) {
object_tree_modify_access(tree, ace->access_mask);
}
bits_remaining &= ~ace->access_mask;
break;
case SEC_ACE_TYPE_ACCESS_DENIED:
if (bits_remaining & ace->access_mask) {
return NT_STATUS_ACCESS_DENIED;
}
break;
case SEC_ACE_TYPE_ACCESS_DENIED_OBJECT:
case SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT:
/*
* check only in case we have provided a tree,
* the ACE has an object type and that type
* is in the tree
*/
type = get_ace_object_type(ace);
if (!tree) {
continue;
}
if (!type) {
node = tree;
} else {
if (!(node = get_object_tree_by_GUID(tree, type))) {
continue;
}
}
if (ace->type == SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT) {
object_tree_modify_access(node, ace->access_mask);
if (node->remaining_access == 0) {
return NT_STATUS_OK;
}
} else {
if (node->remaining_access & ace->access_mask){
return NT_STATUS_ACCESS_DENIED;
}
}
break;
default: /* Other ACE types not handled/supported */
break;
}
}
done:
if (bits_remaining != 0) {
return NT_STATUS_ACCESS_DENIED;
}
return NT_STATUS_OK;
}
