Fixed incorrect checking of PRINCIPAL_SELF permissions.

If an ace has the PRINCIPAL_SELF as trustee, this sid has to be replaced with
the onjectSid of the object being checked. PRINCIPAL_SELF is the way to grant rights
to an account over itself.

3 files changed, 139 insertions, 16 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/acl.c b/source4/dsdb/samdb/ldb_modules/acl.c
index dcd015b2a5..6cb50b2098 100644
--- a/source4/dsdb/samdb/ldb_modules/acl.c
+++ b/source4/dsdb/samdb/ldb_modules/acl.c
@@ -204,6 +204,33 @@ static const struct GUID *get_oc_guid_from_message(struct ldb_module *module,
 						      (char *)oc_el->values[oc_el->num_values-1].data);
 }
 
+static int get_dom_sid_from_ldb_message(TALLOC_CTX *mem_ctx,
+				   struct ldb_message *acl_res,
+				   struct dom_sid **sid)
+{
+	struct ldb_message_element *sid_element;
+	enum ndr_err_code ndr_err;
+
+	sid_element = ldb_msg_find_element(acl_res, "objectSid");
+	if (!sid_element) {
+		*sid = NULL;
+		return LDB_SUCCESS;
+	}
+	*sid = talloc(mem_ctx, struct dom_sid);
+	if(!*sid) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	ndr_err = ndr_pull_struct_blob(&sid_element->values[0], *sid, NULL, *sid,
+				       (ndr_pull_flags_fn_t)ndr_pull_dom_sid);
+
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	return LDB_SUCCESS;
+}
+
+
 static void acl_debug(struct security_descriptor *sd,
 		      struct security_token *token,
 		      struct ldb_dn *dn,
@@ -232,10 +259,12 @@ static int check_access_on_dn(struct ldb_module *module,
 	struct ldb_context *ldb = ldb_module_get_ctx(module);
 	struct ldb_result *acl_res;
 	struct security_descriptor *sd = NULL;
+	struct dom_sid *sid = NULL;
 	NTSTATUS status;
 	uint32_t access_granted;
 	static const char *acl_attrs[] = {
 		"nTSecurityDescriptor",
+		"objectSid",
 		NULL
 	};
 
@@ -254,10 +283,16 @@ static int check_access_on_dn(struct ldb_module *module,
 	if (!sd) {
 		return LDB_SUCCESS;
 	}
+	ret = get_dom_sid_from_ldb_message(mem_ctx, acl_res->msgs[0], &sid);
+	if (ret != LDB_SUCCESS) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
 	status = sec_access_check_ds(sd, acl_user_token(module),
 				     access,
 				     &access_granted,
-				     tree);
+				     tree,
+				     sid);
 	if (!NT_STATUS_IS_OK(status)) {
 		acl_debug(sd,
 			  acl_user_token(module),
@@ -272,16 +307,15 @@ static int check_access_on_dn(struct ldb_module *module,
 static int acl_check_access_on_attribute(struct ldb_module *module,
 					 TALLOC_CTX *mem_ctx,
 					 struct security_descriptor *sd,
+					 struct dom_sid *rp_sid,
 					 uint32_t access,
 					 struct dsdb_attribute *attr)
 {
 	int ret;
-	struct ldb_context *ldb = ldb_module_get_ctx(module);
 	NTSTATUS status;
 	uint32_t access_granted;
 	struct object_tree *root = NULL;
 	struct object_tree *new_node = NULL;
-	const struct dsdb_schema *schema = dsdb_get_schema(ldb);
 	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 	struct security_token *token = acl_user_token(module);
 	if (attr) {
@@ -310,7 +344,8 @@ static int acl_check_access_on_attribute(struct ldb_module *module,
 	status = sec_access_check_ds(sd, token,
 				     access,
 				     &access_granted,
-				     root);
+				     root,
+				     rp_sid);
 	if (!NT_STATUS_IS_OK(status)) {
 		ret = LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
 	}
@@ -325,6 +360,7 @@ fail:
 static int acl_check_access_on_class(struct ldb_module *module,
 				     TALLOC_CTX *mem_ctx,
 				     struct security_descriptor *sd,
+				     struct dom_sid *rp_sid,
 				     uint32_t access,
 				     const char *class_name)
 {
@@ -355,7 +391,8 @@ static int acl_check_access_on_class(struct ldb_module *module,
 	status = sec_access_check_ds(sd, token,
 				     access,
 				     &access_granted,
-				     root);
+				     root,
+				     rp_sid);
 	if (!NT_STATUS_IS_OK(status)) {
 		ret = LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
 	}
@@ -373,8 +410,6 @@ static int acl_allowedAttributes(struct ldb_module *module,
 				 struct acl_context *ac)
 {
 	struct ldb_message_element *oc_el;
-	struct ldb_message_element *allowedAttributes;
-	struct ldb_message_element *allowedAttributesEffective;
 	struct ldb_context *ldb = ldb_module_get_ctx(module);
 	const struct dsdb_schema *schema = dsdb_get_schema(ldb);
 	TALLOC_CTX *mem_ctx;
@@ -411,6 +446,7 @@ static int acl_allowedAttributes(struct ldb_module *module,
 	}
 	if (ac->allowedAttributesEffective) {
 		struct security_descriptor *sd;
+		struct dom_sid *sid = NULL;
 		ldb_msg_remove_attr(msg, "allowedAttributesEffective");
 		if (ac->user_type == SECURITY_SYSTEM) {
 			for (i=0; attr_list && attr_list[i]; i++) {
@@ -424,6 +460,11 @@ static int acl_allowedAttributes(struct ldb_module *module,
 		if (ret != LDB_SUCCESS) {
 			return ret;
 		}
+		ret = get_dom_sid_from_ldb_message(mem_ctx, sd_msg, &sid);
+
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
 		for (i=0; attr_list && attr_list[i]; i++) {
 			struct dsdb_attribute *attr = dsdb_attribute_by_lDAPDisplayName(schema,
 											attr_list[i]);
@@ -439,6 +480,7 @@ static int acl_allowedAttributes(struct ldb_module *module,
 			ret = acl_check_access_on_attribute(module,
 							    msg,
 							    sd,
+							    sid,
 							    SEC_ADS_WRITE_PROP,
 							    attr);
 			if (ret == LDB_SUCCESS) {
@@ -517,6 +559,7 @@ static int acl_childClassesEffective(struct ldb_module *module,
 	const struct dsdb_schema *schema = dsdb_get_schema(ldb);
 	const struct dsdb_class *sclass;
 	struct security_descriptor *sd;
+	struct dom_sid *sid = NULL;
 	int i, j, ret;
 
 	if (ac->user_type == SECURITY_SYSTEM) {
@@ -536,7 +579,11 @@ static int acl_childClassesEffective(struct ldb_module *module,
 	if (ret != LDB_SUCCESS) {
 		return ret;
 	}
+	ret = get_dom_sid_from_ldb_message(msg, sd_msg, &sid);
 
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
 	for (i=0; oc_el && i < oc_el->num_values; i++) {
 		sclass = dsdb_class_by_lDAPDisplayName_ldb_val(schema, &oc_el->values[i]);
 		if (!sclass) {
@@ -548,6 +595,7 @@ static int acl_childClassesEffective(struct ldb_module *module,
 			ret = acl_check_access_on_class(module,
 							msg,
 							sd,
+							sid,
 							SEC_ADS_CREATE_CHILD,
 							sclass->possibleInferiors[j]);
 			if (ret == LDB_SUCCESS) {
@@ -587,6 +635,7 @@ static int acl_sDRightsEffective(struct ldb_module *module,
 	struct ldb_message_element *rightsEffective;
 	int ret;
 	struct security_descriptor *sd;
+	struct dom_sid *sid = NULL;
 	uint32_t flags = 0;
 
 	/* Must remove any existing attribute, or else confusion reins */
@@ -604,10 +653,15 @@ static int acl_sDRightsEffective(struct ldb_module *module,
 		if (ret != LDB_SUCCESS) {
 			return ret;
 		}
+		ret = get_dom_sid_from_ldb_message(msg, sd_msg, &sid);
 
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
 		ret = acl_check_access_on_attribute(module,
 						    msg,
 						    sd,
+						    sid,
 						    SEC_STD_WRITE_OWNER,
 						    NULL);
 		if (ret == LDB_SUCCESS) {
@@ -616,6 +670,7 @@ static int acl_sDRightsEffective(struct ldb_module *module,
 		ret = acl_check_access_on_attribute(module,
 						    msg,
 						    sd,
+						    sid,
 						    SEC_STD_WRITE_DAC,
 						    NULL);
 		if (ret == LDB_SUCCESS) {
@@ -624,6 +679,7 @@ static int acl_sDRightsEffective(struct ldb_module *module,
 		ret = acl_check_access_on_attribute(module,
 						    msg,
 						    sd,
+						    sid,
 						    SEC_FLAG_SYSTEM_SECURITY,
 						    NULL);
 		if (ret == LDB_SUCCESS) {
@@ -695,10 +751,12 @@ static int acl_modify(struct ldb_module *module, struct ldb_request *req)
 	NTSTATUS status;
 	struct ldb_result *acl_res;
 	struct security_descriptor *sd;
+	struct dom_sid *sid = NULL;
 	TALLOC_CTX *tmp_ctx = talloc_new(req);
 	static const char *acl_attrs[] = {
 		"nTSecurityDescriptor",
 		"objectClass",
+		"objectSid",
 		NULL
 	};
 
@@ -732,6 +790,11 @@ static int acl_modify(struct ldb_module *module, struct ldb_request *req)
 		goto fail;
 	}
 
+	ret = get_dom_sid_from_ldb_message(req, acl_res->msgs[0], &sid);
+	if (ret != LDB_SUCCESS) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
 	if (!insert_in_object_tree(tmp_ctx, guid, SEC_ADS_WRITE_PROP,
 				   &root, &new_node)) {
 		DEBUG(10, ("acl_modify: cannot add to object tree\n"));
@@ -774,7 +837,8 @@ static int acl_modify(struct ldb_module *module, struct ldb_request *req)
 		status = sec_access_check_ds(sd, acl_user_token(module),
 					     SEC_ADS_WRITE_PROP,
 					     &access_granted,
-					     root);
+					     root,
+					     sid);
 
 		if (!NT_STATUS_IS_OK(status)) {
 			DEBUG(10, ("Object %s nas no write property access\n",
@@ -792,7 +856,8 @@ static int acl_modify(struct ldb_module *module, struct ldb_request *req)
 		status = sec_access_check_ds(sd, acl_user_token(module),
 					     SEC_STD_WRITE_DAC,
 					     &access_granted,
-					     NULL);
+					     NULL,
+					     sid);
 
 		if (!NT_STATUS_IS_OK(status)) {
 			DEBUG(10, ("Object %s nas no write dacl access\n",
@@ -860,6 +925,7 @@ static int acl_rename(struct ldb_module *module, struct ldb_request *req)
 	struct ldb_dn *newparent = ldb_dn_get_parent(req, req->op.rename.newdn);
 	struct ldb_context *ldb;
 	struct security_descriptor *sd = NULL;
+	struct dom_sid *sid = NULL;
 	struct ldb_result *acl_res;
 	const struct GUID *guid;
 	struct object_tree *root = NULL;
@@ -870,6 +936,7 @@ static int acl_rename(struct ldb_module *module, struct ldb_request *req)
 	static const char *acl_attrs[] = {
 		"nTSecurityDescriptor",
 		"objectClass",
+		"objectSid",
 		NULL
 	};
 
@@ -914,10 +981,16 @@ static int acl_rename(struct ldb_module *module, struct ldb_request *req)
 	if (!sd) {
 		return LDB_SUCCESS;
 	}
+	ret = get_dom_sid_from_ldb_message(req, acl_res->msgs[0], &sid);
+	if (ret != LDB_SUCCESS) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
 	status = sec_access_check_ds(sd, acl_user_token(module),
 				     SEC_ADS_WRITE_PROP,
 				     &access_granted,
-				     root);
+				     root,
+				     sid);
 
 	if (!NT_STATUS_IS_OK(status)) {
 		DEBUG(10, ("Object %s nas no wp on name\n",
@@ -966,7 +1039,8 @@ static int acl_rename(struct ldb_module *module, struct ldb_request *req)
 	status = sec_access_check_ds(sd, acl_user_token(module),
 				     SEC_STD_DELETE,
 				     &access_granted,
-				     NULL);
+				     NULL,
+				     sid);
 
 	if (NT_STATUS_IS_OK(status)) {
 		return ldb_next_request(module, req);
@@ -989,6 +1063,7 @@ static int acl_search_callback(struct ldb_request *req, struct ldb_reply *ares)
 	static const char *acl_attrs[] = {
 		"objectClass",
 		"nTSecurityDescriptor",
+		"objectSid",
 		NULL
 	};
 	int ret, i;
diff --git a/source4/lib/ldb/tests/python/acl.py b/source4/lib/ldb/tests/python/acl.py
index ae35ddfb29..4544f60736 100755
--- a/source4/lib/ldb/tests/python/acl.py
+++ b/source4/lib/ldb/tests/python/acl.py
@@ -393,8 +393,6 @@ userAccountControl: %s""" % userAccountControl
         res = self.ldb_admin.search( self.base_dn, expression="(distinguishedName=%s,%s)" \
                 % ("CN=test_add_group1,OU=test_add_ou2,OU=test_add_ou1", self.base_dn) )
         self.assertEqual( res, [])
- 
-# ace is not inherited - filered out...
 
     def test_add_granted_user(self):
         """ 3 Testing OU with the rights of regular user granted the right 'Create User child objects' """
@@ -749,6 +747,47 @@ url: www.samba.org"""
             # This 'modify' operation should always throw ERR_INSUFFICIENT_ACCESS_RIGHTS
             self.fail()
 
+
+    def test_modify_u4(self):
+        """11 Grant WP to PRINCIPAL_SELF and test modify"""
+        # Creating acluser1
+        if self.SAMBA:
+            self.delete_force(self.ldb_admin, self.get_user_dn("acluser3"))
+            self.create_user(self.ldb_admin, self.get_user_dn("acluser3"))
+            self.enable_account(self.get_user_dn("acluser3"))
+        # Test if we have any additional groups for user than default
+        if self.WIN:
+            res = self.ldb_admin.search( self.base_dn, expression="(distinguishedName=%s)" \
+                    % self.get_user_dn("acluser3") )
+            try:
+                self.assertEqual( res[0]["memberOf"][0], "" )
+            except KeyError:
+                pass
+            else:
+                self.fail()
+        # Create user connection that we will test with
+        ldb_user = self.get_ldb_connection("acluser3", "samba123@")
+        ldif = """
+dn: """ + self.get_user_dn("acluser3") + """
+changetype: modify
+add: adminDescription
+adminDescription: blah blah blah"""
+        try:
+            ldb_user.modify_ldif(ldif)
+        except LdbError, (num, _):
+            self.assertEquals(num, ERR_INSUFFICIENT_ACCESS_RIGHTS)
+        else:
+            # This 'modify' operation should always throw ERR_INSUFFICIENT_ACCESS_RIGHTS
+            self.fail()
+
+        mod = "(OA;;WP;bf967919-0de6-11d0-a285-00aa003049e2;;PS)"
+        self.dacl_add_ace(self.get_user_dn("acluser3"), mod)
+        # Modify on attribute you have rights for
+        ldb_user.modify_ldif(ldif)
+        res = self.ldb_admin.search( self.base_dn, expression="(distinguishedName=%s)" \
+                                    % self.get_user_dn("acluser3"), attrs=["adminDescription"] )
+        self.assertEqual(res[0]["adminDescription"][0], "blah blah blah")
+
 #enable these when we have search implemented
     def _test_search_u1(self):
         """See if can prohibit user to read another User object"""
diff --git a/source4/libcli/security/access_check.c b/source4/libcli/security/access_check.c
index fb78e0aa47..19fb160d58 100644
--- a/source4/libcli/security/access_check.c
+++ b/source4/libcli/security/access_check.c
@@ -180,12 +180,14 @@ 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 object_tree *tree,
+			     struct dom_sid *replace_sid)
 {
         int i;
         uint32_t bits_remaining;
         struct object_tree *node;
         const struct GUID *type;
+	struct dom_sid *ps_sid = dom_sid_parse_talloc(NULL, SID_NT_SELF);
 
         *access_granted = access_desired;
         bits_remaining = access_desired;
@@ -228,13 +230,20 @@ NTSTATUS sec_access_check_ds(const struct security_descriptor *sd,
 
         /* 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 (!security_token_has_sid(token, &ace->trustee)) {
+		if (dom_sid_equal(&ace->trustee, ps_sid) && replace_sid) {
+			trustee = replace_sid;
+		}
+		else
+		{
+			trustee = &ace->trustee;
+		}
+                if (!security_token_has_sid(token, trustee)) {
                         continue;
                 }