[tarantool-patches] [PATCH 2/4] Add entities user, role to access control.

[Serge Petrenko <sergepetrenko@tarantool.org>]

Previously the only existing entities in access control were space,
funciton and sequence. Added user and role entities, so it is now
possible to create users or roles without create privilege on universe.
Also added all the needed checks and modified tests accordingly.

Closes #3524
---
 src/box/alter.cc            | 72 +++++++++++++++++++++++++++++++++------------
 src/box/lua/schema.lua      | 27 ++++++++++-------
 src/box/schema.h            |  6 ++++
 src/box/user.cc             | 25 +++++++++++++++-
 test/box/access.result      | 20 ++++++-------
 test/box/access.test.lua    | 15 ++++------
 test/box/access_misc.result |  2 +-
 test/box/role.result        | 25 ++++++++++++++--
 test/box/role.test.lua      | 12 ++++++--
 9 files changed, 150 insertions(+), 54 deletions(-)

diff --git a/src/box/alter.cc b/src/box/alter.cc
index bd50e457a..6293dcc50 100644
--- a/src/box/alter.cc
+++ b/src/box/alter.cc
@@ -2186,7 +2186,7 @@ on_replace_dd_user(struct trigger * /* trigger */, void *event)
 	struct user *old_user = user_by_id(uid);
 	if (new_tuple != NULL && old_user == NULL) { /* INSERT */
 		struct user_def *user = user_def_new_from_tuple(new_tuple);
-		access_check_ddl(user->name, user->owner, SC_USER, PRIV_C, true);
+		access_check_ddl(user->name, user->owner, user->type, PRIV_C, true);
 		auto def_guard = make_scoped_guard([=] { free(user); });
 		(void) user_cache_replace(user);
 		def_guard.is_active = false;
@@ -2195,7 +2195,7 @@ on_replace_dd_user(struct trigger * /* trigger */, void *event)
 		txn_on_rollback(txn, on_rollback);
 	} else if (new_tuple == NULL) { /* DELETE */
 		access_check_ddl(old_user->def->name, old_user->def->owner,
-				 SC_USER, PRIV_D, true);
+				 old_user->def->type, PRIV_D, true);
 		/* Can't drop guest or super user */
 		if (uid <= (uint32_t) BOX_SYSTEM_USER_ID_MAX || uid == SUPER) {
 			tnt_raise(ClientError, ER_DROP_USER,
@@ -2221,6 +2221,14 @@ on_replace_dd_user(struct trigger * /* trigger */, void *event)
 		 * correct.
 		 */
 		struct user_def *user = user_def_new_from_tuple(new_tuple);
+		/* Do not allow changes for system users and roles. */
+		struct credentials *cr = effective_user();
+		if ((uid <= (uint32_t) BOX_SYSTEM_USER_ID_MAX || uid == SUPER) &&
+		    cr->uid != ADMIN) {
+			struct user *current_user = user_find_xc(cr->uid);
+			tnt_raise(AccessDeniedError, "alter", "user or role",
+				  old_user->def->name, current_user->def->name);
+		}
 		access_check_ddl(user->name, user->uid, SC_USER, PRIV_A,
 				 true);
 		auto def_guard = make_scoped_guard([=] { free(user); });
@@ -2641,26 +2649,49 @@ priv_def_check(struct priv_def *priv, enum priv_type priv_type)
 	}
 	case SC_ROLE:
 	{
-		struct user *role = user_by_id(priv->object_id);
-		if (role == NULL || role->def->type != SC_ROLE) {
-			tnt_raise(ClientError, ER_NO_SUCH_ROLE,
-				  role ? role->def->name :
-				  int2str(priv->object_id));
-		}
-		/*
-		 * Only the creator of the role can grant or revoke it.
-		 * Everyone can grant 'PUBLIC' role.
-		 */
-		if (role->def->owner != grantor->def->uid &&
-		    grantor->def->uid != ADMIN &&
-		    (role->def->uid != PUBLIC || priv->access != PRIV_X)) {
+		if (priv->object_id != 0) {
+			struct user *role = user_by_id(priv->object_id);
+			if (role == NULL || role->def->type != SC_ROLE) {
+				tnt_raise(ClientError, ER_NO_SUCH_ROLE,
+					  role ? role->def->name :
+					  int2str(priv->object_id));
+			}
+			/*
+			 * Only the creator of the role can grant or revoke it.
+			 * Everyone can grant 'PUBLIC' role.
+			 */
+			if (role->def->owner != grantor->def->uid &&
+			    grantor->def->uid != ADMIN &&
+			    (role->def->uid != PUBLIC || priv->access != PRIV_X)) {
+				tnt_raise(AccessDeniedError,
+					  priv_name(priv_type),
+					  schema_object_name(SC_ROLE), name,
+					  grantor->def->name);
+			}
+			/* Not necessary to do during revoke, but who cares. */
+			role_check(grantee, role);
+		} else if (grantor->def->uid != ADMIN) {
+			/* only admin may grant privileges on an entire entity. */
 			tnt_raise(AccessDeniedError,
 				  priv_name(priv_type),
 				  schema_object_name(SC_ROLE), name,
 				  grantor->def->name);
 		}
-		/* Not necessary to do during revoke, but who cares. */
-		role_check(grantee, role);
+		break;
+	}
+	case SC_USER:
+	{
+		struct user *user = NULL;
+		if (priv->object_id != 0)
+			user = user_by_id(priv->object_id);
+		if ((user == NULL || user->def->owner != grantor->def->uid) &&
+		    grantor->def->uid != ADMIN) {
+			tnt_raise(AccessDeniedError,
+				  priv_name(priv_type),
+				  schema_object_name(SC_USER), name,
+				  grantor->def->name);
+		}
+		break;
 	}
 	default:
 		break;
@@ -2681,7 +2712,12 @@ grant_or_revoke(struct priv_def *priv)
 	struct user *grantee = user_by_id(priv->grantee_id);
 	if (grantee == NULL)
 		return;
-	if (priv->object_type == SC_ROLE) {
+	/*
+	 * Grant a role to a user only when privilege type is 'execute'
+	 * and the role is specified.
+	 */
+	if (priv->object_type == SC_ROLE && !(priv->access & ~PRIV_X) &&
+	    priv->object_id != 0) {
 		struct user *role = user_by_id(priv->object_id);
 		if (role == NULL || role->def->type != SC_ROLE)
 			return;
diff --git a/src/box/lua/schema.lua b/src/box/lua/schema.lua
index ef544c879..4b7a14411 100644
--- a/src/box/lua/schema.lua
+++ b/src/box/lua/schema.lua
@@ -1739,6 +1739,8 @@ local priv_object_combo = {
                            box.priv.C, box.priv.D),
     ["role"]     = bit.bor(box.priv.X, box.priv.U,
                            box.priv.C, box.priv.D),
+    ["user"]	 = bit.bor(box.priv.C, box.priv.U,
+                           box.priv.D),
 }
 
 --
@@ -1842,21 +1844,25 @@ local function object_resolve(object_type, object_name)
         end
         return seq
     end
-    if object_type == 'role' then
+    if object_type == 'role' or object_type == 'user' then
         local _vuser = box.space[box.schema.VUSER_ID]
-        local role
+        local role_or_user
+        if object_name == nil or object_name == 0 then
+            return 0
+        end
         if type(object_name) == 'string' then
-            role = _vuser.index.name:get{object_name}
+            role_or_user = _vuser.index.name:get{object_name}
         else
-            role = _vuser:get{object_name}
+            role_or_user = _vuser:get{object_name}
         end
-        if role and role[4] == 'role' then
-            return role[1]
-        else
+        if role_or_user and role_or_user[4] == object_type then
+            return role_or_user[1]
+        elseif object_type == 'role' then
             box.error(box.error.NO_SUCH_ROLE, object_name)
-        end
+        else
+            box.error(box.error.NO_SUCH_USER, object_name)
+	end
     end
-
     box.error(box.error.UNKNOWN_SCHEMA_OBJECT, object_type)
 end
 
@@ -2102,7 +2108,8 @@ local function grant(uid, name, privilege, object_type,
     if privilege_hex ~= old_privilege then
         _priv:replace{options.grantor, uid, object_type, oid, privilege_hex}
     elseif not options.if_not_exists then
-            if object_type == 'role' then
+            if object_type == 'role' and object_name ~= nil and
+	       object_name ~= 0 then
                 box.error(box.error.ROLE_GRANTED, name, object_name)
             else
                 box.error(box.error.PRIV_GRANTED, name, privilege,
diff --git a/src/box/schema.h b/src/box/schema.h
index 0822262d0..f78ea43cc 100644
--- a/src/box/schema.h
+++ b/src/box/schema.h
@@ -240,6 +240,8 @@ struct on_access_denied_ctx {
 struct entity_access {
        struct access space[BOX_USER_MAX];
        struct access function[BOX_USER_MAX];
+       struct access user[BOX_USER_MAX];
+       struct access role[BOX_USER_MAX];
        struct access sequence[BOX_USER_MAX];
 };
 
@@ -255,6 +257,10 @@ entity_access_get(enum schema_object_type type)
                return entity_access.space;
        case SC_FUNCTION:
                return entity_access.function;
+       case SC_USER:
+	       return entity_access.user;
+       case SC_ROLE:
+	       return entity_access.role;
        case SC_SEQUENCE:
                return entity_access.sequence;
        default:
diff --git a/src/box/user.cc b/src/box/user.cc
index fbf06566a..4edef1d5f 100644
--- a/src/box/user.cc
+++ b/src/box/user.cc
@@ -229,6 +229,29 @@ access_find(struct priv_def *priv)
 			access = func->access;
 		break;
 	}
+	case SC_USER:
+	{
+		/*
+		 * user ID 0 is shared between user 'guest' and granting
+		 * privileges upon whole entity user. This is not a problem,
+		 * since we don't want to grant privileges on any system user,
+		 * including 'guest'.
+		 */
+		if(priv->object_id == 0) {
+			access = entity_access.user;
+			break;
+		}
+		/* No grants on a single object user yet. */
+	}
+	case SC_ROLE:
+	{
+		/* Tha same remark as in case SC_USER applies. */
+		if (priv->object_id == 0) {
+			access = entity_access.role;
+			break;
+		}
+		/* No grants on a single object role yet. */
+	}
 	case SC_SEQUENCE:
 	{
 		if (priv->object_id == 0) {
@@ -315,7 +338,7 @@ user_reload_privs(struct user *user)
 			 * Skip role grants, we're only
 			 * interested in real objects.
 			 */
-			if (priv.object_type != SC_ROLE)
+			if (priv.object_type != SC_ROLE || !(priv.access & PRIV_X))
 				user_grant_priv(user, &priv);
 		}
 	}
diff --git a/test/box/access.result b/test/box/access.result
index f4669a4a3..31095aec2 100644
--- a/test/box/access.result
+++ b/test/box/access.result
@@ -878,8 +878,6 @@ box.schema.user.create('test')
 box.schema.user.grant('test', 'read', 'space', '_collation')
 ---
 ...
---box.schema.user.grant('test', 'write', 'space', '_collation')
--- FIXME: granting create on 'collation' only doesn't work
 box.schema.user.grant('test', 'create', 'universe')
 ---
 ...
@@ -1427,16 +1425,18 @@ box.session.su("admin")
 box.schema.user.grant('tester', 'write', 'universe')
 ---
 ...
--- no entity user currently, so have to grant create
--- on universe in order to create a user.
-box.schema.user.grant('tester', 'create', 'universe')
+box.schema.user.grant('tester', 'create', 'user')
+---
+...
+box.schema.user.grant('tester', 'create', 'space')
+---
+...
+box.schema.user.grant('tester', 'create', 'function')
+---
+...
+box.schema.user.grant('tester', 'create' , 'sequence')
 ---
 ...
--- this should work instead:
---box.schema.user.grant('tester', 'create', 'user')
---box.schema.user.grant('tester', 'create', 'space')
---box.schema.user.grant('tester', 'create', 'function')
---box.schema.user.grant('tester', 'create' , 'sequence')
 box.schema.user.grant('tester', 'read', 'space', '_sequence')
 ---
 ...
diff --git a/test/box/access.test.lua b/test/box/access.test.lua
index 9ae0e1114..9b7510e64 100644
--- a/test/box/access.test.lua
+++ b/test/box/access.test.lua
@@ -341,8 +341,7 @@ c:close()
 session = box.session
 box.schema.user.create('test')
 box.schema.user.grant('test', 'read', 'space', '_collation')
---box.schema.user.grant('test', 'write', 'space', '_collation')
--- FIXME: granting create on 'collation' only doesn't work
+
 box.schema.user.grant('test', 'create', 'universe')
 session.su('test')
 box.internal.collation.create('test', 'ICU', 'ru_RU')
@@ -538,14 +537,10 @@ box.session.su("admin")
 -- tables from ddl
 --
 box.schema.user.grant('tester', 'write', 'universe')
--- no entity user currently, so have to grant create
--- on universe in order to create a user.
-box.schema.user.grant('tester', 'create', 'universe')
--- this should work instead:
---box.schema.user.grant('tester', 'create', 'user')
---box.schema.user.grant('tester', 'create', 'space')
---box.schema.user.grant('tester', 'create', 'function')
---box.schema.user.grant('tester', 'create' , 'sequence')
+box.schema.user.grant('tester', 'create', 'user')
+box.schema.user.grant('tester', 'create', 'space')
+box.schema.user.grant('tester', 'create', 'function')
+box.schema.user.grant('tester', 'create' , 'sequence')
 box.schema.user.grant('tester', 'read', 'space', '_sequence')
 box.session.su("tester")
 -- successful create
diff --git a/test/box/access_misc.result b/test/box/access_misc.result
index 839b576ac..0f4892533 100644
--- a/test/box/access_misc.result
+++ b/test/box/access_misc.result
@@ -361,7 +361,7 @@ testuser_uid = session.uid()
 ...
 _ = box.space._user:delete(2)
 ---
-- error: Drop access to user 'public' is denied for user 'testuser'
+- error: Drop access to role 'public' is denied for user 'testuser'
 ...
 box.space._user:select(1)
 ---
diff --git a/test/box/role.result b/test/box/role.result
index 806cea90b..243c7bc6c 100644
--- a/test/box/role.result
+++ b/test/box/role.result
@@ -214,7 +214,22 @@ box.schema.role.drop('test')
 box.schema.user.grant('grantee', 'liaison')
 ---
 ...
-box.schema.user.grant('test', 'read,write,create', 'universe')
+box.schema.user.grant('test', 'read,write', 'space', '_priv')
+---
+...
+box.schema.user.grant('test', 'write', 'space', '_schema')
+---
+...
+box.schema.user.grant('test', 'create', 'space')
+---
+...
+box.schema.user.grant('test', 'read,write', 'space', '_space')
+---
+...
+box.schema.user.grant('test', 'write', 'space', '_index')
+---
+...
+box.schema.user.grant('test', 'read', 'space', '_user')
 ---
 ...
 box.session.su('test')
@@ -635,7 +650,13 @@ box.schema.user.create('user')
 box.schema.user.create('grantee')
 ---
 ...
-box.schema.user.grant('user', 'read,write,execute,create', 'universe')
+box.schema.user.grant('user', 'read,write', 'space', '_user')
+---
+...
+box.schema.user.grant('user', 'read,write', 'space', '_priv')
+---
+...
+box.schema.user.grant('user', 'create', 'role')
 ---
 ...
 box.session.su('user')
diff --git a/test/box/role.test.lua b/test/box/role.test.lua
index e97339f49..9845f4c4c 100644
--- a/test/box/role.test.lua
+++ b/test/box/role.test.lua
@@ -69,7 +69,13 @@ box.schema.role.revoke('test', 'liaison')
 box.schema.role.drop('test')
 
 box.schema.user.grant('grantee', 'liaison')
-box.schema.user.grant('test', 'read,write,create', 'universe')
+
+box.schema.user.grant('test', 'read,write', 'space', '_priv')
+box.schema.user.grant('test', 'write', 'space', '_schema')
+box.schema.user.grant('test', 'create', 'space')
+box.schema.user.grant('test', 'read,write', 'space', '_space')
+box.schema.user.grant('test', 'write', 'space', '_index')
+box.schema.user.grant('test', 'read', 'space', '_user')
 box.session.su('test')
 s = box.schema.space.create('test')
 _ = s:create_index('i1')
@@ -248,7 +254,9 @@ box.schema.role.drop("role10")
 box.schema.user.create('user')
 box.schema.user.create('grantee')
 
-box.schema.user.grant('user', 'read,write,execute,create', 'universe')
+box.schema.user.grant('user', 'read,write', 'space', '_user')
+box.schema.user.grant('user', 'read,write', 'space', '_priv')
+box.schema.user.grant('user', 'create', 'role')
 box.session.su('user')
 box.schema.role.create('role')
 box.session.su('admin')
-- 
2.15.2 (Apple Git-101.1)