This is the second article on my Re-generate SQL Server
login series. In my first
column, I focused on server-level role and database-level role
assignment for any assigned login. I also mentioned frequent DBA encountered
tasks related to ensuring login properties setup and what kind of implications might
be created if login permission is not properly defined. In this portion of the
series, I’d like to walk through list of securables
and how to generate login to include securable granting and denying.
What is a securable?
Simply put, any entity within the database engine that
can be secured with permission is called securable. The highest levels of securables are servers and databases, mid-level securables are assemblies, full-text catalogs, message
types, etc., and the finest level securables are
table, view, function, stored procedure, etc. We can grant, deny and revoke
permission on securables.
Server-level permission
Below is the list of server-level permissions. The list
on the left also includes the permission defined on the right. For instance,
once we grant a login control server permission, the
login will also have privilege to do bulk operation, create and alter any
database, create unsafe assembly and shutdown the SQL instance. We need to be
extra careful when granting anyone server-level permission. One thing worth
mentioning is that by default all users have permission to "VIEW ANY
DATABASE." Also, to grant server-level permission, we need to be in the master
database to issue the server scope granting command and we either need to be a sysadmin or possess the server-level permission and higher
with GRANT option to give others permission on server level. The server-level
permission information is stored on sys.server_permissions.
Server Permission |
Finer Server Permission |
CONTROL SERVER |
ADMINISTER BULK OPERATIONS |
CONTROL SERVER |
ALTER ANY CONNECTION |
CONTROL SERVER |
ALTER ANY CREDENTIAL |
CONTROL SERVER |
ALTER ANY DATABASE |
CONTROL SERVER |
ALTER ANY ENDPOINT |
CONTROL SERVER |
ALTER ANY EVENT NOTIFICATION |
CONTROL SERVER |
ALTER ANY LINKED SERVER |
CONTROL SERVER |
ALTER ANY LOGIN |
CONTROL SERVER |
ALTER ANY SERVER AUDIT |
CONTROL SERVER |
ALTER RESOURCES |
CONTROL SERVER |
|
CONTROL SERVER |
ALTER SETTINGS |
CONTROL SERVER |
ALTER TRACE |
CONTROL SERVER |
AUTHENTICATE SERVER |
CONTROL SERVER |
CONNECT SQL |
CONTROL SERVER |
CONTROL SERVER |
CONTROL SERVER |
EXTERNAL ACCESS ASSEMBLY |
CONTROL SERVER |
SHUTDOWN |
CONTROL SERVER |
UNSAFE ASSEMBLY |
CONTROL SERVER |
VIEW ANY DEFINITION |
ALTER ANY EVENT NOTIFICATION |
CREATE DDL EVENT NOTIFICATION |
ALTER ANY EVENT NOTIFICATION |
CREATE TRACE EVENT NOTIFICATION |
ALTER ANY ENDPOINT |
CREATE ENDPOINT |
|
|
ALTER ANY DATABASE |
CREATE ANY DATABASE |
VIEW ANY DEFINITION |
VIEW ANY DATABASE |
Permission on database-level securable
Unlike server-level permission that you can only define
when connecting to the master database, each database has its list of
pre-defined class of securable that you can grant permission on database
principal (database user). Here is the list of securable class on which
permission exists:
- Database
- Object or column
- Schema
- Database principal
- Assembly
- Type
- XML schema collection
- Message type (Service Broker securable)
- Service contract (Service Broker securable)
- Service (Service Broker securable)
- Remote Service Binding (Service Broker
securable) - Route (Service Broker securable)
- Full-Text Catalog
- Symmetric Key
- Certificate
- Asymmetric Key
Database-level Permission information is stored on sys.database_permissions. Unless sys.server_permissions, sys.database_permissions
exists for every database.
Grant, revoke and deny
The definition for GRANT, REVOKE and DENY can be
confusing sometimes. Simply put, revoke is used to remove the permission that
has been GRANTED or DENIED on the same securable.
But what if we grant permission to a lower scope
securable and then issue DENY or REVOKE on a higher scope securable, what will
happen to the lower scope securable? No surprise, there is a difference.
When Denying on a higher-level securable, the principal
will be denied on the lower-level securable.
When Revoking on a higher-level securable, the
principal will keep his granted permission on the lower scope securable.
A principal can grant permission to another principal
if his permission is granted with grant option.
Generate script for server and database securable class
We have briefly gone over the available list of server-level
and database-level securable class. We often face tasks like listing out what
permission a login has. In my first article in this series, we talked about
server role and database role assignment for any given login. But there are
cases where login was given more specific permission that was not given through
server or database role but through server and database securable. This is the
most easily forgotten part of login permission.
It would be nice to simply input the login name that we are interested in and get ready
to use script to recover permission on server level and database level
securable for the specified principal. In this article, I am only focusing on
database and server-level securables. If you are
interested to see how to generate login creation, server role assignment or
database role assignment, please refer to the first article of the series.
Now, we can look into the script. To use the script, here are the steps. This script
works on SQL 2005, SQL 2008 and SQL 2008 R2.
1. Open Microsoft SQL
Server Management Studio (a.k.a SSMS), make a
connection to the SQL instance, then click New Query.
Make sure the credential you use to run the code has adequate privileges to
generate the script.
2. Copy below code
into the query window
3. Replace ‘YourloginName’ with the login you
would like to re-generate securable permission script, then execute
———————————————-
–Login Pre-requisites
———————————————-
set concat_null_yields_null off
USE master
go
SET NOCOUNT ON
DECLARE @login_name varchar(100)
SET @login_name = ‘YourLoginName’
—————————————————————–
IF lower(@login_name) IN (‘sa’,‘public’)
BEGIN
RAISERROR (15405,11,1,@login_name)
RETURN
END
IF NOT EXISTS (SELECT * FROM sys.server_principals WHERE name =
@login_name AND type
IN (‘G’,‘U’,‘S’))
BEGIN
PRINT ‘Please input valid
login name’
RETURN
END
DECLARE @login_sid varbinary(85)
SELECT @login_sid = sid FROM sys.server_principals WHERE
name = @login_name
DECLARE @maxid int
IF OBJECT_ID(‘tempdb..#db_users’) is not null
BEGIN
DROP TABLE #db_users
END
SELECT id = identity(int,1,1), sql_cmd = ‘SELECT ”’+name+”’, * FROM [’+name+‘].sys.database_principals’ INTO
#db_users FROM sys.databases
WHERE state_desc <> ‘OFFLINE’
SELECT @maxid = @@ROWCOUNT
———————————————-
–Create Server Role Temp table
———————————————-
IF OBJECT_ID(‘tempdb..#srvrole’) IS NOT NULL
BEGIN
DROP TABLE #srvrole
END
CREATE TABLE #srvrole(ServerRole sysname, MemberName sysname, MemberSID varbinary(85))
INSERT INTO [#srvrole] EXEC sp_helpsrvrolemember
DECLARE @login_srvrole varchar(1000)
SET @login_srvrole = ”
IF EXISTS (select * from [#srvrole] where
ServerRole = ‘sysadmin’
AND MemberName =
@login_name)
BEGIN
PRINT ‘–Login [’+@login_name+‘] is part of sysadmin server role, hence possesses full
privileges for SQL instance: ‘+@@servername
PRINT ‘GO’
SELECT @login_srvrole =
@login_srvrole + ‘EXEC
sp_addsrvrolemember ”’+MemberName+”’,”’+ServerRole+””+CHAR(10) FROM #srvrole
WHERE [MemberName] =
@login_name
PRINT @login_srvrole
RETURN
RETURN
END
—————————————————
–Find out list of db that the
login has access to
—————————————————
PRINT ”
PRINT ‘———————————————-‘
PRINT ‘–Create database user for login ‘
PRINT ‘———————————————-‘
IF OBJECT_ID(‘tempdb..#alldb_users’) is not null
BEGIN
DROP TABLE
#alldb_users
END
CREATE TABLE #alldb_users(
[dbname]
[sysname] NOT NULL,
[name]
[sysname] NOT NULL,
[principal_id]
[int] NOT NULL,
[type]
[char](1) NOT NULL,
[type_desc]
[nvarchar](60) NULL,
[default_schema_name]
[sysname] NULL,
[create_date]
[datetime] NOT NULL,
[modify_date]
[datetime] NOT NULL,
[owning_principal_id]
[int] NULL,
[sid]
[varbinary](85)
NULL,
[is_fixed_role]
[bit] NOT NULL
)
DECLARE @id int, @sqlcmd varchar(500)
SET @id = 1
WHILE @id <=@maxid
BEGIN
SELECT @sqlcmd =
sql_cmd FROM #db_users WHERE
id = @id
INSERT INTO
#alldb_users EXEC (@sqlcmd)
SET @id = @id + 1
END
DELETE FROM #alldb_users WHERE sid is null
DELETE FROM #alldb_users WHERE sid <> @login_sid
IF NOT EXISTS (SELECT * FROM #alldb_users )
BEGIN
PRINT ‘–Login [’+@login_name+‘] doesnt have access to any database’
END
DECLARE @name sysname, @dbname sysname, @schema sysname, @dbuser_cmd varchar(8000)
DECLARE dbuser_cursor CURSOR
FAST_FORWARD FOR
SELECT dbname, name, default_schema_name
FROM #alldb_users
OPEN dbuser_cursor
FETCH NEXT FROM dbuser_cursor INTO @dbname, @name, @schema
WHILE @@FETCH_STATUS = 0
BEGIN
IF @schema IS NOT NULL
BEGIN
SELECT @dbuser_cmd = ‘USE [’+dbname+‘]
IF NOT EXISTS (SELECT * FROM
sys.database_principals WHERE name = ”’+name+”’)
BEGIN
CREATE
USER [’+@name+‘] FOR LOGIN [’+@login_name+‘]’+isnull(‘ WITH DEFAULT_SCHEMA=[’+default_schema_name+‘]’,”)+‘
END
GO
‘ FROM #alldb_users WHERE name = @name and dbname = @dbname
END
ELSE
BEGIN
SELECT @dbuser_cmd = ‘USE [’+dbname+‘]
IF NOT EXISTS (SELECT * FROM
sys.database_principals WHERE name = ”’+name+”’)
BEGIN
CREATE
USER [’+@name+‘] FOR LOGIN [’+@login_name+‘]
END
GO
‘ FROM #alldb_users WHERE name = @name and dbname = @dbname
END
print @dbuser_cmd
FETCH NEXT FROM dbuser_cursor INTO
@dbname, @name,
@schema
END
CLOSE dbuser_cursor
DEALLOCATE dbuser_cursor
———————————————-
–Create DB Role Temp table
———————————————-
IF OBJECT_ID(‘tempdb..#dbrole’) is not null
BEGIN
DROP TABLE #dbrole
END
create table #dbrole (id int identity(1,1), dbname varchar(100), dbrole varchar (100), dbrole_member varchar(100), sid varbinary(85),
default_schema_name varchar(100), login_name varchar(100), db_principal_id int)
DECLARE @dbrole_sqlcmd varchar(max)
DECLARE dbrole_cursor CURSOR
FAST_FORWARD FOR
SELECT
‘SELECT ”’+dbname+”’, c.name, b.name, b.sid, b.default_schema_name, d.name,
b.principal_id as login_name
from [’+dbname+‘].sys.database_role_members
a
inner join [’+dbname+‘].sys.database_principals b on a.member_principal_id =
b.principal_id
inner join [’+dbname+‘].sys.database_principals c on a.role_principal_id =
c.principal_id
left join sys.server_principals d on
b.sid = d.sid
where d.name= ”’+@login_name+””
from #alldb_users
OPEN dbrole_cursor
FETCH NEXT FROM dbrole_cursor INTO
@dbrole_sqlcmd
WHILE @@FETCH_STATUS = 0
BEGIN
INSERT INTO #dbrole (dbname, dbrole,
dbrole_member, sid, default_schema_name,
login_name, db_principal_id) exec(@dbrole_sqlcmd)
FETCH NEXT FROM dbrole_cursor INTO
@dbrole_sqlcmd
END
CLOSE dbrole_cursor
DEALLOCATE dbrole_cursor
DELETE FROM #dbrole WHERE sid <> @login_sid
IF EXISTS (SELECT * FROM #dbrole where
dbrole = ‘db_owner’)
BEGIN
PRINT ‘———————————————-‘
PRINT‘–Login is db_owner of
below databases’
PRINT‘———————————————-‘
END
DECLARE @dbname_dbowner varchar(100), @dbrole_member
varchar(100)
DECLARE dbowner_cursor CURSOR
FAST_FORWARD FOR
SELECT dbname, dbrole_member from #dbrole where
dbrole = ‘db_owner’
OPEN dbowner_cursor
FETCH NEXT FROM dbowner_cursor INTO
@dbname_dbowner, @dbrole_member
WHILE @@FETCH_STATUS = 0
BEGIN
PRINT ‘USE [’+@dbname_dbowner+‘]
EXEC sp_addrolemember ”db_owner”,”’+@dbrole_member +”’
GO’
FETCH NEXT FROM dbowner_cursor INTO
@dbname_dbowner, @dbrole_member
END
CLOSE dbowner_cursor
DEALLOCATE dbowner_cursor
——————————————————————————————————–
–Find out what database the login
has permission to access (avoid restricted and single user database)
——————————————————————————————————–
DELETE From #srvrole where MemberName <>
@login_name
IF OBJECT_ID(‘tempdb..#alldb_users_access’) IS NOT NULL
BEGIN
DROP TABLE
#alldb_users_access
END
SELECT a.*, collation_name INTO #alldb_users_access FROM
#alldb_users a inner join
sys.databases b ON a.dbname = b.name
WHERE user_access = 0
OR
(user_access = 2 and exists (SELECT * FROM #srvrole WHERE
ServerRole in (‘dbcreator’,‘sysadmin’)))
OR
(user_access = 2 and a.dbname in (SELECT dbname FROM #dbrole WHERE
dbrole = ‘db_owner’
AND login_name =
@login_name))
——————————————————————————————————–
–Remove database that login doesnt
have permission to connect
——————————————————————————————————–
IF OBJECT_ID(‘tempdb..#dbconnect’) is not null
BEGIN
DROP TABLE #dbconnect
END
CREATE TABLE #dbconnect ( dbname varchar(100), connect_status bit)
DECLARE @dbconnect_sqlcmd varchar(1000)
SET @dbconnect_sqlcmd = ”
DECLARE dbbconnect_cursor CURSOR
FAST_FORWARD FOR
SELECT ‘select distinct ”’+dbname+”’, 1 from [’+dbname+‘].sys.database_permissions
a
inner join [’+dbname+‘].sys.database_principals b on a.grantee_principal_id =
b.principal_id
inner join [’+dbname+‘].sys.server_principals c on b.sid = c.sid
where c.name = ”’+@login_name+””
from #alldb_users_access
OPEN dbbconnect_cursor
FETCH NEXT FROM dbbconnect_cursor INTO
@dbconnect_sqlcmd
WHILE @@FETCH_STATUS = 0
BEGIN
INSERT INTO
#dbconnect exec(
@dbconnect_sqlcmd)
FETCH NEXT FROM dbbconnect_cursor INTO
@dbconnect_sqlcmd
END
CLOSE dbbconnect_cursor
DEALLOCATE dbbconnect_cursor
insert into #dbconnect
select a.dbname, 0 from
#alldb_users_access a left join #dbconnect b on
a.dbname = b.dbname
where b.dbname is null
—————————————————————————————
— Grant
all securable class to login
—————————————————————————————-
PRINT ”
PRINT ‘———————————————-‘
PRINT ‘–Grant all securable class to
login ‘
PRINT ‘———————————————-‘
IF OBJECT_ID(‘tempdb..#securable_class’) is not null
BEGIN
DROP TABLE
#securable_class
END
IF OBJECT_ID(‘tempdb..#dblevel’) is not null
BEGIN
DROP TABLE #dblevel
END
create table #dblevel (login_name varchar(256), dbname sysname, dbuser_name varchar(100), class_desc varchar(100), permission_name varchar(100), state_desc varchar(100))
DECLARE @dblevel_sqlcmd varchar(1000)
DECLARE dblevel_cursor CURSOR
FAST_FORWARD FOR
SELECT ‘select ”’+@login_name+”’ as login_name, ”’+dbname+”’ as dbname, b.name as
dbuser_name, a.class_desc, a.permission_name, state_desc from [’+dbname+‘].sys.database_permissions a inner join [’+dbname+‘].sys.database_principals b
on a.grantee_principal_id =
b.principal_id
where b.name in (”public”,”’+name+”’)
and class_desc = ”DATABASE”’
FROM #alldb_users_access
union
SELECT ‘select ”’+@login_name+”’ as login_name, ”master” as dbname, b.name as
dbuser_name, a.class_desc, a.permission_name, state_desc from
sys.server_permissions a inner join sys.server_principals b
on a.grantee_principal_id =
b.principal_id
where b.name = ”’+@login_name+””
UNION
SELECT ‘select ”’+@login_name+”’ as login_name, ”master” as dbname, b.name as
dbuser_name, a.class_desc, a.permission_name, state_desc from
sys.server_permissions a inner join sys.server_principals b
on a.grantee_principal_id =
b.principal_id and class_desc = ”SERVER”
where b.name = ”public”’
OPEN dblevel_cursor
FETCH NEXT FROM dblevel_cursor INTO
@dblevel_sqlcmd
WHILE @@FETCH_STATUS = 0
BEGIN
INSERT INTO #dblevel (login_name, dbname, dbuser_name, class_desc,
permission_name, state_desc) EXEC (@dblevel_sqlcmd)
FETCH NEXT FROM dblevel_cursor INTO
@dblevel_sqlcmd
END
CLOSE dblevel_cursor
DEALLOCATE dblevel_cursor
SET NOCOUNT ON
DELETE FROM #dblevel WHERE permission_name IN (‘SELECT’,‘INSERT’,‘UPDATE’,‘DELETE’,‘REFERENCES’)
DELETE FROM #dblevel WHERE dbname IN (SELECT dbname FROM
#dbrole WHERE sid
= @login_sid AND
dbrole = ‘db_owner’)
DECLARE @securable_sqlcmd varchar(150)
DECLARE securable_cursor CURSOR
FAST_FORWARD FOR
SELECT distinct ‘USE [’+dbname+‘]
GRANT ‘+permission_name+‘ TO [’+@login_name+‘]
GO
‘ FROM #dblevel
OPEN securable_cursor
FETCH NEXT FROM securable_cursor INTO
@securable_sqlcmd
WHILE @@FETCH_STATUS = 0
BEGIN
PRINT @securable_sqlcmd
FETCH NEXT FROM securable_cursor INTO
@securable_sqlcmd
END
CLOSE securable_cursor
DEALLOCATE securable_cursor
If you input a bad login name to the script, it will
produce an exception; below are the scenarios.
Scenario 1: If you enter either ‘sa’ or
‘public’,
then you will see results similar to the below snapshot in the SSMS result
pane (Fig. 1.1).
Fig
1.1
Scenario 2: If the login you provide doesn’t exist on
the SQL instance, then you will see results similar to the below snapshot in
the SSMS result pane (Fig 1.2)
Fig 1.2
Now we can look into the real scenario about a valid
login with permissions on server and database-level securables.
By replacing ‘YourLoginName’ with a valid login,
below is an example of how the outcome of the script will look. It contains the
creation of the database user for the login and the permission setting for
server and database securables. If a login is db_owner for any database or is part of sysadmin
server role member, then the resulting script will only contain the execution
of system stored procedure sp_addrolemember and sp_addsrvrolemember
instead of printing out granting securables one by
one.
Fig
1.3
Scenario 4: Input login is member of db_owner on
AdventureWorksDW, not for the rest of the databases (Fig 1.4)
———————————————-
–Create database user for login
———————————————-
USE [master]
IF NOT EXISTS (SELECT * FROM sys.database_principals
WHERE name = ‘chsu’)
BEGIN
CREATE USER [chsu]
FOR LOGIN
[chsu] WITH DEFAULT_SCHEMA=[dbo]
END
GO
USE [AdventureWorks]
IF NOT EXISTS (SELECT * FROM sys.database_principals
WHERE name = ‘chsu’)
BEGIN
CREATE USER [chsu]
FOR LOGIN
[chsu] WITH DEFAULT_SCHEMA=[dbo]
END
GO
USE [Northwind]
IF NOT EXISTS (SELECT * FROM sys.database_principals
WHERE name = ‘chsu’)
BEGIN
CREATE USER [chsu]
FOR LOGIN
[chsu] WITH DEFAULT_SCHEMA=[dbo]
END
GO
USE [AdventureWorksDW]
IF NOT EXISTS (SELECT * FROM sys.database_principals
WHERE name = ‘chsu’)
BEGIN
CREATE USER [chsu]
FOR LOGIN
[chsu] WITH DEFAULT_SCHEMA=[dbo]
END
GO
———————————————-
–Login is db_owner of below
databases
———————————————-
USE [AdventureWorksDW]
EXEC sp_addrolemember ‘db_owner’,‘user_dbo_bond_bg’
GO
———————————————-
–Grant all securable class to
login
———————————————-
USE [Northwind]
GRANT ALTER ANY APPLICATION ROLE TO [chsu]
GO
USE [Northwind]
GRANT ALTER ANY ROUTE TO [chsu]
GO
USE [Northwind]
GRANT CONNECT TO [chsu]
GO
USE [Northwind]
GRANT CREATE ROUTE TO [chsu]
GO
USE [Northwind]
GRANT SHOWPLAN TO [chsu]
GO
USE [master]
GRANT ALTER ANY LINKED SERVER TO [chsu]
GO
USE [master]
GRANT ALTER SETTINGS TO [chsu]
GO
USE [master]
GRANT CONNECT SQL TO [chsu]
GO
USE [master]
GRANT CONNECT TO [chsu]
GO
USE [master]
GRANT EXTERNAL ACCESS ASSEMBLY TO [chsu]
GO
USE [master]
GRANT UNSAFE ASSEMBLY TO [chsu]
GO
USE [master]
GRANT VIEW ANY DATABASE TO [chsu]
GO
USE [AdventureWorks]
GRANT CONNECT TO [chsu]
GO
USE [AdventureWorks]
GRANT SHOWPLAN TO [chsu]
GO
Fig 1.4
Conclusion
We have covered login regeneration in the first article with
login creation, server-level role and database-level role assignment. In this
artcile, we have summarized how to produce script for login on server-level and
database-level securables.
In my final article of the series, I’ll tackle the
login generation for the finest scope securable – object-level permission for
the login.