Buradaki sorun, Sertifikanın DatabaseA'daki saklı yordamı INSERTiki tabloda izinleri olan DatabaseB'deki Kullanıcı ile ilişkilendirmesine karşın , doğrudan depolanan yordamdan eklenen tablodaki Tetikleyici zincirdeki başka bir modül ve edinilen izinler Sertifikalardaki zincirdeki diğer modüllere geçilmez. Yani Sertifika, Saklı Yordamın Kullanıcı aracılığıyla tabloya girmesine ve hatta Tetikleyiciyi yürütmesine izin verdi. Ancak, Tetikleyiciye nesnelerle ilgili herhangi bir şey yapma izni verilmemiştir ( SELECT 1;işe yarayacak bir şey yapmak ).
Bu durumda, gerekli tüm işlemleri yapabilmesi için aynı Sertifika aracılığıyla Tetikleyiciye izinlerin verilmesi gerekir. Bu, en azından Tetikleyicinin karşı imzalanmasıyla gerçekleştirilebilir. Ve bunu idam ederek yaparsınız ADD COUNTER SIGNATURE TO [TriggerSchema].[TriggerName] BY CERTIFICATE ...;. Bundan sonra INSERT, Tetikleyici tarafından eklenen tablodaki Sertifika Tabanlı Kullanıcı için doğrudan izin alınmadan bile çalışmalıdır .
Aşağıdaki örnek kod sorunu yeniden oluşturur, sayaç imzası ekleyerek sorunu düzeltir, ancak INSERTtetikleyici doldurulmuş tabloya izin vermez .
TEMİZLEMEK
USE [master];
GO
IF EXISTS (SELECT 1 FROM [sys].[databases] WHERE [name] = N'DatabaseA')
BEGIN
PRINT 'Dropping [DatabaseA] DB...';
ALTER DATABASE [DatabaseA] SET OFFLINE WITH ROLLBACK IMMEDIATE;
ALTER DATABASE [DatabaseA] SET ONLINE;
DROP DATABASE [DatabaseA];
END;
IF EXISTS (SELECT 1 FROM [sys].[databases] WHERE [name] = N'DatabaseB')
BEGIN
PRINT 'Dropping [DatabaseB] DB...';
ALTER DATABASE [DatabaseB] SET OFFLINE WITH ROLLBACK IMMEDIATE;
ALTER DATABASE [DatabaseB] SET ONLINE;
DROP DATABASE [DatabaseB];
END;
IF (SUSER_ID(N'JohnnyLunchbucket') IS NOT NULL)
BEGIN
PRINT 'Dropping [JohnnyLunchbucket] Login...';
DROP LOGIN [JohnnyLunchbucket];
END;
IF (OBJECT_ID(N'tempdb..#CertInfo') IS NOT NULL)
BEGIN
PRINT 'Dropping [#CertInfo] Temp Table...';
DROP TABLE #CertInfo;
END;
KURMAK
USE [master];
EXECUTE AS LOGIN = N'sa';
PRINT 'Creating databases...';
CREATE DATABASE [DatabaseA] COLLATE Latin1_General_100_CI_AS_SC;
CREATE DATABASE [DatabaseB] COLLATE Latin1_General_100_CI_AS_SC;
REVERT;
GO
-- Default for both options should be OFF, but just to be sure:
ALTER DATABASE [DatabaseA] SET DB_CHAINING OFF;
ALTER DATABASE [DatabaseA] SET TRUSTWORTHY OFF;
ALTER DATABASE [DatabaseB] SET DB_CHAINING OFF;
ALTER DATABASE [DatabaseB] SET TRUSTWORTHY OFF;
GO
CREATE LOGIN [JohnnyLunchbucket] WITH PASSWORD = 'OhSoSecure;)';
USE [DatabaseA];
CREATE USER [JohnnyLunchbucket] FOR LOGIN [JohnnyLunchbucket];
GO
--DROP PROCEDURE dbo.InsertIntoTableWithoutTrigger;
CREATE PROCEDURE dbo.InsertIntoTableWithoutTrigger
(
@SomeValue NVARCHAR(50)
)
AS
SET NOCOUNT ON;
INSERT INTO [DatabaseB].[dbo].[TableWithoutTrigger] (SomeValue)
VALUES (@SomeValue);
GO
GRANT EXECUTE ON dbo.InsertIntoTableWithoutTrigger TO [JohnnyLunchbucket];
GO
CREATE PROCEDURE dbo.InsertIntoTableWithTrigger
AS
SET NOCOUNT ON;
INSERT INTO [DatabaseB].[dbo].[TableWithTrigger] (SomeOtherValue)
VALUES (NEWID());
GO
GRANT EXECUTE ON dbo.InsertIntoTableWithTrigger TO [JohnnyLunchbucket];
CREATE CERTIFICATE [PermissionsCert]
AUTHORIZATION [dbo]
ENCRYPTION BY PASSWORD = 'WeakPassword'
WITH SUBJECT = 'Used to test granting permissions to code',
EXPIRY_DATE = '2099-12-31';
ADD SIGNATURE TO [dbo].[InsertIntoTableWithoutTrigger]
BY CERTIFICATE [PermissionsCert]
WITH PASSWORD = 'WeakPassword';
ADD SIGNATURE TO [dbo].[InsertIntoTableWithTrigger]
BY CERTIFICATE [PermissionsCert]
WITH PASSWORD = 'WeakPassword';
-- Save Certificate info in temporary table so we can recreate in DatabaseB
SELECT CERTENCODED(CERT_ID(N'PermissionsCert')) AS [PublicKey],
CERTPRIVATEKEY(CERT_ID(N'PermissionsCert'), 'OtherPassword', 'WeakPassword')
AS [PrivateKey]
INTO #CertInfo;
GO
USE [DatabaseB];
DECLARE @SQL NVARCHAR(MAX);
SELECT @SQL = N'CREATE CERTIFICATE [PermissionsCert] AUTHORIZATION [dbo] FROM BINARY = '
+ CONVERT(NVARCHAR(MAX), [PublicKey], 1)
+ N' WITH PRIVATE KEY (BINARY = '
+ CONVERT(NVARCHAR(MAX), [PrivateKey], 1)
+ N', DECRYPTION BY PASSWORD = N''OtherPassword'''
+ N', ENCRYPTION BY PASSWORD = ''WeakPassword'');'
FROM #CertInfo;
PRINT @SQL;
EXEC (@SQL);
CREATE USER [PermissionsUser] FROM CERTIFICATE [PermissionsCert];
--DROP TABLE dbo.[TableWithoutTrigger];
CREATE TABLE dbo.[TableWithoutTrigger]
(
[TableWithoutTriggerID] INT NOT NULL IDENTITY(1, 1)
CONSTRAINT [PK_TableWithoutTrigger] PRIMARY KEY,
[SomeValue] NVARCHAR(50)
);
GRANT INSERT ON [dbo].[TableWithoutTrigger] TO [PermissionsUser];
CREATE TABLE dbo.[TableWithTrigger]
(
[TableWithTriggerID] INT NOT NULL IDENTITY(1, 1)
CONSTRAINT [PK_TableWithTrigger] PRIMARY KEY,
[SomeOtherValue] NVARCHAR(50)
);
GRANT INSERT ON [dbo].[TableWithTrigger] TO [PermissionsUser];
CREATE TABLE dbo.[TablePopulatedByTrigger]
(
[TablePopulatedByTriggerID] INT NOT NULL IDENTITY(1, 1)
CONSTRAINT [PK_TablePopulatedByTrigger] PRIMARY KEY,
[DuplicatedValue] NVARCHAR(50)
);
GO
CREATE TRIGGER dbo.CopySomeOtherValue
ON dbo.[TableWithTrigger]
AFTER INSERT
AS
BEGIN
SET NOCOUNT ON;
INSERT INTO dbo.[TablePopulatedByTrigger] ([DuplicatedValue])
SELECT ins.[SomeOtherValue]
FROM inserted ins;
END;
GO
TEST 1: Tetikleyici başarısız
USE [DatabaseA];
EXECUTE AS LOGIN = 'JohnnyLunchbucket';
SELECT SESSION_USER AS [User], ORIGINAL_LOGIN() AS [OriginalLogin];
GO
SELECT * FROM [DatabaseB].[dbo].[TableWithoutTrigger];
SELECT * FROM [DatabaseB].[dbo].[TableWithTrigger];
SELECT * FROM [DatabaseB].[dbo].[TablePopulatedByTrigger];
INSERT INTO [DatabaseB].[dbo].[TableWithoutTrigger] ([SomeValue]) VALUES (N'test 0');
USE [DatabaseB];
/* -- All 5 statements above get the following error:
Msg 916, Level 14, State 1, Line xxxxxx
The server principal "JohnnyLunchbucket" is not able to access the database
"DatabaseB" under the current security context.
*/
EXEC [dbo].[InsertIntoTableWithoutTrigger] @SomeValue = N'test A'; -- SUCCESS!!!
EXEC [dbo].[InsertIntoTableWithTrigger]; -- ERROR:
/*
Msg 916, Level 14, State 1, Procedure CopySomeOtherValue, Line xxxxxx
The server principal "JohnnyLunchbucket" is not able to access the database
"DatabaseB" under the current security context.
*/
REVERT;
SELECT SESSION_USER AS [User], ORIGINAL_LOGIN() AS [OriginalLogin];
-- Check to make sure that dbo.InsertIntoTableWithoutTrigger really did work:
SELECT * FROM [DatabaseB].[dbo].[TableWithoutTrigger];
-- 1 test A
TEST 2: Tetikleyici başarılı
Lütfen yapılan tek değişikliğin ADD COUNTER SIGNATURE; yok GRANT INSERT ON dbo.TablePopulatedByTrigger TO [PermissionsUser];.
USE [DatabaseB];
ADD COUNTER SIGNATURE
TO dbo.[CopySomeOtherValue]
BY CERTIFICATE [PermissionsCert]
WITH PASSWORD = 'WeakPassword';
GO
USE [DatabaseA];
EXECUTE AS LOGIN = 'JohnnyLunchbucket';
SELECT SESSION_USER AS [User], ORIGINAL_LOGIN() AS [OriginalLogin];
GO
INSERT INTO [DatabaseB].[dbo].[TableWithTrigger] ([SomeOtherValue]) VALUES (N'Test B');
INSERT INTO [DatabaseB].[dbo].[TablePopulatedByTrigger]([DuplicatedValue]) VALUES ('Test B')
/*
Msg 916, Level 14, State 1, Line xxxxxx
The server principal "JohnnyLunchbucket" is not able to access the database
"DatabaseB" under the current security context.
*/
EXEC [dbo].[InsertIntoTableWithTrigger]; -- SUCCESS!!!
REVERT;
SELECT SESSION_USER AS [User], ORIGINAL_LOGIN() AS [OriginalLogin];
SELECT * FROM [DatabaseB].[dbo].[TableWithTrigger];
SELECT * FROM [DatabaseB].[dbo].[TablePopulatedByTrigger];
-- 2 968DB092-C3DE-4E4B-92B9-E21CA551A5FA
-- 1 968DB092-C3DE-4E4B-92B9-E21CA551A5FA