El problema aquí es que si bien el Certificado vincula el procedimiento almacenado en la Base de datos A con el Usuario en la Base de datos B que tiene INSERTpermisos en las dos tablas, el Activador en la tabla que se inserta directamente desde el procedimiento almacenado es otro módulo en la cadena, y los permisos adquiridos Los certificados no se transfieren a otros módulos en una cadena. Es decir, el Certificado permitió que el Procedimiento almacenado se inserte en la tabla a través del Usuario e incluso ejecute el Disparador. Pero, no se han otorgado permisos al Trigger para hacer nada relacionado con objetos (hacer algo como SELECT 1;funcionaría).
En este caso, se deben otorgar permisos al Disparador, a través de ese mismo Certificado, para que pueda tomar las medidas necesarias. Esto se puede lograr, al menos, contrafirmando el disparador. Y lo haces ejecutando ADD COUNTER SIGNATURE TO [TriggerSchema].[TriggerName] BY CERTIFICATE ...;. Después de eso, debería funcionar, incluso sin INSERTpermiso directo para el usuario basado en certificado en la tabla en la que se inserta el activador.
El siguiente código de ejemplo reproduce el problema, lo soluciona agregando una firma de contador, pero no otorga INSERTpermisos a la tabla llena de activadores.
LIMPIAR
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;
PREPARAR
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
PRUEBA 1: el disparador falla
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
PRUEBA 2: el disparador tiene éxito
Tenga en cuenta que el único cambio que se está haciendo es ADD COUNTER SIGNATURE; No existe 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
