Great Article!

I have a couple of suggestions to make the stored proc more flexible.

1.Make the certificate name and certificate user name parameters so that it could be used for multiple certificate/users without changing code within the Proc.

2.If you changed the cursor to be a temp table or table variable that is populated from the select, it could then be used to loop through instead of a cursor. You could then use the same table variable to loop back through to add the signatures with the newly recreated certificate user.

3.Add a loop similar to above for the granting of the table permissions so that it can be dynamically granted to the cert user based on what it was before the user was dropped.

Sample procedure code:

-- **********************************************************************

-- PROCEDURE GrantCertificateAccess

-- Drops all certificate signatures and recreates them for existing certificate signed stored procs

-- for the cert value, cert user, and the new password passed in through parameters

-- Exeample Execution: EXEC GrantCertificateAccess 'myCertName', 'myCertUserName','myNewPassword'

-- **********************************************************************

CREATE PROCEDURE [dbo].[GrantCertificateAccess]

(

@CertificateName AS sysname = 'myCertName',

@CertificateUserName AS sysname = 'myCertUserName',

@Password AS sysname = 'myNewPassword'

)AS

BEGIN

--Declare Variables

DECLARE @sSql varchar(4000)

DECLARE @NewLine varchar(4000)

SET @NewLine = CHAR(13) + CHAR(10)

DECLARE @ProcRowsToProcess int

DECLARE @TableRowsToProcess int

DECLARE @currentrow int

DECLARE @ProcedureName AS sysname

DECLARE @TableName AS varchar(100)

DECLARE @Permission AS varchar(20)

--Table variable for list of Procedures with Certificate Signature

DECLARE @ProcList TABLE

(ProcedureName VARCHAR(200), Row_ID int not null primary key identity(1,1))

--Table variable for table permissions granted to Certificate User

DECLARE @TableList TABLE

(TableName VARCHAR(200), Permission VARCHAR(20), Row_ID int not null primary key identity(1,1))

--Populate the table variable for the Procedure list

INSERT INTO @ProcList (ProcedureName)

SELECT Object_Name(CP.major_id) ProcedureName

FROM sys.certificates C

INNER JOIN sys.crypt_properties CP ON CP.thumbprint = C.thumbprint

WHERE C.Name = @CertificateName

SET @ProcRowsToProcess=@@ROWCOUNT

--Populate the table variable for the Table permission list

INSERT INTO @TableList (TableName, Permission)

SELECT '['+db_name()+'].['+Object_Name(p.major_id)+']' AS tablename,

p.permission_name

FROM sys.database_permissions p

LEFT OUTER JOIN sys.all_objects o ON p.major_id = o.OBJECT_ID

INNER JOIN sys.database_principals dp ON p.grantee_principal_id = dp.principal_id

WHERE o.type = 'U' --only pull permissions for user tables

AND p.state_desc = 'GRANT'

AND p.permission_name IN ('SELECT','INSERT','UPDATE','DELETE')

AND dp.NAME = @CertificateUserName

--initialize this variable for the current loop

SET @CurrentRow=0

--*********************************************************************

-- Drop the signatures signed by the Certificate from stored procedures

--*********************************************************************

PRINT '-- Dropping existing Signatures from Procedures...'

WHILE @CurrentRow < @ProcRowsToProcess

BEGIN

SET @CurrentRow = @CurrentRow + 1

SELECT @ProcedureName = ProcedureName

FROM @ProcList

WHERE Row_ID = @currentrow

SET @sSql = 'DROP SIGNATURE FROM ' + QuoteName(@ProcedureName) + ' BY CERTIFICATE ' + @CertificateName

PRINT @sSql

EXEC sp_executesql @sSql

END --END WHILE

PRINT @NewLine + '-- Dropping Certificate User...'

IF EXISTS(SELECT 1

FROM sysusers

WHERE name = @CertificateUserName)

BEGIN

SET @sSql = 'DROP USER ' + @CertificateUserName

PRINT @sSql

EXEC(@sSql)

END --END IF

PRINT @NewLine + '-- Dropping Certificate...'

IF EXISTS(SELECT 1

FROM sys.certificates C

WHERE C.[name] = @CertificateName)

BEGIN

SET @sSql = 'DROP CERTIFICATE ' + QuoteName(@CertificateName)

PRINT @sSql

EXEC (@sSql)

END --END IF

-- Create a new certificate if it does not exist

IF NOT EXISTS(SELECT 1

FROM sys.certificates C

WHERE C.[name] = @CertificateName)

BEGIN

PRINT @NewLine + '-- Creating new certificate...'

SET @sSql = 'CREATE CERTIFICATE ' + QuoteName(@CertificateName) + @NewLine

+ ' ENCRYPTION BY PASSWORD = ''' + @Password + '''' + @NewLine

+ ' WITH SUBJECT = ''Certificate for stored procedures using dynamic SQL'',' + @NewLine

+ ' START_DATE = ''2010-01-01'',' + @NewLine

+ ' EXPIRY_DATE = ''2100-01-01'''

PRINT @sSql

EXEC (@sSql)

PRINT @NewLine + '-- Creating User...'

SET @sSql = 'CREATE USER ' + QuoteName(@CertificateUserName) + ' FROM CERTIFICATE ' + QuoteName(@CertificateName)

EXEC (@sSql)

PRINT @sSql

END --END IF

--initialize this variable for the current loop

SET @CurrentRow=0

--**********************************************************

-- Add back in the table permissions to the certificate user

--**********************************************************

PRINT @NewLine + '-- Granting Select to Certificate User...'

WHILE @CurrentRow < @TableRowsToProcess

BEGIN

SET @CurrentRow = @CurrentRow + 1

SELECT @TableName = TableName, @Permission = Permission

FROM @TableList

WHERE Row_ID = @currentrow

SET @sSql = 'GRANT ' + @Permission + ' ON ' + @TableName + ' TO ' + QuoteName(@CertificateUserName)

PRINT @sSql

EXEC (@sSql)

END --END WHILE

--initialize this variable for the current loop

SET @CurrentRow=0

--****************************************************

-- Add back in the signatures to the stored procedures

--****************************************************

PRINT 'Signing procedures...'

WHILE @CurrentRow < @ProcRowsToProcess

BEGIN

SET @CurrentRow = @CurrentRow + 1

SELECT @ProcedureName = ProcedureName

FROM @ProcList

WHERE Row_ID = @currentrow

SET @sSql = 'ADD SIGNATURE TO ' + QuoteName(@ProcedureName) + ' BY CERTIFICATE ' + QuoteName(@CertificateName) + ' WITH PASSWORD = ''' + @Password + ''''

PRINT @sSql

EXEC (@sSql)

END --END WHILE

END--END Procedure

GO