Williams Orellana

DECLARE @ObjectOwnerOrSchema NVARCHAR(128)

DECLARE @ObjectName NVARCHAR(128)

SET @ObjectOwnerOrSchema = 'dbo'

SET @ObjectName = 'NameOfTheStoredProcedureHERE'

DECLARE @i INT

DECLARE @ObjectDataLength INT

DECLARE @ContentOfEncryptedObject NVARCHAR(MAX)

DECLARE @ContentOfDecryptedObject VARCHAR(MAX)

DECLARE @ContentOfFakeObject NVARCHAR(MAX)

DECLARE @ContentOfFakeEncryptedObject NVARCHAR(MAX)

DECLARE @ObjectType NVARCHAR(128)

DECLARE @ObjectID INT

SET NOCOUNT ON

SET @ObjectID = OBJECT_ID('[' + @ObjectOwnerOrSchema + '].[' + @ObjectName + ']')

-- Check that the provided object exists in the database.

IF @ObjectID IS NULL

BEGIN

RAISERROR('El nombre del objeto provisto no existe en la base de datos.', 16, 1)

RETURN

END

-- Check that the provided object is encrypted.

IF NOT EXISTS(SELECT TOP 1 * FROM syscomments WHERE id = @ObjectID AND encrypted = 1)

BEGIN

RAISERROR('El objeto provisto existe, sin embargo no esta encriptado. Abortando.', 16, 1)

RETURN

END

-- Determine the type of the object

IF OBJECT_ID('[' + @ObjectOwnerOrSchema + '].[' + @ObjectName + ']', 'PROCEDURE') IS NOT NULL

SET @ObjectType = 'PROCEDURE'

ELSE

IF OBJECT_ID('[' + @ObjectOwnerOrSchema + '].[' + @ObjectName + ']', 'TRIGGER') IS NOT NULL

SET @ObjectType = 'TRIGGER'

ELSE

IF OBJECT_ID('[' + @ObjectOwnerOrSchema + '].[' + @ObjectName + ']', 'VIEW') IS NOT NULL

SET @ObjectType = 'VIEW'

ELSE

SET @ObjectType = 'FUNCTION'

-- Get the binary representation of the object- syscomments no longer holds

-- the content of encrypted object.

SELECT TOP 1 @ContentOfEncryptedObject = imageval

FROM sys.sysobjvalues

WHERE objid = OBJECT_ID('[' + @ObjectOwnerOrSchema + '].[' + @ObjectName + ']')

AND valclass = 1 AND subobjid = 1

SET @ObjectDataLength = DATALENGTH(@ContentOfEncryptedObject)/2

-- We need to alter the existing object and make it into a dummy object

-- in order to decrypt its content. This is done in a transaction

-- (which is later rolled back) to ensure that all changes have a minimal

-- impact on the database.

SET @ContentOfFakeObject = N'ALTER ' + @ObjectType + N' [' + @ObjectOwnerOrSchema + N'].[' + @ObjectName + N'] WITH ENCRYPTION AS'

WHILE DATALENGTH(@ContentOfFakeObject)/2 < @ObjectDataLength

BEGIN

IF DATALENGTH(@ContentOfFakeObject)/2 + 8000 < @ObjectDataLength

SET @ContentOfFakeObject = @ContentOfFakeObject + REPLICATE(N'-', 8000)

ELSE

SET @ContentOfFakeObject = @ContentOfFakeObject + REPLICATE(N'-', @ObjectDataLength - (DATALENGTH(@ContentOfFakeObject)/2))

END

-- Since we need to alter the object in order to decrypt it, this is done

-- in a transaction

SET XACT_ABORT OFF

BEGIN TRAN

EXEC(@ContentOfFakeObject)

IF @@ERROR <> 0

ROLLBACK TRAN

-- Get the encrypted content of the new "fake" object.

SELECT TOP 1 @ContentOfFakeEncryptedObject = imageval

FROM sys.sysobjvalues

WHERE objid = OBJECT_ID('[' + @ObjectOwnerOrSchema + '].[' + @ObjectName + ']')

AND valclass = 1 AND subobjid = 1

IF @@TRANCOUNT > 0

ROLLBACK TRAN

-- Generate a CREATE script for the dummy object text.

SET @ContentOfFakeObject = N'CREATE ' + @ObjectType + N' [' + @ObjectOwnerOrSchema + N'].[' + @ObjectName + N'] WITH ENCRYPTION AS'

WHILE DATALENGTH(@ContentOfFakeObject)/2 < @ObjectDataLength

BEGIN

IF DATALENGTH(@ContentOfFakeObject)/2 + 8000 < @ObjectDataLength

SET @ContentOfFakeObject = @ContentOfFakeObject + REPLICATE(N'-', 8000)

ELSE

SET @ContentOfFakeObject = @ContentOfFakeObject + REPLICATE(N'-', @ObjectDataLength - (DATALENGTH(@ContentOfFakeObject)/2))

END

SET @i = 1

--Fill the variable that holds the decrypted data with a filler character

SET @ContentOfDecryptedObject = N''

WHILE DATALENGTH(@ContentOfDecryptedObject)/2 < @ObjectDataLength

BEGIN

IF DATALENGTH(@ContentOfDecryptedObject)/2 + 8000 < @ObjectDataLength

SET @ContentOfDecryptedObject = @ContentOfDecryptedObject + REPLICATE(N'A', 8000)

ELSE

SET @ContentOfDecryptedObject = @ContentOfDecryptedObject + REPLICATE(N'A', @ObjectDataLength - (DATALENGTH(@ContentOfDecryptedObject)/2))

END

WHILE @i BEGIN

--xor real & fake & fake encrypted

SET @ContentOfDecryptedObject = STUFF(@ContentOfDecryptedObject, @i, 1,

NCHAR(

UNICODE(SUBSTRING(@ContentOfEncryptedObject, @i, 1)) ^

(

UNICODE(SUBSTRING(@ContentOfFakeObject, @i, 1)) ^

UNICODE(SUBSTRING(@ContentOfFakeEncryptedObject, @i, 1))

)))

SET @i = @i + 1

END

-- PRINT the content of the decrypted object

SELECT substring(@ContentOfDecryptedObject, len(@ContentOfDecryptedObject) - 1000, 1000)

-- PRINT the content of the decrypted object

PRINT(@ContentOfDecryptedObject)