/*==================================================================================
NAME: Decrypt SQL 2005 stored procedures, functions, views, and triggers
DESCRIPTION: HEADS UP: In order to run this script you must log in
to the server in DAC mode: To do so, type
ADMIN:<SQLInstanceName> as your server name and use the "sa"
or any other server admin user with the appropriate password.
CAUTION! DAC (dedicated admin access) will kick out all other
server users.
The script below accepts an object (schema name + object name)
that were created using the WITH ENCRYPTION option and returns
the decrypted script that creates the object. This script
is useful to decrypt stored procedures, views, functions,
and triggers that were created WITH ENCRYPTION.
The algorithm used below is the following:
1. Check that the object exists and that it is encrypted.
2. In order to decrypt the object, the script ALTER (!!!) it
and later restores the object to its original one. This is
required as part of the decryption process: The object
is altered to contain dummy text (the ALTER uses WITH ENCRYPTION)
and then compared to the CREATE statement of the same dummy
content.
Note: The object is altered in a transaction, which is rolled
back immediately after the object is changed to restore
all previous settings.
3. A XOR operation between the original binary stream of the
enrypted object with the binary representation of the dummy
object and the binary version of the object in clear-text
is used to decrypt the original object.
USER PARAMETERS: @ObjectOwnerOrSchema
@ObjectName
RESULTSET: NA
RESULTSET SORT: NA
USING TABLES/VIEWS: sys.sysobjvalues
syscomments
REVISIONS
DATE DEVELOPER DESCRIPTION OF REVISION VERSION
========= =============== ================================= ===========
01/01/2007 Omri Bahat Initial release 1.00
==================================================================================*/
DECLARE @ObjectOwnerOrSchema NVARCHAR(128)
DECLARE @ObjectName NVARCHAR(128)
DECLARE @i INT
DECLARE @ObjectDataLength INT
DECLARE @ContentOfEncryptedObject NVARCHAR(MAX)
DECLARE @ContentOfDecryptedObject NVARCHAR(MAX)
DECLARE @ContentOfFakeObject NVARCHAR(MAX)
DECLARE @ContentOfFakeEncryptedObject NVARCHAR(MAX)
DECLARE @ObjectType NVARCHAR(128)
DECLARE @ObjectID INT
SET NOCOUNT ON
DECLARE ProcedureCursor CURSOR FOR
SELECT DISTINCT P.ROUTINE_SCHEMA, P.ROUTINE_NAME, C.id
FROM INFORMATION_SCHEMA.ROUTINES AS P
LEFT JOIN syscomments AS C ON
OBJECT_ID('[' + P.ROUTINE_SCHEMA + '].[' + P.ROUTINE_NAME + ']') = C.id
AND C.encrypted = 1
WHERE P.ROUTINE_TYPE = 'PROCEDURE'
AND C.id IS NOT NULL;
OPEN ProcedureCursor;
FETCH NEXT FROM ProcedureCursor
INTO @ObjectOwnerOrSchema, @ObjectName, @ObjectID;
WHILE @@FETCH_STATUS = 0
BEGIN
-- Check that the provided object exists in the database.
IF @ObjectID IS NULL
BEGIN
RAISERROR('The object name or schema provided does not exist in the database', 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('The object provided exists however it is not encrypted. Aborting.', 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 + 4000 < @ObjectDataLength
SET @ContentOfFakeObject = @ContentOfFakeObject + REPLICATE(N'-', 4000)
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 + 4000 < @ObjectDataLength
SET @ContentOfFakeObject = @ContentOfFakeObject + REPLICATE(N'-', 4000)
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 + 4000 < @ObjectDataLength
SET @ContentOfDecryptedObject = @ContentOfDecryptedObject + REPLICATE(N'A', 4000)
ELSE
SET @ContentOfDecryptedObject = @ContentOfDecryptedObject + REPLICATE(N'A', @ObjectDataLength - (DATALENGTH(@ContentOfDecryptedObject)/2))
END
WHILE @i <= @ObjectDataLength
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
SET @ContentOfDecryptedObject = REPLACE(REPLACE(@ContentOfDecryptedObject, 'With Encryption', ''), 'Create Procedure', 'Alter Procedure');
EXECUTE (@ContentOfDecryptedObject)
FETCH NEXT FROM ProcedureCursor
INTO @ObjectOwnerOrSchema, @ObjectName, @ObjectID;
END
CLOSE ProcedureCursor;
DEALLOCATE ProcedureCursor;