Decrypt encrypted stored procedures

Here is a stored procedure used to decrypt compiled T-SQL stored procedures.

This stored procedure will decrypt stored procedures, views or triggers that were encrypted using "with encryption". It is adapted from a script by Joseph Gama and ShoeBoy. There are two versions: one for SP's only and the other one for SP's, triggers and views. For version 1, the input is object name (stored procedure, view or trigger), and for version 2, the input is object name (stored procedure, view or trigger), object type ('T'-trigger,...

'P'-stored procedure or 'V'-view). From PlanetSourceCode.com.

create PROCEDURE sp_decrypt_sp (@objectName varchar(50)) AS DECLARE @OrigSpText1 nvarchar(4000), @OrigSpText2 nvarchar(4000) , @OrigSpText3 nvarchar(4000), @resultsp nvarchar(4000) declare @i int , @t bigint --get encrypted data SET @OrigSpText1=(SELECT ctext FROM syscomments WHERE id = object_id(@objectName)) SET @OrigSpText2='ALTER PROCEDURE '+ @objectName +' WITH ENCRYPTION AS '+REPLICATE('-', 3938) EXECUTE (@OrigSpText2) SET @OrigSpText3=(SELECT ctext FROM syscomments WHERE id = object_id(@objectName)) SET @OrigSpText2='CREATE PROCEDURE '+ @objectName +' WITH ENCRYPTION AS '+REPLICATE('-', 4000-62) --start counter SET @i=1 --fill temporary variable SET @resultsp = replicate(N'A', (datalength(@OrigSpText1) / 2)) --loop WHILE @i<=datalength(@OrigSpText1)/2 BEGIN --reverse encryption (XOR original+bogus+bogus encrypted) SET @resultsp = stuff(@resultsp, @i, 1, NCHAR(UNICODE(substring(@OrigSpText1, @i, 1)) ^ (UNICODE(substring(@OrigSpText2, @i, 1)) ^ UNICODE(substring(@OrigSpText3, @i, 1))))) SET @i=@i+1 END --drop original SP EXECUTE ('drop PROCEDURE '+ @objectName) --remove encryption --preserve case SET @resultsp=REPLACE((@resultsp),'WITH ENCRYPTION', '') SET @resultsp=REPLACE((@resultsp),'With Encryption', '') SET @resultsp=REPLACE((@resultsp),'with encryption', '') IF CHARINDEX('WITH ENCRYPTION',UPPER(@resultsp) )>0 SET @resultsp=REPLACE(UPPER(@resultsp),'WITH ENCRYPTION', '') --replace Stored procedure without enryption execute( @resultsp) GO 

Reader Feedback

Joakim M. writes: I tried this script with mixed results. It works for some encrypted procedures, but for others I get error meassages like:

Server: Msg 512, Level 16, State 1, Procedure sp_decrypt_sp, Line 7. Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression. 

Karl C writes: I got the same message as Joakim M. but upon further investigation I found that this happens only when stored procedures exceed 4000 characters. When this happens, SQL Server stores the procedure across multiple rows so you get the error 'subquery returne more than 1 row'. To get around that you can change the statement

SELECT ctext FROM syscomments WHERE id = object_id(@objectName to SELECT top 1 ctext FROM syscomments WHERE id = object_id(@objectName order by colid 

That will get you the first part of the stored procedure, which can't be created because it is missing the end part and is not a valid syntax but you can print @resultsp out to see it.

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This was first published in July 2002

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