Re: how to decrypt an encrypted stored proc in 2005

Op 28 Aug 2006 12:37:17 -0700 schreef VJ:
I've changed the code in the script a bit to accommodate >4K SP's, and reformatted it a bit to make it a bit more readable.

Enjoy

Theo

CREATE PROCEDURE dbo.sp_SpDeObfuscation (@procedure sysname = NULL, @safety int = 1)
AS

/*
Name: sp_SpDeObfuscation
Purpose: Decrypt SP's in SQL 2005
Author: Theo Ekelmans (theo@xxxxxxxxxxxx)
Based on: A script that is discussed in news://microsoft.public.sqlserver.security
Version: 1.0 - 2006-11-16
Changes: none (yet)

Input: exec sp_SpDeObfuscation '<sp_name>', 0

Output: Switch to text output!

Note: You need to use the Dedicated Administrator Connection with
SQL Server Management Studio be in DAC to be able to run this SP
*/

SET NOCOUNT ON


IF @safety = 1
BEGIN
PRINT 'CAUTION: THIS PROCEDURE DELETES AND REBUILDS THE ORIGINAL STORED PROCEDURE.'
PRINT ' '
PRINT 'MAKE A BACKUP OF YOUR DATABASE BEFORE RUNNING THIS PROCEDURE.'
PRINT ' '
PRINT 'IDEALLY, THIS PROCEDURE SHOULD BE RUN ON A NON-PRODUCTION COPY OF THE PROCEDURE.'
PRINT ' '
PRINT 'To run the procedure, change the @safety parameter to 0'
RETURN 0
END


DECLARE @intProcSpace bigint
DECLARE @t bigint
DECLARE @maxColID smallint
DECLARE @intEncrypted tinyint
DECLARE @procNameLength int

DECLARE @real_01 nvarchar(max)
DECLARE @fake_01 nvarchar(max)
DECLARE @fake_encrypt_01 nvarchar(max)
DECLARE @real_decrypt_01 nvarchar(max)
DECLARE @real_decrypt_01a nvarchar(max)

-- create this table for later use
create table #output ( [ident] [int] IDENTITY (1, 1) NOT NULL ,
[real_decrypt] NVARCHAR(MAX) )

SELECT @maxColID = max(subobjid)
FROM sys.sysobjvalues
WHERE objid = object_id(@procedure)

select @procNameLength = datalength(@procedure) + 29

select @real_decrypt_01a = ''

-- extract the encrypted imageval rows from sys.sysobjvalues
SET @real_01= ( SELECT imageval
FROM sys.sysobjvalues
WHERE objid = object_id(@procedure)
and valclass = 1
and subobjid = 1 )

-- We'll begin the transaction and roll it back later
BEGIN TRAN

-- alter the original procedure, replacing with dashes ( the cast('-' as nvarchar(max)) is to allow for SP's larger than 4K)
SET @fake_01 = 'ALTER PROCEDURE '+ @procedure +' WITH ENCRYPTION AS ' + REPLICATE(cast('-' as nvarchar(max)), 40003 - @procNameLength)

EXECUTE (@fake_01)

-- extract the encrypted fake imageval rows from sys.sysobjvalues
SET @fake_encrypt_01=( SELECT imageval
FROM sys.sysobjvalues
WHERE objid = object_id(@procedure)
and valclass = 1 and subobjid = 1)

SET @fake_01 = 'CREATE PROCEDURE '+ @procedure +' WITH ENCRYPTION AS ' + REPLICATE(cast('-' as nvarchar(max)), 40003 - @procNameLength)

--start counter
SET @intProcSpace=1

--fill temporary variable with with a filler character ( the cast(N'A' as nvarchar(max)) is to allow for SP's larger than 4K)
SET @real_decrypt_01 = replicate(cast(N'A' as nvarchar(max)), (datalength(@real_01) /2 ))

--loop through each of the variables sets of variables, building the real variable one byte at a time.
SET @intProcSpace=1

-- Go through each @real_xx variable and decrypt it, as necessary
WHILE @intProcSpace <= (datalength(@real_01)/2)
BEGIN
--xor real & fake & fake encrypted
SET @real_decrypt_01 = stuff( @real_decrypt_01,
@intProcSpace,
1,
NCHAR ( UNICODE( substring(@real_01, @intProcSpace, 1) )
^ ( UNICODE( substring(@fake_01, @intProcSpace, 1) )
^ UNICODE( substring(@fake_encrypt_01, @intProcSpace, 1) )
)))

SET @intProcSpace=@intProcSpace+1
END


-- Load the variables into #output for handling by sp_helptext logic
insert #output (real_decrypt) select @real_decrypt_01

--select real_decrypt AS '#output check' from #output -- Testing

-- -------------------------------------
-- Beginning of extract from sp_helptext
-- -------------------------------------
declare @dbname sysname
declare @BlankSpaceAdded int
declare @BasePos int
declare @CurrentPos int
declare @TextLength int
declare @LineId int
declare @AddOnLen int
declare @LFCR int --lengths of line feed carriage return
declare @DefinedLength int
declare @SyscomText nvarchar(max)
declare @Line nvarchar(255)


Select @DefinedLength = 255
SELECT @BlankSpaceAdded = 0

--Keeps track of blank spaces at end of lines. Note Len function ignores trailing blank spaces
CREATE TABLE #CommentText ( LineId int ,
Text nvarchar(255) collate database_default)


-- use #output instead of sys.sysobjvalues
DECLARE ms_crs_syscom CURSOR LOCAL FOR
SELECT real_decrypt
from #output
ORDER BY
ident
FOR READ ONLY


-- Else get the text.
SELECT @LFCR = 2
SELECT @LineId = 1

OPEN ms_crs_syscom

FETCH NEXT FROM ms_crs_syscom into @SyscomText

WHILE @@fetch_status >= 0
BEGIN

SELECT @BasePos = 1
SELECT @CurrentPos = 1
SELECT @TextLength = LEN(@SyscomText)

WHILE @CurrentPos != 0
BEGIN
--Looking for end of line followed by carriage return
SELECT @CurrentPos = CHARINDEX(char(13)+char(10), @SyscomText, @BasePos)

--If carriage return found
IF @CurrentPos != 0
BEGIN
--If new value for @Lines length will be > then the set length then insert current contents of @line and proceed.
While (isnull(LEN(@Line),0) + @BlankSpaceAdded + @CurrentPos-@BasePos + @LFCR) > @DefinedLength
BEGIN
SELECT @AddOnLen = @DefinedLength-(isnull(LEN(@Line),0) +@BlankSpaceAdded)

INSERT #CommentText VALUES ( @LineId, isnull(@Line, N'') + isnull(SUBSTRING(@SyscomText, @BasePos, @AddOnLen), N''))
SELECT @Line = NULL, @LineId = @LineId + 1, @BasePos = @BasePos + @AddOnLen, @BlankSpaceAdded = 0
END

SELECT @Line = isnull(@Line, N'') + isnull(SUBSTRING(@SyscomText, @BasePos, @CurrentPos-@BasePos + @LFCR), N'')
SELECT @BasePos = @CurrentPos+2

INSERT #CommentText VALUES( @LineId, @Line )
SELECT @LineId = @LineId + 1

SELECT @Line = NULL
END
ELSE --else carriage return not found
BEGIN
IF @BasePos <= @TextLength
BEGIN
--If new value for @Lines length will be > then the defined length
While (isnull(LEN(@Line),0) + @BlankSpaceAdded + @TextLength-@BasePos+1 ) > @DefinedLength
BEGIN
SELECT @AddOnLen = @DefinedLength - (isnull(LEN(@Line),0) + @BlankSpaceAdded)

INSERT #CommentText VALUES ( @LineId, isnull(@Line, N'') + isnull(SUBSTRING(@SyscomText, @BasePos, @AddOnLen), N''))
SELECT @Line = NULL, @LineId = @LineId + 1, @BasePos = @BasePos + @AddOnLen, @BlankSpaceAdded = 0
END

SELECT @Line = isnull(@Line, N'') + isnull(SUBSTRING(@SyscomText, @BasePos, @TextLength-@BasePos+1 ), N'')

if LEN(@Line) < @DefinedLength and charindex(' ', @SyscomText, @TextLength+1 ) > 0
BEGIN
SELECT @Line = @Line + ' ', @BlankSpaceAdded = 1
END
END
END
END

FETCH NEXT FROM ms_crs_syscom into @SyscomText
END


IF @Line is NOT NULL INSERT #CommentText VALUES( @LineId, @Line )

select Text from #CommentText order by LineId

-- Clean up
CLOSE ms_crs_syscom
DEALLOCATE ms_crs_syscom
DROP TABLE #CommentText

-- -------------------------------------
-- End of extract from sp_helptext
-- -------------------------------------

ROLLBACK TRAN
DROP TABLE #output

-- Drop the procedure that was setup with dashes and rebuild it with the good stuff

GO


SET QUOTED_IDENTIFIER OFF
GO
SET ANSI_NULLS ON
GO














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