解密加密了的SQL存储过程

CREATE PROCEDURE [dbo].[sp_decrypt](@objectname varchar(50))
AS
begin
set nocount on

begin tran
declare @objectname1 varchar(100),@orgvarbin varbinary(8000)
declare @sql1 nvarchar(4000),@sql2 varchar(8000),@sql3 nvarchar(4000),@sql4 nvarchar(4000)
DECLARE @OrigSpText1 nvarchar(4000), @OrigSpText2 nvarchar(4000) , @OrigSpText3 nvarchar(4000), @resultsp nvarchar(4000)
declare @i int,@status int,@type varchar(10),@parentid int
declare @colid int,@n int,@q int,@j int,@k int,@encrypted int,@number int
select @type=xtype,@parentid=parent_obj from sysobjects where id=object_id(@objectname)

create table #temp(number int,colid int,ctext varbinary(8000),encrypted int,status int)
insert #temp Select number,colid,ctext,encrypted,status FROM syscomments Where id = object_id(@objectname)
select @number=max(number) from #temp
set @k=0

while @k<=@number 
begin
if exists(select 1 from syscomments where id=object_id(@objectname) and number=@k)
begin
if @type='P'
set @sql1=(case when @number>1 then 'Alter PROCEDURE '+ @objectname +';'+rtrim(@k)+' WITH ENCRYPTION AS '
else 'Alter PROCEDURE '+ @objectname+' WITH ENCRYPTION AS '
end)

if @type='TR'
begin
declare @parent_obj varchar(255),@tr_parent_xtype varchar(10)
select @parent_obj=parent_obj from sysobjects where id=object_id(@objectname)
select @tr_parent_xtype=xtype from sysobjects where id=@parent_obj
if @tr_parent_xtype='V'
begin
set @sql1='Alter TRIGGER '+@objectname+' ON '+OBJECT_NAME(@parentid)+' WITH ENCRYPTION INSTERD OF Insert AS PRINT 1 '
end
else
begin
set @sql1='Alter TRIGGER '+@objectname+' ON '+OBJECT_NAME(@parentid)+' WITH ENCRYPTION FOR Insert AS PRINT 1 '
end

end
if @type='FN' or @type='TF' or @type='IF'
set @sql1=(case @type when 'TF' then 
'Alter FUNCTION '+ @objectname+'(@a char(1)) returns @b table(a varchar(10)) with encryption as begin insert @b select @a return end '
when 'FN' then
'Alter FUNCTION '+ @objectname+'(@a char(1)) returns char(1) with encryption as begin return @a end'
when 'IF' then
'Alter FUNCTION '+ @objectname+'(@a char(1)) returns table with encryption as return select @a as a'
end)

if @type='V'

set @sql1='Alter VIEW '+@objectname+' WITH ENCRYPTION AS Select 1 as f'

set @q=len(@sql1)
set @sql1=@sql1+REPLICATE('-',4000-@q)
select @sql2=REPLICATE('-',8000)
set @sql3='exec(@sql1'
select @colid=max(colid) from #temp where number=@k 
set @n=1
while @n<=CEILING(1.0*(@colid-1)/2) and len(@sql3)<=3996
begin 
set @sql3=@sql3+'+@'
set @n=@n+1
end
set @sql3=@sql3+')'
exec sp_executesql @sql3,N'@sql1 nvarchar(4000),@ varchar(8000)',@sql1=@sql1,@=@sql2

end
set @k=@k+1
end

set @k=0
while @k<=@number 
begin

if exists(select 1 from syscomments where id=object_id(@objectname) and number=@k)
 begin
 select @colid=max(colid) from #temp where number=@k 
set @n=1
 
while @n<=@colid
 begin
 select @OrigSpText1=ctext,@encrypted=encrypted,@status=status FROM #temp Where colid=@n and number=@k
 
SET @OrigSpText3=(Select ctext FROM syscomments Where id=object_id(@objectname) and colid=@n and number=@k)
 if @n=1
 begin
 if @type='P'
 SET @OrigSpText2=(case when @number>1 then 'Create PROCEDURE '+ @objectname +';'+rtrim(@k)+' WITH ENCRYPTION AS '
 else 'Create PROCEDURE '+ @objectname +' WITH ENCRYPTION AS '
 end)

 
if @type='FN' or @type='TF' or @type='IF'
 SET @OrigSpText2=(case @type when 'TF' then 
'Create FUNCTION '+ @objectname+'(@a char(1)) returns @b table(a varchar(10)) with encryption as begin insert @b select @a return end '
 when 'FN' then
 'Create FUNCTION '+ @objectname+'(@a char(1)) returns char(1) with encryption as begin return @a end'
 when 'IF' then
 'Create FUNCTION '+ @objectname+'(@a char(1)) returns table with encryption as return select @a as a'
 end)
 
if @type='TR' 
begin
 
if @tr_parent_xtype='V'
 begin
 set @OrigSpText2='Create TRIGGER '+@objectname+' ON '+OBJECT_NAME(@parentid)+' WITH ENCRYPTION INSTEAD OF Insert AS PRINT 1 '
 end
 else
 begin
 set @OrigSpText2='Create TRIGGER '+@objectname+' ON '+OBJECT_NAME(@parentid)+' WITH ENCRYPTION FOR Insert AS PRINT 1 '
 end
 
end
 
if @type='V'
 set @OrigSpText2='Create VIEW '+@objectname+' WITH ENCRYPTION AS Select 1 as f'
 set @q=4000-len(@OrigSpText2)
 set @OrigSpText2=@OrigSpText2+REPLICATE('-',@q)
 end
 else
 begin
 SET @OrigSpText2=REPLICATE('-', 4000)
 end
 SET @i=1
 
SET @resultsp = replicate(N'A', (datalength(@OrigSpText1) / 2))
 
WHILE @i<=datalength(@OrigSpText1)/2
 BEGIN
 
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
 set @orgvarbin=cast(@OrigSpText1 as varbinary(8000))
 set @resultsp=(case when @encrypted=1 
then @resultsp 
else convert(nvarchar(4000),case when @status&2=2 then uncompress(@orgvarbin) else @orgvarbin end)
 end)
 print @resultsp
 
set @n=@n+1
 
end
 
end
 set @k=@k+1
 end
 
drop table #temp
 rollback tran
 end