SqlServer存储过程加密与解密

★ 加密存储过程 ★：

IF EXISTS (SELECT name FROM sysobjects WHERE name = 'encrypt_this' AND type = 'P')   
DROP PROCEDURE encrypt_this 
GO 
USE pubs 
GO 
CREATE PROCEDURE encrypt_this 
WITH ENCRYPTION  ---添加WITH ENCRYPTION即可 AS 
SELECT * FROM authors
GO  
--查看存储过程文本： 
EXEC sp_helptext encrypt_this 
--下面是结果集： 
--***The object's comments have been encrypted.  
------对象已经被加密

★ 解密存储过程 ★： 
 
***CREATE  PROCEDURE 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=@nand number=@k 
SET @OrigSpText3=(SELECT ctext FROM syscomments WHERE id=object_id(@objectName) andcolid=@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 
----创建存储过程sp_decrypt后，执行以下操作. 
----调用时，exec sp_decrypt '要解密的存储过程名' 
---此时 使用 exec sp_helptext '存储过程名'，即可查看存储过程的文本信息