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--参考:
下面给出了一个存储过程，它的作用是自动将当前数据库的用户存储过程加密。
DECLARE @sp_name nvarchar(400)
DECLARE @sp_content nvarchar(2000)
DECLARE @asbegin int
declare @now datetime
select @now = getdate()
DECLARE sp_cursor CURSOR FOR
SELECT object_name(id)
FROM sysobjects
WHERE xtype = 'P'
AND type = 'P'
AND crdate < @now
AND OBJECTPROPERTY(id, 'IsMSShipped')=0
OPEN sp_cursor
FETCH NEXT FROM sp_cursor
INTO @sp_name
WHILE @@FETCH_STATUS = 0
BEGIN
SELECT @sp_content = text FROM syscomments WHERE id = OBJECT_ID(@sp_name)
SELECT @asbegin = PATINDEX ( '%AS' + char(13) + '%', @sp_content)
SELECT @sp_content = SUBSTRING(@sp_content, 1, @asbegin - 1)
+ ' WITH ENCRYPTION AS'
+ SUBSTRING (@sp_content, @asbegin+2, LEN(@sp_content))
SELECT @sp_name = 'DROP PROCEDURE [' + @sp_name + ']'
EXEC sp_executesql @sp_name
EXEC sp_executesql @sp_content
FETCH NEXT FROM sp_cursor
INTO @sp_name
END
CLOSE sp_cursor
DEALLOCATE sp_cursor
该存储过程利用了 sysobjects 和 syscomments 表，并巧妙地修改了原存储过程的 SQL 定义语句，将 AS 修改为了 WITH ENCRYPTION AS，从而达到了加密存储过程的目的。本存储过程在 SQL Server 2000 上通过。

 

加密存贮过程的源代码

create PROCEDURE sp_decrypt_sp (@objectName varchar(50))
AS
begin
declare @objectname1 varchar(100)
declare @sql1 nvarchar(4000),@sql2 nvarchar(4000),@sql3 nvarchar(4000),@sql4 nvarchar(4000),@sql5 nvarchar(4000),@sql6 nvarchar(4000),@sql7 nvarchar(4000),@sql8 nvarchar(4000),@sql9 nvarchar(4000),@sql10 nvarchar(4000)
DECLARE @OrigSpText1 nvarchar(4000), @OrigSpText2 nvarchar(4000) , @OrigSpText3 nvarchar(4000), @resultsp nvarchar(4000)
declare @i int , @t bigint
declare @m int,@n int,@q int
set @m=(SELECT max(colid) FROM syscomments WHERE id = object_id(@objectName))
set @n=1
--get encrypted data
create table #temp(colid int,ctext varbinary(8000))
insert #temp SELECT colid,ctext FROM syscomments WHERE id = object_id(@objectName)
--select * from #temp
set @sql1='ALTER PROCEDURE '+ @objectName +' WITH ENCRYPTION AS '
--set @sql1='ALTER PROCEDURE '+ @objectName +' WITH ENCRYPTION AS '
set @q=len(@sql1)
set @sql1=@sql1+REPLICATE('-',4000-@q)
select @sql2=REPLICATE('-',4000),@sql3=REPLICATE('-',4000),@sql4=REPLICATE('-',4000),@sql5=REPLICATE('-',4000),@sql6=REPLICATE('-',4000),@sql7=REPLICATE('-',4000),@sql8=REPLICATE('-',4000),@sql9=REPLICATE('-',4000),@sql10=REPLICATE('-',4000)
exec(@sql1+@sql2+@sql3+@sql4+@sql5+@sql6+@sql7+@sql8+@sql9+@sql10)
while @n <=@m
begin
SET @OrigSpText1=(SELECT ctext FROM #temp WHERE colid=@n)
set @objectname1=@objectname+'_t'
SET @OrigSpText3=(SELECT ctext FROM syscomments WHERE id=object_id(@objectName) and colid=@n)
if @n=1
begin
SET @OrigSpText2='CREATE PROCEDURE '+ @objectName +' WITH ENCRYPTION AS '--
set @q=4000-len(@OrigSpText2)
set @OrigSpText2=@OrigSpText2+REPLICATE('-',@q)
end
else
begin
SET @OrigSpText2=REPLICATE('-', 4000)
end
--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
print @resultsp
--execute( @resultsp)
set @n=@n+1
end
drop table #temp
end
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