SQLServer配置DAC--解密加密存储过程

为什麽需要使用DAC连接？

1) 外围应用配置――启用DAC

EXEC SP_CONFIGURE 'remote admin connections',1

GO

RECONFIGURE

GO

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配置选项 'remote admin connections' 已从 1 更改为 1。请运行 RECONFIGURE 语句进行安装。

命令提示符配置

D:Program FilesMicrosoft SQL ServerMSSQL10_50.MSSQLSERVERMSSQLBinn>sqlcmd -

A -S 192.168.194.20 -U sa -P ******

1> exit

2) 断开所有连接，新进查询 Server 名称格式为 "ADMIN:Servername"

3) 查询以文本格式显示结果，执行解密存储过程 sp_decrypt

USE MyDB

GO

EXEC master.dbo.sp_decrypt 'dbo.encry_1',0

GO

温馨提示，以下解密存储过程摘自网络....

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USE [master]

GO

SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

Create PROCEDURE [dbo].[sp_decrypt]

(@function sysname = NULL,@revfl int = 1)

AS

SET NOCOUNT ON

IF @revfl = 1

BEGIN

PRINT '警告：该存储过程会删除并重建原始的存储过程。'

PRINT ' 在运行该存储过程之前确保你的数据库有一个备份。'

PRINT ' 该存储过程通常应该运行在产品环境的一个备份的非产品环境下。'

PRINT ' 为了运行这个存储过程，将参数@refl的值更改为0。'

RETURN 0

END

DECLARE @intProcSpace bigint,@t bigint,@maxColID smallint,@intEncrypted

tinyint,@procNameLength int

select @maxColID = max(subobjid),@intEncrypted = imageval FROM

sys.sysobjvalues WHERE objid = object_id(@function)

GROUP BY imageval

--select @maxColID as 'Rows in sys.sysobjvalues'

select @procNameLength = datalength(@function) + 29

DECLARE @real_01 nvarchar(max)

DECLARE @fake_01 nvarchar(max)

DECLARE @fake_encrypt_01 nvarchar(max)

DECLARE @real_decrypt_01 nvarchar(max),@real_decrypt_01a nvarchar(max)

select @real_decrypt_01a = ''

-- 从sys.sysobjvalues里提出加密的imageval记录

SET @real_01=(SELECT imageval FROM sys.sysobjvalues WHERE objid =

object_id(@function) and valclass = 1 and subobjid = 0 )

--创建一个临时表

create table #output ( [ident] [int] IDENTITY (1,1) NOT NULL,

[real_decrypt] NVARCHAR(MAX) )

--开始一个事务，稍后回滚

BEGIN TRAN

--更改原始的存储过程，用短横线替换

SET @fake_01='ALTER FUNCTION '+ @function +'() RETURNS INT WITH ENCRYPTION AS BEGIN RETURN 1

/*'+REPLICATE('*',datalength(@real_01) /2 - @procNameLength)+'*/ END'

EXECUTE (@fake_01)

--从sys.sysobjvalues里提出加密的假的

SET @fake_encrypt_01=(SELECT imageval FROM sys.sysobjvalues WHERE objid =

object_id(@function) and valclass = 1 and subobjid = 0)

SET @fake_01='CREATE FUNCTION '+ @function +'() RETURNS INT WITH ENCRYPTION AS BEGIN RETURN 1

/*'+REPLICATE('*',datalength(@real_01) /2 - @procNameLength)+'*/ END'

--开始计数

SET @intProcSpace=1

--使用字符填充临时变量

SET @real_decrypt_01 = replicate(N'A',(datalength(@real_01) /2 ))

--循环设置每一个变量，创建真正的变量

--每次一个字节

SET @intProcSpace=1

--如有必要，遍历每个@real_xx变量并解密

WHILE @intProcSpace<=(datalength(@real_01)/2)

BEGIN

--真的和假的和加密的假的进行异或处理

SET @real_decrypt_01 = stuff(@real_decrypt_01,@intProcSpace,1,

NCHAR(UNICODE(substring(@real_01,1)) ^

(UNICODE(substring(@fake_01,1)) ^

UNICODE(substring(@fake_encrypt_01,1)))))

SET @intProcSpace=@intProcSpace+1

END

--通过sp_helptext逻辑向表#output里插入变量

insert #output (real_decrypt) select @real_decrypt_01

-- select real_decrypt AS '#output chek' from #output --测试

-- -------------------------------------

--开始从sp_helptext提取

-- -------------------------------------

declare @dbname sysname

,@BlankSpaceAdded int

,@BasePos int

,@CurrentPos int

,@TextLength int

,@LineId int

,@AddOnLen int

,@LFCR int --回车换行的长度

,@DefinedLength int

,@SyscomText nvarchar(4000)

,@Line nvarchar(255)

Select @DefinedLength = 255

SELECT @BlankSpaceAdded = 0 --跟踪行结束的空格。注意Len函数忽略了多余的空格

CREATE TABLE #CommentText

(LineId int

,Text nvarchar(255) collate database_default)

--使用#output代替sys.sysobjvalues

DECLARE ms_crs_syscom CURSOR LOCAL

FOR SELECT real_decrypt from #output

ORDER BY ident

FOR READ ONLY

--获取文本

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

--通过回车查找行的结束

SELECT @CurrentPos = CHARINDEX(char(13)+char(10),@SyscomText,

@BasePos)

--如果找到回车

IF @CurrentPos != 0

BEGIN

--如果@Lines的长度的新值比设置的大就插入@Lines目前的内容并继续

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

--如果回车没找到

BEGIN

IF @BasePos <= @TextLength

BEGIN

--如果@Lines长度的新值大于定义的长度

While (isnull(LEN(@Line),0) + @BlankSpaceAdded +

@TextLength-@BasePos+1 ) > @DefinedLength

BEGIN

SELECT @AddOnLen = @DefinedLength -

(isnull(LEN(@Line),0) + @BlankSpaceAdded)

INSERT #CommentText VALUES

( @LineId,@BlankSpaceAdded =

0

END

SELECT @Line = isnull(@Line,@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

CLOSE ms_crs_syscom

DEALLOCATE ms_crs_syscom

DROP TABLE #CommentText

-- -------------------------------------

--结束从sp_helptext提取

-- -------------------------------------

--删除用短横线创建的存储过程并重建原始的存储过程

--版本1.1，重建不必要的存储过程

ROLLBACK TRAN

DROP TABLE #output

GO

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（编辑：李大同）

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