SQLServer解密存储过程

1.创建解密存储过程

先在对应的库里创建解密存储过程,
存储过程参考如下：

SET ANSI_NULLS ON

GO

SET QUOTED_IDENTIFIER ON

GO

-- =============================================

-- Author: <Author,,Name>

-- Create date: <Create Date,,>

-- Description: <Description,,>

-- =============================================

CREATE PROCEDURE [dbo].[sp_decrypt]

(@procedure sysname = NULL) 

AS 

SET NOCOUNT ON 

BEGIN

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

tinyint,@procNameLength int 

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

sys.sysobjvalues WHERE objid = object_id(@procedure) 

GROUP BY imageval 

select @procNameLength = datalength(@procedure) + 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) 

declare @objtype varchar(2),@ParentName nvarchar(max) 

select @real_decrypt_01a = '' 

--提取对象的类型如是存储过程还是函数，如果是触发器，还要得到其父对象的名称 

select @objtype=type,@parentname=object_name(parent_object_id) 

from sys.objects where [object_id]=object_id(@procedure) 

-- 从sys.sysobjvalues里提出加密的imageval记录 

SET @real_01=(SELECT top 1 imageval FROM sys.sysobjvalues WHERE objid = 

object_id(@procedure) and valclass = 1 order by subobjid) 

--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 

if @objtype='P' 

SET @fake_01='ALTER PROCEDURE '+ @procedure +' WITH ENCRYPTION AS 

'+REPLICATE('-', 40003 - @procNameLength) 

else if @objtype='FN' 

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

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

else if @objtype='V' 

SET @fake_01='ALTER view '+ @procedure +' WITH ENCRYPTION AS select 1 as col 

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

else if @objtype='TR' 

SET @fake_01='ALTER trigger '+ @procedure +' ON '+@parentname+'WITH ENCRYPTION AFTER INSERT AS RAISERROR (''N'',16,10) 

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

EXECUTE (@fake_01) 

--从sys.sysobjvalues里提出加密的假的 

SET @fake_encrypt_01=(SELECT top 1 imageval FROM sys.sysobjvalues WHERE objid = 

object_id(@procedure) and valclass = 1 order by subobjid ) 

if @objtype='P' 

SET @fake_01='Create PROCEDURE '+ @procedure +' WITH ENCRYPTION AS 

'+REPLICATE('-', 40003 - @procNameLength) 

else if @objtype='FN' 

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

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

else if @objtype='V' 

SET @fake_01='Create view '+ @procedure +' WITH ENCRYPTION AS select 1 as col 

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

else if @objtype='TR' 

SET @fake_01='Create trigger '+ @procedure +' ON '+@parentname+'WITH ENCRYPTION AFTER INSERT AS RAISERROR (''N'',16,10) 

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

--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, @intProcSpace, 1)) ^ 

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

UNICODE(substring(@fake_encrypt_01, @intProcSpace, 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, 

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 

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 

ROLLBACK TRAN 

DROP TABLE #output

END

2.开启DAC

facets→外围应用配置器→RemoteDacEnabled

3.SSMS连接

必须本地环境开启ssms，当初始界面提示你连接到服务器的时候，我们不连接，而是关闭窗口，进入之后新建查询，此时再次弹出连接服务器窗口，这时输入admin:实例名即可连接(也可以输入主机名，或者ip地址)

用户必须用sysadmin权限账号登录

4.执行sp_decrypt解密

例如：

USE Testwenjie

GO

exec sp_decrypt 'dbo.db_backup_log'