SQL加密

  
CREATE PROCEDURE [dbo].[sp_undecrypt]
	(
	  @procedure SYSNAME = NULL ,
	  @revfl INT = 1
	)
AS /**//*  
王成辉翻译整理，转贴请注明出自微软BI开拓者www.windbi.com  
调用形式为：  
exec dbo.sp__windbi$decrypt @procedure,0  
如果第二个参数使用1的话，会给出该存储过程的一些提示。  
--版本4.0  修正存储过程过长解密出来是空白的问题  
*/  
	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 ,
		@procNameLength INT  
	SELECT	@maxColID = MAX(subobjid)
	FROM	sys.sysobjvalues
	WHERE	objid = OBJECT_ID(@procedure)  
--select @maxColID as 'Rows in sys.sysobjvalues'  
	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 select 1  
  /**//*' + REPLICATE(CAST('*' AS NVARCHAR(MAX)),
					  DATALENGTH(@real_01) / 2 - @procNameLength) + '*/'  
	ELSE 
		IF @objtype = 'FN' 
			SET @fake_01 = 'ALTER FUNCTION ' + @procedure
				+ '() RETURNS INT WITH ENCRYPTION AS BEGIN RETURN 1  
  /**//*' + REPLICATE(CAST('*' AS NVARCHAR(MAX)),
					  DATALENGTH(@real_01) / 2 - @procNameLength) + '*/ END'  
		ELSE 
			IF @objtype = 'V' 
				SET @fake_01 = 'ALTER view ' + @procedure
					+ ' WITH ENCRYPTION AS select 1 as col  
  /**//*' + REPLICATE(CAST('*' AS NVARCHAR(MAX)),
					  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(CAST('*' AS NVARCHAR(MAX)),
					  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 select 1  
  /**//*' + REPLICATE(CAST('*' AS NVARCHAR(MAX)),
					  DATALENGTH(@real_01) / 2 - @procNameLength) + '*/'  
	ELSE 
		IF @objtype = 'FN' 
			SET @fake_01 = 'CREATE FUNCTION ' + @procedure
				+ '() RETURNS INT WITH ENCRYPTION AS BEGIN RETURN 1  
  /**//*' + REPLICATE(CAST('*' AS NVARCHAR(MAX)),
					  DATALENGTH(@real_01) / 2 - @procNameLength) + '*/ END'  
		ELSE 
			IF @objtype = 'V' 
				SET @fake_01 = 'Create view ' + @procedure
					+ ' WITH ENCRYPTION AS select 1 as col  
  /**//*' + REPLICATE(CAST('*' AS NVARCHAR(MAX)),
					  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(CAST('*' AS NVARCHAR(MAX)),
					  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(CAST('A' AS NVARCHAR(MAX)),
									 ( 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(MAX) ,
		@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