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    SQLSERVER对加密的存储过程、视图、触发器进行解密(推荐)

    栏目:Linux/apache问题 时间:2020-01-03 19:05

    加密测试的存储过程

    IF EXISTS(SELECT 1 FROM SYSOBJECTS WHERE TYPE='P' AND NAME='P_TEST')
    DROP PROCEDURE P_TEST
    GO
    CREATE PROCEDURE P_TEST(@USERNAME VARCHAR(20),@MSG VARCHAR(20) OUTPUT)
    WITH ENCRYPTION
    AS
    BEGIN
      IF(SELECT COUNT(1) FROM Custs WHERE NAME=@USERNAME)>0
        SET @MSG='此用户名存在'
      ELSE
        SET @MSG='此用户名不存在'
    END

    解密的存储过程

    Create PROCEDURE Decryption(@procedure sysname = NULL)
    AS
    SET NOCOUNT ON
    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
    GO
    启用DAC
    SP_CONFIGURE 'remote admin connections';
    GO
    ----0:仅允许本地连接使用 DAC,1:允许远程连接使用 DAC
    SP_CONFIGURE 'remote admin connections', 0;
    GO
    RECONFIGURE WITH OVERRIDE;
    GO