range check error,感兴趣的进

[caizhuxi]

最近用到DES加密,在网上找了一个加密的单元,但使用时出现了range check error.
我在同一台机器做了简单工程,使用加密程序测试没有问题,但是将加密程序应用到项目中就出现了上面的异常.
我的测试程序和项目在同一台机器,很不解,难道是冲突了.希望得到大家的帮助.
下面是部分加密单元的源程序:错误出现在218行:key28l[2] := (outData56[1] shl 4) or (outData56[2] shr 4);



unit DES;

interface

uses SysUtils;

type
TKeyByte = array[0..5] of Byte;
TDesMode = (dmEncry, dmDecry);

function EncryStr(Str, Key: String): String;
function DecryStr(Str, Key: String): String;
function EncryStrHex(Str, Key: String): String;
function DecryStrHex(StrHex, Key: String): String;

const
BitIP: array[0..63] of Byte = //初始值置IP
(57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7,
56, 48, 40, 32, 24, 16, 8, 0,
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6 );

BitCP: array[0..63] of Byte = //逆初始置IP-1
( 39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30,
37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28,
35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25,
32, 0, 40, 8, 48, 16, 56, 24 );

BitExp: array[0..47] of Integer = // 位选择函数E
( 31, 0, 1, 2, 3, 4, 3, 4, 5, 6, 7, 8, 7, 8, 9,10,
11,12,11,12,13,14,15,16,15,16,17,18,19,20,19,20,
21,22,23,24,23,24,25,26,27,28,27,28,29,30,31,0 );

BitPM: array[0..31] of Byte = //置换函数P
( 15, 6,19,20,28,11,27,16, 0,14,22,25, 4,17,30, 9,
1, 7,23,13,31,26, 2, 8,18,12,29, 5,21,10, 3,24 );

sBox: array[0..7] of array[0..63] of Byte = //S盒
( ( 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13 ),

( 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 ),

( 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 ),

( 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 ),

( 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 ),

( 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 ),

( 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12 ),

( 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 ) );

end;

[SQLDebug_Fan]

range check error表示溢出了，你可以把Project->Compiler->Range checking的选项去掉，这样就不会报错。检查一下你的算法为什么会溢出。

[caizhuxi]

谢谢楼上的回答,我将Project->Compiler->Range checking选项去掉,程序能正常执行了,我单步调试时
key28l[2] := (outData56[1] shl 4) or (outData56[2] shr 4);抛异常
执行到这句时key28l={0,15,0,236}
outData56={0,255,255,20,19,72,33}
问题还在找

[yangruyang]

garylicd No.：355781

[jiangzhanjun]

测试了一下,没发现LZ所说的问题啊。

[caizhuxi]

问题找到了,忘了结贴,谢谢大家的参与

[hityu]

请问是为什么呢？
我们也遇到相似问题了，gzip压缩程序简单程序没有问题，但是放到应用项目中就range check error

[lissdd]

这种range check问题在加密算法中很常见, 因为加密算法经常会循环求和、移位操作, 其结果很容易溢出, 而且我们常常是利用这种溢出而加密。所以在该类算法前加入{$R-} 和{$Q-} 取消这种范围检查，而在其他代码中恢复这种检查即可。这样既能查出我们想找的非法越界或者溢出错误，又能避免误报加密部分的故意溢出。