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我对 C 语言和在 Linux 中编译它不是很熟悉，但我有一些问题要问，希望你能提供帮助。

我有这行代码，它使用已安装的命令及其参数来加入域。（见图）。在我运行gcc join.c编译它之后，它创建了一个文件a.out。到目前为止一切顺利，但是当我运行vim a.out查看该文件的内容时，我mypassword可以通过简单的文本编辑器轻松查看。（见第二张图）

在编译我的 C 代码时，我能做些什么来避免这种情况吗？

#include <stdio.h>
#include <unistd.h>

int main ()
{
        printf("Running 'net join' with the following parameters: \n");
        char *domain="mydomain";
        char *user="domainjoinuser";
        char *pass="mypassword";
        char *vastool="/opt/quest/bin/vastool";
        char *ou="OU=test,DC=mtdomain,DC=local";
        char unjoin[512];

        sprintf(unjoin,"/opt/quest/in/vastool -u %s -w '%s' unjoin -f",user,pass);

        printf("Domain: %s\n",domain);
        printf("User: %s\n",user);
        printf("-----------------\n");

        printf("Unjoin.............\n");
        system(unjoin);

        printf("Join................\n");
        execl("/opt/quest/bin/vastool", "vastool", "-u", user, "-w", pass, "join", "-c", "ou", "-f", domain, (char*)0);

}

vim中查看的源代码

00000000 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 |.ELF............|
00000010 02 00 3e 00 01 00 00 00 40 83 04 08 00 00 00 00 |..>.....@........|
00000020 40 00 00 00 00 00 00 00 40 0a 00 00 00 00 00 00 |@.......@.......|
00000030 00 00 00 00 40 00 38 00 04 00 40 00 1c 00 1b 00 |....@.8...@.....|
00000040 03 00 00 00 04 00 00 00 20 01 00 00 00 00 00 00 |...................|
00000050 20 81 04 08 00 00 00 00 20 81 04 08 00 00 00 00 | ....... .......|
00000060 1c 00 00 00 00 00 00 00 1c 00 00 00 00 00 00 00 |......|
00000070 01 00 00 00 00 00 00 00 01 00 00 00 05 00 00 00 |......|
00000080 20 01 00 00 00 00 00 00 20 81 04 08 00 00 00 00 | ....... .......|
00000090 20 81 04 08 00 00 00 00 b0 05 00 00 00 00 00 00 | ......|
000000a0 b0 05 00 00 00 00 00 00 00 10 00 00 00 00 00 00 |......|
000000b0 01 00 00 00 06 00 00 00 e0 06 00 00 00 00 00 00 |......|
000000c0 e0 96 04 08 00 00 00 00 e0 96 04 08 00 00 00 00 |......|
000000d0 60 02 00 00 00 00 00 00 60 02 00 00 00 00 00 00 |`.......`.......|
000000e0 00 10 00 00 00 00 00 00 02 00 00 00 06 00 00 00 |......|
000000f0 24 08 00 00 00 00 00 00 24 98 04 08 00 00 00 00 |$.......$.......|
00000100 24 98 04 08 00 00 00 00 a0 00 00 00 00 00 00 00 |$........|
00000110 a0 00 00 00 00 00 00 00 04 00 00 00 00 00 00 00 |......|
00000120 2f 6c 69 62 36 34 2f 6c 64 2d 6c 69 6e 75 78 2d |/lib64/ld-linux-|
00000130 78 38 36 2d 36 34 2e 73 6f 2e 32 00 00 00 00 00 |x86-64.so.2.....|
00000140 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |......|
00000150 00 00 00 00 01 00 00 00 12 00 00 00 70 86 04 08 |............p......|
00000160 00 00 00 00 c0 01 00 00 00 00 00 00 13 00 00 00 |......|
00000170 12 00 00 00 80 86 04 08 00 00 00 00 a1 00 00 00 |......|
00000180 00 00 00 00 1a 00 00 00 12 00 00 00 90 86 04 08 |......|
00000190 00 00 00 00 8f 00 00 00 00 00 00 00 22 00 00 00 |............"......|
000001a0 12 00 00 00 a0 86 04 08 00 00 00 00 61 00 00 00 |............a......|
000001b0 00 00 00 00 29 00 00 00 12 00 00 00 b0 86 04 08 |.......)............|
000001c0 00 00 00 00 b0 01 00 00 00 00 00 00 2f 00 00 00 |............/......|
000001d0 12 00 0c 00 80 86 04 08 00 00 00 00 00 00 00 00 |......|
000001e0 00 00 00 00 35 00 00 00 20 00 00 00 00 00 00 00 |....5... ....|
000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 5f 5f 6c |......__l|
00000200 69 62 63 5f 73 74 61 72 74 5f 6d 61 69 6e 00 70 |ibc_start_main.p|
00000210 72 69 6e 74 66 00 73 70 72 69 6e 74 66 00 73 79 |rintf.sprintf.sy|
00000220 73 74 65 6d 00 65 78 65 63 6c 00 5f 69 6e 69 74 |stem.execl._init|
00000230 00 5f 5f 67 6d 6f 6e 5f 73 74 61 72 74 5f 5f 00 |.__gmon_start__.|
00000240 6c 69 62 63 2e 73 6f 2e 36 00 00 00 04 00 00 00 |libc.so.6.......|
00000250 08 00 00 00 06 00 00 00 04 00 00 00 03 00 00 00 |......|
00000260 07 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 |......|
00000270 02 00 00 00 00 00 00 00 00 00 00 00 05 00 00 00 |......|
00000280 00 00 00 00 f8 98 04 08 00 00 00 00 07 00 00 00 |......|
00000290 01 00 00 00 00 00 00 00 00 00 00 00 00 99 04 08 |......|
000002a0 00 00 00 00 07 00 00 00 02 00 00 00 00 00 00 00 |......|
000002b0 00 00 00 00 08 99 04 08 00 00 00 00 07 00 00 00 |......|
000002c0 03 00 00 00 00 00 00 00 00 00 00 00 10 99 04 08 |......|
000002d0 00 00 00 00 07 00 00 00 04 00 00 00 00 00 00 00 |......|
000002e0 00 00 00 00 18 99 04 08 00 00 00 00 07 00 00 00 |......|
000002f0 05 00 00 00 00 00 00 00 00 00 00 00 20 99 04 08 |..................|
00000300 00 00 00 00 07 00 00 00 06 00 00 00 00 00 00 00 |......|
00000310 00 00 00 00 28 99 04 08 00 00 00 00 06 00 00 00 |.......(............|
00000320 07 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |......|
00000330 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |......|
00000340 31 ed 49 89 d1 5e 48 89 e2 48 83 e4 f0 50 54 49 |1.I..^H..H...PTI|
00000350 c7 c0 90 85 04 08 48 c7 c1 00 85 04 08 48 c7 c7 |......H......H..|
00000360 6c 83 04 08 e8 07 03 00 00 f4 66 90 55 48 89 e5 |l.........f..UH..|
00000370 48 81 ec 30 02 00 00 48 8d 05 66 13 00 00 48 89 |H..0...H..f...H.|
00000380 c7 b8 00 00 00 00 e8 f5 02 00 00 48 8d 05 86 13 |............H......|
00000390 00 00 48 89 45 f8 48 8d 05 84 13 00 00 48 89 45 |..嘿.....嘿|
000003a0 f0 48 8d 05 88 13 00 00 48 89 45 e8 48 8d 05 88 |.H......HEH..|
000003b0 13 00 00 48 89 45 e0 48 8d 05 94 13 00 00 48 89 |...HEH.....H.|
000003c0 45 d8 48 8b 45 e8 49 89 c3 48 8b 45 f0 49 89 c2 |EHEI.HEI.|
000003d0 48 8d 05 98 13 00 00 48 89 c6 48 8d 85 d8 fd ff |H......H..H......|
000003e0 ff 48 89 c7 4c 89 d2 4c 89 d9 b8 00 00 00 00 e8 |.H..L..L........|
000003f0 9c 02 00 00 48 8b 45 f8 48 89 c6 48 8d 05 9b 13 |....HEH.H....|
00000400 00 00 48 89 c7 b8 00 00 00 00 e8 71 02 00 00 48 |..H........q...H|
00000410 8b 45 f0 48 89 c6 48 8d 05 8c 13 00 00 48 89 c7 |.EH.H......H..|
00000420 b8 00 00 00 00 e8 56 02 00 00 48 8d 05 82 13 00 |......V......H......|
00000430 00 48 89 c7 b8 00 00 00 00 e8 42 02 00 00 48 8d |.H........B...H.|
00000440 05 81 13 00 00 48 89 c7 b8 00 00 00 00 e8 2e 02 |.....H........|
00000450 00 00 48 8d 85 d8 fd ff ff 48 89 c7 b8 00 00 00 |..H......H......|
00000460 00 e8 3a 02 00 00 48 8d 05 6e 13 00 00 48 89 c7 |..:...H..n...H..|
00000470 b8 00 00 00 00 e8 06 02 00 00 48 b8 00 00 00 00 |............H......|
00000480 00 00 00 00 50 48 8b 45 f8 50 48 8d 05 90 13 00 |....PH.E.PH.......|
00000490 00 50 48 8d 05 85 13 00 00 50 48 8d 05 7a 13 00 |.PH......PH..z..|
000004a0 00 50 48 8d 05 6d 13 00 00 50 48 8b 45 e8 49 89 |.PH..m...PH.EI|
000004b0 c1 48 8d 05 5b 13 00 00 49 89 c0 48 8b 45 f0 49 |.H..[...I..HEI|
000004c0 89 c3 48 8d 05 47 13 00 00 49 89 c2 48 8d 05 35 |..H..G...I..H..5|
000004d0 13 00 00 48 89 c6 48 8d 05 14 13 00 00 48 89 c7 |...H..H......H..|
000004e0 4c 89 d2 4c 89 d9 b8 00 00 00 00 e8 c0 01 00 00 |L..L............|
000004f0 48 83 c4 30 c9 c3 00 00 00 00 00 00 00 00 00 00 |H..0............|
00000500 48 89 6c 24 d8 4c 89 64 24 e0 48 8d 2d 4f 01 00 |Hl$.Ld$.H.-O..|
00000510 00 4c 8d 25 48 01 00 00 48 89 5c 24 d0 4c 89 6c |.L.%H...H.\$.Ll|
00000520 24 e8 4c 89 74 24 f0 4c 89 7c 24 f8 48 83 ec 38 |$.Lt$.L.|$.H..8|
00000530 4c 29 e5 41 89 ff 49 89 f6 48 c1 fd 03 49 89 d5 |L).A..I..H...I..|
00000540 31 db e8 d9 00 00 00 48 85 ed 74 1a 0f 1f 40 00 |1......H..t...@.|
00000550 4c 89 ea 4c 89 f6 44 89 ff 41 ff 14 dc 48 83 c3 |L..L..D..A..H..|
00000560 01 48 39 eb 75 ea 48 8b 5c 24 08 48 8b 6c 24 10 |.H9.uH\$.Hl$.|
00000570 4c 8b 64 24 18 4c 8b 6c 24 20 4c 8b 74 24 28 4c |Ld$.Ll$ Lt$(L|
00000580 8b 7c 24 30 48 83 c4 38 c3 0f 1f 80 00 00 00 00 |.|$0H..8........|
00000590 f3 c3 00 00 01 00 02 00 14 00 00 00 00 00 00 00 |......|
000005a0 01 7a 52 00 01 78 10 01 1b 0c 07 08 90 01 07 10 |.zR..x........|
000005b0 14 00 00 00 1c 00 00 00 88 fd ff ff 2a 00 00 00 |............*......|
000005c0 00 00 00 00 00 00 00 00 14 00 00 00 00 00 00 00 |......|
000005d0 01 7a 52 00 01 78 10 01 1b 0c 07 08 90 01 00 00 |.zR..x........|
000005e0 24 00 00 00 1c 00 00 00 18 ff ff 89 00 00 00 |$........|
000005f0 00 4a 86 06 8c 05 66 0e 40 83 07 8d 04 8e 03 8f |.J....f.@........|
00000600 02 02 58 0e 08 00 00 00 14 00 00 00 44 00 00 00 |..X.........D...|
00000610 80 ff ff ff 02 00 00 00 00 00 00 00 00 00 00 00 |......|
00000620 48 83 ec 08 48 8b 05 fd 12 00 00 48 85 c0 74 05 |H...H......H..t.|
00000630 e8 cb 79 fb f7 48 83 c4 08 c3 00 00 48 83 ec 08 |..y..H......H...|
00000640 48 83 c4 08 c3 00 00 00 00 00 00 00 00 00 00 00 |H.................|
00000650 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |......|
00000660 ff 35 82 12 00 00 ff 25 84 12 00 00 00 00 00 00 |.5.....%........|
00000670 ff 25 82 12 00 00 68 00 00 00 00 e9 e0 ff ff ff |.%..h..........|
00000680 ff 25 7a 12 00 00 68 08 00 00 00 e9 d0 ff ff ff |.%z...h.........|
00000690 ff 25 72 12 00 00 68 10 00 00 00 e9 c0 ff ff ff |.%r...h.........|
000006a0 ff 25 6a 12 00 00 68 18 00 00 00 e9 b0 ff ff ff |.%j...h.........|
000006b0 ff 25 62 12 00 00 68 20 00 00 00 e9 a0 ff ff ff |.%b...h ........|
000006c0 ff 25 5a 12 00 00 68 28 00 00 00 e9 90 ff ff ff |.%Z...h(........|
000006d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |......|
000006e0 00 00 00 00 52 75 6e 6e 69 6e 67 20 27 6e 65 74 |....运行“网络”|
000006f0 20 6a 6f 69 6e 27 20 77 69 74 68 20 74 68 65 20 | 加入'与|
00000700 66 6f 6c 6c 6f 77 69 6e 67 20 70 61 72 61 6d 65 |以下参数|
00000710 74 65 72 73 3a 20 0a 00 6d 79 64 6f 6d 61 69 6e |ters:..mydomain|
00000720 00 64 6f 6d 61 69 6e 6a 6f 69 6e 75 73 65 72 00 |.domainjoinuser。|
00000730 6d 79 70 61 73 73 77 6f 72 64 00 2f 6f 70 74 2f |我的密码./opt/|
00000740 71 75 65 73 74 2f 62 69 6e 2f 76 61 73 74 6f 6f |任务/bin/vastoo|
00000750 6c 00 4f 55 3d 74 65 73 74 2c 44 43 3d 6d 74 64 |l.OU=test,DC=mtd|
00000760 6f 6d 61 69 6e 2c 44 43 3d 6c 6f 63 61 6c 00 2f |主，DC=本地。/|
00000770 6f 70 74 2f 71 75 65 73 74 2f 69 6e 2f 76 61 73 |opt/quest/in/vas|
00000780 74 6f 6f 6c 20 2d 75 20 25 73 20 2d 77 20 27 25 |工具 -u %s -w '%|
00000790 73 27 20 75 6e 6a 6f 69 6e 20 2d 66 00 44 6f 6d |s' unjoin -f.Dom|
000007a0 61 69 6e 3a 20 25 73 0a 00 55 73 65 72 3a 20 25 |ain: %s..用户: %|
000007b0 73 0a 00 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |s..-------------|
000007c0 2d 2d 2d 2d 0a 00 55 6e 6a 6f 69 6e 2e 2e 2e 2e |----..取消连接....|
000007d0 2e 2e 2e 2e 2e 2e 2e 2e 2e 0a 00 4a 6f 69 6e 2e |............加入。|
000007e0 2e 2e 2e 2e 2e 2e 2e 2e 2e 2e 2e 2e 2e 2e 2e 0a |......|
000007f0 00 2f 6f 70 74 2f 71 75 65 73 74 2f 62 69 6e 2f |./opt/quest/bin/|
00000800 76 61 73 74 6f 6f 6c 00 76 61 73 74 6f 6f 6c 00 |vastool.vastool.|
00000810 2d 75 00 2d 77 00 6a 6f 69 6e 00 2d 63 00 6f 75 |-u.-w.join.-c.ou|
00000820 00 2d 66 00 01 00 00 00 00 00 00 00 44 00 00 00 |.-f.........D...|
00000830 00 00 00 00 04 00 00 00 00 00 00 00 4c 82 04 08 |............L......|
...

vim 中查看的二进制文件

4

3 回答 3

22

在编译我的 C 代码时，我能做些什么来避免这种情况吗？

您唯一能做的就是不要将密码或任何敏感信息硬编码到您的 C 程序中：即使您以一种或另一种方式加密此敏感信息，解密密钥也需要在运行时由运行您的程序的用户，或者信息可能被有足够动力的人解密。您不妨提示用户输入密码。

请注意，任何其他形式的隐藏都只是一种混淆 - 对试图访问您的秘密信息的用户来说是一个小障碍。它可能会阻止一些“脚本小子”，但它会落到第一个知识渊博的用户身上。

于 2013-09-24T15:31:00.280 回答
6

正如 dasblinkenlight指出的那样，无论您做什么都不会阻止某人获取您的密码。例如，他可以在您的程序上运行strace以确定哪些参数正在传递给vasool，或者他可以使用调试器。如果您以安全为目的编写程序，请始终牢记Kerkhoff 原则：

一个（加密）系统应该是安全的，即使关于系统的一切 [...] 都是公共知识。

但是，如果你喜欢一些额外的烟幕安全混淆，你可能想看看memfrob(3)函数：

void *memfrob(void *s, size_t n);

memfrob () 函数通过将每个字符与数字 42 进行异或运算来加密内存区域 s 的前n个字节。在加密的内存区域上使用memfrob ()可以反转效果 。

请注意，此函数不是正确的加密例程，因为 XOR 常数是固定的，仅适用于隐藏字符串。

于 2013-09-24T16:14:29.263 回答
2

一种方法是使用函数（rot13()、reverse()、chartobinary() fe）并使用编码字符串调用您的函数。

于 2013-09-24T15:30:46.623 回答