c中隐藏char字符串

-3

我想在C中演示格式字符串漏洞。我想避免字符串命令泄露ASCII字符串sin我的二进制文件。c中隐藏char字符串

继承人我简单的代码：

#include <stdio.h>  
static char secret[] = "mysecretstring"; 
    int main(int argc, char *argv[]) { 
    char buf[64]; 
    strncpy(buf, argv[1], sizeof(buf)); 
    printf(buf); 
    }

来源

2017-08-27 pizzaiolo

究竟是什么问题？此外，这看起来不像C++代码，所以为什么C++标签？ – pmaxim98

如果我编译此代码并对编译后的二进制文件运行字符串，它将显示mysecretstring。我正在寻找隐藏变量的技巧。 – pizzaiolo

@ pmaxim98如果添加了包含，那么这是完全合法的C++代码。就像它是完全合法的C代码一样，如果你添加相同的包含。 – Deduplicator

你可以做一些数学与它例如：

static unsigned char secret[] = {'m' + 10, 'y' + 10, 's' + 10, 'e' + 10, 'c' + 10, 'r' + 10, 'e' + 10, 't' + 10, 's' + 10, 't' + 10, 'r' + 10, 'i' + 10, 'n' + 10, 'g' + 10};

为你的秘密字符串可能在RO段：

char *decode(const unsigned char *str, int c) 
{ 
    int len = 0; 
    char *ml, *cl; 
    while(*str != abs(c)) 
     len++; 
    ml = malloc(len + 1); 
    if(ml != NULL) 
    { 
     cl = ml; 
     while(*str != abs(c)) 
      *cl++ = *str++ + c; 
     *cl = 0; 
    } 
    return ml; 
}

当然编写脚本会更容易，它将为您编写字符串文字。编码机制可能更为复杂 - 在例子中，我只是为一些小事

用C

#define VNAMEMAX 20 
#define VVALUEMAX 200 

typedef struct 
{ 
    char vname[VNAMEMAX]; 
    char vvalue[VVALUEMAX]; 
}VDEF_T; 


VDEF_T varialbles[] = 
{ 
    {.vname = "mystring",.vvalue = "Something very secret"}, 
    {.vname = "secret_var",.vvalue = "Something even more secret" }, 
    {0,}, 
}; 

int code(VDEF_T *v, char *fname, int c) 
{ 
    FILE *fp = fopen(fname, "wt"); 
    int result = (fp == NULL) * -1; 

    if (!result) 
    { 
     fprintf(fp, "#ifndef _MYSECRET\n#define _MYSECRET\n\n\n"); 
     while (!result && v->vname[0]) 
     { 
      fprintf(fp, "static unsigned char %s[] = {\n\t\t", v->vname); 
      for (int i = 0; i <= strlen(v->vvalue); i++) 
      { 
       if (fprintf(fp, "0x%02x,", v->vvalue[i] + c) < 0) 
       { 
        result = -1; 
        break; 
       } 
      } 
      if (fprintf(fp, "};\n\n") < 0) result = -1; 
      v++; 
     } 
     if(fprintf(fp, "#endif") < 0) result = -1; 
     fclose(fp); 
    } 
    return result; 
}

而结果.h文件

例编码功能;

#ifndef _MYSECRET 
#define _MYSECRET 


static unsigned char mystring[] = { 
     0x5d,0x79,0x77,0x6f,0x7e,0x72,0x73,0x78,0x71,0x2a,0x80,0x6f,0x7c,0x83,0x2a,0x7d,0x6f,0x6d,0x7c,0x6f,0x7e,0x0a,}; 

static unsigned char secret_var[] = { 
     0x5d,0x79,0x77,0x6f,0x7e,0x72,0x73,0x78,0x71,0x2a,0x6f,0x80,0x6f,0x78,0x2a,0x77,0x79,0x7c,0x6f,0x2a,0x7d,0x6f,0x6d,0x7c,0x6f,0x7e,0x0a,}; 

#endif

来源

2017-08-27 08:47:55

我能隐藏文件中的字符串吗？例如： static const char * secret =“secret.txt”; – pizzaiolo

是的，你会的。当然，所有的字符串都必须如示例中所示进行编码 –

c中隐藏char字符串

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