forked from smallsun107/AndroidShell
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathmain.cpp
More file actions
108 lines (89 loc) · 2.8 KB
/
Copy pathmain.cpp
File metadata and controls
108 lines (89 loc) · 2.8 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
#include <iostream>
#include "elf.h"
#define MAX_PATH 256
int GetFileSize(FILE *fp)
{
fseek(fp,0,SEEK_END);
int nSize = ftell(fp);
rewind(fp);
return nSize;
}
int FormatElf(unsigned char *buffer)
{
//自定义节名
char *szSection = ".mytext";
//ELF头地址
Elf32_Ehdr *pEhdr = (Elf32_Ehdr*)buffer;
if (!((pEhdr->e_ident[0] == 0x7F) &&
(pEhdr->e_ident[1] == 'E') &&
(pEhdr->e_ident[2] == 'L') &&
(pEhdr->e_ident[3] == 'F')))
{
printf("无效的文件\r\n");
return 0;
}
//定位到节表
Elf32_Shdr *pShdr = (Elf32_Shdr*)(buffer + pEhdr->e_shoff);
//定位字符串表
char *str = nullptr;
Elf32_Shdr *pShdrstr = (Elf32_Shdr *)(buffer + pEhdr->e_shoff + sizeof(Elf32_Shdr) * pEhdr->e_shstrndx);
str = (char*)(pShdrstr->sh_offset + buffer);
int nOffset = 0;
int nSize = 0;
for (int i = 0; i < pEhdr->e_shnum; i++)
{
if (strcmp(str + pShdr->sh_name,szSection) == 0)
{
//获取偏移和大小
nOffset = pShdr->sh_offset;
nSize = pShdr->sh_size;
printf("find section %s offset is 0x%x size is 0x%x\n",szSection,nOffset,nSize);
break;
}
pShdr++;
}
unsigned char *sectionBuf = (unsigned char *)(buffer + nOffset);
//计算section占用内存几页，一个页大小4096
int nPage = nSize / 4096 + (nSize % 4096 == 0 ? 0 :1);
printf("nOffset = 0x%x, nSize = 0x%x\n", nOffset, nSize);
printf("nPage = %d\n",nPage);
pEhdr->e_entry = (nSize << 16) + nPage;
pEhdr->e_shoff = nOffset;
//加密
printf("sectionBuf is %x",sectionBuf);
for (int j = 0; j < nSize; j++)
{
sectionBuf[j] = ~sectionBuf[j];
}
return 1;
}
int main()
{
/*流程
*从文件头读取section偏移shoff，shnum和shstrtab
*读取shstrtab中的字符串
*从shoff读取section header
*通过pShdr->sh_name读取节表名比较是否自定义节表名
*通过pShdr->sh_offset pShdr->sh_size读取节表大小以及内容进行加密
*修改section字段中的e_shoff为pShdr->sh_addr，修改e_entry为pShdr->sh_size
* */
printf("输入SO文件路径:\r\n");
char filePath[MAX_PATH] = {0};
// char *test = "/Users/smallsun/Desktop/SoTest/app/build/outputs/apk/debug/app-debug/lib/armeabi-v7a/libnative-lib.so";
scanf("%s", filePath);
FILE *fp = fopen(filePath,"rb");
if (fp != nullptr)
{
int nSize = GetFileSize(fp);
unsigned char *pBuffer = (unsigned char *)malloc(nSize);
fread(pBuffer,1,nSize,fp);
FormatElf(pBuffer);
FILE *fp = fopen("libnative-lib_new.so","wb");
fwrite(pBuffer,nSize,1,fp);
}
else
{
printf("文件打开失败！\r\n");
}
return 0;
}