/*
** Copyright (C) 2013 - Jonathan Salwan - http://twitter.com/JonathanSalwan
**
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation, either version 3 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program. If not, see .
*/
#include
#include
#include
#include
#include
#include
#include
#include
Elf32_Ehdr *pElf_Header;
Elf32_Phdr *pElf32_Phdr;
Elf32_Shdr *pElf32_Shdr;
char *pMapElf;
struct stat filestat;
static unsigned char *set_header(char *file)
{
int fd;
unsigned char *data;
fd = open(file, O_RDONLY, 0644);
stat(file, &filestat);
printf("[+] Binary size : %d octets\n", (int)filestat.st_size);
data = malloc(filestat.st_size * sizeof(char));
read(fd, data, filestat.st_size);
pMapElf = mmap(0, filestat.st_size, PROT_READ, MAP_SHARED, fd, 0);
pElf_Header = (Elf32_Ehdr *)data;
pElf32_Shdr = (Elf32_Shdr *)((char *)data + pElf_Header->e_shoff);
pElf32_Phdr = (Elf32_Phdr *)((char *)data + pElf_Header->e_phoff);
close(fd);
return (data);
}
int main(int argc, char **argv)
{
unsigned char *data;
unsigned nb_section;
Elf32_Shdr *current;
int i, fd;
if (argc < 2){
printf("Syntax: ./%s \n", argv[0]);
return -1;
}
data = set_header(argv[1]);
printf("--- Step 1 ---\n");
printf("[+] Clean sections...\n");
nb_section = pElf_Header->e_shnum;
for (i = 0 ; i < nb_section ; i++){
pElf32_Shdr->sh_name = 0;
pElf32_Shdr->sh_type = 0;
pElf32_Shdr->sh_flags = 0;
pElf32_Shdr->sh_addr = 0;
pElf32_Shdr->sh_offset = 0;
pElf32_Shdr->sh_size = 0;
pElf32_Shdr->sh_link = 0;
pElf32_Shdr->sh_info = 0;
pElf32_Shdr->sh_addralign = 0;
pElf32_Shdr->sh_entsize = 0;
pElf32_Shdr++;
}
printf("[+] Clean section [DONE]\n");
printf("--- Step 2 ---\n");
printf("[+] Clean elf header...\n");
pElf_Header->e_shnum = 0;
pElf_Header->e_shstrndx = 0;
pElf_Header->e_shentsize = 0;
pElf_Header->e_version = 0;
pElf_Header->e_ehsize = 0;
pElf_Header->e_shoff = 123;
printf("[+] Clean elf header [DONE]\n");
printf("--- Step 3 ---\n");
printf("[+] Writting binary...\n");
fd = open(argv[1], O_WRONLY, 0644);
write(fd, data, filestat.st_size);
close(fd);
printf("[+] Writting binary [DONE]\n");
free(data);
return 0;
}