woody-woodpacker/srcs/woody.c

84 lines
2.7 KiB
C

#include "../includes/woody.h"
int elf_magic_numbers(char *str)
{
return (!ft_strncmp(str, ELFMAG, SELFMAG));
}
void encrypt_zone(char *file, unsigned long int offset, unsigned long int size)
{
size_t i = 0;
while (i < size)
{
file[offset + i] = 0;
++i;
}
}
int save_elf(char *path, char *file, unsigned long int size)
{
int fd = open(path, O_CREAT | O_WRONLY | O_TRUNC, 0755);
if (fd == -1) {
ft_printf("Error: Failed to create new file \'%s\'\n", path);
return EXIT_FAILURE;
}
if (write(fd, file, size) == -1) {
close(fd);
ft_printf("Error: Failed to write new file \'%s\'\n", path);
return EXIT_FAILURE;
}
if (close(fd) == -1) {
ft_printf("Error: Failed to close new file \'%s\'\n", path);
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
int woody(t_efl_content *file_content)
{
Elf64_Ehdr *Ehdr = (Elf64_Ehdr *)secure_access(file_content->file, file_content->file_size, 0, sizeof(Elf64_Ehdr));
if (!Ehdr || !elf_magic_numbers(file_content->file) || Ehdr->e_ident[EI_CLASS] != 2)
{
ft_printf("Error: \'%s\' is not a valid 64-bit ELF file\n", file_content->file_path);
return EXIT_FAILURE;
}
Elf64_Shdr *Shdr = (Elf64_Shdr *)secure_access(file_content->file, file_content->file_size, Ehdr->e_shoff, sizeof(Elf64_Shdr));
if (Shdr == NULL || !secure_access(file_content->file, file_content->file_size, Ehdr->e_shoff, Ehdr->e_shnum * sizeof(Elf64_Shdr)))
{
return ft_put_error("Corrupted file");
}
if (file_content->file_size > Ehdr->e_shoff + Ehdr->e_shnum * sizeof(Elf64_Shdr))
{
printf("extra_data !\n"); // save it in file_content->extra_data and append it to the end of the woody file ? Could be dangerous
}
Elf64_Shdr *symbols_table = NULL;
for (int i = 0; i < Ehdr->e_shnum; i++) {
if (Shdr[i].sh_type == SHT_SYMTAB) {
symbols_table = secure_access(file_content->file, file_content->file_size, Ehdr->e_shoff + (i * sizeof(Elf64_Shdr)), sizeof(Elf64_Shdr));
}
}
if (symbols_table == NULL)
return ft_put_error("Corrupted file");
Elf64_Shdr *strtab_header = (Elf64_Shdr *)secure_access(file_content->file, file_content->file_size, Ehdr->e_shoff + (symbols_table->sh_link * Ehdr->e_shentsize), sizeof(Elf64_Shdr));
if (!strtab_header)
return ft_put_error("Corrupted file");
if (strtab_header->sh_offset + strtab_header->sh_size > file_content->file_size)
{
return ft_put_error("Encrypt after the end of the file");
}
char *woody = malloc(file_content->file_size);
ft_memcpy(woody, file_content->file, file_content->file_size);
encrypt_zone(woody, strtab_header->sh_offset , strtab_header->sh_size);
return save_elf("woody", woody, file_content->file_size);
}