woody-woodpacker/srcs/woody32.c

109 lines
3.5 KiB
C

#include "../includes/woody.h"
int get_load_segment32(t_elf_content *woody, int start, bool executable)
{
t_elf32 *elf = woody->elf32;
for (int i = start; i < elf->Ehdr->e_phnum; i++)
{
if (elf->Phdr[i].p_type == PT_LOAD)
{
if (executable)
{
if (elf->Phdr[i].p_flags & PF_X)
return i;
}
else
return i;
}
}
return -1;
}
int inject32(t_elf_content *woody)
{
t_elf32 *elf = woody->elf32;
t_payload *payload = get_payload();
if (!payload)
return EXIT_FAILURE;
int i = get_load_segment32(woody, 0, true);
int j = get_load_segment32(woody, i + 1, false);
if (i == -1 || j != i + 1)
{
free(payload->payload);
free(payload);
return ft_put_error("PT_LOAD segment missing");
}
size_t code_cave_size = elf->Phdr[j].p_offset - (elf->Phdr[i].p_offset + elf->Phdr[i].p_filesz);
size_t payload_position = elf->Phdr[i].p_offset + elf->Phdr[i].p_filesz;
rsa_t rsa = rsa_generate_keys();
printf("key n : %ld (%lx) key d %ld (%lx), key total : %ld (%lx)\n", rsa.n, rsa.n, rsa.d, rsa.d, (rsa.n << 32) + rsa.d, (rsa.n << 32) + rsa.d);
if (code_cave_size < (size_t)payload->len)
{
free(payload->payload);
free(payload);
return ft_put_error("Unable to insert payload, not enough space for code cave");
}
payload_position = encrypt(woody->file, elf->Phdr[i].p_offset, elf->Phdr[i].p_memsz, rsa);
if (insert_payload(woody, payload, payload_position, elf->text_section->sh_offset, elf->Phdr[i].p_offset, elf->Phdr[i].p_memsz, rsa))
{
free(payload->payload);
free(payload);
return ft_put_error("Unable to insert payload, please regenerate it");
}
printf("code_cave_size = %ld (%lx)\n", code_cave_size, code_cave_size);
printf("payload_position = %ld (%lx)\n", payload_position, payload_position);
printf("elf->Phdr[i].p_offset = %d (%x)\n", elf->Phdr[i].p_offset, elf->Phdr[i].p_offset);
printf("elf->Phdr[i].p_filesz = %d (%x)\n", elf->Phdr[i].p_filesz, elf->Phdr[i].p_filesz);
printf("elf->Phdr[j].p_offset = %d (%x)\n", elf->Phdr[j].p_offset, elf->Phdr[j].p_offset);
elf->Phdr[i].p_filesz += payload->len;
elf->Phdr[i].p_memsz += payload->len;
elf->Phdr[i].p_flags = PF_X | PF_W | PF_R;
free(payload->payload);
free(payload);
return EXIT_SUCCESS;
}
int get_elf_sections32(t_elf_content *woody)
{
t_elf32 *elf = woody->elf32;
elf->Ehdr = (Elf32_Ehdr *)fetch(woody->file, woody->file_size, 0, sizeof(Elf32_Ehdr));
if (!elf->Ehdr)
return EXIT_FAILURE;
elf->Phdr = (Elf32_Phdr *)fetch(woody->file, woody->file_size, elf->Ehdr->e_phoff, sizeof(Elf32_Phdr));
if (!elf->Phdr)
return EXIT_FAILURE;
elf->Shdr = (Elf32_Shdr *)fetch(woody->file, woody->file_size, elf->Ehdr->e_shoff, sizeof(Elf32_Shdr));
if (!elf->Shdr || !fetch(woody->file, woody->file_size, elf->Ehdr->e_shoff, elf->Ehdr->e_shnum * sizeof(Elf32_Shdr)))
return EXIT_FAILURE;
if (!fetch(woody->file, woody->file_size, elf->Ehdr->e_shoff + (elf->Ehdr->e_shstrndx * sizeof(Elf32_Shdr)), sizeof(Elf32_Shdr)))
return EXIT_FAILURE;
char *Sshstrtab = (char *)fetch(woody->file, woody->file_size, elf->Shdr[elf->Ehdr->e_shstrndx].sh_offset, 0);
if (Sshstrtab == NULL)
return EXIT_FAILURE;
for (int i = 0; i < elf->Ehdr->e_shnum;i++)
{
if (elf->Shdr[i].sh_type == SHT_PROGBITS && elf->Shdr[i].sh_flags & SHF_EXECINSTR && elf->Shdr[i].sh_flags & SHF_ALLOC && elf->Shdr[i].sh_flags & SHF_EXECINSTR)
{
if (Sshstrtab + elf->Shdr[i].sh_name < (char *)woody->file + woody->file_size && !ft_strncmp(".text\0", Sshstrtab + elf->Shdr[i].sh_name, 6))
{
elf->text_section = &elf->Shdr[i];
return EXIT_SUCCESS;
}
}
}
return EXIT_FAILURE;
}