encrypt text section

.gitignore

@@ -1,4 +1,7 @@
 *.o
 *.a
 woody_woodpacker
-woody
+woody
+asm
+payload
+print

.vscode/settings.json

@@ -1,8 +0,0 @@
-{
-	"files.associations": {
-		"stdio.h": "c",
-		"mman.h": "c",
-		"stdint.h": "c",
-		"compare": "c"
-	}
-}

includes/woody.h

@@ -15,6 +15,8 @@
 #include <stdint.h>
 
 #define JUMP "\xe9"
+// #define TEXT_OFFSET "\xba\xba\xba\xba\xba\xba\xba\xba"
+// #define SECTION_SIZE "\xca\xca\xca\xca\xca\xca\xca\xca"
 
 typedef struct payload
 {
@@ -30,12 +32,15 @@ typedef struct elf_content
 	Elf64_Ehdr *Ehdr;
 	Elf64_Phdr *Phdr;
 	Elf64_Shdr *Shdr;
+	Elf64_Shdr *text_section;
 	char *extra_data;
 } t_elf_content;
 
 // utils.c
 void *fetch(char *file, unsigned long file_size, unsigned long offset_to_data, unsigned long supposed_data_size);
 int ft_put_error(char *str);
+char *get_string(char *str, char *end_file);
+int	get_symbols_count(int sh_size, int sh_entsize);
 
 // woody.c
 int prepare_injection(t_elf_content *woody);

print.s

@@ -7,11 +7,6 @@ _start:
 		push rsi
 		push rdx
 
-		mov rdi, 1
-		mov rdi, 1
-		mov rdi, 1
-		mov rdi, 1
-		mov rdi, 1
 		mov rdi, 1
 		lea     rsi, [rel msg]
 		mov rdx, 10

srcs/encrypt.c

@@ -5,7 +5,7 @@ void	encrypt(char *file, unsigned long int offset, unsigned long int size)
 	size_t i = 0;
 	while (i < size)
 	{
-		file[offset + i] = 0;
+		file[offset + i] = file[offset + i] + 1;
 		++i;
 	}
 }

srcs/main.c

@@ -20,7 +20,7 @@ int get_elf_file(t_elf_content *woody)
     }
 	woody->file_size = off;
 	woody->file = mmap(NULL, woody->file_size, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
-    if (woody->file  == MAP_FAILED)
+    if (woody->file == MAP_FAILED)
 	{
 		close(fd);
 		ft_printf("Error: Failed to map file \'%s\'\n", woody->file_path);

srcs/utils.c

@@ -7,6 +7,26 @@ void	*fetch(char *file, unsigned long file_size, unsigned long offset_to_data, u
 	return NULL;
 }
 
+int	get_symbols_count(int sh_size, int sh_entsize)
+{
+	if (sh_size <= 0 || sh_entsize <= 0)
+		return 0;
+	return (sh_size / sh_entsize);
+}
+
+char *get_string(char *str, char *end_file)
+{
+	char *search_end = str;
+	while (search_end < end_file)
+	{
+		if (*search_end == 0)
+			return str;
+		++search_end;
+
+	}
+	return NULL;
+}
+
 int ft_put_error(char *str)
 {
 	ft_putstr_fd("Error: ", STDERR_FILENO);

srcs/woody.c

@@ -6,7 +6,7 @@ int elf_magic_numbers(char *str)
 	return (!ft_strncmp(str, ELFMAG, SELFMAG));
 }
 
-int		save_elf(char *path, char *file, unsigned long int size)
+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) {
@@ -113,7 +113,6 @@ int	insert_payload(t_elf_content *woody, t_payload *payload, size_t payload_posi
 		printf("Code cave start = %ld (%lx)\n", payload_position, payload_position);
 		printf("Payload size = %ld (%lx)\n", payload->len, payload->len);
 		printf("Backwar d offset = %d (%x)\n", jump_value, jump_value);
-		
 		return EXIT_SUCCESS;
 	}
 	return EXIT_FAILURE;
@@ -122,7 +121,6 @@ int	insert_payload(t_elf_content *woody, t_payload *payload, size_t payload_posi
 void	inject(t_elf_content *woody)
 {
 	t_payload *payload = get_payload();
-
 	int i = get_load_segment(woody, 0, true);	
 	int j = get_load_segment(woody, i + 1, false);
 	
@@ -149,6 +147,14 @@ void	inject(t_elf_content *woody)
 	printf("New entry = %ld (%lx)\n", woody->Ehdr->e_entry, woody->Ehdr->e_entry);
 }
 
+int is_special_section_indice(uint16_t section_index) {
+  return (section_index == SHN_LOPROC || section_index == SHN_BEFORE ||
+          section_index == SHN_AFTER || section_index == SHN_HIPROC ||
+          section_index == SHN_LOOS || section_index == SHN_HIOS ||
+          section_index == SHN_ABS || section_index == SHN_COMMON ||
+          section_index == SHN_XINDEX || section_index == SHN_HIRESERVE);
+}
+
 int get_elf_sections(t_elf_content *woody)
 {
 	woody->Ehdr = (Elf64_Ehdr *)fetch(woody->file, woody->file_size, 0, sizeof(Elf64_Ehdr));
@@ -160,40 +166,30 @@ int get_elf_sections(t_elf_content *woody)
 	woody->Phdr = (Elf64_Phdr *)fetch(woody->file, woody->file_size, woody->Ehdr->e_phoff, sizeof(Elf64_Phdr));
 
 	woody->Shdr = (Elf64_Shdr *)fetch(woody->file, woody->file_size, woody->Ehdr->e_shoff, sizeof(Elf64_Shdr));
-	if (woody->Shdr == NULL || !fetch(woody->file, woody->file_size, woody->Ehdr->e_shoff, woody->Ehdr->e_shnum * sizeof(Elf64_Shdr)))
+	if (!woody->Shdr|| !fetch(woody->file, woody->file_size, woody->Ehdr->e_shoff, woody->Ehdr->e_shnum * sizeof(Elf64_Shdr)))
+		return EXIT_FAILURE;
+
+	if (!fetch(woody->file, woody->file_size, woody->Ehdr->e_shoff + (woody->Ehdr->e_shstrndx * sizeof(Elf64_Shdr)), sizeof(Elf64_Shdr)))
 	{
-		return ft_put_error("Corrupted file");
+		return EXIT_FAILURE;
+	}
+	char *Sshstrtab = (char *)fetch(woody->file, woody->file_size, woody->Shdr[woody->Ehdr->e_shstrndx].sh_offset, 0);
+	if (Sshstrtab == NULL)
+	{
+		return EXIT_FAILURE;
+	}
+	for (int j = 0; j < woody->Ehdr->e_shnum;j++)
+	{
+		if (woody->Shdr[j].sh_name > woody->Shdr[woody->Ehdr->e_shstrndx].sh_size) return EXIT_FAILURE;
+    	if (woody->Shdr[j].sh_type == SHT_PROGBITS && woody->Shdr[j].sh_flags & SHF_EXECINSTR &&
+        woody->Shdr[j].sh_flags & SHF_ALLOC &&
+        Sshstrtab + woody->Shdr[j].sh_name < (char *)woody->file + woody->file_size &&
+        !ft_strncmp(".text\0", Sshstrtab + woody->Shdr[j].sh_name, 6))
+		{
+			woody->text_section = &woody->Shdr[j];
+ 		    break;
+		}
 	}
-
-
-
-	// Elf64_Shdr *symbols_table = NULL;
-    // for (int i = 0; i < woody->Ehdr->e_shnum; i++) {
-	// 	if (Shdr[i].sh_type == SHT_SYMTAB) {
-    //         symbols_table = fetch(woody->file, woody->file_size, woody->Ehdr->e_shoff + (i * sizeof(Elf64_Shdr)), sizeof(Elf64_Shdr));
-    //     }
-    // }
-	// if (symbols_table == NULL)
-	// 	return ft_put_error("No symbols");
-
-	// if (!fetch(woody->file, woody->file_size, woody->Ehdr->e_shoff + (woody->Ehdr->e_shstrndx * sizeof(Elf64_Shdr)), sizeof(Elf64_Shdr)))
-	// 	return ft_put_error("Corrupted file");
-
-	// char *Sshstrtab = (char *)fetch(woody->file, woody->file_size, Shdr[woody->Ehdr->e_shstrndx].sh_offset, 0);
-	// if (Sshstrtab == NULL)
-	// 	return ft_put_error("Corrupted file");
-
-    // Elf64_Shdr *strtab_header = (Elf64_Shdr *)fetch(woody->file, woody->file_size, woody->Ehdr->e_shoff + (symbols_table->sh_link * woody->Ehdr->e_shentsize), sizeof(Elf64_Shdr)); 
-	// if (!strtab_header)
-	// 	return ft_put_error("Corrupted file");
-
-    // char *strtab = fetch(woody->file, woody->file_size, strtab_header->sh_offset, 0);
-	// if (strtab == NULL)
-	// 	return ft_put_error("Corrupted file");
-    // Elf64_Sym *symbols = (Elf64_Sym *)fetch(woody->file, woody->file_size, symbols_table->sh_offset, sizeof(Elf64_Sym));
-	// if (symbols == NULL)
-	// 	return ft_put_error("Corrupted file");
-
 	return EXIT_SUCCESS;
 }
 
@@ -202,16 +198,12 @@ int prepare_injection(t_elf_content *woody)
 	int elf_statut = get_elf_sections(woody);
 	if (elf_statut)
 		return elf_statut;
-
 	inject(woody);
-
+	// encrypt(woody->file, woody->text_section->sh_offset, woody->text_section->sh_size);
 	char *woody_file;
 	if (!(woody_file = malloc(woody->file_size)))
 		return ft_put_error("Allocation error");
-
 	ft_memcpy(woody_file, woody->file, woody->file_size);
-
-	// encrypt(woody_file, strtab_header->sh_offset , strtab_header->sh_size);
 	munmap(woody_file, woody->file_size);
 	save_elf("woody", woody_file, woody->file_size);
 	free(woody_file);