diff --git a/inc/woody.h b/inc/woody.h
index 1be701a..2ab6267 100644
--- a/inc/woody.h
+++ b/inc/woody.h
@@ -22,6 +22,7 @@ typedef struct s_map {
 typedef struct s_payload64 {
 	int		(*encrypt)(t_map, void *, Elf64_Phdr);
 	int		(*gen_key)(void **);
+	char	*algo_name;
 	size_t	jump_offset;
 	size_t	woody_offset;
 	size_t	load_ptr_offset;
diff --git a/src/debug_mode.c b/src/debug_mode.c
index 17360db..578ec39 100644
--- a/src/debug_mode.c
+++ b/src/debug_mode.c
@@ -3,6 +3,7 @@
 t_payload64 get_debug_payload64(void) {
 	t_payload64 payload;
 
+	payload.algo_name = ft_strdup("debug");
 	payload.len = 55;
 	payload.jump_offset = 37;
 	payload.encrypt = NULL;
diff --git a/src/woody_woodpacker.c b/src/woody_woodpacker.c
index 2ec830a..fea9f8e 100644
--- a/src/woody_woodpacker.c
+++ b/src/woody_woodpacker.c
@@ -49,19 +49,13 @@ int get_load_segment64(
 	return RET_ERR;
 }
 
-// TODO refacto
-t_map get_code_cave(t_map file, Elf64_Phdr load_segment) {
+int get_code_cave64(t_map file, Elf64_Phdr load_segment, t_map *code_cave) {
 	size_t page_size = load_segment.p_align;
 	size_t len = page_size - load_segment.p_filesz % page_size; 
 	size_t offset = load_segment.p_offset + load_segment.p_filesz;
 	unsigned char *seg = fetch(file, offset, len);
 	if (!seg) {
-		printf("fallback to weird code cave finder\n");
-		seg = fetch(file, offset, file.size - offset);
-		len = file.size - offset;
-		if (!seg) {
-			ft_printf("unreachable !!!\n");
-		}
+		return RET_ERR;
 	}
 
 	size_t longest = 0;
@@ -72,23 +66,17 @@ t_map get_code_cave(t_map file, Elf64_Phdr load_segment) {
 			while (i + j < len && seg[i + j] == 0) {
 				j++;
 			}
-
 			if (j > longest) {
 				longest_i = i;
 				longest = j;
 			}
 			i += j;
-
 		}
 	}
 
-	t_map code_cave;
-	code_cave.data = fetch(file, longest_i + offset, longest);
-	code_cave.size = longest;
-	if (!code_cave.data) {
-		ft_printf("unreachable !!!\n");
-	}
-	return code_cave;
+	code_cave->data = fetch(file, longest_i + offset, longest);
+	code_cave->size = longest;
+	return RET_OK;
 }
 
 int pack_elf64(t_map file) {
@@ -121,9 +109,13 @@ int pack_elf64(t_map file) {
 	to_encrypt.size = load_segment.p_filesz + encryption_block_size - load_segment.p_filesz % encryption_block_size;
 	 */
 
-	t_map code_cave = get_code_cave(file, *load_segment);
+	t_map code_cave;
+	if (get_code_cave64(file, *load_segment, &code_cave) == RET_ERR) {
+		return wdy_error("can't get code cave");
+	}
 
 	t_payload64 payload = get_xor_payload64();
+	ft_printf("info: using %s algorithm\n", payload.algo_name);
 	// This should fallback to compression algorithm, or smaller payload (eg rsa->xor)
 	if (payload.len > (size_t)code_cave.size) {
 		printf("code cave size: %ld (0x%lx) bytes\n", code_cave.size, code_cave.size);
diff --git a/src/xor_mode.c b/src/xor_mode.c
index 1c00407..50179da 100644
--- a/src/xor_mode.c
+++ b/src/xor_mode.c
@@ -54,6 +54,7 @@ int encrypt_xor(t_map file, void *key_ptr, Elf64_Phdr load_segment) {
 t_payload64 get_xor_payload64(void) {
 	t_payload64 payload;
 
+	payload.algo_name = ft_strdup("xor");
 	payload.len = 155;
 	payload.jump_offset = 113;
 	payload.load_ptr_offset = 131;