Needs to decode other types inside grf

[carloshenrq]

Needs to add the decrypt and decode methods for files.

https://github.com/carloshenrq/grf/blob/master/includes/libgrf.h#L72-L77

/* do not ask questions about that */
#define GRF_FLAG_FILE 1
#define GRF_FLAG_MIXCRYPT 2
#define GRF_FLAG_DES 4
/* extra custom-flag to delete a file while updating */
#define GRF_FLAG_DELETE 8

https://github.com/carloshenrq/grf/blob/master/src/grf.c#L1104-L1121

GRFEXPORT uint32_t grf_file_get_contents(grf_node fhandler, void *target) {
	void *comp;
	struct grf_handler *handler;
	uint32_t count;
	handler = fhandler->parent;
	if ((fhandler->flags & GRF_FLAG_FILE) == 0) return 0; // not a file
	comp = calloc(1, fhandler->len_aligned + 1024); // seems that we need to allocate 1024 more bytes to decrypt file safely
	lseek(handler->fd, fhandler->pos + GRF_HEADER_SIZE, SEEK_SET);
	count = read(handler->fd, (char *)comp, fhandler->len_aligned);
	if (count != fhandler->len_aligned) { free(comp); return 0; }
	// decrypt (if required)
	//static void decode_des_etc(unsigned char *buf, int len, int type, int cycle) 
	if (fhandler->cycle >= 0) decode_des_etc((unsigned char *)comp, fhandler->len_aligned, (fhandler->cycle)==0, fhandler->cycle);
	// decompress to target...
	count = zlib_buffer_inflate(target, fhandler->size, comp, fhandler->len);
	free(comp);
	return count;
}

https://github.com/carloshenrq/grf/blob/master/src/grf.c#L892-L964

			if (fstat(handler->fd, (struct stat *)&grfstat) != 0) return false;
			if ((handler->table_offset + GRF_HEADER_SIZE) > grfstat.st_size) return false;

			lseek(handler->fd, handler->table_offset + GRF_HEADER_SIZE, SEEK_SET);
			if (read(handler->fd, (void *)&posinfo, sizeof(posinfo)) != sizeof(posinfo)) return false;
			// posinfo[0] = comp size
			// posinfo[1] = decomp size

			if ((handler->table_offset + GRF_HEADER_SIZE + 8 + posinfo[0]) > grfstat.st_size) return false;
			table_comp = malloc(posinfo[0]);
			table = malloc(posinfo[1]);
			if (read(handler->fd, table_comp, posinfo[0]) != posinfo[0]) { free(table); free(table_comp); return false; }
			if (zlib_buffer_inflate(table, posinfo[1], table_comp, posinfo[0]) != posinfo[1]) { free(table); free(table_comp); return false; }

			free(table_comp);

			pos = table;
			pos_max = table + posinfo[1];
			result = handler->filecount;
			wasted_space = grfstat.st_size - GRF_HEADER_SIZE - 8 - posinfo[0]; // in theory, all this space should be used for files
			while(pos < pos_max) {
				size_t av_len = pos_max - pos;
				int fn_len = prv_grf_strnlen((char *)pos, av_len);
				struct grf_table_entry_data tmpentry;
				result--;
				if (fn_len + sizeof(struct grf_table_entry_data) > av_len) { free(table); return false; }
				entry = calloc(1, sizeof(struct grf_node));
				entry->filename = calloc(1, fn_len + 1);
				memcpy(entry->filename, pos, fn_len); // fn_len + 1 is already 0x00
				pos += fn_len + 1;
				memcpy((void *)&tmpentry, pos, sizeof(struct grf_table_entry_data));
				pos += sizeof(struct grf_table_entry_data);
				if ( ((tmpentry.flags & GRF_FLAG_FILE) == 0) || (tmpentry.size == 0)) {
					// do not register "directory" entries and empty(bogus) files
					free(entry->filename);
					free(entry);
					continue;
				}
				entry->flags = tmpentry.flags;
				entry->size = tmpentry.size;
				entry->len = tmpentry.len;
				entry->len_aligned = tmpentry.len_aligned;
				entry->pos = tmpentry.pos;
				entry->parent = handler;
				entry->cycle = -1;
				if (entry->flags & GRF_FLAG_MIXCRYPT) {
					entry->cycle = 1;
					for(int i=10; entry->len>=i; i=i*10) entry->cycle++;
				}
				if (entry->flags & GRF_FLAG_DES) {
					entry->cycle = 0;
				}
				wasted_space -= tmpentry.len_aligned;

				if (last == NULL) {
					last = entry;
					handler->first_node = entry;
				} else {
					last->next = entry;
					entry->prev = last;
					last = entry;
				}
				hash_add_element(handler->fast_table, entry->filename, entry);
				if (--hcall<=0) {
					hcall = 100;
					if (handler->callback != NULL) {
						if (!handler->callback(handler->callback_etc, handler, handler->filecount - result, handler->filecount, entry->filename)) return false;
					}
				}
			}
			free(table);
			break;