From 4d498e18ec4906b59d86f3ae6be38ab2776cb4a6 Mon Sep 17 00:00:00 2001 From: David Nikdel Date: Sun, 3 Sep 2023 18:14:30 -0400 Subject: [PATCH] Remove nondeterminism in pck_packer PCK files (like other build products) should be deterministic based on their inputs. Removed calls to Math::rand() that are being used to generate padding. Looks like these were introduced as part of adding encryption support, but the padding being random does not have any cryptographic significance. This can be trivially inferred since file blocks that happen to be aligned don't get padding anyway. If there's a desire to indroduce something that functions as a nonce it should probably be added explicitly and only if encryption is enabled. remove Math::rand() calls in editor_export_platform.cpp follow up to make consistent with pck_packer (cherry picked from commit 067807c1cb7a13624c1d226f301b0431c6edec87) --- core/io/pck_packer.cpp | 4 ++-- editor/export/editor_export_platform.cpp | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/core/io/pck_packer.cpp b/core/io/pck_packer.cpp index 9b49cc3d8c7..a7c715c3189 100644 --- a/core/io/pck_packer.cpp +++ b/core/io/pck_packer.cpp @@ -205,7 +205,7 @@ Error PCKPacker::flush(bool p_verbose) { int header_padding = _get_pad(alignment, file->get_position()); for (int i = 0; i < header_padding; i++) { - file->store_8(Math::rand() % 256); + file->store_8(0); } int64_t file_base = file->get_position(); @@ -244,7 +244,7 @@ Error PCKPacker::flush(bool p_verbose) { int pad = _get_pad(alignment, file->get_position()); for (int j = 0; j < pad; j++) { - file->store_8(Math::rand() % 256); + file->store_8(0); } count += 1; diff --git a/editor/export/editor_export_platform.cpp b/editor/export/editor_export_platform.cpp index ddc5548594e..8ea30ab53fb 100644 --- a/editor/export/editor_export_platform.cpp +++ b/editor/export/editor_export_platform.cpp @@ -233,7 +233,7 @@ Error EditorExportPlatform::_save_pack_file(void *p_userdata, const String &p_pa int pad = _get_pad(PCK_PADDING, pd->f->get_position()); for (int i = 0; i < pad; i++) { - pd->f->store_8(Math::rand() % 256); + pd->f->store_8(0); } // Store MD5 of original file. @@ -1656,7 +1656,7 @@ Error EditorExportPlatform::save_pack(const Ref &p_preset, b int header_padding = _get_pad(PCK_PADDING, f->get_position()); for (int i = 0; i < header_padding; i++) { - f->store_8(Math::rand() % 256); + f->store_8(0); } uint64_t file_base = f->get_position();