ZipWriter: Keep LFH and CFH in sync
We change the GPB in the LocalFileHeader if the entry can not
have a trailing DataDescriptor. Make sure to patch the
CentralFileHeader to have the same bits set.
Modify ZipArchive to check that the data descriptor bit is consistent
between Central and Local file headers.
Test: make ziparchive-tests
Bug: 36686974
Change-Id: Ied167570abcf6426b1c678cd40123e5ad65909db
diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc
index c2055b7..779ef2f 100644
--- a/libziparchive/zip_archive.cc
+++ b/libziparchive/zip_archive.cc
@@ -573,6 +573,17 @@
// Paranoia: Match the values specified in the local file header
// to those specified in the central directory.
+
+ // Verify that the central directory and local file header agree on the use of a trailing
+ // Data Descriptor.
+ if ((lfh->gpb_flags & kGPBDDFlagMask) != (cdr->gpb_flags & kGPBDDFlagMask)) {
+ ALOGW("Zip: gpb flag mismatch. expected {%04" PRIx16 "}, was {%04" PRIx16 "}",
+ cdr->gpb_flags, lfh->gpb_flags);
+ return kInconsistentInformation;
+ }
+
+ // If there is no trailing data descriptor, verify that the central directory and local file
+ // header agree on the crc, compressed, and uncompressed sizes of the entry.
if ((lfh->gpb_flags & kGPBDDFlagMask) == 0) {
data->has_data_descriptor = 0;
if (data->compressed_length != lfh->compressed_size
diff --git a/libziparchive/zip_writer.cc b/libziparchive/zip_writer.cc
index 2edf224..6d28bdb 100644
--- a/libziparchive/zip_writer.cc
+++ b/libziparchive/zip_writer.cc
@@ -479,7 +479,9 @@
for (FileEntry& file : files_) {
CentralDirectoryRecord cdr = {};
cdr.record_signature = CentralDirectoryRecord::kSignature;
- cdr.gpb_flags |= kGPBDDFlagMask;
+ if ((file.compression_method & kCompressDeflated) || !seekable_) {
+ cdr.gpb_flags |= kGPBDDFlagMask;
+ }
cdr.compression_method = file.compression_method;
cdr.last_mod_time = file.last_mod_time;
cdr.last_mod_date = file.last_mod_date;