[zip] Set all entry times before 1980 to 1980-01-01
Before this change, entry times before 1980 had the year changed to 1980
but the month/day/hour/minutes/seconds were all kept as-is.
Bug: 277978832
Test: atest zipalign_tests
Change-Id: I9f87e98a6b985002578490b87c654fee86c65d62
diff --git a/tools/zipalign/ZipEntry.cpp b/tools/zipalign/ZipEntry.cpp
index dd2eac6..0355e56 100644
--- a/tools/zipalign/ZipEntry.cpp
+++ b/tools/zipalign/ZipEntry.cpp
@@ -363,13 +363,22 @@
struct tm tmResult;
struct tm* ptm = localtime_r(&even, &tmResult);
- int year;
- year = ptm->tm_year;
- if (year < 80)
- year = 80;
+ // The earliest valid time for ZIP file entries is 1980-01-01. See:
+ // https://users.cs.jmu.edu/buchhofp/forensics/formats/pkzip.html.
+ // Set any time before 1980 to 1980-01-01.
+ if (ptm->tm_year < 80) {
+ ptm->tm_year = 80;
+ ptm->tm_mon = 0;
+ ptm->tm_mday = 1;
+ ptm->tm_hour = 0;
+ ptm->tm_min = 0;
+ ptm->tm_sec = 0;
+ }
- uint16_t zdate = (year - 80) << 9 | (ptm->tm_mon+1) << 5 | ptm->tm_mday;
- uint16_t ztime = ptm->tm_hour << 11 | ptm->tm_min << 5 | ptm->tm_sec >> 1;
+ uint16_t zdate = static_cast<uint16_t>(
+ (ptm->tm_year - 80) << 9 | (ptm->tm_mon + 1) << 5 | ptm->tm_mday);
+ uint16_t ztime = static_cast<uint16_t>(
+ ptm->tm_hour << 11 | ptm->tm_min << 5 | ptm->tm_sec >> 1);
mCDE.mLastModFileTime = mLFH.mLastModFileTime = ztime;
mCDE.mLastModFileDate = mLFH.mLastModFileDate = zdate;