From cef20e24a7d37383057e2ea5f0a2632e787cb9e2 Mon Sep 17 00:00:00 2001
From: Caleb <23644849+ctrlaltf2@users.noreply.github.com>
Date: Sat, 22 Mar 2025 12:57:42 +0000
Subject: [PATCH] patterns/zip: Fix 0x5455 extended timestamp fields crash,
 improve date/time presentation (#363)

Co-authored-by: Nik <werwolv98@gmail.com>
---
 patterns/zip.hexpat | 42 +++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/patterns/zip.hexpat b/patterns/zip.hexpat
index 1d69a7b..50d0ea2 100644
--- a/patterns/zip.hexpat
+++ b/patterns/zip.hexpat
@@ -21,26 +21,13 @@ struct EndOfCentralDirectory {
 
 namespace extra {
 
-    bitfield Flags {
+    bitfield UTFlags {
           bool modification_time_set : 1;
           bool access_time_set : 1;
           bool creation_time_set : 1;
           reserved: 5;  //reserved for additional timestamps; not set
     };
 
-    struct X5455_ExtendedTimestamp {
-        Flags Flags;
-        if (Flags.modification_time_set){
-            u32 ModTime;
-        }
-        if (Flags.access_time_set){
-            u32 AcTime;
-        }
-        if (Flags.creation_time_set){
-            u32 CrTime;
-        }
-    };
-
     struct X000A_NTFS {
         u32 reserved;
         u16 tag;
@@ -75,8 +62,25 @@ namespace extra {
     struct ExtraField {
         u16 tag;
         u16 TSize;
+
         if (tag == 0x5455) {
-            extra::X5455_ExtendedTimestamp x5455_ExtendedTimestamp;
+            // 0x5455 needs parsed with TSize in context to prevent overshoot from mismatched TSize/flags set
+            UTFlags Flags;
+            u64 extraEndFromFlags = $ + 4*(Flags.modification_time_set + Flags.access_time_set + Flags.creation_time_set);
+            u64 extraEndFromTSize = $ + TSize - 1;
+            u64 extraEnd = std::math::min(extraEndFromFlags, extraEndFromTSize);
+
+            if ( ($ < extraEnd) && Flags.modification_time_set) {
+                type::time32_t ModTime;
+            }
+
+            if ( ($ < extraEnd) && Flags.access_time_set) {
+                type::time32_t AcTime;
+            }
+
+            if ( ($ < extraEnd) && Flags.creation_time_set) {
+                type::time32_t CrTime;
+            }
         } else if (tag == 0x000a) {
             extra::X000A_NTFS x000A_NTFS;
         } else if (tag == 0x7875) {
@@ -182,8 +186,8 @@ struct LocalFileHeader {
     u16 version [[ comment("The minimum supported ZIP specification version needed to extract the file") ]];
     GeneralPurposeBitFlags generalPurposeBitFlags  [[ comment("General purpose bit flag") ]];
     CompressionMethod compressionMethod [[ comment("Compression method") ]];
-    u16 lastModifyTime [[ comment("File last modification time") ]];
-    u16 lastModifyDate [[ comment("File last modification date") ]];
+    type::DOSTime lastModifyTime [[ comment("File last modification time") ]];
+    type::DOSDate lastModifyDate [[ comment("File last modification date") ]];
     u32 crc32 [[ comment("CRC-32") ]];
     u32 compressedSize [[ comment("Compressed size") ]];
     u32 uncompressedSize [[ comment("Uncompressed size") ]];
@@ -207,8 +211,8 @@ struct CentralDirectoryFileHeader {
     u16 versionExtract [[comment("Minimum version needed to extract")]];
     GeneralPurposeBitFlags generalPurposeBitFlags [[comment("General purpose bit flag")]];
     CompressionMethod compressionMethod;
-    u16 fileLastModifyTime [[comment("File last modification time")]];
-    u16 fileLastModifyDate [[comment("File last modification date")]];
+    type::DOSTime fileLastModifyTime [[comment("File last modification time")]];
+    type::DOSDate fileLastModifyDate [[comment("File last modification date")]];
     u32 crc32 [[comment("CRC-32 of uncompressed data")]];
     u32 compressedSize;
     u32 uncompressedSize;