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Check for presence of unexpected entries in the ZIP64 extra field #28

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Merged
pmqs merged 6 commits into from
Feb 9, 2026
Merged

Check for presence of unexpected entries in the ZIP64 extra field #28

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5e74d3d
fix: update
Its-Just-Nans Feb 6, 2026
ea2b56f
fix: add info if not used
Its-Just-Nans Feb 7, 2026
54f36f3
always assign and print value
Its-Just-Nans Feb 7, 2026
34084e7
fix texts
Its-Just-Nans Feb 7, 2026
dad4998
add warning
Its-Just-Nans Feb 7, 2026
de4b391
fmt
Its-Just-Nans Feb 7, 2026
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52 changes: 47 additions & 5 deletions bin/zipdetails
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Original file line number Diff line number Diff line change
Expand Up @@ -4157,6 +4157,11 @@ sub walk_Zip64_in_LD
$entry->uncompressedSize(unpack "Q<", $data);
out2 $data, "Uncompressed Size", Value_Q($entry->uncompressedSize)
if $display;
if (! full32 $entry->std_uncompressedSize)
{
info $data, "Uncompressed Size should not be present in the ZIP64 extra field. Corresponding uncompressedSize from local header is not set to 0xFFFFFFFF, value is " . Value_V($entry->uncompressedSize)
if $display;
}
}

if ($assumeLengthsPresent || $assumeAllFieldsPresent || full32 $entry->std_compressedSize)
Expand All @@ -4175,6 +4180,11 @@ sub walk_Zip64_in_LD
$entry->compressedSize( unpack "Q<", $data);
out2 $data, "Compressed Size", Value_Q($entry->compressedSize)
if $display;
if (! full32 $entry->std_compressedSize)
{
info $data, "Compressed Size should not be present in the ZIP64 extra field. Corresponding compressedSize from local header is not set to 0xFFFFFFFF, value is " . Value_V($entry->compressedSize)
if $display;
}
}

# Zip64 in local header should not have localHeaderOffset or disk number
Expand All @@ -4188,6 +4198,11 @@ sub walk_Zip64_in_LD
my $localHeaderOffset = unpack "Q<", $data;
out2 $data, "Offset to Local Dir", Value_Q($localHeaderOffset)
if $display;
if (! full32 $entry->std_localHeaderOffset)
{
info $data, "Offset to Local Dir should not be present in the ZIP64 extra field. Value is " . Value_V($entry->localHeaderOffset)
if $display;
}
}

if ($assumeAllFieldsPresent)
Expand All @@ -4198,6 +4213,11 @@ sub walk_Zip64_in_LD
my $diskNumber = unpack "v", $data;
out2 $data, "Disk Number", Value_V($diskNumber)
if $display;
if (! full16 $entry->std_diskNumber)
{
info $data, "Disk Number should not be present in the ZIP64 extra field. Value is " . Value_V($entry->diskNumber)
if $display;
}
}

if (length $zip64Extended)
Expand Down Expand Up @@ -4230,9 +4250,13 @@ sub walk_Zip64_in_CD
return;
}

my $assumeAllFieldsPresent = (length($zip64Extended) == 28) ;
# The order of the fields in the zip64 extended
# information record is fixed, but the fields MUST
# only appear if the corresponding Local or Central
# directory record field is set to 0xFFFF or 0xFFFFFFFF.
my $assumeAllFieldsPresent = (length($zip64Extended) == 28);

if ($assumeAllFieldsPresent || full32 $entry->std_uncompressedSize )
if ($assumeAllFieldsPresent || full32 $entry->std_uncompressedSize)
{
if (length $zip64Extended < 8)
{
Expand All @@ -4247,6 +4271,11 @@ sub walk_Zip64_in_CD
$entry->uncompressedSize(unpack "Q<", $data);
out2 $data, "Uncompressed Size", Value_Q($entry->uncompressedSize)
if $display;
if (! full32 $entry->std_uncompressedSize)
{
info $data, "Uncompressed Size should not be present in the ZIP64 extra field. Corresponding uncompressedSize from central header is not set to 0xFFFFFFFF, value is " . Value_V($entry->uncompressedSize)
if $display;
}
}

if ($assumeAllFieldsPresent || full32 $entry->std_compressedSize)
Expand All @@ -4265,6 +4294,11 @@ sub walk_Zip64_in_CD
$entry->compressedSize(unpack "Q<", $data);
out2 $data, "Compressed Size", Value_Q($entry->compressedSize)
if $display;
if (! full32 $entry->std_compressedSize)
{
info $data, "Compressed Size should not be present in the ZIP64 extra field. Corresponding compressedSize from central header is not set to 0xFFFFFFFF, value is " . Value_V($entry->compressedSize)
if $display;
}
}

if ($assumeAllFieldsPresent || full32 $entry->std_localHeaderOffset)
Expand All @@ -4279,34 +4313,42 @@ sub walk_Zip64_in_CD

$fieldOffset += 8;

my $here = $FH->tell();
my $data = substr($zip64Extended, 0, 8, "") ;
$entry->localHeaderOffset(unpack "Q<", $data);
out2 $data, "Offset to Local Dir", Value_Q($entry->localHeaderOffset)
if $display;

my $commonMessage = "'Offset to Local Dir' field in 'Zip64 Extra Field' is invalid";
$entry->localHeaderOffset(checkOffsetValue($entry->localHeaderOffset, $fieldStart, 0, $commonMessage, $fieldStart, ZIP_LOCAL_HDR_SIG, 0) );
if (! full32 $entry->std_localHeaderOffset)
{
info $data, "Offset to Local Dir should not be present in the ZIP64 extra field. Corresponding localHeaderOffset from central header is not set to 0xFFFFFFFF, value is " . Value_V($entry->localHeaderOffset)
if $display;
}
}

if ($assumeAllFieldsPresent || full16 $entry->std_diskNumber)
{
if (length $zip64Extended < 4)
{
my $message = extraFieldIdentifier($extraID) . ": Expected " . decimalHex0x(4) . " bytes for 'Disk Number': only " . decimalHex0x(length $zip64Extended) . " bytes present";
my $message = extraFieldIdentifier($extraID) . ": Expected " . decimalHex0x(4) . " bytes for 'Disk Number': only " . decimalHex0x(length $zip64Extended) . " bytes present";
error $fieldOffset, $message;
out2 $zip64Extended, $message;
return;
}

$fieldOffset += 4;

my $here = $FH->tell();
my $data = substr($zip64Extended, 0, 4, "") ;
$entry->diskNumber(unpack "v", $data);
out2 $data, "Disk Number", Value_V($entry->diskNumber)
if $display;
$entry->zip64_diskNumberPresent(1);
if (! full16 $entry->std_diskNumber)
{
info $data, "Disk Number should not be present in the ZIP64 extra field. Corresponding diskNumber from central header is not set to 0xFFFF, value is " . Value_V($entry->diskNumber)
if $display;
}
}

if (length $zip64Extended)
Expand Down
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