Fix zip64 extra field

lib/Open/directory.js

@@ -121,7 +121,7 @@ module.exports = function centralDirectory(source, options) {
       // https://github.com/golang/go/blob/master/src/archive/zip/reader.go#L503
       // For zip64 files, need to find zip64 central directory locator header to extract
       // relative offset for zip64 central directory record.
-      if (vars.numberOfRecords == 0xffff|| vars.numberOfRecords == 0xffff ||
+      if (vars.diskNumber == 0xffff || vars.numberOfRecords == 0xffff ||
         vars.offsetToStartOfCentralDirectory == 0xffffffff) {
 
         // Offset to zip64 CDL is 20 bytes before normal CDR

lib/parseExtraField.js

@@ -6,19 +6,22 @@ module.exports = function(extraField, vars) {
   while(!extra && extraField && extraField.length) {
     const candidateExtra = parseBuffer.parse(extraField, [
       ['signature', 2],
-      ['partsize', 2],
-      ['uncompressedSize', 8],
-      ['compressedSize', 8],
-      ['offset', 8],
-      ['disknum', 8],
+      ['partSize', 2],
     ]);
 
     if(candidateExtra.signature === 0x0001) {
-      extra = candidateExtra;
+      // parse buffer based on data in ZIP64 central directory; order is important!
+      const fieldsToExpect = [];
+      if (vars.uncompressedSize === 0xffffffff) fieldsToExpect.push(['uncompressedSize', 8]);
+      if (vars.compressedSize === 0xffffffff) fieldsToExpect.push(['compressedSize', 8]);
+      if (vars.offsetToLocalFileHeader === 0xffffffff) fieldsToExpect.push(['offsetToLocalFileHeader', 8]);
+
+      // slice off the 4 bytes for signature and partSize
+      extra = parseBuffer.parse(extraField.slice(4), fieldsToExpect);
     } else {
       // Advance the buffer to the next part.
       // The total size of this part is the 4 byte header + partsize.
-      extraField = extraField.slice(candidateExtra.partsize + 4);
+      extraField = extraField.slice(candidateExtra.partSize + 4);
     }
   }
 
@@ -31,7 +34,7 @@ module.exports = function(extraField, vars) {
     vars.uncompressedSize= extra.uncompressedSize;
 
   if (vars.offsetToLocalFileHeader === 0xffffffff)
-    vars.offsetToLocalFileHeader= extra.offset;
+    vars.offsetToLocalFileHeader = extra.offsetToLocalFileHeader;
 
   return extra;
 };

test/zip64.js

@@ -9,6 +9,7 @@ const temp = require('temp');
 const UNCOMPRESSED_SIZE = 5368709120;
 const ZIP64_OFFSET = 72;
 const ZIP64_SIZE = 36;
+const ZIP64_EXTRA_FIELD_OFFSET = 0;
 
 t.test('Correct uncompressed size for zip64', function (t) {
   const archive = path.join(__dirname, '../testData/big.zip');
@@ -43,7 +44,77 @@ t.test('Correct uncompressed size for zip64', function (t) {
   t.end();
 });
 
-t.test('Parse files from zip64 format correctly', function (t) {
+t.test('Parse files with all zip64 extra fields correctly', function (t) {
+  const archive = path.join(__dirname, '../testData/zip64-allextrafields.zip');
+
+  t.test('in unzipper.Open', function(t) {
+    unzip.Open.file(archive)
+      .then(function(d) {
+        d.files[0].stream()
+          .on('vars', function(vars) {
+            t.same(vars.extra.uncompressedSize, ZIP64_SIZE, 'Open: Extra field');
+            t.same(vars.extra.compressedSize, ZIP64_SIZE, 'Open: Extra field');
+            t.same(vars.extra.offsetToLocalFileHeader, ZIP64_EXTRA_FIELD_OFFSET, 'Open: Extra field');
+            t.same(vars.uncompressedSize, ZIP64_SIZE, 'Open: File header');
+            t.same(vars.compressedSize, ZIP64_SIZE, 'Open: File header');
+            t.same(vars.offsetToLocalFileHeader, ZIP64_EXTRA_FIELD_OFFSET, 'Open: File header');
+            t.end();
+          })
+          .on('error', function(e) {
+            t.same(e.message, 'FILE_ENDED');
+            t.end();
+          });
+      });
+  });
+
+  t.test('in unzipper.extract', function (t) {
+    temp.mkdir('node-unzip-', function (err, dirPath) {
+      if (err) {
+        throw err;
+      }
+      fs.createReadStream(archive)
+        .pipe(unzip.Extract({ path: dirPath }))
+        .on('close', function() { t.end(); });
+    });
+  });
+
+  t.end();
+});
+
+t.test('Parse files with zip64 extra field with only offset length correctly', function (t) {
+  const archive = path.join(__dirname, '../testData/zip64-extrafieldoffsetlength.zip');
+
+  t.test('in unzipper.Open', function(t) {
+    unzip.Open.file(archive)
+      .then(function(d) {
+        d.files[0].stream()
+          .on('vars', function(vars) {
+            t.same(vars.extra.offsetToLocalFileHeader, ZIP64_EXTRA_FIELD_OFFSET, 'Open: Extra field');
+            t.same(vars.offsetToLocalFileHeader, ZIP64_EXTRA_FIELD_OFFSET, 'Open: File header');
+            t.end();
+          })
+          .on('error', function(e) {
+            t.same(e.message, 'FILE_ENDED');
+            t.end();
+          });
+      });
+  });
+
+  t.test('in unzipper.extract', function (t) {
+    temp.mkdir('node-unzip-', function (err, dirPath) {
+      if (err) {
+        throw err;
+      }
+      fs.createReadStream(archive)
+        .pipe(unzip.Extract({ path: dirPath }))
+        .on('close', function() { t.end(); });
+    });
+  });
+
+  t.end();
+});
+
+t.test('Parse files from regular zip64 format correctly', function (t) {
   const archive = path.join(__dirname, '../testData/zip64.zip');
 
   t.test('in unzipper.Open', function(t) {